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SUMMER SCHOOL

Light in Science, Light in Life - LiSci 2015

Tequisquiapan, Querétaro, México —August th to st,

PROCEEDINGS


SUMMER SCHOOL

Light in Science, Light in Life - LiSci 2015

Tequisquiapan, Querétaro, México —August th to st,

International Year of Light and Light-based Technologies 2015

This Summer School is organized as part of the celebrations dedicated to the International Year of Light

and Light-based Technologies 2015.

The event covers a wide range of frontier topics in optics and photonics, including applications in other

areas of physics, as well as in biological and health-care research. The main goal is to bring together

international top-level scientists, early-stage researchers and students to share one week.

TOPICS

• Biophotonics and Microscopy

• Quantum Optics and

Quantum Information

• Plasmonics

• Ultracold Matter

• Liquid Crystal Optics

• Singular optics, Structured Light

and Optical Angular Momentum

• Scattering and Surface Optics

• Nonlinear Optics

• Multidisciplinary Applications

of Optics

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INVITED SPEAKERS

Prof. Govind Agrawal

University of Rochester, USA

Prof. Michael V. Berry

University of Bristol, UK

Prof. Etienne Brasselet

Université Bordeaux 1, France

Prof. Carlos Bustamante

University of California Berkeley, USA

Prof. Luiz Davidovich

Universidade Federal do Rio de Janeiro, Brazil

Prof. Kishan Dholakia

University of Saint Andrews, UK

Prof. Julio C. Gutiérrez-Vega

Instituto Tecnológico de Monterrey, Mexico

Prof. Rocío Jáuregui

Instituto de Física, Universidad Nacional Autónoma de México

Prof. Pablo Loza-Alvarez

The Institute of Photonic Sciences-ICFO, Spain

Prof. J. Eduardo Lugo

Université de Montreal, Canada

Prof. Daniel Malacara-Hernández

Centro de Investigaciones en Óptica, Mexico

Prof. Oscar E. Martínez

Universidad de Buenos Aires, Argentina

Prof. Eugenio Méndez

Centro de Investigación Científica y de Estudios Superiores de Ensenada, Mexico

Prof. Paras Prasad

University at Buffalo, USA

Prof. Romain Quidant

The Institute of Photonic Sciences-ICFO, Spain

Dr. Fernando Ramírez Martínez

Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México

Prof. Monika Ritsch-Marte

Medizinische Universität Innsbruck, Austria

Prof. Halina Rubinsztein-Dunlop

The University of Queensland, Australia

Prof. Juan P. Torres

The Institute of Photonic Sciences-ICFO, Spain

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ORGANIZING COMMITTEE

Dr. Karen Volke-Sepúlveda, Chair

Instituto de Física, Universidad Nacional Autónoma de México

Dr. Ana María Cetto

Instituto de Física, Universidad Nacional Autónoma de México

Member of the International Steering Committee IYL2015

Dr. Mayo Villagrán-Muniz

Centro de Ciencias Aplicadas y Dessarrollo Tecnológico

Universidad Nacional Autónoma de México

Dr. Fernando Ramírez Martínez

Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México

Dr. Rocío Jáuregui

Instituto de Física, Universidad Nacional Autónoma de México

Dr. Alejandro V. Arzola

Instituto de Física, Universidad Nacional Autónoma de México

Dr. Remy Ávila-Foucat

Centro de Física Aplicada y Tecnología Avanzada

Universidad Nacional Autónoma de México

Dr. Rubén Ramos-García

Instituto Nacional de Astrofísica, Óptica y Electrónica

Dr. José Luis Hernández-Pozos

Universidad Autónoma Metropolitana-Plantel Iztapalapa

Dr. Amalia Martínez

Centro de Investigaciones en Óptica

President of Academia Mexicana de Óptica

Dr. Eric Rosas

Centro de Investigaciones en Óptica

Representative of The Optical Society of America

Dr. Braulio Gutiérrez-Medina

Instituto Potosino de Investigación Científica y Tecnológica

Dr. Raúl Rangel-Rojo

Centro de Investigación Científica y de Estudios Superiores de Ensenada

Dr. Eduardo Gómez

Instituto de Física, Universidad Autónoma de San Luis Potosí

With the participation of OSA-UNAM Student Chapter

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SPONSORS

CONACyT

Consejo Nacional de Ciencia y Tecnología

Universidad Nacional Autónoma de México

Posgrado en Ciencias Físicas

Universidad Nacional Autónoma de México

Instituto de Física

Universidad Nacional Autónoma de México

Instituto de Ciencias Nucleares

Universidad Nacional Autónoma de México

Instituto Nacional de Astrofísica, Óptica y Electrónica

Centro de Investigaciones en Optica

Universidad Autónoma Metropolitana-Plantel Iztapalapa

Sociedad Mexicana de Física

Academia Mexicana de Óptica

Institute of Physics, UK

The Optical Society of America

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INDEX

Invited Speakers

Lectures Program

Short biographies and abstracts

Poster Sessions

Poster Session 1M

Program

Abstracts

Poster Session 2T

Program

Abstracts

Poster Session 3Th

Program

Abstracts

Credits and Acknowledgments

.............................................................. 7

.............................................................. 9

.............................................................. 51

.............................................................. 55

.............................................................. 103

.............................................................. 107

.............................................................. 157

.............................................................. 161

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INVITED SPEAKERS


Lectures

Monday • Optics in Nature, Biophotonics and Optical Trapping

• Prof. Paras Prasad

General overview and emerging opportunities in Nanophotonics and Biophotonics / Openning Lecture

• Prof. Sir Michael V. Berry

Nature’s optics and our understanding of Light / Part I

• Prof. Carlos Bustamante

Mechanisms of Celular Proteostasis: Insights from Single Molecule Studies

• Prof. Kishan Dholakia

Basics of optical trapping and beam zapping

• Prof. Oscar E. Martínez

Microscopy Imaging in 3D / Part I

• Prof. Monika Ritsch-Marte

Wavefront-shaping techniques for optical trapping and imaging / Part I

• Prof. Halina Rubinsztein-Dunlop

Catch, move and twist using optical tweezers / Part I

• Prof. Pablo Loza-Alvarez

Strategies in light sheet microscopy for fast imaging of biological samples / Part I

Tuesday • Optics in Nature, Biophotonics and Optical Trapping

• Prof. J. Eduardo Lugo

Photonic applications by example: from photonic crystals, brain spectroscopy to muscle contractions /

Part I

• Prof. Romain Quidant

Nanoplasmonics and its applications to biosciences

• Prof. Sir Michael V. Berry

Nature’s optics and our understanding of Light / Part II

• Prof. Carlos Bustamante

Division of Labor Among the Subunits of a Highly Coordinated RIng ATPase

• Prof. Kishan Dholakia

Advanced optical trapping studies in liquid, air and vacuum

• Prof. Oscar E. Martínez: Microscopy

Imaging in 3D / Part II

• Prof. Monika Ritsch-Marte

Wavefront-shaping techniques for optical trapping and imaging / Part II

• Prof. Halina Rubinsztein-Dunlop

Catch, move and twist using optical tweezers / Part II

• Prof. Pablo Loza-Alvarez

Strategies in light sheet microscopy for fast imaging of biological samples / Part II

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Wednesday • Optical Trapping, Applied Optics and Photonics

• Prof. J. Eduardo Lugo

Photonic applications by example: from photonic crystals, brain spectroscopy to muscle contractions / Part

II

• Prof. Romain Quidant

Nano-optical manipulation and nano-optomechanics

• Prof. Etienne Brasselet

Topological liquid crystal photonics

• Prof. Govind Agrawal

Nonlinear Photonics with Optical Waveguides

Thursday • Photonics, Quantum Optics, Ultracold Matter and Classical Optics

• Prof. Daniel Malacara-Hernández

The International Year of Light: Why?

• Prof. Etienne Brasselet

Liquid crystals as a test-bed for chiral optomechanics

• Prof. Govind Agrawal

Highly Nonlinear Fibers and their Applications

• Prof. Rocío Jauregui

Light for control and manipulation of atomic systems

• Prof. Luiz Davidovich

Exploring The Subtleties Of The Quantum World: From Photons To Qubits

• Prof. Julio C. Gutiérrez-Vega

Fundamentals of structured light fields

• Prof. Juan P. Torres

Information and quantum coherence: everything that can happen does happen

• Prof. Eugenio Méndez

Light scattering by particles and rough surfaces / Part I

Friday • Quantum Optics and Classical Optics

• Prof. Fernado Ramírez-Martínez

Laser cooling and trapping of atoms: controlling atoms with light

• Prof. Luiz Davidovich

From Quantum To Classical: Light, Photons, Entanglement, And Decoherence

• Prof. Julio C. Gutiérrez-Vega

Optical applications of fractional calculus

• Prof. Eugenio Méndez

Light scattering by particles and rough surfaces / Part II

• Prof. Juan P. Torres

Entanglement and Bell’s inequalities: Does reality exist?

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Prof. Paras N. Prasad

University of Buffalo, NY

USA

pnprasad@buffalo.edu

Short Biography

Paras N. Prasad obtained his Bachelor degree in Physics in 1964 from Bihar University of

India, and his PhD in 1971 from the University of Pennsylvania. At present, he is a

Distinguished Professor of Chemistry, Physics, Medicine and Electrical Engineering, the

highest rank in the New York State University system. He also holds the Samuel P. Capen

Chair at the University at Buffalo and is the Executive Director of the Multidisciplinary

Institute for Lasers, Photonics and Biophotonics. He has published over 700 scientific

papers, with more than 42000 citations, co-edited six books, and co-authored the

monograph “Introduction to Nonlinear Optical Effects in Molecules and Polymers”. He

also published the book “Introduction to Biophotonics,” the first in this field, which

authoritatively defines the field, details its scope and identifies emerging opportunities,

and the monographs, “Nanophotonics,” and “Introduction to Nanomedicine and

Nanobioengineering”. He holds a number of patents.

Professor Prasad has received much international recognition for his pioneering

contributions. Among many others, he received the Scientific American’s Top 50 (2005),

a Fellow of SPIE (2005), the 2003- and 2008 Inventor of the Year in Life Sciences Award

by the Technical Council of the Niagara Frontier. He is also a Fellow of the American

Physical Society and a Fellow of the Optical Society of America, and he has received the

Schoellkopf Award of the Western New York American Chemical Society for his

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academic achievements. He was awarded as well the Technology/Discovery Award from

the Western New York Health Care Industries Association for his pioneering work on

“Nanoclinics” for Biophotonics. Recently he received an Honorary Doctorate from the

Royal Institute of Technology in Sweden (KTH). He has been awarded by the Chancellor

of the State University of New York system the Excellence in Pursuit of Knowledge

award.

Lecture

General overview and emerging opportunities in Nanophotonics and

Biophotonics

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Prof. Michael Victor Berry

Bristol University

Short Biography

United Kingdom

asymptotico@bristol.ac.uk

Sir Michael Berry has a Bachelor degree in Physics from the University of Exeter and

obtained his PhD in Theoretical Physics from the University of St. Andrews in 1965. Since

then, he has been researcher, lecturer in Physics, reader in Physics and full Professor at

Bristol University. In 2006, he became the Melville Wills Professor of Physics at Bristol

University (Emeritus).

As he states, his principal interest in physics resides in the incompletely understood

phenomena that lurk in the borderlands between physical theories (e.g. between classical

and quantum, between rays and wave). These borderlands –the domain of physical

asymptotics– are his intellectual habitat, with an emphasis on geometrical aspects of waves

(especially phase) and chaos. He has made many seminal contributions in quantum physics

and optics, one the most known is the Pancharatnam-Berry Phase.

Professor Berry has supervised 20 PhD students and has published about 480 books, reviews

and articles in important journals. He was elected a fellow of the Royal Society of London

in 1982. In 1996, he received the Knight Bachelor Queen's Birthday Honours. Sir Michael

Berry won the Wolf Prize in Physics in 1998 and the Ig Nobel Prize in Physics in 2000 for

“using magnets to levitate a frog”. He has served as Editor for the Journal of Physics A

and Proceedings A of the Royal Society of London.

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Prof. Michael Victor Berry

Lectures

Nature’s optics and our understanding of light

Optical phenomena visible to everyone have been central to the development of, and

abundantly illustrate, important concepts in science and mathematics. The phenomena

considered include rainbows, sparkling reflections on water, mirages, green flashes,

earthlight on the moon, glories, daylight, crystals, and the squint moon. The concepts

include refraction, caustics (focal singularities of ray optics), wave interference,

numerical experiments, mathematical asymptotics, dispersion, complex angular

momentum (Regge poles), polarization singularities, Hamilton’s conical intersections of

eigenvalues (‘Dirac points’), geometric phases, and visual illusions.

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Prof. Carlos Bustamante

University of California

Berkeley

Short Biography

USA

carlosb@berkeley.edu

Carlos Bustamante has a Bachelor degree in Biology from the Universidad

Peruana Cayatano Heredia (1973), a M.S. in Biochemistry from the Universidad Nacional

Mayor de San Marcos, Peru (1975), and in 1981, he received his PhD in Biophysics from

the University of California, Berkeley, CA. He is Fellow of the American Physical

Society; Professor of Molecular and Cell Biology, Professor of Physics, and

Professor of Chemistry, at the University of California, Berkeley; Raymond and

Beverly Sackler Chair of Biophysics and researcher for Howard Hughes Medical

Institute. He has authored more than 300 publications in prestigious international

journals, many of them being seminal papers in the highest-impact journals in science.

Among other projects, Professor Bustamante’s Lab develops novel methods of singlemolecule

manipulation and detection, such as optical and magnetic tweezers and singlemolecule

fluorescence microscopy, and apply them to characterize the dynamics and the

mechanochemical properties of various molecular motors that interact with DNA, RNA,

or proteins. His team uses and develops as well, novel methods of superresolution

microscopy to study the organization and function of protein complexes in cells.

They also use Scanning Force Microscopy to investigate the structure of chromatin

and the global structure of protein-nucleic acid complexes relevant to the molecular

mechanisms of control of transcription in prokaryotes.

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He has received a number of honours; among them, he received the Alexander

Hollaender Award in Biophysics given by National Academy of Sciences and the Hans

Neurath Prize given by The Protein Society. The American Physical Society awarded him

with the Biological Physics Prize. He is member of the National Academy

of Sciences of the USA and the American Academy of Arts and Sciences.

Lectures

Mechanisms of Celular Proteostasis: Insights from Single Molecule Studies

Division of Labor Among the Subunits of a Highly Coordinated RIng ATPase

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Prof. Kishan Dholakia

University of St.Andrews

Short Biography

United Kingdom

kd1@st-andrews.ac.uk

Kishan Dholakia obtained his PhD in Laser Physics from the Imperial College, London,

in 1994, working on laser cooling of trapped ions. From 1994 to 1997 he was

Postdoctoral Research Assistant at the University of St Andrews and the Imperial

College. Since then, he joined the University of St Andrews with a research fellowship

from the Royal Society of Edinburgh (1997-2000) and as Lecturer-Reader in the

School of Physics and Astronomy (2000-2003). In 2003, he was designated full Professor.

The research interests of Prof. Kishan Dholakia span all areas of photonics to

applied research at the physics-life sciences interface. He is distinguished for his work

with shaped optical fields. These include studies in particle manipulation, namely optical

sorting, optical binding, and the rotation of micro-particles. His seminal contributions to

the understanding and use of shaped and complex light fields, including propagationinvariant

Airy and Bessel modes, have led to these being deployed in optical

manipulation, cell nanosurgery and light sheet imaging. He has authored over

270 journal publications and has supervised 33 students to PhD level since 1999.

He has commercialized with a UK company, Elliot Scientific, the World’s first

portable compact optical trap for biophysics: This product won the Photonics Circle of

Excellence Award (January 2005) in the USA at the Optics Meeting, Photonics West.

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Kishan Dholakia has received a number of awards including the European Optics Prize

in 2003, a Royal Society Wolfson Merit Award in 2008, and a Royal Society

Leverhulme Trust Senior Fellowship for 2015-2016. In 2005, the UK Engineering and

Physical Sciences Research Council named him as a "Researcher of the Decade". He was

elected Fellow of the Optical Society of America in 2008 and of the SPIE in 2009. His

group's work on a spinning microparticle in vacuum has been cited in the 2015 Guinness

Book of World Records as the world's "fastest man-made rotation". In addition, he is

passionate about broader awareness of optics and has raised over $1M to undertake

outreach activities in optics for the wider public.

Lectures

Basics of optical trapping and beam zapping

Optical manipulation of mesoscopic particles remains a very powerful method for both

fundamental and applied science. The field has seen great advances for the biosciences

including new studies of single molecules and force studies on cells. In the physical

sciences, studies have also seen groundbreaking work in many areas. In these two

lectures I will describe the following

• In the first lecture I will give an overview of the origins of the field and how we

may consider the applications of optical forces for guiding and trapping. Clear

examples such as optical levitation, optical guiding, a three dimensional optical

tweezers will be discussed. The work will be placed in context of fundamental

physics and applications in bioscience. A consideration of trap characterisation

and theoretical considerations will also be given.

• The second lecture will describe the use of beam shaping for optical manipulation.

Applications using “non-diffracting” Airy and Bessel beams will be described. In

additions methods for transfering transfer spin angular momentum to

trapped birefringent particles in air and vacuum will be discussed. The

dynamics and rotational behaviour of such particles will be described and can

lead to new studies of viscosity

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Prof. Oscar E. Martínez

Universidad de Buenos Aires

Argentina

oem@df.uba.ar

Short Biography

Oscar E. Martínez is Senior Researcher of CONICET (Consejo Nacional

de Investigaciones Científicas y Tecnológicas) and the Universidad de Buenos

Aires, Argentina. Founder and Coordinator of the Photophysics First Division of the

Asociación de Física Argentina. In 1994, he was appointed Fellow of the Optical Society

of America in recognition of his contributions to the development of techniques for the

generation and measurement of ultrashort laser pulses.

In recent years he devoted himself to the development of interdisciplinary applications in

industry, materials sciences, chemistry and biology. This work led to publications and

patents including new methods for measuring surface cleaning, coating thickness

profiles, new methods of surface treatment, and new techniques of near field microscopy

with resolutions several orders of magnitude higher than conventional microscopes.

Professor Martínez was a member of the Advisory Committee of Physics and

Astronomy of the CONICET, Head of the Department of Physics of FCEN-UBA and

FOMEC Project Coordinator.

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Prof. Oscar E. Martínez

Lectures

Microscopy: Imaging in 3D

In the first part a review of the different 3D imaging techniques available for microscopic

observation will be critically reviewed. A comparison between confocal microscopy,

STED, PALM, light sheet illumination and other techniques will be introduced and their

relative advantages discussed. In the second part the 3DD (3D Deconvolution) technique

will be presented. It will be shown how deconvolving a multifocal image the 3D structure

can be reconstructed under certain restrictions. The main constraint is that the different

points of the sample must emit incoherently, condition easily fulfilled by fluorescent

objects or scattered light from white light illumination. The second constraint is that the

emitted light from each object point travels free of obstacles (besides focusing optics) to

the detector. The two constraints are easily fulfilled by topographic opaque objects and

many biological samples.

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Prof. Monika Ritsch-Marte

Medizine Universitat

Innsbruck

Short Biography

Austria

monika.ritsch-marte@i-med.ac.at

Monika Ritsch-Marte obtained his Bachelor degree in Physics in 1984 from

the University of Innsbruck, Austria, and her PhD degree in Quantum Optics in 1988

from the University of Waikato, New Zealand. Then, she joined as full Professor for

Medical Physics at the Medical Faculty of the University of Innsbruck (now Medical

University of Innsbruck) in 1998. Since 2005, she is the Director of the Division of

Biomedical Physics.

Her main field of activity is optical micromanipulation, nonlinear microscopy, and

applications for light modulators in microscopy. Her scientific production includes

more than one hundred papers in well known optics journals, which had been cited in the

scientific literature more than a thousand times. She has been author and editor of several

well known books in optics.

Professor Ritsch-Marte is a Fellow of the Optical Society of America (OSA). She

received the Dissertation prize of the University of Wakato in 1988, the Ludwig

Boltzmann Prize from the Austrian Physical Society in 1993, Science Award from the

State of Vorarlberg in 2008, Cardinal Innitzer Prize in the Natural Sciences in 2009,

European Research Council Advanced Investigator Grant in 2009, and the Sciencie Prize

from the State of Tyrol in 2011.

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Prof. Monika Ritsch-Marte

Lectures

Wavefront-shaping techniques for optical trapping and imaging

Applications of liquid-crystal based spatial light modulators (SLMs) in optical trapping

and imaging will be discussed. After a brief introduction on SLMs in general, it will be

explained how an SLM can act as a programmable Fourier filter, to emulate various

contrast mechanisms such as bright field, dark field, or (spiral) phase contrast. Some

examples demonstrating the great flexibility the SLM-based “synthetic holography”

approach offers will be given, e.g. holographic multiplexing in order to target multiple

focal planes or to combine images of different parameter settings in one exposure.

The second lecture will deal with wavefront shaping for optical manipulation, e.g. for

optical stretchers, or for combined optical and acoustic trapping for large swimming

organisms.

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Prof. Halina Rubinztein-Dunlop

University of Queensland

Australia

halina@physics.uq.edu.au

Short Biography

Dr. Halina Rubinsztein-Dunlop obtained her PhD degree from the University of Gothenburg

and the Chalmers University of Technology in Sweden. She also holds a Docent Degree

from the same university. Halina moved to The University of Queensland in 1989 where she

established a large research team actively involved in several areas of laser science. Her

research interests are in laser physics, laser micromanipulation, atom optics, quantum

science, linear and nonlinear high resolution laser spectroscopy, and nano-optics. She is well

known as one of the originators of laser enhanced ionization spectroscopy, and for her work

in laser micromanipulation and atom optics.

Professor Rubinsztein-Dunlop has over 200 publications in international peer refereed

journals as well as books and other media. She delivers frequent lectures to scientific

organizations and societies worldwide. She is regularly interviewed by the mainstream media

and has made many television and radio appearances.

She is a member of the Scientific Advisory Board of NTT Basic Research Laboratories,

Japan, a member of the Editorial Boards of IOP Journal of Optics, Journal of Biophotonics,

and a Member of the Advisory Board of Laser Beckmann Institute. She was the AIP 2003

Women in Physics Lecturer. She is a Fellow of SPIE and OSA. Currently, she is Director of

the Quantum Science Laboratoy at the University of Queensland.

Lectures

Catch, move and twist using optical tweezers

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Prof. Pablo Loza-Alvarez

The Institute of Photonic

Sciences(ICFO)

Short Biography

Spain

pablo.loza@icfo.es

Pablo Loza­Alvarez received his PhD in Laser Physics from the University of St Andrews,

Scotland UK in 2000. He stayed in St Andrews as a postdoctoral researcher, and then he

joined the Universitat Politecnica de Catalunya with the “Ramon y Cajal” programme. In

2004 he was incorporated to the Institute of Photonic Sciences (ICFO) as a Group Leader.

In 2006 he entered in the I3 ANEP­MICINN programme. Currently, he is the head of the

Super Resolution Light Microscopy and Nanoscopy Lab at ICFO.

Professor Loza­Alvarez has now a strong experience in microscopy and, by introducing

novel photonics tools, he has developed a number of novel imaging techniques. These have

been used for a wide variety of applications ranging from the imaging of large model

organisms (mesoscopic level) to the visualization of subcellular components (super

resolution).

He has supervised six PhD students, co­authored over 200 publications in international

journals and conferences (h=23, Google Scholar), and has written 6 patents. Prof. Loza­

Alvarez, has leaded three European projects and several national projects (Spain) and

participated in several other EU projects; he is also active in several Networks of Excellence

such as Photonics for Life (Awarded 3 P4L­projects), LASERLAB EUROPE, COST

ACTION Raman4Clinics and ActPhast.

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Prof. Pablo Loza-Alvarez

Lectures

Strategies in light sheet microscopy for fast imaging of biological samples

Omar E. Olarte 1 , Jordi Andilla 1 , Jacob Licea-Rodrigues,

David Artigas 1,2 , and Pablo Loza-Alvarez 1

1

ICFO-Institut de Ciencies Fotoniques,Av.Carl Friedrich Gauss, 3,

08860 Castelldefels (Barcelona), Spain

2

Department of Signal Theory and Communications,

Universitat Politècnica de Catalunya, Jordi Girona 1-3, 08034 Barcelona, Spain

In selective plane illumination microscopy (SPIM), a static sheet of excitation light is

produced onto the sample plane using a cylindrical lens. Then, the fluorescence light

emerging from this plane is collected through a microscope objective placed along the

axis orthogonal to the excitation sheet. This uncoupling between the excitation and

collection branches provides SPIM with 2D optical sectioning capability in large fields of

view (FOV).

Perhaps the most valuable benefit of this technique is the reduction of the photodamage to

the sample, due to the restriction of the irradiation to the plane under observation.

Since it also can provide fast acquisition speeds, SPIM has emerged as a powerful tool for

in vivo studies, from single cells to whole organisms and tissues.

Two-Photon excited fluorescence (TPEF) in Selective Plane Illumination Microscopy

(2p-SPIM) was demonstrated a few years ago as an interesting alternative to

its commonly used single-photon counterpart [1]. Although this technique is ideal

for accessing larger penetration depths in biological samples it is not optimal in terms of

efficiency of fluorescence excitation due to the reduced intensities involved [2].

To overcome this limitation, a variant in which light is focused to produce a line that is

scanned in one direction, forming a digitally scanned light sheet (DSLM), can be

employed to recover the high intensities required for TPEF. Nevertheless, the involved

high numerical apertures, limit the effective field of view (FOV) covered by the light

sheet [2]. Here we propose the use of an optimized TPEF-DSLM system that is able to

cover large FOVs by employing Bessel beams [3,4]. The laser wavelength and power as

well as the spatial properties of the beams employed were optimized to obtain

an effective FOV of approx. 400x400 µm 2 and to produce high resolution 3D images

of fluorescently labeled multicellular tumor spheroids.

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In the first part of my lecture, I will show a practical multimodal SPIM/

DSLM microscope able to work in the linear and nonlinear regimes, and with Gaussian

an BB. With this multimodal setup, I will compare the obtained results in

terms of optical sectioning, resolution and the intensity distribution uniformity of

the light sheet generated with the different modalities for several biological samples.

LSFM, being based on an intrinsic plane illumination, allows for fast 2D

imaging. Therefore, LSFM has been put forward as an interesting candidate for fast

volumetric (3D) imaging.

Thus, in the second part of my lecture I will present a LSFM microscope, combined with

the use of wavefront coding (WFC) techniques [5], for fast volumetric imaging. WFC is

used to extend the depth of field (DOF) of the collecting objective in a LSFM. This

results in a system in which the light sheet can be scanned through the sample, which

remains static. This provides LSFM with intrinsic 3D imaging capabilities. In addition,

because of the extended DOF, the light sheet can be axially scanned at fast speeds. As

only the light sheet is moved, fast 3D imaging can be achieved without the need of any

sample or objective movement [6]. Since typical light scanning devices can run at KHz

rates, 3D volumetric acquisition speeds will only be limited by the reading speed of the

camera or the required signal to noise ratio.

WFC works at the expenses of introducing a controlled aberration to the system that blurs

the resulting images. Then it requires a final deconvolution step to recover the image

sharpness that would impose a limitation on the application. To speed up

such deconvolution processes, a routine directly developed in the GPUs has been

developed. I will present preliminary results on realistic computer generated images

showing that real-time deconvolution and visualization is possible.

To practically implement a WFC-LSFM system, we use a deformable mirror (DM) lying

in a conjugated plane with the exit pupil of the objective lens. The use of the DM allows

the generation of different phase masks that can achieve different extensions of the DOF

or with different functions that present different properties when extending the DOF. I

will present a comparative study of the performance of different wavefront coding masks

suitable for light-sheet microscopy by using biological samples such as C. elgans worms

and Drosophila melanogaster embryos.

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REFERENCES

[1] J. Palero et al., "A simple scanless two-photon fluorescence microscope

using selective plane illumination," Opt. Express 18, 8491-8498 (2010).

[2] T. V. Truong et al., "Deep and fast live imaging with two-photon scanned light-sheet

microscopy," Nat Meth 8, 757-760 (2011).

[3] T. A. Planchon et al., "Rapid three-dimensional isotropic imaging of living cells using

Bessel beams plane illumination," Nat Meth 8, 417-423 (2011).

[4] O. E. Olarte et al., "Image formation by linear and nonlinear digital scanned lightsheet

fluorescence microscopy with Gaussian and Bessel beam profiles," Biomed. Opt.

Express 3, 1492-1505 (2012)

[5] Dowski, J. & Cathey, W. T. Extended depth of field through wave-front coding. Appl.

Opt. 34, 1859–1866 (1995).

[6] Omar E. Olarte, et al; "Decoupled illumination detection in light sheet microscopy for

fast volumetric imaging," Optica 2, 702-705 (2015).

25


Prof. Jesus Eduardo Lugo-Arce

University of Montreal

Short Biography

Canada

eduardo.lugo@gmail.com

Jesus Eduardo Lugo has a Bachelor degree in Physics and a MSc in Photovoltaic Solar

Energy with honors from the Universidad Nacional Autónoma de México (UNAM).

He attended two research visits with Dr. P.M. Fauchet in the Electrical and

Computer Engineering Department at the University of Rochester in 1996 and in

1997. He obtained his PhD in Physics from the Universidad Autónoma del Estado de

Morelos, México, in 1997, where he was designated Associated Professor in 1998.

In 1998, he attended the University of Rochester for a research visit with Dr. P.M. Fauchet,

and was awarded a Postdoctoral Fellowship in Electrical Engineering at the Department

of Electrical and Computer Engineering and the Center for Future Health (1999-2000).

There he performed studies in fabrication and characterization of silicon nanostructures,

fabrication of superlattices of silicon quantum dots by using a Magnetron Sputtering

System, and a theoretical analysis of one-dimensional and two-dimensional photonics

crystals. From 2000 to 2001 he was Associated Professor at the Center for Energy Research

of UNAM.

During 2001-2002, Eduardo Lugo was awarded a Postodoctoral Fellowship in

Electrical Engineering at the Department of Electrical and Computer Engineering of McGill

University in Montreal, Canada, where he stayed as Associated Researcher from 2002 to

2005. Since 2005, he has been Associated Researcher in psychophysics, neurodynamics

and biophotonics at the School of Optometry of the University of Montreal, where he

participated in the creation of a group to apply photonic concepts to study human vision and

neurodynamics of multisensory integration. Since 2011, he serves as Associated

Researcher for the Canadian company Cognisens Inc. Dr. Lugo has focused his interests

in nanoscience, transport in porous media, multiphysics computer simulation, electrochemistry,

instrumentation, sensors, optics, photonics, psychophysics and brain dynamics.

26


Prof. Jesus Eduardo Lugo-Arce

Lectures

Photonic applications by example:

From photonic crystals, brain spectroscopy to muscle contractions

The previous century has been characterized by the amazing development of materials and

devices. For instance, the appearance of the electronic transistor marked the beginning of an

era of technology. In 1990, John Maddox wrote down “If only it were possible to make

dielectric materials in which electromagnetic waves cannot propagate at certain

frequencies, all kind of almost-magical things would be possible”. Interestingly nature long

time ago made the Golden bugs (members of the order Coleoptera). These insects have

developed by evolution such sort of structures. Currently there exists a class of materials

known as photonic crystals, where the light is prohibited to propagate inside the material, or it

is allowed to propagate only in certain directions at certain frequencies, or it is localized in

specified areas.

The most important property of this kind of system is the photonic band structure and the

photonic band gap that the geometry creates. In these structures, light is forced to travel in the

structure only at certain frequencies and light is prohibited at frequencies lying inside the gap.

The photonic crystals are classified as one-(1D), two-(2D), and three-dimensional (3D)

depending on the number of translational symmetries they have. Nowadays many groups are

working with three and two-dimensional structures. The best-known examples of onedimensional

photonic crystals are dielectric mirrors, dielectric Fabry–Perot filters, distributed

feedback lasers, vertical cavity surface emitting laser, which are use in many optoelectronic

very-large scale integration systems that we found in the telecommunication industry. Photonic

crystals may serve as sensors, specially as biosensors. Recently photonic crystals have been

used to manipulate micro-objects by using radiation pressure. For instance, optical tweezers

can be used to levitate microorganisms. Such instruments use a highly focused laser beam to

create an attractive or repulsive force. When the laser power provided to the optical tweezers is

150mW, the maximum trapping force that can be achieved is on the order of 198pN.

In addition, the rapid development of electromagnetic wave-driven micromotors has motivated

investigations on their novel working principles. The radiation pressure produced with these

motors, however, is normally too small to move large objects with practical relevance. Certain

resonance principles can be used to significantly increase the force associated with

electromagnetic wave-driven micromotors or to create a dynamical system that is capable of

performing oscillations (e.g., self and forced oscillations).

27


The perception of blur in humans is intrinsic to our visual system, and dioptric power can

improve clarity in many cases. This can be evaluated experimentally to establish the best

correction with dioptric power shifts. Near Infrared Spectroscopy (NIRS) can be used to

measure Oxy-, Deoxy- and Total-hemoglobin concentration changes in the brain while

viewing images and reading a Snellen chart. The concept of Approximate Entropy (AE)

can be applied to quantify the regularity of these hemoglobin time series of finite length.

AE computations are based on the likelihood that similar templates in a time series

remain similar on the next incremental comparison, so that time series with large AE

have high irregular fluctuation.

The relationship between muscle anatomy and physiology and its corresponding

electromyography activity (EMGA) is complex and not well understood. EMGA

models may be broadly divided in stochastic and motor-unit-based models. For example,

these models have successfully described many muscle physiological variables such as

the value of the muscle fiber velocity and the linear relationship between median

frequency and muscle fiber velocity. However they cannot explain the behavior of many

of these variables with changes in intramuscular temperature, or muscle PH acidity, for

instance. Recently, we propose that the motor unit action potential can be treated as an

electromagnetic resonant mode confined at thermal equilibrium inside the muscle. The

motor units comprising the muscle form a system of standing waves or modes, where the

energy of each mode is proportional to its frequency. Therefore, the power spectral

density of the EMGA is well described and fit by Planck’s law and from its distribution

we developed theoretical relationships that explain the behavior of known physiological

variables with changes in intramuscular temperature or muscle PH acidity, for instance.

That is, only by considering the motor unit action potentials as electromagnetic resonant

modes confined at thermal equilibrium inside the muscle suffices to predict known or

new theoretical relationships for muscle physiological variables that other models have

failed to do.

In this lecture we will present some applications of photonic crystals, especially onedimensional

photonic crystals and the interesting finding that Beetles use these

structures to display their beautiful colors. We conclude that section by discussing a new

application: the creation of oscillators activated only with light. Then we will present

how NIRS can help us to prescribe optical lenses by using information

and thermodynamic concepts such as entropy. We will wrap up by describing that the

power spectral density of the EMGA in muscle contractions is described by Planck’s

radiation law.

28


Prof. Romain Quidant

The Institute of Photonic

Sciences(ICFO)

Short Biography

Spain

romain.quidant@icfo.es

Romain Quidant received his PhD in Physics in 2002 from the University of Dijon (France).

Since then, he has worked in Barcelona at ICFO The Institute of Photonic Sciences, in the

field of nanoplamonics. In 2006, he was appointed Junior Professor and Group Leader of the

Plasmon NanoOptics Group at the ICFO.

The research of Professor Quidant focuses on the study of optical properties of metal nanostructures,

know as nanoplasmonics. Part of his work is mainly directed towards enhaced

light-matter interactions for quantum optics. From a more applied viewpoint, his group

investigates news strategies to control light and heat at the nanoscale for bimedical

applications, including early detection and photothermal therapy of cancer. His research

trajectory has been acknowledged by several national and international prizes. Among them,

he was awarded the Fresnel Prize from the European Physics Society (2009), the Prize of the

City of Barcelona (2010), the Prize of the Fundación Príncep de Girona (2010), as well as the

ICO Prize 2012 from the International Commission for Optics.

In 2012 he received a Starting Grant from the European Reserch Council (ERC) that was

complemented by ERC Proof-of-concept grant in 2011. Since September 2014, he serves as

Associate Editor of the ACSphotonics Journal.

29


Prof. Romain Quidant

Lectures

Bioplasmonics: designing novel nanotools for biosciences

Two decades of extensive research in the field of plasmonics have shown that

metallic nanostructures supporting localized surface plasmon (LSP) resonances stand

as ideal systems to control light and heat on the nanometer scale. These unique physical

properties offer new opportunities in the field of biotechnologies. In this lecture we

review our recent activities in the development of novel tools for biosciences based on

metallic nanostructures.

We first present an integrated analytical platform that combines the sensing

capability of plasmonic antennas with advanced microfluidic technologies for the

label-free multiplexed detection of protein cancer markers in blood. Our platform

enables parallel, real-time detection of several markers from a single drop of human

serum with a sub-ng/ml sensitivity and is currently tested for early diagnosis and

treatment monitoring. Next we discuss how this technology can be extended to on-a-chip

chiral sensing capable to detect the handiness of biomolecules. The second part of

the lecture focuses on exploiting the photothermal properties of metallic nanoparticles

in nanomedicine and in particular for less-invasive treatment of cancer.

30


Prof. Romain Quidant

Lectures

Nano-optical manipulation and nano-optomechanics

Extending optical trapping to the true nanometre scale offers unprecedented

opportunities in many fields of science, where nano-optical tweezers would allow

the ultra-accurate manipulation of single nano-objects. To this aim we have

developed parallel strategies aiming at trapping nano-objects both in solution and

vacuum. We here review recent advances in optical nano-manipulation and discuss its

applications to both biophysics and quantum optics.The lecture is organized in two

main parts. The first part focuses on plasmon-assisted nano-trapping in which

trapping is achieved in the optical near field of a plasmonic nanostructure. We first

present the concept of Self Induced Back Action (SIBA) for trapping of individual

nano-objects at a nano-patterned metallic surface. We then show that SIBA trapping

can be extended at the extremity of a near field scanning optical microscopy

(NSOM) probe to enable 3D nano-manipulation of the trapped specimen.

Subsequently we show how plasmonic optical forces can be exploited to assist the

immobilization of artificial atoms in a plasmonic hotspot.

In particular, we demonstrate deterministic positioning of individual

nanodiamonds hosting a single nitrogen vacancy (NV) in the gap of a gold nanoantenna

and characterize their optical coupling through fluorescence lifetime measurements. The

second part of the lecture focuses on vacuum trapping and cooling of single

nanoparticles. In this experiment, a 150nm silica nanoparticle levitates in the focus

of a tightly focused laser beam. We show its motion can be cooled down along

all three spatial axes by applying parametric feedback acting on the trapping

laser intensity. Due to the absence of clamping, we reach mechanical quality factor

Q as high as 10 8 at pressure of 10 -6 mBar. This unprecedented Q confers the

levitating nanoparticle a huge sensitivity to its environment. In particular, we

demonstrate that the thermal energy of remaining molecules is sufficient

to drive the nanoparticle motion in a nonlinear regime.

31


Prof. Etienne Brasselet

Univeristé Bordeaux 1

France

etienne.brasselet@u-bordeaux.fr

Short Biography

Etienne Brasselet obtained his MSc in Physics with a speciality in “Statistical Physics

and Nonlinear phenomena” in 1997, from the Ecole Normale Supérieure de Lyon,

France. In 2001, he received his PhD in Physics within a partnership of the Université

Paris-Sud in France and the Centre for Optics Photonics and Lasers in Canada with the

thesis “Spatio-temporal non-resonant optical manipulation of nematic liquid crystals”. He

received a fellowship to visit the Nonlinear Physics Center of the Australian National

University where he worked with Dr. Andrey Miroshnichenko on research on lightinduced

effects in periodic structures with liquid crystal defects in 2009 and 2008.

In June 2011 he got his Habilitation (“Accreditation to supervise research”) with a

speciality in “Lasers, Matter and Nanosciences” from the University Bordeaux 1,

France. He is the principal researcher in the Singular Optics & Liquid Crystals Group at

the Laboratory of waves and matter of Aquitaine, France.

Among the research interests of Prof. Etienne Brasselet are light-matter interactions in presence

of spin and orbital optical angular momentum. Currently, he is working on orbital

angular momentum of light; optical vortices; singularities of light fields;

optomechanics: electromagnetic forces and torques; spin-orbit interaction of light;

orientational optical nonlinearities of liquid crystals; and topological defects of liquid crystals.

Professor Brasselet is an expert in optical vortex generation; optical angular momentum

analysis; micropolarimetry and light-induced three-dimensional structuring of liquid crystals.

32


Lectures

Topological liquid crystal photonics

Optical systems enabling the control of the orbital angular momentum of light found

many uses in photonics research and technology. It happens that the natural selforganization

of liquid crystals into various kinds of topological defects suits well for this

task. This represents an interesting self­engineering route towards the realization of

advanced photonic devices, which will be reviewed.

Liquid crystals as a test­bed for chiral optomechanics

Optical radiation forces are the mechanical manifestation of the transfer of the linear and

angular momentum of light to matter. The interplay between the chirality of matter and

light allows considering several options to manipulate, in a selective manner

the mechanical degrees of freedom of chiral objects depending on their chirality. This will

be illustrated by several experimental demonstrations where the optical angular

momentum of light is at play.

33


Prof. Govind P. Agrawal

The Institute of Optics

University of Rochester

USA

Short Biography

gpa@optics.rochester.edu

Govind P. Agrawal received the MSc and PhD degrees from the Indian Institute of

Technology, New Delhi, in 1971 and 1974, respectively. After holding positions at the

École Polytechnique, France, the City University of New York, and AT&T

Bell Laboratories, USA, he joined the University of Rochester in January 1989.

Professor Agrawal's research interests focus on quantum electronics, nonlinear

photonics, silicon photonics and fiber-optic communications. He has made important

contributions to the fields of semiconductor lasers, nonlinear fiber optics, and optical

communications. He has supervised 18 PhD theses, multiple MSc and BSc projects,

and more than 20 Master’s research papers. He has authored eight books, several of which

are used worldwide for teaching and graduate education. In particular, his book “Fiber-

Optic Communication Systems” (Wiley, 4th ed. 2010) is a standard graduate textbook in

many universities for training telecommunication engineers. His book on “Nonlinear

Fiber Optics” (Academic, 5th ed. 2013) appears among the 10 top cited books in

Physics at Goggle Scholar and has helped in training a whole generation of

scientists. He has published more than 400 research papers in internationally reputed

scientific journals. He is also the author of six patents and has worked with research

funding from sources such as National Science Foundation, Army Research Office,

New York State, NASA, and private industry.

34


Prof. Govind P. Agrawal

Lectures

Highly Nonlinear Fibers and their Applications

Optical fibers are behind the 21st century information revolution, as it is their use in the

worldwide optical communication network that led to the advent of the Internet during

the 1990s. Less well known but equally important is the advent of highly nonlinear fibers

whose emerging biomedical applications are revolutionizing the field of medical

imaging. In the first part of this lecture I review the properties of several kinds of highly

nonlinear fibers with emphasis on the microstructured fibers and photonic-crystal fibers.

The second part focuses on the nonlinear applications of such fibers. Topics covered

include Raman-induced frequency shifts, soliton fission, and supercontinuum generation.

When intense femtosecond pulses are launched into a highly nonlinear fiber such that

they experience anomalous dispersion, the pulses propagate initially as a high-order

soliton that undergoes a fission process, resulting in the formation of

multiple fundamental solitons of shorter widths. The onset of the Raman-induced red

shifts of these solitons and simultaneous generations of multiple blue-shifted

dispersive waves then lead to the formation of a supercontinuum whose spectral width

may exceed 100 THz (or 1000 nm). The applications of such broadband optical spectra

are also discussed.

35


Prof. Daniel Malacara-Hernández

Centro de

Investigaciones en

Óptica

México

Short Biography

dmalacara@cio .m

Daniel Malacara obtained his Bachelor degree in Physics in 1961 from the Universidad

Nacional Autónoma de México (UNAM), and his PhD in Optics in 1965 from the

University of Rochester, NY. He joined the Instituto Nacional de Astrofísica, Optica y

Electrónica (INAOE) in 1972, and then promoted the creation of the Centro de

Investigaciones en Optica (CIO), Mexico, becoming its first General Director, from 1980 to

1989. He was the Rudolf and Hilda Kingslake Professor at the University of Rochester in

1989 and 1990. At present, he is Emeritus Professor and Research Director at CIO.

The main field of activity of Professor Malacara is optical testing and optical

instrumentation. His scientific production includes more than one hundred papers in well

known optics journals, which had been cited in the scientific literature more than

a thousand times. Also, he has been author and editor of several well known books

in optics, the most popular of which is the book Optical Shop Testing, which has

been translated into several languages.

He is a Fellow of the The International Society for Optical Engineering (SPIE), and of the

Optical Society of America (OSA). He was vicepresident of the International Commission

for Optics (ICO) and also a Topical Editor for Applied Optics. He has been a co-organizer of

many international scientific meetings. In 1986, he received the Mexican National Prize for

Technology; the Conrady Award from the SPIE in 1994, the Galileo Galilei Prize from the

ICO in 1997, and the Fraunhofer Award from the OSA in 2002.

36


Lecture

2015 is the International Year of light. Why?

The motivations of the United Nations to designate 2015 as the “International year of

light” on December 20 2013, sponsored by the United Nations Educational, Scientific,

and Cultural Organization (UNESCO) are described. The most important reason was to

recognize the great importance that the study of light has had for the human been

civilization. The reason for selecting this year is that this year has been the anniversary

for many important events in the history of the study of light:

• 1015 (1000 years ago) In Arabia, Ibn Al-Haytham performed first studies

in geometrical optics and wrote the book: Book of Optics.

• 1815 (200 years ago) Agustin-Jean Fresnel studied diffraction, interference and

geometrical optics.

• 1865 (150 years ago) James Clerk Maxwell published the work “A Dynamical

Theory of the Electromagnetic Field”.

• 1905 (110 years ago) Albert Einstein in his annus mirabilis explains

the photoelectric effect.

• 1915 (100 years ago) Albert Einstein develops his Theory of Relativity.

• 1965 (50 years ago) Arno Pensias and Robert Wilson discover the microwave

background radiation that set the foundations for the Big Bang Theory.

And to celebrate these events and to start the year of light in January 19-20, UNESCO

Headquarters they had in Paris the following talks by Nobel laureates:

• Ahmed Zewaill Chemistry 1999

• Steven Chu Physics 1997

• Zhores Alferov Physics 2000

• William Phillips Phyisics 1997

• Serge Haroche Physics 2012

37


Dr. Agrawal is a Fellow of the Institute of Electrical and Electronics Engineers (IEEE)

and of the Optical Society of America. He has served on the editorial boards of many

journals devoted to optics and is currently serving as the Editor-in-Chief for the OSA

journal Advances in Optics and Photonics. He chaired the OSA Publication Council in

2009 and 2010 and was also on the OSA Board of Directors during that period. Professor

Agrawal received the IEEE Photonics Society’s prestigious Quantum Electronics Award

in 2012, the William H. Riker University Award for Graduate Teaching in 2013, and in

the same year he became the James C. Wyant Professor of Optics.

Lectures

Nonlinear Photonics with Optical Waveguides

Optical waveguides make it possible to observe nonlinearphenomena at much lower

power levels than bulk materials. After reviewing the basic concepts such as waveguide

loss and dispersion, my lecture will focus on five major nonlinear effects occurring inside

optical waveguides:

• Self-Phase Modulation

• Cross-Phase Modulation

• Four-Wave Mixing

• Stimulated Raman Scattering

• Stimulated Brillouin Scattering

After introducing the third-order nonlinear susceptibility, I focus on the Kerr nonlinearity

governed by a single nonlinear parameter g, whose real and imaginary govern self-phase

modulation (SPM) and two-photon absorption, respectively. I discuss SPM-induced

spectral changes and modulation instability that can lead to the formation of optical

solitons in the case of anomalous dispersion. Cross-phase modulation is discussed next

together with its harmful impact on telecommunication systems and useful applications in

optical switching and mode locking. Theory of four-wave mixing (FWM) is discussed

together with its applications for parametric amplification, phase conjugation, and

wavelength conversion. I describe briefly the nonlinear phenomeno of stimulated Raman

and Brillouin scattering before concluding the lecture.

38


Prof. Rocío Jauregui

Instituto de Física,

Universidad Nacional

Autónoma de México

México

rocio@fisica.unam.mx

Short Biography

Rocio Jauregui obtained her Bachelor degree in Physics in 1979 and her PhD in 1985

from the Universidad Nacional Autónoma de México (UNAM). She is full Professor at the

Institute of Physics of UNAM and a top-level member of the National System of

Researchers (Mexico).

Professor Jauregui’s main field of activity is in atomic and molecular physics, quantum

electrodynamics, quantum opctics and ultracold matter. Her scientific production includes

more than one hundred papers in well known physics journals, which have been cited in

the scientific literature more than eight hundred times. She has supervised many students,

including BSc, MSc and PhD.

Being a recognized scientist in theoretical physics, she has promoted the creation of

several laboratories, among which is the Optical Micromanipulation Lab and, more

recently, the National Laboratory of Quantum Matter, which was approved in 2014.

39


Prof. Rocío Jauregui

Lecture

Light for control and manipulation of atomic systems

The atom-light interaction is revisited. Basic laser cooling techniques like Doppler

cooling, Sisyphus cooling and two photon Raman cooling, and their first principle bases

are briefly described. The relevance of external electric and magnetic fields for the

implementation of light assisted control of the coupled internal and center of mass

quantum state of atomic systems is also emphasized. Some illustrative examples of

current systems of interest are discussed. In particular we describe:

(i) the implementation of evaporative cooling giving rise to degenerate atomic clouds via

optical fields;

(ii) the usage of structured optical lattices for the simulation of solid state

systems including inter atomic interaction control via Feshbach resonances;

(iii) studies on the frontier between classical and quantum dynamics using cold and ultra

cold atom clouds in structured optical lattices;

(iv)

the possibility of modifying atomic transition rates by laser shaping.

40


Prof. Luiz Davidovich

Federal University of Río de

Janeiro

Brazil

david@if.ufrj.br

Short Biography

Luiz Davidovich is Professor of Physics at the Federal University of Rio de Janeiro. He

got his PhD at the University of Rochester in 1975, and has worked since then in quantum

optics and quantum information. His major contributions are in the topics of decoherence,

entanglement, laser theory, and quantum metrology. He has analyzed in detail the role of

the environment in the dynamics of quantum coherence and quantum entanglement, and

also in quantum metrology, contributing with theoretical developments and proposals for

experiments, which have been performed in Europe and by his own group in Brazil.

He is foreign associate of the National Academy of Sciences of the United States of

America, and member of The World Academy of Sciences (TWAS). In 2000, he was

awarded the Brazilian Grand-Cross of the National Order of Scientific Merit. He won the

2001 Physics Prize of TWAS. He also won, in 2010, the most important prize for science

in Brazil, the Admiral Alvaro Alberto Prize, awarded by the Brazilian National Research

Council. He is Fellow of the Optical Society of America and of the American Physical

Society. He is member of the Executive Board of the Brazilian Academy of Sciences. He

was also member of the Executive Board of the International Council for Science (ICSU)

from 2011 to 2014. He was Secretary-General of the 4 th Brazilian National Conference on

Science, Technology, and Innovation for a Sustainable Development, held in Brasilia,

Brazil, in May 2010. He has supervised 21 PhD theses.

41


Prof. Luiz Davidovich

Lectures

Exploring The Subtleties Of The Quantum

World: From Photons To Qubits

From Quantum To Classical:

Light, Photons, Entanglement, And Decoherence

42


Prof. Julio César Gutiérrez Vega

Instituto Tecnológico

y de Estudios Superiores

de Monterrey

México

juliocesar@itesm.mx

Short Biography

Julio César Gutiérrez-Vega obtained his Bachelor degree in Physics and MSc

in Electrical Engineering from the Instituto Tecnológico y de Estudios Superiores

de Monterrey (ITESM), Mexico, in 1991 and 1995 respectively. In 2000 he received

his PhD in Optics from the Instituto Nacional de Astrofísica, Óptica y Electrónica,

Mexico.

The research interests of Prof. Gutiérrez-Vega are primarily in the propagation of

classical fields; especially in propagation invariant optical fields (PIOFs), solutions of the

Helmholtz and Paraxial Wave equation, laser resonators, numerical methods of special

functions and quantum and classical billiards. In particular, he introduced the Mathieu

and parabolic families of PIOFs, as well as the Ince-Gaussian beams. He has supervised

over 16 MSc and PhD thesis.

Julio C. Gutiérrez-Vega is a Professor in the Physics Department and leads the Optics

Center and the Photonics and Mathematical Optics Group at ITESM. He is a top-level

member of the National System of Researchers (Mexico). He is also an Associate Editor

of the journal Optics Express of the Optical Society of America (OSA) since January

2009. Member of the Mexican Academy of Sciences since 2004. He is a Senior Member

of OSA and SPIE since 2010.

43


Prof. Julio César Gutiérrez Vega

Lectures

Fundamentals of structured light fields

Hermite­Gaussian and Laguerre­Gaussian beams are well known family solutions of the

wave equation in the paraxial domain in the context of optical beams. Their properties

are relevant because they form complete basis to describe any paraxial beam and also

because they are eigenmodes of stable resonators. Laguerre­Gaussian beams carry orbital

angular momentum that can be transferred to microscopic particles. In this talk we review

a third family of solutions of the paraxial wave equation that smoothly connects the

Hermite­ and Laguerre­Gaussian modes through a continuous transition using elliptic

coordinates. The solutions are termed Ince­Gaussian beams because its transverse profile

is characterized by Ince polynomials. The general properties of the beams is discussed in

the context of optics and its transition between Hermite modes in Cartesian geometries

and Laguerre modes in circular geometries.

Optical applications of fractional calculus

Fractional calculus is an old topic in Mathematics but its applications in Physics and

Engineering are relatively new. Fractional models of well­studied physical phenomena

are providing new insights and strategies to handle complicated problems. Roughly

speaking, fractional Calculus is the theory of derivatives, integrals and differential

equations of fractional order. In this talk, we will review some applications of fractional

calculus in Optics, particularly in optical beam propagation, and non­linear phenomena.

44


Prof. Juan P. Torres

The Insttitute of Photonic

Sciences (ICFO)

Spain

Short Biopraphy

juanp.torres@icfo.es

Dr Juan P. Torres received his PhD in Physics in 1994 from the Universitat Politecnica de

Catalunya (Spain). Since then, he has worked in Barcelona at ICFO The Institute of Photonic

Sciences, in the field of quantum optics. In 2005, he was apointed group leader of the

Quantum Engineering of Light Group at ICFO.The research of Professor Juan P. Torres

focuses on the study of use and detection of new types of classical and quantum light for

exploring fundamental aspects of quantum theory and enabling or enhancing

the implementation of applications that might require specific types of quantum or

classical light, especially in communications and high-resolution probing and imaging. His

scientific production includes more than a hundred papers in well known optics journals,

which have been cited in the scientific literature more than one thousand times. He has been

author and editor of several well known books in optics.

His research trajectory has been acknowledged by several national and international prizes.

Among them, he was awarded the Best Doctoral Thesis of the Univeristat Politencnica de

Catalunya in 1997, he received the Award of the Goverment of Catalunya for reserch

promotion of in 2003, and three of his papers were selected for the Best Optics of the Year

issue of the magazine Optics and Photonics News (OSA) in 2001, 2002 and 2008.

45


Prof. Juan P. Torres

Lectures

Information and quantum coherence:

Everything that can happen does happen

When physicists envision a machine that makes use of quantumness to function they are

thinking of using two fundamental characteristics of quantum theory: the possibility to

generate superpositions of states (qubits) and the ability to intertwine distant objects

(entanglement). The implementation in the lab of such ideas requires harnessing concepts

such as available information, distinguishability and coherence. In this talk we will

explain the meaning of these ideas, how we play with them in experiments and why they

are important to get a more insightful understanding of how Nature works at its most

fundamental level.

Entanglement and Bell’s inequalities: Does reality exist?

The set of inequalities, equalities and similar expressions generally encompassed by the

term Bell’s inequalities are a cornerstone of our understanding of quantum theory. In

spite that they are now more than 50 years old, it is a rather puzzling situation that we

cannot agree on what they tell us about reality. Maybe this is because this is too much to

ask for! In this talk we will explain what these inequalities are, why they are closely

related to the concept of entanglement, how we measure them in the lab and how they

give us clues about how to think about reality.

46


Prof. Eugenio R. Méndez Méndez

Centro de Investigación Científica

y de Educación Superior

de Ensenada

CICESE

México

emendez@cicese. mx

Short Biography

Eugenio R. Mendez-Mendez obtained his B. Sc. In Physics in 1978 from

the Autonomous Metropolitan University (Universidad Autónoma Metropolitana,

UAM), Mexico, and his Ph D. in Applied Optics in 1985 from the Imperial College of

Science and Technology, United Kingdom. Then, he joined UAM in México only for 6

months, and latter, in 1987, the Center for Scientific Research and Superior

Education of Ensenada (Centro de Investigación Cientifica y Educación Superior

de Ensenada, CICESE).

His main field of research is optical testing and optical instrumentation. His scientific

production includes more than one hundred papers in well known optics journals, which

had been cited in the scientific literature more than one thousand times. He has been the

author and editor of several well known books in optics. Professor Mendez is a fellow of

the Optical Society of America (OSA). He was a topical Editor for Applied Optics. He

has been a co-organizer of many international scientific meetings. In 2006 he was

awarded the Premio Estatal de Ciencia y Tecnología, Mexico.

Lectures

Light scattering by particles and rough surfaces

47


Prof. Fernando Ramírez Martínez

Instituto de Ciencias Nucleares,

Universidad Nacional

Autónoma de México

Short Biography

México

ferama@nucleares.unam.mx

Fernando Ramirez obtained his Bachelor degree in Physics in 2003 from the Universidad

Nacional Autónoma de México (UNAM), and his PhD in Physics from the Imperial

College of London, England, in 2008. He joined the Institute of Nuclear Sciences of

UNAM as postdoctoral researcher first, and later, in 2011, he obtained the position of

Assistant Professor.

The research of Professor Ramírez is mainly focused on atomic spectroscopy, light-matter

interactions in atomic systems and ultracold matter. His scientific production includes

several papers in well known optics journals.

48


Prof. Fernando Ramírez Martínez

Lectures

Laser Spectroscopy of Atomic Systems: basic experimental techniques

In this talk we begin with a review of some basic concepts concerning the interaction

between a monochromatic electromagnetic radiation field and an atom. Based on this

information, some particularly representative experimental techniques are described.

These techniques are routinely used in atomic physics modern laboratories to stabilize the

frequency of laser sources to atomic resonances. Next, the basic functioning principles of

a magneto-optical trap are revised together with the most commonly used techniques for

imaging cold atom clouds. We conclude by demonstrating how these techniques, jointly

with a time of flight measurement, are routinely used to determine important physical

parameters of cold atom clouds such as their temperature.

49


SUMMER

SCHOOL

L

i S c

i

2 0 1 5

POSTER SESSION

1M


Poster Session 1M

Title Presenting Author ID

Thermoregulation on IR reflecting leaf sitting frogs

Rapid Raman imaging using light sheet microscopy

and interferometric filters

Information encoding in DNA through UV-C light dissipation

at the beginnings of life

Light as an External Field in Soft Matter

Gold as intruder in ZnO nanowires

Rotationally Resolved Electronic Spectra of 2- and 3-Tolunitrile

in the Gas Phase: A Study of Methyl Group Internal Rotation

Metallic Nanoparticles Produced by Thermal

and Laser Annealing for Optical Applications

Characterization of energy circulation in focused Bessel beams

as a function of the topological charge

Denaturation of DNA by Dissipation of UV-C Photons:

Experiment

to test the Thermodynamic Dissipation Theory for the Origin of

Life

Infrared Thermography Analysis of Light Collecting Fluids

Optical Methods Comparison to Vegetal Chlorophyll

Quantification

Inhibition of Fungi Cultures with Eosin Solution and Green Light

Growth Control of Fungus in Plants due to Ultraviolet Radiation

Francisco Herrerías Azcué

University of Manchester

Pablo Loza-Alvarez

ICFO-Institut de Ciencies

Fotoniques

Julián Mejía Morales

Instituto de Física, UNAM

Erick Sarmiento Gomez

Instituto de Fisica, Universidad

Autonoma de San Luis Potosí

José Miguel Méndez

Reyes

Universidad Nacional

Autónoma de México

José Arturo Ruiz Santoyo

Universidad de Guanajuato

Adriana Ivonne Canales

Ramos

Facultad de Ciencias, UNAM

E. Gómez-López

Facultad de Ciencias, UNAM

Norberto Santillán Padilla

Facultad de Ciencias, UNAM

Ada Lilí Alvarado Leaños

Universidad Autónoma de

Yucatán

Irving Herrera Luna, Edgar

Santiago Reyes Reyes

Universidad Veracruzana

José de Jesus García

López

Universidad Veracruzana

Alan Roberto Martinez

Cortes

Universidad Veracruzana

020

026

032

034

035

037

042

047

048

050

057

058

059

51


Title Presenting Author ID

Dynamical Casimir effect in a Kerr Cavity

Light Scattering Applications: Microrheology in Absorbing Media

Optical methods for measurement of glucose levels

Mechanical and Rheological Properties of Cells

Comparative study for the optical properties of organic

nanoparticles synthesized by reprecipitation and laser ablation

method and their use has a contrast agent in cell images

Arbitrary structured light beams: generation

and application to micromanipulation

Optically Chaining Tens of Silica Micro-Spheres

Unambiguous Discrimination Strategies for the Lifted Trine

Ensemble

Gold nanoparticles functionalized with POSS-THIOL

fabricated by laser ablation for biosensor applications

Massive manipulation of microparticles using termophoresis

Controlling Light Propagation Through a static scattering media

Calibrating of an optical tweezers setup for trapping red blood cells

Acoustic Orbital Angular Momentum Transfer to Matter

by Chiral Scattering

Positional rearrangement of colloidal particles induced

by two-dimensional optical forces

Ricardo Román Ancheyta

Instituto de Ciencias Físicas,

UNAM

Antonio Tavera Vázquez

Instituto de Física, UNAM

Naara González Viveros

Universidad Veracruzana

Yareni Aguilar Ayala

Instituto de Física, UNAM

Jorge Enrique Alba

Rosales

Universidad de Guanajuato/

Centro de Investigaciones en

Optica

Andrés de los Ríos

Sommer

Instituto de Física, UNAM

Alberto Ascencio

Rodríguez

Universidad Veracruzana

Graeme Weir

University of Glasgow

Jean Yves Tovar Sánchez

Centro de Ciencias Aplicadas y

Desarrollo Tecnológico, UNAM

Rafael Páez López

Instituto Nacional de

Astrofísica Óptica y Electrónica

Beatriz Coyotl Ocelotl

Instituto Nacional de

Astrofísica Óptica y Electrónica

Nahúm Méndez Alba

Universidad Autónoma

Metropolitana- Iztapalapa

Juan Israel Vázquez

Lozano

Instituto Nacional de

Astrofísica Óptica y Electrónica

Daniel Josafat Ríos

González

Instituto de Física, UNAM

068

069

073

075

079

082

094

099

104

109

110

117

118

119

52


Title Presenting Author ID

Liquids Jets Generated by Thermocavitation in Capillary Tubes

Use of co-occurrence matrix in the visualization of blood vessels

deep in Laser Speckle imaging

Optical Turbulence produced by a Drone Propeller

Quasi-1D Trapping

Temporal vs Spatial Laser Speckle Imaging to measure relative

blood flow speed in deep blood vessel: In-vitro study

Relation between rheological and microstrutural properties

of systems of wormlike micelles.

Implementation of a Leakage Radiation Microscope for Imaging

Surface Plasmon Polaritons Interaction on Nano-structures

Diffuse light transmission profiles using time resolved imaging

with temporal extrapolation given by different solutions

to the transport equation

Study and simulation of the physics phenomena in a solar cell

Periodic Cavitation in an Optical Tweezer

DMPC/CHOL Model Membrane Monolayers Analized

by Brewster Angle Microscopy

Finite Element Simulations and Experimental Measurement

of Dielectrophoretic Force in Optoelectronic Tweezers

with Different Particle Sizes

Trapping DNA-like networks structures at low pH

Julián Ramírez Ramírez

Instituto Nacional de

Astrofísica Óptica y Electrónica

Jose Angel Arias Cruz

Instituto Nacional de

Astrofísica Óptica y Electrónica

Raúl Rodríguez García

Instituto de Astronomía, UNAM

Arantza Berenice Zavala

Martinez

Universidad Veracruzana

Cruz Elizabeth Pérez

Corona

Instituto Nacional de

Astrofísica Óptica y Electrónica

Brisa L. Arenas Gómez

Universidad de Guanajuato

Gaspar Uriarte Medina

Centro de Investigación

Científica

y de Educación Superior de

Ensenada

Eduardo Ortiz Rascón

Centro de Ciencias Aplicadas y

Desarrollo Tecnológico, UNAM

Andrés Ávila Perea

Universidad Autonoma de

Queretaro

Viridiana Carmona Sosa

Instituto de Ciencias Nucleares,

UNAM

Alan Bañuelos Frías

Universidad Autónoma de San

Luis Potosí

Angel Fuente Garcia

Instituto Nacional de

Astrofísica Óptica y Electrónica

Alda Yadira Sánchez

Treviño

Instituto de Física, Universidad

Autónoma de San Luis Potosí

120

124

128

131

132

144

148

150

151

154

169

174

177

53


Title Presenting Author ID

Exploring assembling conditions to encapsidate a mRNA

from enhanced green fluorescence protein into Cowpea Chlorotic

Mottle virus capsid

Real Time Register of Viral Capsid Self Asembly Protein

by Single Molecule Fluorescence

Characterization of photoelectric properties of the organic

semiconductor based on polymer: sensitizer blend

Mammalian Cells Trasfected by a Plant Virus Capsid Containing

an mRNA in Observed by Fluorescence Microscopy

RNA Nanoring Structures Observed by Atomic Force Microscopy

Highly Monodisperse and Ultrasmall Gold Nanoshells

for Photothermal Applications

Influence of Cross-link density on Structural and Optical

Properties of Nanogeles

Viridiana de la Cruz

GonzÁlez

Instituto de Física, Universidad

Autónoma de San Luis Potosí

Mario Alberto Martínez

Partida

Universidad Autónoma de San

Luis Potosí

Miriam Cuatecatl

Tlapapatl

Instituto Nacional de

Astrofísica, Óptica y

Electrónica

Mayra Colunga Saucedo

Instituto de Física, Universidad

Autónoma de San Luis Potosí

Adriana Margarita

Longoria Hernández

Instituto de Física, Universidad

Autónoma de San Luis Potosi

Xóchitl Fabiola Segovia

González

Instituto de Física, Universidad

Autónoma de San Luis Potosi

Mónica Ledesma-

Motolinía

Departamento de Ciencias

Básicas UAM Azcapotzalco

182

183

184

186

187

188

196

54


ID020

Thermoregulation on IR reflecting leaf sitting frogs

F. Herrerías-Azcué 1,* , M. Dickinson 1 , A. Gray 2

1

Photon Science Institute, University of Manchester, Oxford Road, Manchester, M13 9PL

2 Manchester Museum, Oxford Road, Manchester, M13 9PL

*Corresponding Author: francisco.herreriasazcue@postgrad.manchester.ac.uk

KEY WORDS: Thermoregulation, pterorhodin, frogs, infra-red, spectrum

Pterorhodin, a darkening pigment that replaces melanin in some neo-tropical tree frogs, causes

them to reflect light in the near infra-red [1] . This results in a trough in the absorptivity that could

enhance the ability of such frogs to stay at cooler temperatures and conserve their humidity.

To test this hypothesis, a comprehensive simulation of the thermoregulatory process in

anurans was programed using MATLAB. The theoretical framework has been relatively well

understood since the 1970’s [2] , but until now, it neglected the importance of the frog’s optical

absorption spectrum. The simulation is presented in a graphical user interphase, encompassing

radiation, convection, conduction, evaporative water loss and, most importantly, solar absorption.

A solar position calculator [3] and spectrum generator [4] were included in the simulation,

which allows it to reproduce realistic scenarios all around the globe. It is also programmed to be

able to calculate most parameters in at least one mode, minimizing the field measurements

necessary. However, it also allows for direct input.

A technique was developed to measure the surface of the specimens from photographs

(using 3D reconstruction software), which allows the acquisition of precise data (~0.1 mm).

This technique also offers the possibility of surface comparison in different species.

Optical reflection spectra of different frogs were measured and used as input, and the

resulting differences in temperature and water balance of frogs with and without pterorhodin are

discussed.

The thermoregulation process of infra-red reflecting frogs (left) was modelled and programmed into a graphical user

interphase (center), and a surface measurement technique via 3D model rendering was developed (right).

1 J.T. Bagnara, Enigmas of Pterorhodin, a Red Melanosomal Pigment of Tree Frogs, Pigment Cell Research, 16-5

(2003) 510-516.

2 C.R. Tracy, A model of the dynamic exchanges of water and energy between a terrestrial amphibian and its

environment, Ecological Monographs, 46-3 (1976) 293-326.

3 M. Blanco-Muriel et al, Computing the solar vector, Solar Energy, 70-5 (2001) 431-441.

4 C. Gueymard, SMARTS2: a simple model of the atmospheric radiative transfer of sunshine: algorithms and

performance assessment, Florida Solar Energy Center, (1995).

55


ID026

Rapid Raman imaging using light sheet microscopy and interferometric filters

Israel Rocha-Mendoza 1* , Jacob Licea-Rodriguez 2* , Mónica Marro-Sánchez 2 ,Omar Olarte 2

and Pablo Loza-Alvarez 2

1

Centro de Investigación Científica y de Educación Superior de Ensenada, Carretera Ensenada-Tijuana, No. 3918, Zona

Playitas, 22860 Ensenada B.C., México

2

ICFO-Institut de Ciencies Fotoniques, Av. Carl Friedrich Gauss, 3

08860 Castelldefels (Barcelona), Spain

Corresponding Author’s e-mail address: jacob.licea@icfo.es

KEY WORDS: Spontaneous Raman imaging, light-sheet microscopy

We present the implementation of a cost effective technique for rapid 2D spontaneous

Raman imaging based on a digital scanned light sheet microscope (DSLM) reported previously 1

We used cw sources in the excitation and interferometric tunable filters in the detection to

retrieve the spectral information. A controlled tilt of the filter tunes its cut on/off wavelength

along the excited Raman bands tracing in that way the integration of their intensities on each

image pixel; resembling the so called razor blade technique to measure laser intensity profiles. A

further derivation of the images stack with respect the tuned cut off wavelength retrieves the

Raman spectral information with good spectral resolution and allows the discrimination of nonresonant

signal from auto fluorescence and Rayleigh scattering. The proof of principle of the

technique is shown at the C-H (2700-3100cm -1 ) region of DMSO. Raman spectra (Figure 1a) and

the feasibility of the technique for hyper spectral imaging on 3D samples is demonstrated using a

composition of polystyrene beads and lipid droplets immersed agar (Figure 1b). This technique

paves the way for studies on microbiological samples using spontaneous Raman imaging as

widely used in CARS and SRS microscopy.

Figure 1.- Proof of principle of Raman imaging using DSLM. a) Spectrally resolved Raman on

DMSO and b) maximum intensity projection Raman image of a sample containing polystyrene beads

(PB) and lipids droplets (LD).

Acknowledges:

*I.Rocha-Mendoza and J.Licea-Rodriguez acknowledge funding support from CONACyT

through research grants 155803 and 233012, and 238390, respectively.

1 A. O. Olarte, J. Licea-Rodriguez, J. A. Palero, E. J. Gualda, D. Artigas, J. Mayer, J. Swoger, J. Sharpe, I. Rocha-

Mendoza, R. Rangel-Rojo, and P. Loza-Alvarez, Biomed. Opt. Express., 3 (2012) 1492-.1505

56


ID032

Information encoding in DNA through UV-C light dissipation at the

beginnings of life

J. Mejía-Morales 2 , K. Michaelian 1

Instituto de Física, Universidad Nacional Autónoma de México, Cto. de la Investigación Científica,

Cuidad Universitaria, C.P. 04510, Mexico 2

Posgrado en Ciencias Físicas, Universidad Nacional Autónoma de México, Cto. de la Investigación Científica,

Cuidad Universitaria, C.P. 04510, Mexico 1

julianmejia@fisica.unam.mx 2 , karo@fisica.unam.mx 1

KEY WORDS: Origin of life, non-equilibrium thermodynamics, central biological dogma, codonamino

acid affinity, genetic information, UV-C light, potential dissipation

DNA contains all the information to determine the phenotype of a living organism, where the

information is used in the translation of the genetic code for producing amino acid sequences. This

process is currently very complex incurring DNA translation to protein, and protein reproduction

of DNA, known as the central dogma of biology, but leads to a cyclical problem at the origin of

life.

The dissipative thermodynamic theory of the origin of life 1 provides a novel perspective base on

non-equilibrium thermodynamics 2,3 for explaining the origin and evolution of biological processes.

The theory has suggested a mechanism for enzyme-less DNA/RNA replication in which

DNA/RNA dissipates UV-C light and can use the thermal energy of this process to denature itself.

From within this framework we suggest a hypothesis of how the stereochemical affinity between

codons and aminoacids 4 allowed an increase in the production of entropy in the irreversible process

of the dissipation of solar photon potential (since the aromatic amino acids are good UV-C light

absorbers and can donate their electronic excitation energy to DNA/RNA) thus allowing an

increase in the probability of DNA/RNA denaturation. Analyzing this process in detail from this

thermodynamic perspective leads to a deeper understanding of genetic information.

[1] K. Michaelian, Thermodynamic dissipation theory for the origin of life, Earth Syst. Dynam., 2, 37–51,

2011.

[2] I. Progogine, Introduction to thermodynamics of irreversible processes, Interscience Publishes, 1955.

[3] G.Lebon, D. Jou, J. Casas-Vázquez, Understanding Non-equilibrium Thermodynamics, Springer, 2008.

[4] M. Yarus, J. Widmann, R Knight, RNA–Amino Acid Binding: A Stereochemical Era for the Genetic

Code, J Mol Evol (2009) 69:406–429.

57


ID034

Light as an External Field in Soft Matter

E. Sarmiento-Gomez 1 , J. L. Arauz-Lara 1

Instituto de Física “Manuel Sandoval Vallara”, Universidad Autónoma de San Luis Potosí, Álvaro Obregón 64, San Luis Potosí,

S.L.P. México

Corresponding Author’s e-mail address and URL: esarmiento@ifisica.uaslp.mx

KEY WORDS: Optical trapping, Soft Matter, Brownian motion

Optical trapping has become one on the most successful techniques for measuring forces of the

order of piconewtons for a wide variety of applications 1 . From a fundamental point of view,

single particle optical trapping is based on the interaction of an external field with a dielectric

colloidal particle, produced by conservation of momentum of photons being refracted in the

interface of the colloidal particle 2 . However, less attention has been paid to the use of light as

external field, in which an inhomogeneous distribution of light produces an external force acting

on a dielectric particle undergoing Brownian motion.

In this work, we present several preliminary results of the interaction of Brownian

particles with laser induced external fields. Our experimental set-up is based in a recently

published set up that uses interference between two coherent beams 3 . In particular we analyze the

coupling between the motion of a anisotropic particle with an external periodical potential. We

also analyze a particular case of the well-known Kramers’s problem 4 . Additionally, an

experimental insight of the response of a perfect colloidal crystal to deformation is given. These

results show the beginning of an emergent field of great importance in soft matter.

Brownian spherical particles interacting with an external periodical potential. A pseudo-crystalline

configuration is highlighted in the upper left part.

1 J. R. Moffitt, Y. R. Chemla, S. B. Smith, C. Bustamante, Annu. Rev. Biochem., 77 (2008) 205-228.

2 E. Furst, Curr. Opi. Coll. Int. Sci ., 10 (2005) 79-86.

3 M. C. Jenkins, S. U. Egelhaaf, J. Phys.: Condens. Matter, 20 (2008) 404220.

4 H. A. Kramers, Physica, 7 (1940) 284-304.

58


ID035

Gold as intruder in ZnO nanowires

José. M. Méndez-Reyes 1 , B. Marel Monroy 1 , Monserrat Bizarro 1 , Frank Güell 2 , Ana Martinez 1 ,

Estrella Ramos 1

1

Instituto de Investigaciones en Materiales, Facultad de Ciencias y Facultad de Química, Universidad Nacional Autónoma de

México. Circuito Interior, S N. Ciudad Universitaria. P.O. Box 70-360, Coyoacán, 04510. México DF, México

21

Departament d’Electrònica, Universitat de Barcelona, C/Martí i Franquès 1, E-08028 Barcelona, Catalunya, Spain

Corresponding Author’s e-mail address and URL: mendezreyesjosemiguel8@gmail.com

KEY WORDS: ZnO nanowires, photonic applications, electronic properties,

Several techniques for obtaining ZnO nanowires (ZnO NWs) have been reported in the

literature 1 . In particular, the vapour-liquid-solid (VLS) with Au as catalyst is widely used. During

this process, Au impurities in the ZnO NWs are incorporated accidentally, as intruders. It is

thought that these intruders may produce interesting alterations in the electronic characteristics of

nanowires 2 . In the experiment, it is not easy to detect either Au atoms, or the modification that

intruders produce in different electrical, optical and other properties 3 . For this reason, in this

Density Functional Theory investigation, the effect of Au intruders in ZnO NWs is analysed. Au

extended (thread) and point defects (atoms replacing Zn or O, or Au interstitials) are used to

simulate the presence of Au atoms. Optimised geometries, band-gap and density of states indicate

that the presence of small amounts of Au drastically modifies the electronic states of ZnO NWs.

The results reported here clearly indicate that small amounts of Au have strong impact on the

electronic properties of ZnO NWs, introducing states in the band edges that may promote

transitions in the visible spectral region 4 . The results enhance the potential use of these systems

for photonic and photovoltaic applications.

Electrostatic potential (PES). Highest occupied orbital molecular (HOMO), and lowest (LUMO), and partial density

of states (DOS for Zn and Au) of a ZnO NW doped with an Au atom inside the unite cell.

[1] José. M. Méndez-Reyes , B. Marel Monroy, Monserrat Bizarro, Frank Güell, Ana Martinez, Estrella

Ramos, Gold as intruder in ZnO nanowires, Phys. Chem. Chem. Phys. XX, XXXX (2015) (accepted)

1 Zhang. Y., Ram. M. K., Stefanakos. K., Goswami. Y., J. Nanomaterials, 2012 (2012) 1-22 .

2 Brewster. M. M., Zhou. X., Lim. S. K., Gradecak. S., J. Phys. Chem. Lett. 2 (2011) 586-591.

3 Güell. F., Ossó. J. O., Goñi. A. R., Cornet. A., Morante. J. R., Nanotechnology 20 (2009) 315701-315708.

4 Wang. C., Wang. Y., Zhang. G., Peng. C. and Yang. G., Phys. Chem. Chem. Phys. 16 (2014) 3771-3776.

59


ID037

ROTATIONALLY RESOLVED ELECTRONIC SPECTRA OF 2- AND 3-

TOLUNITRILE IN THE GAS PHASE: A STUDY OF METHYL GROUP

INTERNAL ROTATION

José Arturo Ruiz-Santoyo 1 * , Josefin Wilke 2 , Martin Wilke 2 , John T. Yi 3 , Michael Schmitt 2 , David

W. Pratt 4 , and Leonardo Álvarez-Valtierra 1 **

1 Physical Engineering Department, University of Guanajuato; León, Guanajuato, México 37150

2 Institut für Physikalische Chemie, Heinrich-Heine-Universität; Düsseldorf, Deutschland 40225

3 Chemistry Department, Winston-Salem State University; Winston-Salem, NC 27110

4 Chemistry Department, University of Vermont; Burlington, VT 05405

* arrturosantoyo@gmail.com

** leoav@fisica.ugto.mx https://www.dci.ugto.mx/~leoav/

KEY WORDS: High resolution molecular spectroscopy; Electron-withdrawing groups; Internal

Rotation

Rotationally resolved fluorescence excitation spectra of the origin bands in the S 1 ←S 0 transition

of 2-tolunitrile (2-TN) and 3-tolunitrile (3-TN) have been recorded in the collision-free

environment of a molecular beam and subsequently analyzed. Inertial parameters, such as

rotational constants were measured in both electronic states. From the spectral analyses

performed on these molecular systems, it was possible to determine the potential energy curves

of the internal rotation of the methyl group in both electronic states. The change of the barrier

height by electronic excitation in tolunitriles, where the –CN group (an electron-withdrawing

substituent) is present, is compared with other toluene derivatives 1 (possessing either electronattractive

or withdrawing groups) in terms of the internal rotational motion of the attached –CH 3

group.

Diagram showing the change of the potential barrier height related to the methyl torsional motion in 2-

tolunitrile molecule

[1] Fujii, M., Yamauchi, M., Takazawa, K., Ito, M., Electronic Spectra of o-, m- and p-tolunitrile - substituent Effect

on Internal Rotation of the Methyl Group, Spectrochimica Acta Part A: Molecular Spectroscopy 50, 1421-1433

(1994)

60


ID042

Metallic Nanoparticles Produced by Thermal and Laser Annealing for Optical

Applications

A.Canales 1,2 , J. Martínez 1 , C. Sánchez-Aké 1 , M. Villagrán-Muniz 1

1 Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, P.O. Box 70-186, C.P.

04510, México D.F., México.

2 Facultad de Ciencias, Universidad Nacional Autónoma de México, Cd. Universitaria, C.P. 04510, México D.F., México.

E-mail address: adriana_23@ciencias.unam.mx

KEY WORDS: Nanoparticles, thermal annealing, laser annealing, pulsed laser photoacoustic,

optical transmission and reflectivity.

Two methods to synthesize metallic nanoparticles (NPs) are thermal and laser annealing of thin

metal films. The thermal annealing method is a straightforward one, where a dielectric substrate

coated with a metal thin film is placed inside an oven. Then temperature is increased up to below

the metal fusion point, as to provide the disaggregation of the film into particles as a result of the

minimization of surface energy 1 . With the laser annealing, it is possible to produce nanoparticles

of tens of nm by irradiating metal thin films with nanosecond laser pulses.

It is well known 2 that the shape, mean size and size distribution of the resulting NPs are

function of the film thickness and the temperature during the thermal annealing process. In the

case of laser annealing, the shape and size of the NPs depend on the number of pulses 3 . In this

work, we study the formation of gold NPs by thermal and laser annealing of thin films. To

achieve this we use, simultaneously, the pulsed laser photoacoustic and optical transmission and

reflectivity techniques to detect changes in Au metal films during thermal and laser annealing,

respectively. To study the influence of the initial film thickness on the size and size distribution

of the resulting NPs, the thickness was ranged from 5 to 65 nm. The changes in the photoacoustic

and optical signals were compared with the Scanning Electron Microscopy images of the

samples. The current assessment suggests that both techniques are suitable for real time

monitoring of the changes produced by the annealing.

SEM images of NPs produced from 15nm Au films by (a) Thermal Annealing , (b) Laser Annealing.

1 C. Worsch, M. Kracker, W. Wisniewski, C. Rüssel, Thin solid films 520, 4941-4946, 2012.

2 C.V. Thompson, Annu. Rev. Mater. Res., 42, 399-434, 2012.

3 S. Imamovaa, N. Nedyalkov, A. Dikovska, P. Atanasov, M. Sawczak, R. Jendrzejewski, G. Sliwinski, M. Obara,

Appl. Surf. Sci., 257, 1075-1079, 2010.

61


ID047

Characterization of energy circulation in focused Bessel Beams as a function

of the topological charge.

E. Gómez-López 1,2* , A. De Los Ríos 2 , A. V. Arzola 2 , K. Volke-Sepúlveda 2

1

Facultad de Ciencias, Universidad Nacional Autónoma de México, Av. Universidad 300, Circuito Exterior S/N,

Ciudad Universitaria, México D.F., México, 04510

2 Instituto de Física, Universidad Nacional Autónoma de México, Apdo. Postal 20-364, México D.F., México, 01000

* egomez@ciencias.unam.mx

KEY WORDS: Optical vortex, Bessel beam, energy flux, holographic encoding.

We focused different Bessel beams (BB) onto a single slit and analyzed the propagation of the

resulting intensity lobes on perpendicular planes to the propagation axis. The lobes shift away from

the slit axis due to the skew angle of the wave-fronts of the BB, which is directly related with the

transverse energy flux 1 . The analysis is done both numerically and experimentally.

The numerical analysis consists of simulations of the propagation of a single-ringed

Laguerre-Gaussian beam (LG) of topological charge l by means of Fresnel diffraction. The LG

beam impinges onto an axicon to form a BB of order l 2 , which in turn enters a positive lens. A ring

of fixed radius, regardless of the topological charge, is formed at the focal plane of the lens, where

we place a single slit. The resulting diffraction patterns are analyzed for different propagation

lengths. The experimental setup is analogous to the simulation. The only difference is that the BB

is formed using digital holographic encoding by means of a spatial light modulator.

We show that the dependence of the lateral displacement of the diffraction lobes after the

slit is a linear function of the propagation distance. Furthermore, the slope of these functions is also

a linear function of the topological charge (l) of the beam.

Left column: intensity pattern of a focused Bessel Beam of order l=3 (top) and l=9 (bottom). Center: intensity pattern

at the slit plane. Right: diffraction patterns at the same propagation distance after the slit plane.

[1] R. Terborg, K. Volke-Sepúlveda, Quantitative characterization of the energy circulation in helical

beams by means of near-field diffraction, Optics Express 21, 3379 (2013)

[2] J. Arlt,, K. Dholakia, Generation of high-order Bessel beams by use of an axicon, Optics

Communications 177, 297 (2000)

62


ID048

Denaturation of DNA by Dissipation of UV-C Photons:

Experiment to test the Thermodynamic Dissipation Theory for the Origin of

Life

N. Santillán 1 , K. Michaelian 2

1

Facultad de Ciencias, Universidad Nacional Autónoma de México, Av. Universidad 3000, Circuito Exterior S/N,

Ciudad Universitaria, C.P. 04510, México D.F.

norberto__07@hotmail.com(double underscore)

2

Instituto de Física, Universidad Nacional Autónoma de México, Circuito de la Investigación Científica, Ciudad Universitaria,

C.P. 04510, México, D.F

KEY WORDS: Dissipation of energy, UV light, denaturation of DNA.

Sunlight directs and maintains almost all processes in the atmosphere and at Earth's surface,

including life. DNA and RNA are efficient dissipators of UV-C photons into heat and their

dissipative capacity may have been crucial to their replication at the first steps of evolution.

Thermodynamic Dissipation Theory for the Origin of Life 1 proposes a non-enzymatic

mechanism, called UVTAR mechanism, for replication of DNA and RNA at the beginning of life

(some 3.8 Ga) driven by UV light and temperature.

This work test the first step of proposed mechanism subjecting different DNA solutions

(at constant temperature) to cycles of UV-C radiation from a deuterium lamp in order to simulate

day/night UV-C cycle in the Archean. Our results show that denaturation of DNA, essential for its

replication, under UV-C radiation (day) and renaturation during dark periods (night) is feasible

for either short synthetic or, a partial denaturing, for long biological DNA at several temperatures.

So these results confirm the first step of the proposed mechanism and therefore give the first

experimental evidence in favor of the Thermodynamic Dissipation Theory for the Origin of Life.

Evolution of extinction at 260nm during tests at 40°C with salmon sperm DNA dissolved in purified

water. Increase in extinction is a signal of denaturation. During dark periods DNA strands renature.

Straight lines of negative slope corresponds to dark periods, so there is no data from the spectrometer.

1 K. Michaelian, arXiv:0907.0040v2 [physics.gen-ph] (2009); Earth Sys. Dynam., 2 (2011) 37-51.

63


ID050

Infrared Thermography Analysis of Light Collecting Fluids

A.L. Alvarado-Leaños 1 , I.Y. Forero-Sandoval 2 , J.D. Macias 2 , O. Ares 2 , J.J. Alvarado-Gil 2

1 Facultad de Matemáticas, Universidad Autónoma de Yucatán, Av. Industrias no Contaminantes por Periférico, A.P. Cordemex,

Mérida, Yucatán México. 2 Department of Applied Physics, CINVESTAV-Unidad Mérida, Carretera Antigua a Progreso km.6, A.P.

73 Cordemex, C.P.97310, Mérida, Yucatán, México

Corresponding Author’s e-mail: alea.ada89@gmail.com

KEY WORDS: Solar thermal energy, infrared thermography, ferrofluids

Solar irradiation is one of the most promising and easily accessible energy sources. Due to this, a

great variety of solar thermal collectors have been developed. A widely used configuration

consists in collecting the solar energy using containers, in which the surface is in charge of

absorbing the solar energy, converting it into heat and then transferring this heat to a working

fluid. Not long ago, it was suggested that a variant of this configuration can be developed by

using a transparent recipient, where the fluid inside the recipient contains particles which could

strongly absorb the solar energy 1 .

In this paper, the light into heat conversion process, of solar thermal collecting fluids is

explored using infrared thermography. The studies were performed using an Infrared

Thermographic camera (InSb ImageIR 8300, spectral range of 2-5 µm). Samples of EMG 900

ferrofluids from Ferro Tec, based on Magnetite nanoparticles (diameter: 10 nm) were studied.

Samples are contained inside a 1mm thick glass recipient, with lateral 150 µm windows. The

heating was generated using a solid state high power laser (THORLABS, ASm808-20CS)

operating with a driver unit THORLABS model: LCD3065. Images of the surface of the nonilluminated

glass window were taken and the rise and decay of the surface temperature was

analyzed. Results show that the light collection, by the sample, is strong and that most of the

losses are due to the emission of infrared light. Our results can be relevant in the development of

novel light harvesting, energy concentration and high efficiency solar thermal energy systems 2 .

Heating-cooling process of the non-illuminated window of the container with the ferrofluid sample. Infrared images

of the sample when it is (a) non-illuminated, then (b) after 2 seconds, and finally (c) at the maximum temperature.

(d) Time evolution of the temperature at the center of the sample at the heating zone

1 A. Lenert and E. N. Wang, Sol. Energy, 86 (2012) 253-265.

2 H. Ghasemi, G. Ni, A.M. Marconnet, J. Loomis, S. Yerci, N. Milijkovic and G. Chen. Nat. Commun., 5 (2014)

4449-4456.

64


ID057

Optical Methods Comparison to Vegetal Chlorophyll Quantification

I. Herrera Luna 1 , H.H. Cerecedo Nuñez 1 , J. I. Bañuelos Trejo 2 , P. Sosa Padilla 1 , E. S. Reyes Reyes 1 ,

J. A. González Contreras 1

1 Laboratorio de Óptica Aplicada, Faculta de Física, 2 Laboratorio de Organismos Benéficos, Facultad de Ciencias Agrícolas,

Universidad Veracruzana, Xalapa, Ver. México.

irving.hluna@live.com.mx

KEY WORDS: Optical instrumentation, design and testing; Multidisciplinary applications of

optics; Biophotonics; UV light Absorption.

The study quantifying chlorophyll requires specialized equipment, in some cases it is expensive

and it has a considerable margin of error. Chlorophyll can be quantified by invasive and noninvasive

methods. In this work two known methods are studied and two are proposed. These

known methods are based on a field scope and quantification by a spectrophotometer; these

methods were the base to measure the error of the proposed two methods. In this case, the

methods proposed aim to design in the future, a noninvasive optical device that measures the

amount of plant chlorophyll, based on transmittance of light though plant leaves. And a method

of image analysis based on the contents of RGB, a low cost method, compared to high-cost

commercial devices and destructive methods. The importance of quantifying chlorophyll is

essential for the sustainability of agricultural development in Mexico, and that chlorophyll is an

indicator of the health of the plants.

Figure. Non-invasive LED based Chlorophyllometer prototype.

[1] Vollmann, J., H. Walter, T. Sato and P. Schweiger, 2011. “Digital image analysis and chlorophyll metering for

phenotyping the effects of nodulation in soybean”. Computers and Electronics in Agriculture, 75: 190-5.

65


ID058

Inhibition of Fungi Cultures with Eosin Solution and Green Light

J.J. Garcia-Lopez 1 , A.R. Trigos-Landa 2 , H. H. Cerecedo-Nuñez 1 .

1 Laboratorio de Óptica Aplicada, 2 LATEX, Universidad Veracruzana, Xalapa, Ver. México.

KEY WORDS: Biophotonics, photodynamic therapy, fungi, eosin, peroxide of ergosterol.

Photodynamic therapy (PDT) is a technique that involves excite of a molecule (photosensitizer),

by light absorption, which can react chemically with a specific substrate (which could be oxygen)

[1]. Light must be of a specific wavelength. This type of technique provides a selective

destruction of cells [1, 2]. Photosensitizer can react with oxygen and produce oxygen singlet,

which can deals damage to target cells directly or by production of very reactive molecules like

peroxides [2-4].

In the present work, we produced peroxide of ergosterol in fungi cultures, submerged in a

solution of eosin at 1%, by irradiated with green light of 540 nm, from a dichroic lamp. We make

4 samples of T. rubrum, in squares of PDA agar. We irradiated the samples with one, three and

five dichroics lamps. The fourth samples were used as a control, irradiated with white light from

a quartz lamp. The samples were irradiated 4 hours and were reseeded in steriles cultures of PDA

agar to watch the growth of the fungi cultures.

1.1

1.0

0.9

0.8

Lampara directa (Normalizada)

0.7

Intensidad

0.6

0.5

0.4

0.3

0.2

0.1

0.0

-0.1

200 250 300 350 400 450 500 550 600 650 700 750 800 850 900

Longitud de onda

Figure. Left, Sample immerse in eosin solution, irradiated by one dichroic lamp. Right, eosin optical absorption.

All the samples re-growth in the reseeding, but, the samples irradiated with green light

show a inhibition in their macroscopic characteristics pattern. The development of aerial hyphae,

which give a cotton aspect, and the production of red pigment, by vegetative hyphae, were lower

by raised the number of green lamps employed. For a total inhibition it is needed a more

powerful source of light.

[1] T. Vo-Dinh, Biomedical photonics Handbook, Chap. 36. (CRC Press LLC, Boca Ratón, 2003).

[2] B. Henderson, T. Dougherty, Photochemistry and Photobiology 55(1) (1992) 145-157.

[3] A. Trigos, A. Ortega, Mycologia, 94(4) (2002) 563-568.

[4] A. Trigos, El maravilloso mundo de los hongos Chap. 10, (Universidad Veracruzana, Xalapa, 2007).

66


ID059

Growth Control of Fungus in Plants due to Ultraviolet Radiation

A.R. Martínez Cortés 1 , J. Trejo Bañuelos 2 , H. H. Cerecedo Nunez 1 , P. Padilla Sosa 1 , M. E.

Herrera Cortina 1 , A. L. Robles Fernandez 1 .

1 Laboratorio de Óptica Aplicada, Faculta de Física, 2 Laboratorio de Organismos Benéficos, Facultad de Ciencias

Agrícolas, Universidad Veracruzana, Xalapa, Ver. México.

irving.hluna@live.com.mx

KEY WORDS: Optical instrumentation, design and testing; Multidisciplinary applications

of optics; Biophotonics; UV light Absorption.

The aim of this work is to develop a physical treatment to eliminate microorganisms that

affects plants. Currently ultraviolet (UV) radiation is used as very effective method to

sterilize substances, usually, the UV range used is between 240 and 280 nm, with maximum

disinfecting efficiency near to 254 nm. In this work we apply this technique to control

microorganism growth. UV radiation can cause photochemical effects which vary

depending on the microorganism, effects ranging from stop cell growth to cause death and

it depends on the absorption of ultraviolet light by the DNA. By irradiating microorganisms

with UV rays, their body's cells alter, destroying their ability to reproduce or eliminating

deadlier way.

The treatment we wish to develop is to perform a selective control of

microorganism growth by irradiation, and thereby eliminate or control, the organisms that

are harmful, without killing any that are beneficial.

To achieve selective irradiation, we need to know the molecular structures of the

objects of study, and thus better understand the effects and alterations that arise in

organisms exposed to UV radiation. Moreover, due to the UV radiation exposure, unwanted

microorganisms in a sample are being removed selectively leaving alive only some species

which are desired to grow in vitro.

So that, an appropriate methodology is developed using a UV radiation source and

optical devices to control the exposure time of the sample.

Figure. Characterization of a UV lamp for growth control of microorgism.

References

[1] Kowalski and William. “UVGI Design Basics”. January 2000.

[2] Productores de hortaliza. “Aplicación de Tecnología de luz ultravioleta en control de hongos

patógenos en hortalizas”. Mayo 2011.

67


ID068

Dynamical Casimir effect in a Kerr Cavity

R. Román-Ancheyta, C. González-Gutiérrez, and J. Récamier

Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México,

C.P. 62210 Cuernavaca, Morelos, México

Corresponding Author: ancheyta6@gmail.com

KEY WORDS: Dynamical Casmir effect, Kerr effect

We study the dynamical Casimir effect in an electromagnetic cavity containing a Kerr medium.

Using justified approximations, a closed analytical expression for the time evolution and number

operators were obtained. We found that the generation of photons from quantum vacuum is

strongly affected by the presence of the Kerr medium, sharing physical features with the case of

two two-level atoms in a cavity with oscillating walls. Our analytical results are in good

agreement with exact numerical calculations for times shorter than the revival time.

Fig.1. Generation of photons from quantum vacuum. Solid (dashed) lines correspond to the numerical

(analytical) solutions.

________________

[1] R. Roman-Ancheyta and C. Gonzalez-Gutierrez, “Dynamical Casimir effect in a Kerr Cavity,”

arXiv: quantph/ 1504.06379v1 (2015).

68


ID069

Light Scattering Applications: Microrheology in Absorbing Media

A. Tavera-Vázquez 1 , B. L. Arenas-Gomez 1 , E. Sarmiento-Gomez 2 , R. Castillo 1

1 Institute of Physics, Circuito de la Investigación Científica, Ciudad Universitaria 04510, UNAM, México DF

2 Institute of Physics, Av. Manuel Nava 6, Zona Universitaria 78290, UASLP, San Luis Potosí, SLP, México

a.tavera@fisica.unam.mx, http://www.fisica.unam.mx/liquids

KEY WORDS: Complex fluids, soft matter, self-assembly, micro-rheology, light scattering,

carbon nanotubes.

One way to find out the behavior of a complex fluid (CF) is by means of light scattering

experiments. One of these is the Diffusing Wave Spectroscopy technique (DWS) used as a

method of micro-rheology in order to get the viscoelastic spectrum of CFs 1 . However, a

limitation in this kind of fluids that are allowed to be under study is that these must be transparent

to the wavelength of the light used during the experiment. A theory of DWS that takes into

account the effects of absorption of light in the medium was recently developed generalizing its

use to a wider range of CFs 2 .

Sketch of DWS which is based on the diffusive approximation of light. Here the light is scattered multiple times by

the probe particles embedded into the sample to analyze.

Experiments of DWS allow us to obtain the viscoelastic spectrum of a CF on an interval

of frequencies longer than the interval achievable with mechanical rheometry (10 -2 rad/s –

10 6 rad/s against 10 -2 rad/s – 10 2 rad/s). This enables us to obtain indirectly estimation of the most

important characteristic lengths of the Maxwellian fluids (MF) networks (e. g. aqueous solutions

of worm-like micelles made by self-assembly of surfactants).

In this work we show some preliminary experimental results for the calculation of the

absorption mean free path, l a and the transport mean free path of light, l * , that have to be

measured independently of each other. For this purpose we applied the method of inverse adding

doubling (IAD) developed by Prahl 3 , to a system of single walled carbon nanotubes (SWNTs) in

aqueous solutions. Here we present a protocol of preparation for dispersing the SWNTs in water.

We also present some UV-vis-NIR absorption spectra of SWNT. These spectra show van Hove

singularities related with the grade of dispersion of SWNTs in solution 4 . We applied the IAD

method as well to a system of block copolymers (polybutadiene – polyethylene oxide or PB-

PEO). With these we can use the DWS technique to get the viscoelastic spectrum of SWNT and

PB-PEO looking for an interesting rheological behavior with potential technological applications.

_____________________

1 T. G. Mason and D. A Weitz, Phys. Rev. Lett., 74 (1995) 1250.

2 E. Sarmiento – Gomez, et al., Appied Optics, 53 (2014) 21.

3 S. A. Prahl, et al., Applied Optics, 32 (1993) 4.

4 S. E. Smalley et al., Science, 297 (2002) 593.

5 D. Lopez – Diaz and R. Castillo, Soft Matter, 7 (2011) 5926-5937.

69


ID073

Optical methods for measurement of glucose levels.

N. González Viveros 1 , H.H Cerecedo Nuñez 2 , J. García Guzman 3

Facultad de Instrumentación Electrónica y Ciencias Atmosféricas 1 , Facultad de Física 2 , Facultad de Ingeniería Mecánica y

Eléctrica 3

naara.gv@gmail.com, hcerecedo@uv.mx, jesusgarcia@ieee.org

KEY WORDS: biophotonics; optical instrumentation; multidisciplinary applications of optics;

optical methods; spectroscopy; blood glucose, diabetes.

Self-monitoring of blood glucose by diabetics is crucial in the reduction of complications related

to this disease. For it, devices exist based on electrochemical enzymatic principle. To measure of

glucose levels exists several new methods, including: the extraction of interstitial fluid; bioelectromagnetic

resonance; bioimpedance; metabolic heat conformation; ultrasound, reverse

iontophoresis; electromagnetic; and optical methods.

Optical methods can be used to perform measurements, both invasive and non-invasive;

applying a beam of light on the skin or in a blood sample. Here, the light is modified by the tissue

after transmission through the target area.

This work reviews the different optical methods for measurement of glucose. Among

these methods are: the polarimetry, the infrared spectroscopy, the Raman spectroscopy, the

fluorescent, the thermal spectroscopy, the photo acoustic, the optical coherence tomography

(OCT), the ocular Spectroscopy [1-5], and others. These methods are applied in measurement of

body tissues such as skin, cornea, oral mucosa, tongue or tympanic membrane, as well as in the

blood itself [6, 7]. The final aim of this work is to develop an optimum, precise and non invasive

optical method for the detection of glucose levels in blood.

[1] C. E. Ferrante do Amaral, B. Wolf, "Current development in non-invasive glucose monitoring,"

Medical Engineering & Physics, vol. 30, p. 541–549, 2008.

[2] A. Srivastava, Md K. Chowdhury, et al., "Blood Glucose Monitoring Using Non Invasive Optical

Method: Design Limitations and Challenges," International Journal of Advanced Research in

Electrical, Electronics and Instrumentation Engineering, vol. 2, no. 1, pp. 615-620, 2013.

[3] L. Ben Mohammadi,T. Klotzbuecher et al., "In vivo evaluation of a chip based near infrared sensor for

continuous glucose monitoring," Biosensors and Bioelectronics, vol. 53, p. 99–104, 2014.

[4] C. Dale Chua,I. M. Gonzales, et al., "Design and Fabrication of a Non-Invasive Blood Glucometer

Using Paired Photo-Emitter and Detector Near-Infrared LEDs," in DLSU Research Congress 2014,

Manila, Philippines, 2014.

[5] J. Zhang, K. Hoshino , "Optical transducers: optical molecular sensors and optical spectroscopy," in

Molecular Sensors and Nanodevices., Elsevier, 2014, pp. 233-320.

[6] L. Heinemann, G. Schmelzeisen-Redeker, "Non-invasive continuous glucose monitoring in Type I

diabetic patients with optical glucose sensors," Diabetologia, vol. 41, pp. 848-854, 1998.

[7] E.B. Hanlon, R. Manoharan, T.W. Koo, et al., "Prospects for in vivo Raman spectroscopy,," Phys.

Med. Biol., vol. 45, pp. R1-R59, 2000.

70


ID075

Mechanical and Rheological Properties of Cells

Yareni A. Ayala 1,2 , B. Pontes 2 , Z. M. Farina 2 , V. Moura-Neto 2 , N.B. Viana 1,2 , and H. M.

Nussenzveig 1,2

1

LPO-COPEA, Instituto de Ciências Biomédicas,Universidade Federal do Rio de Janeiro, RJ, 21941-902, Brazil.

2 Instituto de Física,Universidade Federal do Rio de Janeiro, Caixa Postal 68528, Rio de Janeiro, RJ, 21941-972, Brazil.

Corresponding Author: yareni.ayala@gmail.com

KEY WORDS: Optical Tweezers, Cell Mechanics, Plasma Membrane, Cytoskeleton.

Cells are highly dynamic complex systems that are constantly subjected to mechanical stimulus

that influence their biological functions. The plasma membrane and its attached cortical

cytoskeleton are the main responsible for controlling the cell mechanical response and processes

such as mechanotransduction, migration and cytokinesis 1 . In this work we study the membrane

and cytoskeleton mechanical properties of NIH3T3 fibroblast cells using an optical tweezers

system. The optical tweezers allows to measure forces in the picoNewton scale in which many

important cellular process occur. We use the tether extraction 2 and microrheology 3 techniques to

study the mechanical response of plasma membrane and the viscoelastic nature of cytoskeleton,

respectively.

In the figure below, we shown in A) a typical force-displacement curve for the tether

extraction experiment. The maximum correspond to the force needed to start the formation of the

plasma membrane tether, then the force decays to a constant value associated to the tether

elongation. In B) is shown the viscoelastic response of NIH3T3 fibroblast to an oscillating

stimulus varying in frequency. In order to characterize the influence of cytoskeleton integrity in

mechanical cells response, the NIH3T3 cells were treated with disrupting cytoskeleton drugs. The

drug effects were verified by using confocal microscopy as shown in C).

Figure1. A) Typical force curve of the tether extraction experiment. B) Viscoelastic response of

NIH3T3 fibroblast cells to a sinusoidal external stimulus varying from 1 to 35 Hz. γ represents the

power law exponent that describes the viscoelastic modulus of cell G(Pa). C) Image of the NIH3T3

fibroblast cytoskeleton stained for F-actin with phalloidin-FITC.

1 P.A. Janmey and C.A. McCulloch, Annu. Rev. Biomed. Eng., 9 (2007)1-34

2 B. Pontes, NB. Viana, LT. Salgado, M.Farina V. Moura Neto and HM. Nussenzveig, Biophys. J.,101(2011)43-52.

3 B. Fabry, G.N. Maksym, J.P: Butler, M. Glogauer, D. Navajas and J. Fredberg. Phys. Rev. Lett.,87 (2001)148102.

71


ID079

Comparative study for the optical properties of organic nanoparticles

synthesized by reprecipitation and laser ablation method and their use has a

contrast agent in cell images

J. E. Alba-Rosales 1,2 , G. Ramos-Ortiz 2* , V. Álvarez-Venicio 2 , L. Aparicio-Ixta 2 , M. Rodríguez 2 ,

G. Gutierrez-Juarez 2

1 Division de Ciencias e Ingenierias, Campus Leon, Universidad de Guanajuato. Loma del Bosque 103, Col. Lomas del

Campestre León, Guanajuato, México. C.P. 37150.

2 Centro de Investigaciones en Optica. Loma del Bosque 115, Col. Lomas del Campestre León, Guanajuato, México. C.P. 37150.

* Corresponding autor garamoso@cio.mx

KEY WORDS: Organic nanoparticles, Reprecipitation, Laser Ablation, Two photon absorption,

Agent Contrast.

In this work, organic nanoparticles intended for two-photon fluorescent microscopy were

synthesized using reprecipitation and laser ablation methods; the laser ablation method was

applied to an amorphous film and a crystal layer of the organic material. A comparative study of

their optical properties is presented; the obtained nanoparticles were fully characterized by

absorption and emission spectroscopies, SEM, DLS and by TPEF. Our results shows that

absorption and emission spectra are different for reprecipitation and laser ablation methods for

the same material; also the laser ablation nanoparticles shows an irregular morphology, small size

and better fluorescence emission than the nanoparticles produced by reprecipitation. Finally these

nanoparticles were used for multi-photon images of some cellular lines of interest.

Experimental setup for the nanoparticles synthesis.

72


ID082

Arbitrary structured light beams: generation and application to

micromanipulation

Andrés de los Ríos Sommer 1 , Alejandro V. Arzola 1 , Karen Volke Sepúlveda 1

1

Instituto de Física, Universidad Nacional Autónoma de México, Apartado Postal 20-364, 01000 Mexico, Distrito Federal,

Mexico

adlrs@ciencias.unam.mx

KEY WORDS: Spatial light modulator, holography, structured light, micromanipulation, optical

tweezers

By spatially modulating the phase of a light beam it is possible to encode any complex

function onto the beam. 1 This makes phase-only holograms a powerful tool for the study of light

and its interaction with matter.

In this work we use a spatial light modulator (SLM) to modify the phase of a TEM 00

mode locally. The phase distribution imprinted on the beam is made up of a diffraction grating to

spatially separate the beam of interest from non diffracting defects owing to the limitations of the

optical system. The phase distribution of the function to be encoded is added directly to the

grating. To obtain amplitude modulation, the parameters relevant to the diffraction efficiency of

the grating are modified locally, changing the amount of energy diffracted to the order of interest.

After the SLM, the beam is then focused by a lens and the undesired diffraction orders are

filtered spatially . The image of the encoded function is finally formed by a second lens after the

filter. This setup also enables in situ wavefront correction 2 . Different diffraction gratings are

compared to find optimal efficiency and accuracy in the encoding.

Using this method we were able to generate light beams that are solutions to the

Helmholtz equation; particularly Laguerre-Gauss, Bessel-Gauss, and Hermite-Gauss modes. The

precision and real-time capabilities of this method open several possibilities in the field of optical

micromanipulation, for example: trapping particles of low refractive indices, generating various

trapping potentials or particle sorting. 3 The figure shows particles rotating under the action of a

tightly focused Laguerre-Gauss beam.

Particles rotating in an optical trap due to a Laguerre-Gauss beam of topological charge 5.

[1] Davis, A., Cottrell D.M., Campos J, Yzuel M.J., and Moreno I.. Encoding Amplitude Information onto

Phase-Only Filters, Applied Optics 38, 5004 ( 1999).

[2] Čižmár, ., Mazilu M., and Dholakia K. In Situ Wavefront Correction and Its Application to

Micromanipulation. Nature Photonics 4, 388 (2010).

[3] Arlt J., Garces-Chavez V., Campos J, Yzuel M.J., Sibbet W., and Dholakia K..Optical

micromanipulation using a Bessel Light Beam, Optics Communications 197, 239 (2001).

73


'

ID094

OPTICAL TWEEZERS EXPERIMENTS FOR FIBROBLAST CELL

GROWTH STIMULATION

J.A. Ascencio-Rodríguez 1 , N. Medina-Villalobos 2 , E. Tamariz 2 , H. H. Cerecedo-Nuñez 1 , R. Ávila 3 ,

1 Facultad de Física, Universidad Veracruzana, Xalapa, Veracruz, México 2 Instituto de Ciencias de la Salud, Universidad

Veracruzana, Xalapa, Veracruz, México. 3 Centro de Física Aplicada y Tecnología Avanzada, UNAM, Querétaro, México

j.albertoar10@gmail.com; norzmalyz@gmail.com; etamariz@uv.mx; cerecedo.nunez@gmail.com; remy@fata.unam.mx

(

KEY WORDS: optical tweezers, fibroblast cell, optical guidance, cell growth.

!

In 1991 Albrecht-Buehler 1 observed a strange phenomenon involving 3T3 fibroblast cells that

extend pseudopodia towards a distant infrared laser light source and in 2002 Ehrlicher 2 succeeded

in demonstrating that a near infrared laser light source placed on or near a growth cone of NG108

or PC12 cells can enhance the growth speed and turn the growth cone towards the direction of the

laser. Neuronal optical guidance has been clearly demonstrated over a broad range of laser

wavelengths, spot sizes, spot intensities beam shapes and beam modulation 3, 4 .

The purpose of our work is to understand the biophysical mechanisms underlying optical

guidance, this research will include the conjunction of optical and biological techniques. Here

results of the first stage of the project are reported: the projection induction of NIH3T3 fibroblast

cells. The results show an increase in lamellipodia growth rate and changes in the direction of

movement. Our experimental setup consists of a confocal inverted microscope equiped with

Differential Interferometry Constrast (DIC) and an optical tweezers system. A Gaussian laser

beam of wavelength of 980nm, 60mW, is inserted into a 60x microscope objective with 1.40

numerical apertura. A temperature-controlled warming plate maintains cell viability (37ºC).

Figure 1: The NIH3T3 fibroblast cell line is a good model to study the stimulation growth with optical tweezer.

These cells have structures known as filopodia and lamellipodia, which serve as environmental sensors and are

related to the process of cell migration. (A) The cytoskeleton of NIH3T3 fibroblast cell was visualised by

fluorescence technique to identify the Actine filaments in the cytoplasm (red staining) and the nucleous (blue

staining) (40x). (B-C) The images represent the extension of the lamellipodium along the apical zone of a NIH3T3

cells were irradiated for 13 min with a spot of infrared light at 980 nm by inverted microscopy with DIC (60x).

(Scale bar: 10 µm).

[1] G. Albrecht-Buehler, The Journal of Cell Biology, 3, (1991), 493–502.

[2] A. Ehrlicher, B. Stuhrmann, D. Koch, PNAS, 99, (2002), 16024–16028.

[3] D. J. Stevenson, T. K. Lake, K. Dholakia, F. Gunn-Moore, Optics Express, 14 (2006), 9786–9793.

[4] Carnegie, D. J., Stevenson, D. J., Mazilu, M., Gunn-Moore, F. Opt. Express 16, (2008), 10507–10517.

74


ID099

Unambiguous Discrimination Strategies for the Lifted Trine Ensemble

G. Weir 1 , S. Croke 1 , S. M. Barnett 1

1 - School of Physics and Astronomy, University of Glasgow, Kelvin Building, University Avenue, Glasgow,

G12 8QQ

g.weir.2@research.gla.ac.uk, http://www.gla.ac.uk/schools/physics/research/groups/qtg/

KEY WORDS: Quantum measurements, quantum information, unambiguous discrimination

To extract information from a quantum system we must measure it; as this process disturbs the

system (and thus this information stored therein), it is important to know the optimum

measurement strategy for our purposes. Different figures of merit give rise to different

measurement strategies - if we consider two non-orthogonal states, it is known that we cannot

always unambiguously discriminate between these states (i.e. know with 100% confidence which

state the system was prepared in) 1 . However, we might wish to unambiguously discriminate

between these states at the cost of sometimes receiving an inconclusive outcome, or we might

simply wish to always receive an outcome which has the smallest probability of incorrectly

identifying which state our system was prepared in. In the former case, our measurement has

three outcomes - two stating with certainty which state the system was prepared in, and one

inconclusive outcome - while in the latter case we only have two outcomes, each stating that the

system was probably prepared in a certain state.

In this poster we consider strategies for discriminating between the states of the "lifted

trine" ensemble, introduced by Shor 2 , and parameterised by a lifting angle α. We consider

strategies which provide unambiguous information - either unambiguously identifying a state, or

ruling out at least one of the three with certainty. Such a strategy is know to provide the optimal

Shannon mutual information for the case α=0. We introduce strategies for which no inconclusive

outcome is necessary for certain values of α, and evaluate the Shannon mutual information

provided by such strategies, compared to the optimal mutual information found by Shor.

Representation of the lifted trine ensemble.

[1] Barnett, Stephen M., and Sarah Croke. "Quantum state discrimination." Advances in Optics and

Photonics 1.2 (2009): 238-278.

[2] Shor, Peter W. "On the number of elements needed in a POVM attaining the accessible information."

arXiv preprint quant-ph/0009077 (2000).

75


ID0104

Gold nanoparticles functionalized with POSS-THIOL fabricated by laser

ablation for biosensor applications

Jean Yves Tovar Sánchez 1 , M.B de la Mora 2 , E. Esparza-Alegría, M. A. Valverde-Alva, T.

García-Fernández

Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, México D.F. 04510,

Mexico .

Universidad Autónoma de la Ciudad de México (UACM), Prolongación San Isidro 151, Col. San Lorenzo Tezonco, México D.F.,

C.P. 09790, México.

1.-jtovarsan@gmail.com, 2.- betarina@gmail.com

KEY WORDS: Gold nanoparticles, functionalization, plasmon, biosensor, POSS-thiol

Abstract:

Laser ablation in liquids is a synthesis technique that provides the possibility of one-step

method for the production of functionalized nanoparticles (NPs) . Here by using a Nd:YAG laser

(1064 nm, 5 Hz, 10 ns and 60 mJ) functionalized NPs were obtained by laser ablation of a gold

target in solutions of ethanol with different concentrations of polyoctahedral oligomeric

silsesquioxane thiol (POSS-thiol. The UV-Vis spectra show that the functionalization improves

the plasmonic response of the NPs in comparison with the no functionalizated NPs. The

morphology and the distribution of the functionalized NPs on the POSS-thiol chains was

obtained from electronic microscopy. Pulsed photoacoustic technique was used to study in-situ

the synthesis process. Based on their biocompatibility, the organic functional groups in the

POSS-thiol and the improvement of the plasmonic response, we propose the use of functionalized

gold NPs with POSS-thiol) as a platform for optical biosensing.

a)

b) c)

Fig. 1.-a) Schematic representation of functionalization of gold nanoparticles with POSS-thiol. b) TEM

image of gold nanoparticles (blue) on POSS-thiol (red). c) Comparison of absorbance spectra between a

gold nanoparticles with and without POSS-thiol.

76


ID0109

Massive manipulation of microparticles using termophoresis

R. Páez López, S. A. Torres-Hurtado, U. Ruiz, R. Ramos-García

Instituto Nacional de Astrofísica, Óptica y Electrónica, Luis Enrique Erro No.1, Tonanzintla, Puebla, México.

*ralphcerezo@inaoep.mx

KEY WORDS: Holographic optical tweezers, phase holograms, photophoresis, spatial light

modulator.

In this work we demonstrate 2D optical trapping and manipulation of microparticles dissolved in

water due to thermophoretic forces or thermophoresis. Thermophoresis is a force resulting from a

temperature gradient generated by laser light absorption in an hydrogenated amorphous silicon

(a:Si-H) thin film. We present an experimental generation of annular beams employing synthetic

phase holograms (SPH) that provide the optimum diffraction efficiency and high quality of

reconstruction [1,2]. The beams are generated with a SPH displayed in a phase-only Spatial Light

Modulator (SLM) and then a common optical tweezers system was used to trap and manipulate

particles.

Particles inside the light ring are expelled symmetrically by thermophoresis. However, given the

radial symmetry of the beam, particles are confined within the ring, allowing 2D optical trapping

in real time (Figure 1). The use of a SLM allows generation of more complex and dynamic light

patterns which makes the system more versatile.

Fig. 1. Manipulation of silica 2.5 microns particles with a ring-shapped light source generated with SPH. The

particles are pushed to the right by moving the chamber in opposite direction.

[1] Méndez, G. et. al., Opt Comm, 175--179 (2013).

[2] V. Arrizón, et. al., Opt Letters. Vol 40–7 (2015).

77


ID0110

CONTROLLING LIGHT PROPAGATION THROUGH A STATIC

SCATTERING MEDIA

B. Coyotl-Ocelotl 1 , R. Porras-Aguilar 1,2,* , R. Ramos-Garcia 1 , J. C. Ramirez-San-Juan 1

1 Instituto Nacional de Astrofisica, Optica y Electronica, Departamento de Óptica, Luis Enrique Erro No. 1,

Tonantzintla, Puebla 72840, México

2 Consejo Nacional de Ciencia y Tecnologia, Av. Insurgentes Sur 1582, 03940, México, D.F,. Mexico

Corresponding Author’s e-mail address: *rporras@inaoep.mx

KEY WORDS: Focusing light, light propagation, scattering media, wavefront shaping, SLM.

Optical imaging through highly scattering media such as biological tissue is limited by light

scattering 1 . Recently, it has been shown that wavefront shaping is a powerful tool to

overcome this problem 2,3 . In this work, wavefront shaping using spatial light modulators

(SLM) is used to compensate static scattering media (piece of opaque tape) to allow

focusing of different intensity distributions. Light propagation is engineered into a specific

region of interest (ROI). For this purpose, the sequential algorithm (SA) proposed by

Vellekoop 4 was implemented experimentally. This algorithm is used to determine a phase

distribution to compensate changes in phase induced on an incident wavefront when it

propagates through the tape. The SA combined with an SLM is used to synthesize a phase

distribution required for re-directing light using wavefront shaping. The scattered light

was re-directed at the detector plane, in order to be: i) focused at a single pixel, ii) line

patterns of 9, 25, and 41 pixels of the camera. The figure below shows the intensity

distributions recorded by the detector before and after phase optimization for a ROI of 41

pixels at the central area of the camera. Furthermore, the ROI was placed outside the

central area of the camera opening the possibility of image formation.

A b C

a) Intensity distribution of light passing through the tape without phase compensation, b) phase distribution in the

SLM’s plane found to focus the light through the tape on a set of 41 pixels in line (c) when the optimal phase

distribution is synthesized.

1 Hayakawa, C. K., Et. Al. Phys. Rev. Lett. 103, (2009) 043903.

2 I. M. Vellekoop and A. P. Mosk. Opt. Lett. 32 (2007) 2309-2311.

3 Popoff, S.M. et al. Phys Rev Lett 104, (2010) 100601.

4 Vellekoop, I.M., LagendijkA & Mosk, A.P. Nature Photon. 4 (2010) 320-322.

78


ID0117

Calibrating of an optical tweezers setup for trapping red blood cells

Méndez-Alba. Nahum 1 , Hernández-Pozos. José Luis 2

Universidad Autónoma Metropolitana – Iztapalapa, San Rafael Atlixco No. 86, Col. Vicentina, C.P. 09340, Del. Iztapalapa, D. F. México

1 nahum@xanum.uam.mx, 2 jlhp@xanum.uam.mx

KEY WORDS: Calibrating optical tweezers, force measurement, RBC's optical trapping.

We have implemented an single-beam optical trap setup able to confidently trap spheres in sizes

ranging from 1 to 7 μm using a 1064 nm Nd:YAG laser. We determinate the particle position by

imaging its interference pattern at the back focal plane of the detection objective onto a quadrant

photodiode (QPD). A LabVIEW program allows us to collect the forward-scattered light signal

from the optically trapped particles and, processing such signal, it is possible to obtain the

vibrational frequencies of the trap.

The calibration of the system was performed using different methods (and software routines) that

can already be found in the literature 1,2 , such as power spectrum analysis, variance calculation,

equipartition theorem and Boltzmann statistics.

(a) Sphere of 2.36 μm diameter trapped by trapping beam (black arrow). (b) Power spectrum

corresponding to a 2.36 μm sphere in two lateral axis where is it easy to get the corner

frequency. (c) The geometry of the trap recorded by the QPD, the voltage are function of the

positions. (d) Histogram of the positions varying along x-axis, in according with a Gaussian

distribution. (e) One red blood cell attached to a 7.26 μm silica bead trapped. It can see how the

cell is deformed when we move the whole containing cell. (f) Two red blood cell attached

through their cellular walls and trapped by the laser beam.

In the future, we plan to extend our research towards trapping red blood cells (RBC), and

measuring the deformation of the RBC membrane of healthy individuals and compare it with those

affected with diabetes.

1

I. M. Tolić-Norrelykke, K. Berg-Sorensen and H. Flyvbjerg, Comp. Phys. Comm. 159(3) 225–240, (2004). 2 N.

Osterman, Comp. Phys. Comm, 181(11) 1911-1916, (2010).

79


ID0118

Acoustic Orbital Angular Momentum Transfer to Matter by Chiral

Scattering

Juan I. Vázquez Lozano 1, 2, 4 , Régis Wunenburger* 1,2 , Rubén Ramos García 4 , Etienne Brasselet +3

1 Sorbonne Universités, UPMC Univ Paris 06, UMR 7190,

Institut Jean le Rond d'Alembert, F-75005, Paris, France

2 CNRS, UMR 7190, Institut Jean le Rond d'Alembert, F-75005, Paris, France

3 Laboratoire Ondes et Matière d'Aquitaine, CNRS, Univ. Bordeaux, F-33400 Talence, France

4 Instituto Nacional de Astrofísica, Óptica y Electrónica. Luis Enrique Erro #1, 72840 Tonantzintla, Puebla, México

*regis.wunenburger@upmc.fr

+ etienne.brasselet@u-bordeaux.fr

KEY WORDS: Orbital angular momentum, acoustic vortices, momentum transfer

Mechanical effects of waves on material media is a powerful option to achieve contactless

manipulation in a controlled manner, which has already found numerous applications in optics and

acoustics. A basic example consists of absorption-mediated wave-matter exchange of linear and/or

angular momentum that light or sound 1 may carry. To date, the demonstration of all kinds of

exchanges mediated by dissipative processes have been carried out experimentally. Moreover, nondissipative

exchanges of linear and angular momentum between waves and matter are also possible.

We report on orbital angular momentum exchange between sound and matter mediated by

a non-dissipative chiral scattering process. The experimental demonstration is made by irradiating

a three-dimensional printed, spiral-shaped chiral object using an incident ultrasonic beam carrying

zero orbital angular momentum. This is the acoustic analog of an optical spiral phase plate (SPP) 2

but for sound waves. Chiral refraction is shown to impart a nonzero orbital angular momentum to

the scattered field and to rotate the object. This result constitutes a proof-of-concept of a novel kind

of acoustic angular manipulation of matter 3 .

x10 3

(a) Magnitude of the acoustic SPP rotation angular velocity as a function of U where U is the

voltage amplitude applied to the ultrasonic transducer, for l = 4. Solid line: linear fit. (b-i) SPP top

view snapshots over a full rotation around the z axis, the black radius line on the SPP is an ink mark

and the angular displacement between two successive snapshots is roughly π⁄ 4.

1

J.-L. Thomas and R. Marchiano, Phys. Rev. Lett. 91, 244302 (2003).

2

L. Zhang and P. L. Marston, J. Acoust. Soc. Am. 129, 1679 (2011).

3

R. Wunenburger, J. I. Vázquez and E. Brasselet. Submitted (2015).

80


ID0119

Positional rearrangement of colloidal particles induced by two-dimensional

optical forces

Daniel J. Rios 1 , Alejandro V. Arzola 1 and Karen Volke-Sepúlveda 1

Instituto de Física, Universidad Nacional Autónoma de México, Apartado Postal 20-364, 01000 México, Distrito Federal, México

Contact email: danieljosafat@gmail.com

KEY WORDS: optical forces, optical lattice, two-dimensional optical potentials.

The study of colloidal crystal systems is very important for the creation of new technologies in

photonic materials. It also allows investigating the fundamentals of structural phase transitions in

condensed matter physics. Although there is a lot of work dealing with ordered structures

induced by potentials with one-dimensional periodicity, there are very few works using patterns

with two-dimensional periodicity, which make the problem much richer.

This investigation was conducted to determine the spatial behavior of micrometer-sized

colloidal particles due to their interaction with two-dimensional optical potentials. The study was

done using the theory of optical forces in the ray optics regime to establish the dependence of the

force on particle size and period of the optical potential, and moreover, on the type of Bravais

lattice. Calculations were made for different intensity distributions.

Varying the spatial period of the optical field for a fixed particle size creates stable

equilibrium points at different positions within the optical lattice. A possible result is shown in

figure 1. In addition, for different types of intensity distributions, different locations of the points

of stable equilibrium are obtained.

In this manner it is possible to create a structural rearrangement of colloidal particles due

to their interaction with an optical potential.

Spheres (blue circle closed) with radii a) a1=4.0 µm and b) a2=3.0 µm, trapped in a square optical lattice

of period d=4.3 µm. Each particle is shown on a stable equilibrium point.

[1] M. M. Burns, J-M. Fournier, and J.A. Golovchenko, Optical matter: Crystallization and binding in

intense optical fields, Science, 249, 749-754 (1990).

[2] L. Zaidouny, T. Bohlein, R. Roth and C. Bechinger, Light-induced phase transitions of colloidal

monolayers with crystalline ordere, Soft Matter 9 (38), 9230 - 9236 (2013).

81


ID0120

Liquids Jets Generated by Thermocavitation in Capillary Tubes

J. Ramírez-Ramírez, C. J. Berrospé-Rodríguez, J. C. Ramírez-San-Juan R. Ramos-García*,

Instituto Nacional de Astrofísica, Óptica y Electrónica, Luis Enrrique Erro #1, Santa Maria Tonanzintla cp.72840

*rgarcia@inaoep.mx

KEY WORDS: Thermocavitation, liquid jets, cavitation bubbles

In the present work the generation of liquid jets created in capillary tubes of different diameters is

reported. Jets generated by thermocavitation is one of the simpler and less expensive cavitation

techniques. Thermocavitation uses a continuous wave laser (λ = 975nm.) focused into a saturated

copper nitrate saline solution 1 . Due to the large absorption coefficient at this wavelength, the

solution is superheated up to a temperature of 300°C without boiling, therefore causing an

explosive vapor-liquid phase transition, resulting in a rapid expansion of vapor bubbles

(cavitation bubble) 2 . Due to fast expanding cavitation bubble inside the capillary, the liquid is

ejected at high speed from the end of the capillary tube. The speed of the jets is measured by

using a high-speed camera (82,000 fps). Three variables are taken into consideration in the

generation of jets: the distance from the point where the cavitation bubble is generated to the

output of the capillary tube, the heated volume, and the power of the laser. Taking these three

factors into account, the optimal conditions for the fastest (57.6 km/h) jet are obtained. These jets

are intended to be used in medical applications for pain-free injections 3 .

500 µm

0 µs

240 µs

480 µs

720 µs

960 µs

1200 µs

Evolution of the liquid jet with a delay between images of 240 µs.

1

J.C Ramirez San Juan et al., “Cavitation induced by CW lasers in liquids”, Proc. SPIE 7562-37, 1-5 (2010).

2

Padilla-Martinez et all. , ., “ Optic cavitation with CW lasers: A review”,physics of fluids (1994-present) 26,122007

(2014)

3

Tae-hee han and Jack J. Yoh, “A laser based reusable microjet injector for transdermal drug delivery”,journal of

applied physics 107, 103110 (2010)

82


ID0124

Use of co-occurrence matrix in the visualization of blood vessels deep in

Laser Speckle imaging

J. A. Arias Cruz, H. Peregrina-Barreto, C. E. Pérez-Corona, R. Ramos-García and J.C.

Ramírez- San-Juan *

Instituto Nacional De Astrofísica, Óptica Y Electrónica (INAOE)

Luis Enrique Erro # 1, Tonantzintla, Puebla, México C.P. 72840

* jcram@inaoep.mx

KEY WORDS: speckle image, visualization of deep blood vessel, co-occurrence matrix.

An important parameter to determine the tissue´s health is the blood flow. Its

measurement has many applications in both clinical and research fields. Blood flow

optical monitoring techniques, such as Laser Speckle Imaging 1 (LSI), are attractive due

its non-invasive character, but they are limited to superficial blood vessels. The

visualization of deep blood vessel is a difficult task because of the highly scattering

properties of biological tissue. There are some techniques that allow the visualization of

deep blood vessels, for example: a) optical clearing, which reduces the scattering of

superficial tissue by applying a topical substance, b) Magnetomotive Laser Speckle

Imaging uses paramagnetic nanoparticles, which, under the influence of a external

magnetic field, increases the mobility of those particles allowing their visualization by

reducing the speckle contrast of integrated speckle and c) Pulsed Photo-Thermal

Radiometry which photo-induces heating of the blood vessels and by means of a thermal

camera one can measure the corresponding increase of temperature on the skin surface to

visualize the blood vessels. In this work, we present a noninvasive technique based on the

co-occurrence matrix to determine the location of in-vitro deep blood vessels through

speckle image processing without modifying the physical properties of the sample. Given

that the speckle image is formed by a quasi-gaussian intensity distribution and that the

dynamic speckle 1,2 theory states that the contrast of the flow region is lower due to the

motion of blood particles, we treat it like a texture region. The proposed methodology is

based in a homogeneity measurement of the co-occurrence matrix by the direct

processing 3 of the speckle image.

a) Speckle image b) vessel location via co-occurrence matrix and homogeneity measurement.

1 Dynamic Laser Speckle and Aplications, Edited Hector J. Rabal and Roberto A. Braga Jr.,CRC Press

2

Image Restoration – Recent Advances and Applications,Edited by Aymeric Histace, First published April, 2012

3 Computer Analysis of Images and Patterns,12th International Conference, CAIP 2007 Vienna, Austria, August 27-29,

2007 Proceedings

83


ID0128

Optical Turbulence produced by a Drone Propeller

R. Rodríguez García 1 , O. Chapa Hernández 1 , L.C. Alvarez 1 , C. Keiman 1 , S. Cuevas 1

Instituto de Astronomía, UNAM,

Circuito Exterior, Ciudad Universitaria,

04510, México D.F, México

raulrodriguegarcia@gmail.com

KEY WORDS: Optical turbulence, Remote Sensing, Imaging.

Drones for aerial imaging have become popular for aerial photography and remote sensing. The

potential of this technology is enormous. A question is what is the limiting resolution for imaging

of a camera mounted on the drone pointing to the earth surface. A limitation is the residual of the

movement that is not compensated by the stabilization camera mount. Another one is the optical

turbulence wave-front distortions produced by the mixing of air heated by the motors and

impulsed by the drone multiple propellers and the surrounding air itself.

In this work we studied this kind of wave-front distortions. A small drone was placed near the

beam of a ZYGO Fizeau interferometer performing a flat wave-front. The optical turbulence

wave-front distortions produced on the circulating air inside the beam by one of the drone

propellers were measured by the ZYGO interferometer. Several wave-fronts were acquired and

processed by the ZYGO analysis software. We found the optical turbulence distortions produced

is negligible for imaging from a small size Drone.

Drone mounted near the optical beam of a Zygo Interferometer (bottom).

Wave-front distortion measurement (top). This distortion is negligible for imaging.

84


ID0131

QUASI-1D TRAPPING

Arantza Zavala *(1), Alejandro V. Arzola *(2), Karen Volke-Sepúlveda + (2), Adrián Huerta + (1)

1. Facultad de Física, Universidad Veracruzana. Circuito Gonzalo Aguirre Beltrán s/n Zona Universitaria Xalapa, Ver.

C.P. 91000. *abere92@gmail.com +adrian.huerta@gmail.com

2. Instituto de Física, Universidad Nacional Autónoma de México, Apdo. Postal 20-364, 01000 México, D. F., México.

*avarzola@gmail.com, +karen@fisica.unam.mx

KEY WORDS: Trapping, optical tweezers, cell model, freezing mechanisms.

It is well known that optical tweezers can induce colloid crystallization in an extended 2D system

[1]. We have proposed a cell model to describe the zigzag order produced by colloids confined

inside a laser lines coming from an interference pattern [2], figure 1. The cell model describe

qualitatively the thermodynamical properties of the trapping particles, figure 2.

Figure 1 Particles in Young's

fringes of light

Figure 2 Cell model of quasi-1D system.

In this work, two alternative experimental approaches were used to address the problem. We

have studied the zigzag dynamics of metal balls shaking by a speaker system and the growing

dynamics of hydrophilic polyacrylamide particles (hydrogel), both systems confined to a quasi 1D

dynamics, figure 3. Similar behaviors have been observed in different granular systems with

granular collapse [3].

Figure 3 Quasi 1D system of hydrogel (left) and metal balls (right)

In the mean time we have started to build an optical trapping device to be used in new softmatter

laboratories of the Universidad Veracruzana Physics Faculty. We expect that this studies

give us more insight to understand the freezing mechanisms and their frustration [4].

[1] "Colloids on patterned substrates", C. Bechinger, E. Frey, in Soft Matter, edited by G. Gompper, M.

Schick (Wiley-VCH) 3, 87 (2007)

[2] “Estudio del proceso de solidificación en presencia de un potencial externo”, Ruth Bustos Ramírez,

advisors: Karen Volke y Adrián Huerta, Universidad Veracruzana (2013)

[3] “Sistemas granulares monodispersos confinados cuasi-1D y cuasi-2D”, Ivany del Carmen Romero

Sánchez, advisors: Rodrigo Sánchez y Adrián Huerta (2013)

[4] A. Huerta, D. Henderson and A. Trokhymchuk, Freezing of two-dimensional hard disks Phys. Rev. E,

74, 061106 ͑(2006͒)

85


ID0132

Temporal vs Spatial Laser Speckle Imaging to measure relative blood flow

speed in deep blood vessel: In-vitro study

C. E. Pérez-Corona, H. Peregrina-Barreto, R. Ramos-García and J.C. Ramírez-San Juan

Instituto Nacional de Astrofísica, Óptica y Electrónica, Luis Enrique Erro #1, Santa Maria Tonantzintla, Puebla

jcram@inaoep.mx

KEY WORDS: blood flow, speckle imaging

The blood flow is one of the most important parameters of cardiovascular function. Relative

measurements of blood changes can be useful to clinicians and physiologists to quantify vascular

changes due to tissue injury and diseases, or for studying responses to mechanical or

pharmacological interventions. For this purpose, different non-invasive techniques have been

developed to provide this information, one of them is Laser Doppler Flowmetry, which provides

absolute speed at specific point on a tissue surface. However, it requires a mechanical system to

scan the region of interest to get the information of the sample 1 . Laser Speckle Imaging (LSI) is

an optical technique based on the statistics of integrated speckle contrast, which allows us to

analyze the dynamics of blood flow at relatively high spatial and temporal resolution and without

the need of scanning the region of interest 2 . LSI has been applied to measure relative flow speed

of superficial blood vessels in retina, skin and brain 3 .

The objective of this work is to evaluate the convenience of the spatial and temporal LSI

to measure the relative flow speed in blood flow phantoms (which simulate the scattering

properties of the epidermis). The phantom consists of a capillary tube (700 m inner diameter)

placed 900 m inside a resin layer. As flow liquid we employed an intralipid solution at 1% in

water to simulate the scattering properties of blood. It is observed that the predicted speckle flow

index (SFI) by the temporal-LSI shows a linear relationship (Fig. 1a) with the actual velocity, as

opposite to the spatial-LSI, where SFI is noisy and unpredictable (Fig. 1b). In conclusion, the

temporal-LSI is more suitable for measurement of relative blood flow in deep blood vessels.

SFI (x10^5)

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0.0

0 2 4 6 8 10 12 14 16 18 20 22

a)

Actual velocity (mm/s)

SFI (x10 3 )

7.0

6.5

6.0

5.5

5.0

b)

4.5

0 2 4 6 8 10 12 14 16 18 20 22

Actual velocity (mm/s)

Fig. 1. SFI vs actual velocity for a) temporal-LSI and b) spatial-LSI

1

Kevin R. Forrester, et al., A Laser Speckle Imaging Technique for Measuring Tissue Perfusion, IEE

TRANSACTIONS ON BIOMEDICAL ENGINEERING, 11 (2004) 2074-2084.

2

Julio C. Ramirez-San-Juan, et al., Spatial versus temporal laser speckle contrast analyses in the presence of static

optical scatterers, Jornal of Biomedical Optics, 19 (2014) 106009-1-106009-5.

3

Ashwin B. Parthasarathy, et all., Robust flow measurement with multi-exposure speckle imaging. OPTICS

EXPRESS, 16 (2008) 1975-1989.

86


ID0144

Relation between rheological and microstrutural properties of systems of

wormlike micelles.

B. L. Arenas-Gomez a , A. Tavera-Vazquez b , J.J. Delgado a and R. Castillo b

a División de Ciencias e Ingenierías de la Universidad de Guanajuato

Lomas del Bosque 103, Col. Lomas del Campestre, C.P. 37 150, León. Gto., México

b Instituto de Física, Universidad Nacional Autónoma de México

Circuito de la Investigación Científica s/n, Ciudad Universitaria, C.P. 04510, México, D.F.

e-mail:brisa@fisica.unam.mx

url: http://fisica.ugto.mx/~ramoncp/

KEY WORDS: birefringence, wormlike micelles, viscoelasticity, shear banding, light scattering.

In this work we focus on rheology and microrheology of complex fluids in semidilute or

concentrated regime, and how their rheological microstructural properties relate. We try to

understand the flow behavior of wormlike micellar systems which may, or may not, exhibit

Maxwellian behavior. We work with three different polymers in aqueous solutions, each type of

polymer self-assembles above a critical micellar concentration to form micelles because of their

amphiphilic properties. These micellar solutions self-assembled in wormlike micelles (elongated

and semiflexible aggregates) and used to present birefringence under flow 1,2,3 . Birefringence is

observed using an optical arrangement in a transparent Coeutte cell, where the solution is under

shearing. Shear banding is a nonequilibrium phenomenon present in some micellar systems

where regions of different turbidity (or fluidities) coexist under shear, and upon the shear flow

cessation micellar solutions revert to their transparent state. Flow birefringence experiments gives

evidence for shear banding but do not give us direct information about the real time

microstructure 4 . The shear stress versus shear rate curve (rheology) presents a plateau region

where shear banding is observed. The main purpose of this study is to understand how the

rheology is related to their structural properties by using microscopy techniques and also through

the analysis of scattering techniques (Inverse Adding Doubling, Diffusion Wave Spectroscopy,

SAXS, TEM, AFM) 5,6 .

Solution of P(1,4)B-PEO/Water at 1.75 wt % between cross polarizers. A spatula is slowly dipped into and out the

fluid.

1 B. Arenas-Gómez et al, Eur. Phys. J. E, 37 (2014) 51.

2 S. Lerouge, J. P.Decruppe, and P. Olmsted, Langmuir, 20, (2004) 26.

3 J. Delgado, R. Castillo, J. Colloid Interf. Sci., 312 (2007) 481-488.

4 J. F. Berret, Rheology of Wormlike Micelles: Equilibrium Properties and Shear Banding Transitions, in Molecular

Gels, edited by R. G. Weiss and P. Terech, (Springer, The Netherlands, 2006). p. 667.

5 S. Prahl, Manual Inverse Adding Doubling, (2011), (available online).

6 O. Glatter, Fourier Transformation and Deconvolution, in Neutrons, X-ray and Light: Scattering Methods Applied

to Soft Condensed Matter, edited by P. Linder, Th. Zemb (North Holland, Amsterdam, 2002)

87


ID0148

Implementation of a Leakage Radiation Microscope for Imaging Surface

Plasmon Polaritons Interaction on Nano-structures

Gaspar Uriarte Medina 1 , Víctor Ruiz Cortés 1

1 Departamento de Óptica, Centro de Investigación Científica y de Educación Superior de Ensenada, Apartado Postal 22830,

Ensenada BC, México .

guriarte@cicese.edu.mx

KEY WORDS: Surface Plasmon Polaritons, Leakage Radiation Microscopy, Near Field.

The implementation of a Leakage Radiation Microscope “LRM” for imaging of surface plasmon

polaritons interaction on nano-estructures is presented, this instrument was implemented on a

inverted optical microscope, allowing the handling of samples with ease. For the development of

this instrument, the main component is a microscope objective with a large numerical aperture

that collects the radiation leak “LR”. Using a focused beam, surface plasmon polaritons are

excited in a gold nano-structure having a thickness of about 50nm on a dielectric substrate. The

leakage radiation generated on the previous system, is collected by the microscope objective with

high numerical aperture (NA=1.49). Using an imaging forming system the surface plasmon

polaritons are recorded by a CCD. Plasmonic nano-structures were fabricated using

photolithographic and focus ion beam lithography.

In this work we present a research of surface plasmon polaritons interaction with nanoestructures,

using optical techniques such as leakage radiation microscopy.

a) Experimental setup of a leakage radiation microscope, f = 40cm and f = 20cm, b)

Image obtained from SEM that shows the grooves of the sample, c) Optical image of the

excitation SPP an array of three grooves.

[1] Drezet, A., Hohenau, A., Koller, D., Stepanov, A., Ditlbacher, H., Steinberger, B., & Krenn, J.

R. (2008). Leakage radiation microscopy of surface plasmon polaritons. Materials science and

engineering: B, 149(3), 220-229.

88


ID0150

Diffuse light transmission profiles using time resolved imaging with temporal

extrapolation given by different solutions to the transport equation

E. Ortiz-Rascón, N. C. Bruce, A. Rodríguez-Rosales, J. Garduño-Mejía

Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México

Circuito Exterior s/n, Ciudad Universitaria, PO Box 70-186

eortize@gmail.com

KEY WORDS: Transillumination imaging, temporal extrapolation, biomedical optics,

biophotonics

In this work we present results of a time-resolved transillumination imaging method using

temporal extrapolation. The results show the main differences in the imaging process when

different times of flight are used to image the intensity profiles of several rods embedded in a

turbid medium. The temporal extrapolation is performed with the cumulant expansion solution to

the transport equation. The results obtained are compared to results of the same method but using

the diffusion approximation solution. It is found that the results are consistent but that the

cumulant expansion method gives better resolution, for the imaging process, because it gives a

better estimation of the photon contribution for shorter integration times.

Limits of the spatial resolution in a diluted milk sample (optical properties are close to that in the breast

tissue), for different times of flight using diffusion approximation and cumulant expansion solution to

the transport equation for the temporal extrapolation.

[1] E. Ortiz-Rascón, N. C. Bruce, A. A. Rodríguez-Rosales, J. Garduño-Mejía and R. Ortega-Martínez,

Improved spatial resolution in time-resolved transillumination imaging using temporal extrapolation with

the cumulant expansion solution to the transport equation, Revista Mexicana de Física 60, 1-7 (2014)

89


ID0153

Molecular Dynamics in the Origin of Life

Adriana Reyna Lara 1 , Karo Michaelian 1

1 Instituto de Física, UNAM. Cto. Interior de la Investigación Científica, Ciudad Universitaria, México D.F., C.P. 04510

adriana.ryl@gmail.com, karo@fisica.unam.mx

KEY WORDS: Origin of Life, DNA Denaturalization, Molecular Dynamics, UV-C Light.

Life is the most astonishing thing of the Universe thanks to it we can study anything, to deeply

understand how life starts, develops and evolve it is necessary to have all the tools that make easier

this goal. The aim of this work is to figure out how DNA surrounded by water is denatured by UV-

C light with molecular dynamics. Previous investigations have shown that 4.5eV photons separate

DNA in two single strings 2 suggesting that could be a first form of duplication leading an

extraordinary beginning to understand the Origin of life by the thermodynamic dissipation theory 1 .

We are trying to comprehend how light’s energy is absorbed and converted in order to

create life, also this study could help others studies like how DNA behaves in different solvents

and see if could be another forms to generate life.

Artistic DNA with an incident photon of UV-C light.

1

Michaelian, K. Thermodynamic origin of life. Cornell ArXiv, arXiv:0907.0042 [physics.gen-ph] (2009).

1

Michaelian, K. Thermodynamic dissipation theory for the origin of life. Earth Syst Dynam 2, 37–51 (2011).

2

Michaelian, K. Santillan Padilla N. DNA Denaturing through UV-C Photon Dissipation: A Possible Route to Archean

Non-enzymatic Replication

90


ID0154

Cavitation of one single particle in an Optical Tweezer

Viridiana Carmona-Sosa* 1 , José E. Alba-Arroyo 1 , Pedro A. Quinto-Su 1

1 Instituto de Ciencias Nucleares, UNAM

Circuito Exterior s/n, Ciudad Universitaria, Apartado Postal 70-543, Deleg. Coyoacán, C. P.

04510, México D. F.

*carsovi108@gmail.com

Key words: Optical tweezer, cavitation.

We demonstrate that is posible to generate microscopic explosions (cavitation) in an

optical tweezer. An microparticle that absorbs at the laser wavelength of the trap is

attracted to the geometrical focus of the beam where it is superheated producing a

cavitation bubble that impulsively pushes the particle close to the starting position where

the cycle restarts. Using a fast camera (with rates up tu 300000 fps) we analyze the

dynamic of the microparticle.

(a) Phase diagram to describe the cycle, p 0 =0.1 MPa, T cav is the temperature in which

the superheated liquid relaxes with the nucleation of a bubble. T sp is the superheat limit at p 0 .

p c = 22MPa and T c =373.9 ° C are the critical pressure and temperature for water. (b) Microparticle

trajectory in the optical tweezer. (1-2) Optical forces attract the particle towards the focus heating it at

atmospheric pressure p 0 , (2-3) increase in speed and heating rate results in superheated liquid at the surface,

(3-4-1) explosive vaporization with adiabatic expansion pushes the particle close to the initial position. 1

1 P. A. Quinto-Su, Nature Communications, 5 (2014) 5889.

91


ID0169

DMPC/CHOL MODEL MEMBRANE MONOLAYERS ANALYZED BY

BREWSTER ANGLE MICROSCOPY

A. Bañuelos-Frias, Y. S. Posadas-Garcia, V. M. Castañeda-Montiel, E. R. Alvizo-Paez, E.

Gomez, J. Ruiz-Garcia

Biological Physics Laboratory, Physics Institute, Universidad Autonoma de San Luis Potosi, Alvaro Obregon 64, San Luis Potosi,

S.L.P. 78000 Mexico

Corresponding Author’s e-mail address and URL: alanb535@yahoo.com

KEY WORDS: Langmuir Blodgett films, model membranes, Atomic Force Microscopy,

Brewster angle microscopy.

As a structural lipid, one of cholesterol´s main function is to rigidify the cell membrane as the

cholesterol fraction rises 1 . In this work we studied mixtures of DMPC/Cholesterol monolayers at

different concentrations as a model membrane system, in order to determine the effect of

cholesterol, from very low to physiological concentrations. Brewster Angle Microscopy images

were acquired in order to observe the morphologies of the molecules that form the monolayers, at

the same time (π − A) isotherms were obtained using a Langmuir Blodgett balance at 37 ± 0.1°C.

From those techniques, mechanical and thermodynamical properties of the model membrane

monolayers were studied. The results show that at low cholesterol molar fraction (1%-4%) an

increase in monolayer fluidity, followed by a stiffness increase at higher molar fractions due to

the well-known cholesterol condensation effect.

Figure 1 BAM image of a 80/20 DMPC/Cholesterol mixed monolayer at 5 mN/m surface pressure

[1] T.P. Mc Mullen, R. N. Lewis, R. N. Elhaney, Cholesterol– p hospholipid interactions, the liquidordered

phase and lipid rafts in model and biological membranes. Current opinion in colloid &

interface science 8 459 (2004)

92


ID0174

Finite Element Simulations and Experimental Measurement of

Dielectrophoretic Force in Optoelectronic Tweezers with Different Particle

Sizes

A. Fuentes-Garcia 1 , R. Ramos-García 1 , S. L. Neale 2

(1)National Institute of Astrophysics, Optics and electronics; Apartado Postal 51 y 216

72000 Puebla, Pue.

(2) University of Glasgow, Glasgow, G12 8QQ, Scotland

angel.fuentesga@inaoep.mx

KEY WORDS: Dielectrophoretic Force, optoelectronic tweezers.

Nowadays Optoelectronic Tweezers (OET) (figure 1) have become a versatile tool for

manipulating objects like nanowires, DNA and biological cells 1 . Even though this technique is

widely used the full manipulation capabilities of OET devices has not been fully explored. In

general, the dielectrophoretic force inside the OET device is proportional to the volume of the

particle being manipulated 2 but the relation between force and volume is no longer true when the

particle is large enough so the electric field gradient within the particle is not constant.

In this work we use finite element analysis to simulate the variation of dielectrophoretic

force in the manipulation of microspheres of different sizes. The first experimental results are

shown below.

(a)

Fig 1. (a) Schematic diagram of the OET device and (b) top speeds obtained with different bead’s

diameter when manipulated with an OET device.

Notice that the speed of trapped beads is much larger than in optical tweezers, and so the

force must be much larger too. Figure 1b show both numerical simulations and experiment of the

velocity of the trapped particles. For small particles ≤ 30 m good agreement between theory and

experiment are found, although their magnitude do not agree. For larger particles the linear

dependence not longer exists, confirming previous reports. There are obvious differences but

further improvements in the experiments and modelling may get better agreement.

(b)

1

H. Hsu, Lab Chip, 10 (2010) 165-172.

2

R. Pethig, Biomicrofluidics, 4 (2010) 1-35.

93


ID0177

Trapping DNA like networks structures at low pH

A.Y. Sánchez-Treviño 1 , J. F. Ruíz-Robles 1 , J. Ruíz-García 1

1 Biological Physics Laboratory, Institute of Physics, Universidad Autónoma de San Luis Potosí, Av. Manuel Nava No. 6, C. P.

78290, San Luis Potosí, San Luis Potosí, México.

Corresponding Author’s e-mail address and URL: alyad24_@hotmail.com; yaditre@ifisica.uaslp.mx;

https://www.researchgate.net/profile/Alda_Yadira_Sanchez_Trevino

KEY WORDS: Brewster Angle Microscopy, Langmuir-Blodgett, Atomic Force Microscopy,

DNA, patterns in biomacromolecules.

The study of biomacromolecules as DNA is of huge scientist and biological interest. In our

group, we recently discovered that DNA can be trapped by the surface. This is very interesting

due to water is considered as an excellent solvent for DNA. Multivalent cations causes free DNA

in solution to arrange into different nanometer scale condensed structures 1 . With Langmuir-

Blodgett (LB) we transfer the DNA monolayers onto mica at high surface density and low pH

values; we found highly organized networks as as 2D foam-like structures and nanowires. The

structural analysis of these organized networks is performed with Brewster Angle Microscope

(BAM) over the water surface and with Atomic Force Microscope (AFM) in the transferred LB

films. BAM and AFM are an optical principle techniques allows the detection and observation of

films of a few nanometers thick as well-organized networks.

[1] I. D. Vilfan, C. C. Conwell, T. Sarkar, and N. V. Hud, Time study of DNA condensate morphology:

Implications regarding the nucleation, growth, and equilibrium populations of toroids and rods,

Biochemistry 45, 8174 (2006).

94


ID0182

EXPLORING ASSEMBLING CONDITIONS TO ENCAPSIDATE AN mRNA

FROM ENHANCED GREEN FLUORESCENCE PROTEIN INTO

COWPEA CHLOROTIC MOTTLE VIRUS CAPSIDE

M.V. Villagrana-Escareño 1 , E. Reynaga-Hernández 1 , V. De la Cruz-González 1,* , O.G. Galicia-Cruz 2 ,

A. Durán-Meza 1 , J.A. Méndez-Cabañas 3 , C.Y. Hernández-Carballo 4 , J. Arreola-Gómez 4 and J. Ruiz-

García 1*

1

Laboratory of Biological Physics, Physics Institute, Universidad Autónoma de San Luis Potosí, SLP, México

2

Laboratory of Analytic Pharmacy, Medicine Faculty, Universidad Autónoma de San Luis Potosí, S.L.P., México

3

Laboratory of Molecular Biophysics, Physics Institute, Universidad Autónoma de San Luis Potosí, Manuel Nava No. 6, San Luis

Potosí, S.L.P, México.

43

Laboratory of Biophysics, Physics Institute, Universidad Autónoma de San Luis Potosí, Manuel Nava No. 6, San Luis Potosí,

S.L.P, México

Alvaro Obregón No 64 CP78000 S. L. P.

jaime@dec1.ifisica.uaslp.mx

*Presenting author

KEY WORDS: UV-Vis spectroscopy, EGFP, mRNA, CCMV virus, mammalian cells.

The aim of this project is the cellular transfection using CCMV (Cowpea Chlorotic Mottle Virus)

capsids with a messanger RNA (mRNA) encoding the enhance green fluorescence protein

(EGFP) as cargo. Using molecular biology techniques, mRNA of EGFP was transcribed from a

plasmid. Afterwards mRNA samples are deposited in solutions at specific pH values in order to

reassembly CCMV capsid. The assemblies were corroborated by UV-Vis spectroscopy and

transmission electron microscopy. We want to prove that CCMV capsid serves as an optimal

vehicle to transport genes to the interior of the cell. The results obtained are of great relevance in

the area of medicine and the pharmaceutical industry.

95


ID0183

REAL TIME REGISTER OF VIRAL CAPSID SELF ASEMBLY PROTEIN

BY SINGLE MOLECULE FLUORESCENCE

M.A. Martínez-Partida 1 , E. Reynaga-Hernández 1 , A.M. Longoria-Hernández 1 , N. Leija-

Martínez 1 , E. Gómez-García 1 , J. Ruiz-García 1

1 Laboratory of Biological Physics, Physics Institute, Universidad Autónoma de San Luis Potosí, Av. Dr. Manuel Nava No. 64,

San Luis Potosí, S.L.P. 78000 México

mario.martinez.partida@gmail.com

KEY WORDS: Single molecule fluorescence, single photon detection, CCMV.

Dynamic pathways for viral capsid assembly is one of the most important questions on virology

still unanswered. In this work, we studied real-time viral capsid formation around its genome by

single molecule fluorescence. This was achieved by registering fluorescence from the arrival of

cromophore-labeled capsid protein over immobilized viral-RNA. An icosahedral plant virus

(Cowpea Chlorotic Mottle Virus, CCMV) was used as a model. The CCMV capsid protein

(CCMV-CP) was cloned and mutated. Single amino acid mutation allows specific fluorescent

labeling of CCMV-CP with a commercial dye. One of the viral-RNA was immobilized inside of

a custom designed sample chamber. Single photon emission from the labeled protein arriving to

an immobilized RNA was acquired with a modified epifluorescence microscope.

96


ID0184

Characterization of photoelectric properties of the organic

semiconductor based on polymer: sensitizer blend

M. Cuatecatl-Tlapaptl 1 , S. Mansurova 1 , R. Ramos-García 1

1 Instituto Nacional de Astrofísica, Óptica y Electrónica, Departamento de Óptica, Luis Enrique Erro # 1,

Tonantzintla, Puebla, México C.P. 72840

e-mail: miriam.cuatecatl@yahoo.com.mx

KEY WORDS: organic semiconductors, photocurrent, photo electromotive force (photo-EMF),

polymer, fullerene.

Small molecule and polymer based organic semiconductors have been extensively studied during

the past decade for photovoltaic applications due to the possibility for tailoring their electronic

properties, mechanical flexibility and ease of scaling up for industrial production. However, the

mechanism of charge generation and transport in these materials are still unclear. The non-steady

state photo-EMF technique that consists in measuring ac current generated due to illumination of

photoconductor material by a vibrating interference pattern proved to be a powerful tool for

characterization of important parameters of charge transport in organic semiconductors.

In this work, the results of the characterization of photoelectric properties of the active thin film

of an organic solar cell are presented. The photoactive film consists of a nanodisperse mixture 1,2

of two organic semiconductors: a polymer P3HT (poli(3-hexiltiofeno)) and a fullerene PCBM

([6,6]-fenil-C61-butirato de metilo), with a concentration ratio (1:1). Thin film of semiconductor

was spin coated on glass substrate and two aluminum electrodes were deposited on top of it by

thermal evaporation. Modulated photocurrent and non-steady state photo-EMF 3,4 techniques were

used for characterization at He-Ne laser operating wavelength (633 nm). Measuring the

dependence of ac photocurrent and photo-EMF current on modulation frequency, external dc

field and illuminating intensity several material parameters were obtained: photoconductivity

response time, drift length and their mobility of the majority carriers.

(a)

(a) Photoactive film sample of the organic semiconductors, P3HT and PCBM.

1 D.M. Chapin, C.S. Fuller, and G.L. Pearson, A New Silicon p-n Junction Photocell for Converting Solar Radiation

into Electrical Power, Optics Letters 32, 2309-2311 (2007).

2

Yu-Wei Su, Shang-Che Lan, and Kung-Hwa Wei, Organic Photovoltaics, National Chiao Tung University,

Hsinchu 30049, Vol. 15, No. 12 (2012).

3

S. I. Stepanov, Photo-electromotive-force efect in semiconductors, Handbook of Advanced Electronic and

Photonic Materials and Devices, edited by H. S. Nalwa, INAOE (2001).

4 M. P. Petrov, I. A. Sokolov, S.I. Stepanov and G. S. Trofimov, Non-steady state photo-electromotive-force induced

by dynamic gratings in partially compensated photoconductors, J. Appl. Phys 58 (5) (1990).

97


ID0186

MAMMALIAN CELLS TRANSFECTED BY A PLANT VIRUS

CAPSID CONTAINING AN mRNA IN OBSERVED BY

FLUORESCENCE MICROSCOPY

MV. Villagrana-Escareño 1 , E. Reynaga-Hernández 1+ , M. Colunga-Saucedo 1+ , OG. Galicia-

Cruz 2 , V. De la Cruz-González 1 , AL. Duran Meza 1 , JA. Méndez-Cabañas 3 , RD. Cadena-

Nava 4 , CY. Hernández-Carballo 5 , J. Arreola-Gómez 5 and J. Ruiz-Garcia 1*

1

Laboratory of Biological Physics, Physics Institute, Universidad Autónoma de San Luis Potosí, Alvaro Obregon

No. 64, San Luis Potosí, S.L.P. 78000, México.

2

Laboratory of Analytic Pharmaceutical, Faculty of Medicine, Universidad Autónoma de San Luis Potosí, Manuel

Nava No. 6, San Luis Potosí, S.L.P. 78290, México.

3

Laboratory of Molecular Biophysics, Physics Institute, Universidad Autónoma de San Luis Potosí, Alvaro

Obregon No. 64, San Luis Potosí, S.L.P. 78000, México.

4

Center for Nanociences and Nanotechnology, Universidad Nacional Autónoma de México, Km. 107 Carretera

Tijuana-Ensenada s/n, Baja California 22800, México

5

Laboratory of Biophysic, Physics Institute, Universidad Autónoma de San Luis Potosí, Alvaro Obregon No. 64,

San Luis Potosí, S.L.P. 78000, México.

*jaime@dec1.ifisica.uaslp.mx

+ These authors contributed equally to this work and presenting authors

KEY WORDS: Fluorescence microscopy, UV- VIS spectrophotometry, CCMV, mRNA,

iRNA.

Single-stranded viral RNA 12,000 nt in length is assembled into Cowpea Chlorotic Mottle

Virus (CCMV) capsids. We use this capsid to produce virus like particles (VLPs), taking into

account the RNA-protein interaction as an advantage. VLPs could be used in nanomedicine

as carriers with directed-site-molecules labeled for specific delivery its content into the cell.

In our laboratory we carried out assemblies of messenger RNA (mRNA) with CCMV capsid

at pH 7.2 and low ionic strength conditions. UV-VIS spectrophotometry was used to measure

the capsid protein absorbance at 280 nm wavelength, its concentration and purity was also

determined. The well-structured assemblies were evaluated by transmission electron

microscopy (TEM). The results of our study indicate that a strange mRNA and the CCMV

protein capsid has a similar behavior as the native CCMV. We have proved the translation

of an mRNA into mammalian cells by fluorescence microscopy. We are trying to assembly

messenger RNA and interference RNA (iRNA) into CCMV capsid to corroborate that the

fluorescence is due to the protein.

98


ID0187

RNA NANORING STRUCTURES OBSERVED BY ATOMIC FORCE

MICROSCOPY

A.M. Longoria-Hernández 1 , J.F. Ruiz-Robles 1 , N.A. Gerling-Cervantes 1 , E. Reynaga-Hernández 1 ,

B. Ivlev 2 , J. Ruiz-García 1

1

Laboratory of Biological Physics, Physics Institute of Autonomous University of San Luis Potosí. 2 Physics Institute of

Autonomous University of San Luis Potosí. Álvaro Obregón 64, San Luis Potosí, SLP, México, 78000.

alongoria@ifisica.uaslp.mx

KEY WORDS: RNA, nanoring structures, atomic force microscopy, cations.

Formation of RNA nanoring structures on mica surface was observed by atomic force

microscopy (AFM). The samples for tapping mode AFM analysis were prepared by drop

evaporation of a solution of RNA with different cations. To the best of our knowledge, this is the

first time that nanorings of RNA have been reported. This result may have great biological

relevance as has been proposed that RNA is the oldest genome coding molecule and the

formation of these structures might have given it a stability against degradation in primeval

times.

99


ID0188

HIGHLY MONODISPERSE AND ULTRASMALL GOLD NANOSHELLS

FOR PHOTOTHERMAL APPLICATIONS

A. L. Duran-Meza, X. F. Segovia-González*, D. S. Moreno-Gutiérrez*, A. Buñuelos-Frías, J. F.

Ruiz-Robles, A. M. Longoria-Hernández, E. Gómez, J. Ruiz-García.

Laboratory of Biological Physics. Institute of Physics, Universidad Autónoma de San Luis Potosí, San Luis Potosí, SLP, México

*These authors contributed equally to this work and are presenting authors.

Xochitl_guao@gmail.com

KEY WORDS: Gold nanoshells, Near Infrared Region, Photothermal applications

Gold nanoshells (AuNSs) present a shift to the near infrared region (NIR) on their absorption

spectra with the increase of their gold layer. This property make them ideal for biological

applications where most of the organic tissues are invisible. Nowadays, methods of AuNSs

synthesis produce particles with diameters above 40 nm. Particles with smaller diameters are

required for in vivo applications. In this work we present a novel method of AuNSs synthesis based

on galvanic replacement with a core of silver nanoparticles (AgNPs). A modification of the Lee-

Meissel method results in smaller AgNPs with higher monodispersity. With this methodology we

can synthetize AuNSs ranging around 20 nm. The characterization of the AuNSs was performed

by Transmission Electronic Microscopy (TEM), Dynamic Light Scattering (DLS) and UV-VIS

spectroscopy.

100


ID0196

Influence of Cross-link density on Structural and Optical Properties of

Nanogeles.

Mónica Ledesma-Motolinía 1* , Marco Braibanti 2 , Luis F. Rojas-Ochoa 3 , and Catalina Haro-Pérez 1*

1 Departamento de Ciencias Básicas, Universidad Autónoma Metropolitana-Azcapotzalco, Av. San Pablo 180, 02200 México

D.F., Mexico

2 Department of Physics, University of Fribourg, CH-1700 Fribourg, Switzerland

3 Departamento de Física, CINVESTAV-IPN, Av. Instituto Politécnico Nacional 2508, 07360 México D.F, Mexico

1 moledesma@gmail.com, cehp@correo.azc.uam.mx

KEY WORDS: Poly (N-isopropylacrylamide), thermoresponsive polymers, particle form factor,

refractive index, light scattering.

The structural and optical properties of thermosensitive particles, nanogels, are studied by light

scattering and refractometry as a function of temperature. These thermoresponsive nanogels

consisted of poly (N-isopropylacrylamide) a polymer that shrinks at temperatures higher than its

lower critical solution temperature, 33°C. Our particles are chemically cross-linked by using two

different weight ratios of N,N-methylenbisacrylamide (BIS), which results in two nanogels

having different polymer densities. The particle form factor measured by light scattering is well

described by considering the particle internal structure as a constant radial mass density profile

convoluted with a Gaussian function. The resulting structural parameters, core and external

radius, are then used as an input in a simple model which allows us to describe the measured

temperature-dependence of the nanogel refractive index. We observe that as we increase the

cross-link density, the particles show a higher core refractive index.

(1) Experimental refractive index of thermosensitive particles having a BIS/NIPAM weight ratio of

1.9% (open circles) and 7.6% (open squares) and water refractive index (solid triangles) as a function

of temperature.

(2) Nanogel radial refractive index profile used in the theory to obtain the experimental nanogel

refractive index values at 25°C (dotted line) and 37°C (dashed line) for nanogel particles having a

BIS/NIPAM weight ratio of 1.9% (2a) and 7.6% (2b). The core and the hydrodynamic radius used as

external radius are represented by vertical lines. Inset: Temperature dependence of the particle core

refractive index used in the calculations.

101


SUMMER

SCHOOL

L

i S c

i

2 0 1 5

POSTER SESSION

2T


Poster Session 2T

Title Presenting Author ID

Synthesis and microstructural characterization

of Al-Mg-Si-Zn-Y_2O_3.

Selective Synthesis of Ceramic Laser Yag-Yap

A tunable wavelength erbium doped fiber ring laser based

on mechanically induced long-period fiber gratings

Second Harmonic Generation in nanocrystals: study in terms of

wavelength, polarization angle, incidend energy and effective area

of excitation

Uniquely Defined 2D MoS2 and WS2 flakes and their size

dependent Nonlinear optical Properties

Modeling of Nonlinear Absorption of AR Family Porphyrins

in the nanosecond regime

Unitary maps between pixelated screens

Polarimetry of light using analysis of the nonlinear volatgeretardance

relationship for liquid-crystal variable retarders

Image transport in Lieb photonic lattices

Band Structure of a photonic crystal waveguide

that include a dispersive metamaterial

Near-Field Diffraction: Cornu Spiral and the Golden Mean

A general optical theorem for propagation invariant beams

Ociel Rodríguez Pérez

Centro de Investigación en

Ingeniería y Ciencias

Aplicadas, UAEM

Adriana Escobar

Centro de Investigación en

Ingenieria y Ciencias

Aplicadas, México

M. Pérez Maciel

Universidad de Guanajuato,

México

O. Sánchez- Dena

Instituto de Física, UNAM

B. M. Szydlowska

Trinity College Dublin School

of Physics Dublin Ireland

B. Tywoniuk

University College Dublin

Beifield Ireland

Alejandro Ricardo Urzúa

Instituto de Ciencias Físicas,

UNAM

Juan Manuel Lopez-Tellez

Centro de Ciencias Aplicadas y

Desarrollo Tecnológico, UNAM

Camilo Cantillano

Departamento de Fisica MSI-

Nucleus on Advanced Optics,

Universidad de Chile

I. Lopez-Lopez

Universidad Michoacana de San

Nicolás de Hidalgo, México

Elizabeth Flores

Instituto Potosino de Investigación

Científica y Tecnológica, México

I. Rondón-Ojeda

Instituto Nacional de Astrofisica,

Óptica y Electrónica, México

029

030

031

041

043

052

054

055

060

061

063

064

103


Title Presenting Author ID

Study of Aluminium Oxide doped with Terbium at Different

Concentrations

Bessel trap at low numerical aperture

Polarization Properties of the Solitons in the Solitons in the

supercontinuum Generation in Twisted Fiber Pumped by Ns

Pulses

Optical resonances in metallic nanostrips

Achromatic Band-limited Uniform Diffusers Fabricated with 3D

Printers

Interaction of Surface Plasmon Polaritons with Grooves of

Different Widths

Laguerre-Gauss and Bessel beams, a proper comparison

Characterization of Spatial Soliton formation in nanocolloids

as a Function of Particle Concentration and Size

Waves to Study the Formation of Points or Poisson Fresnel Spot

Photonic materials: simulation and modeling prototype photonic

structures

Influence of the nonlinear Absorption Effect on the Light

Transmited

in a Local nonlinear media

Optical Chaining of tens of Silica Beads with Single trap

Second-harmonic Generation of nanotubes: First principles studies

Experimental observation of linear localizad state in photonic

Sawtooth lattices

L. Mariscal

Instituto de Física, UNAM

Yareni A. Ayala

Instituto de Física, UNAM

A. Flores-Rosas

Universidad de Chiapas

J. G. Calvillo

Optics Department, CICESE

A. K. Gonzalez-

Alcalde

Division de Física

Aplicada, CICESE

A. Shlyagina

Division de Física

Aplicada, CICESE

J. Mendoza-Hernandez

Facultad de Ciencias Físico-

Matemáticas, BUAP

Monserrat Alvarez-Ortiz

Instituto de Física, UNAM

Beltran Gonzalez

Centro de Física Aplicada y

Tecnología Avanzada, UNAM

L. Hernandez

Centro de Física Aplicada y

Tecnología Avanzada, UNAM

B. A. Martinez Irrivas

Facultad de Ciencias

Físico-Matemáticas, BUAP

J. A. Ascencia-Rodriguez

Facultad de Física Universidad

Veracruzana

R. A. Vazquez-Nava

Centro de Investigaciones en

Óptica Guanajuato

Bastian Real

Departamento de Fisica MSI-

Nucleus on Advanced Optics,

Universidad de Chile

067

076

077

078

081

083

084

087

089

090

092

093

096

097

104


Title Presenting Author ID

Thin Film Coatings for Cylindrical Photonic Devices

Active Control for Polarization State of Spectral Components of Fs

Pulses

Tuning of Liquid Crystals by Electric Fields

Visible-frequency hyperbolic metasurface

Integrated Photoconductive Antenna-Probe Design for Near Field

THz Imaging

Control of the local TEM polarization state of Fs laser pulses

Mid-infrared Multi-Mode Absorption Spectroscopy (MUMAS)

using Interband Cascade Lasers (ICLs)

Fresnel off-Axis Digital Holography Without Zero-Order

Diffraction

and Without Speckle Noise

Deformation of an aperture contained in laminated metal,

de mechanical stress of heat influence

Analisys of Pulse Propagation in Optical Fibers

and nonlinear optical Loop Mirror

Third Order Nonlinear Properties of Colloidal Au Nanorods

Systems

Physical Systems arising from projections betwen the sphere and

the plane

Fabrication of Long-Period Fiber Gratings whit Polymeric

Materials

Wood anomalies in driffraction gratings eith defects

Amado M. Velazquez-

Benitez

Intituto de Investigacion en

Materiales, UNAM

Jesús Delgado-Aguillón

Centro de Ciencias Aplicadas y

Desarrollo Tecnológico, UNAM

M. Clark

Centro de Investigación en

Física, Universidad de Sonora

Robert C. Devlin

Harvard University

Joel Pérez-Urquizo

Centro de Ciencias Aplicadas y

Desarrollo Tecnológico, UNAM

Gustavo Castro-Olvera

Centro de Ciencias Aplicadas y

Desarrollo Tecnológico, UNAM

Seamus O'Hagan

Department of Physics,

University of Oxford UK

Luis Carlos Bermúdez

Instituto de Astronomía, UNAM

H. Valenzuela-Loubert

Universidad de Juarez

Autónoma de Tabasco

Marisol Billión Reyes

Instituto de Investigacion en

Comunicaciones Ópticas

E. V. Garcia-Ramirez

Instituto de Física, UNAM

Cristina Salto-Alegre

Instituto de Ciencias Físicas,

UNAM

Ivan Ramirez-Ortega

Instituto de Investigaciones en

Materiales, UNAM

Iván C. Avilés

Departamento de Óptica,

CICESE

102

103

105

112

114

115

116

122

126

130

134

135

139

142

105


Title Presenting Author ID

Design of an Optical Filter based on Photonic Crystals

using Transmission Line Theory

Nonlinear optical properties of gold nanoparticles embedded in

sapphire

Simplified Bond-Hyperpolarizability Model in THz Range

with Electronic Nonlinear Effects for InN

Calculation of Group Delay Dispersion in Fs Pulses Propagating

Through a Parallel-Plane Plate and a Pair of Wedges

Gerzon Gomez Bravo

Facultad de Ingenieria, UNAM

A. Peña R.

Departamento de Óptica,

CICESE

E. S. Jatirian-Foltides

Instituto de Investigacion en

Ciencias Básicas

y Aplicadas, México

C. Sanchez-Padilla

Centro de Ciencias

Aplicadas y Desarrollo

Tecnológico, UNAM

143

145

147

160

Comparing efficiency and accurancy of the kinoform

and the helical axicon as Bessel-Gauss beam generators

Optimum Generation of Annular Vortice

using Phase Diffractive Optical Elements

Selectively Magnetic Fluid Infiltrated Dual-Core Photonic Crystal

Fiber

based Magnetic Field Sensor

Spiral optical vortices generated by a Mach-Zehnder interferometer

Dilia Aguirre-Olivas

Instituto Nacional de

Astrofisica, Óptica y

Electronica

Gabriel Mellado-

Villaseñor

Instituto Nacional de

Astrofisica, Óptica y

Electrónica

Rahul Kumar Gangwar

Department of Aplied Physics

Indian School of Mines

Jharkhand, India

A. Montes-Pérez

Facultad de Ciencias Físico

Matemáticas, BUAP

164

165

167

181

106


ID029

SYNTHESIS AND MICROSTRUCTURAL CHARACTERIZATION OF

Al-Mg-Si-Zn-Y 2 O 3 .

Ociel Rodríguez a , Arturo Molina a , Socorro Valdez b , Adriana Escobar a

a Centro de Investigación en Ingeniería y Ciencias Aplicadas/UAEM, Cuernavaca, Morelos, México.

b

Instituto de Ciencias Físicas-Universidad Nacional Autónoma de México, Av. Universidad S/N, Col. Chamilpa, 062210,

Cuernavaca, Morelos, México.

Correo: ociel.rodriguez@uaem.mx

KEY WORDS: Composite, Sintering, Mechanical Alloying, Powder Metallurgy,

Microstructure.

Abstract

A composite prepared via powder metallurgy was reinforced with 3% weight of yttrium

oxide (3-15 μm diameter). We studied the distribution and interaction of the reinforcement

Y₂O₃ with Al-Mg-Si-Zn particles. Mechanical hardness and microstructura were also

studied. The composite Al-Mg-Si-Zn-Y₂O₃ and quaternary alloy Al-Mg-Si-Zn were

analyzed using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The

results showed excellent distribution of the Y₂O₃ particles. The hardness of the composite

increases with the addition of Y₂O₃ particles compared to the alloy of Al-Mg-Si-Zn

unreinforced.

Figure 1. X-ray diffraction patterns of mechanically alloyed powders of Al, Mg, Si, Zn, Y₂O with increasing

the milling time.

Reference

1. Regino Castro Grela, Bernardo Campillo Illanes, Socorro Valdez Rodríguez, “Efecto del reforzamiento y

la velocidad de enfriamiento en las propiedades mecánicas de la aleación AlMgSi”, Ingenierías, Vol.

XIV, No. 50, Enero - Marzo (2011).

2. S. Valdez, B. Campillo, R. Pérez, L. Martínez, A. García H, Synthesis and microstructural

characterization of Al–Mg alloy–SiC particle composite, Materials Letters 62, 2623–2625, (2008).

3. S. Valdez, J. Genescá, B. Campillo, O. Flores, R. Pérez, J.A. Juárez-Islas, Effect of Mg addition on the Ƭ

phase distribution of an AlMn alloys modified with zinc, Materials Letters 62, 1139–1142, (2008).

107


ID030

SELECTIVE SYNTHESIS OF CERAMIC LASER YAG-YAP

Escobar Adriana 1 , Vlasova M., 2 Mikolay Kakasey 3 , Rodriguez Ociel 4

a Centro de Investigación en Ingeniería y Ciencias Aplicadas Universidad Autónoma del Estado

de Morelos (CIICAp-UAEMor), Cuernavaca, Estado de Morelos, 1001, MEXICO

adriana.escobar@uaem.mx;

KEY WORDS: laser irradiation, ceramics, Y 2 Al 5 O 12, YAlO 3 .

The formation of the phases in the laser irradiation area of the compacted powder

mixture of 56 mol. % Al 2 O 3 - 44 mol. % Y 2 O 3 was investigated by X-ray diffraction,

scanning electron microscopy SEM. States that in laser heating zone from eutectic melt

comprises two main phases: YAlO 3 and Y 2 Al 5 O 12 , which corresponds to the phase diagram

for the system Al 2 O 3 - Y 2 O 3 [1]. Dependent on the rate of the laser irradiation power (P)

and speed of the laser beam (v), the content is different YAlO 3 and Y 2 Al 5 O 12 . Due to the

presence of a temperature gradient (on the surface temperature is greater than the volume of

the sample) Al 2 O 3 and Y 2 O 3 is also recorded. The ceramic surface has a micro and macro

texture. Due to the high surface temperature of the ceramic forming processes and after

ablation the ablation deposition products on the surface of the ceramic (Figure 1).

Figure 1. Section of the surface trace

obtained after the laser irradiation

from compacted mixtures of 56

mol%. Al2O3 + 44% mol. Y2O3. P

= 45 W, v = 0.038 mm / s. a), b), c)

different magnification, content

elements in areas 1, 2, 3 in c)

present in Table 1 and Table 2.

[1] Medraj, M., Hammond, R., Parvez, M. A., Drew, R. A. L., Thompson, W. T. High temperature neutron

diffraction study of the Al 2 O 3- Y 2 O 3 system Journal of the European Ceramic Society 26, 3515- 3524 (2006).

108


ID031

A tunable wavelength erbium doped fiber ring laser based on mechanically

induced long-period fiber gratings.

M. Pérez Maciel 1 , Y. López Dieguez 1 , J.A. Montenegro Orenday 1 , J.M. Estudillo Ayala 1

1

Universidad de Guanajuato, División de Ingenierías, Campus Irapuato-Salamanca, Carretera Salamanca - Valle de Santiago

Km. 3.5 + 1.8. Comunidad de Palo Blanco Salamanca Gto. C.P. 36730.

M. Pérez Maciel, miguel23mpm@gmail.com

KEY WORDS: tunable, polarization, gratings, filters.

A tunable wavelength erbium doped fiber ring laser, based on mechanically induced longperiod

fiber gratings (LPFG) is presented. The filters were made by pressing a plate with periodic

grooves against a short length of fiber using a digital torque tester. The grooves are at a period of

630 µm. Furthermore, the long-period fiber gratings offers unique advantages, they are tunable,

erasable, reconfigurable and that exhibit transmission spectra and one thermal stability, similar to

photoinduced LPFG's. Here, by changing the polarization of our system with a polarization

controller, experimentally the single line emission can be tuned in the L-band

telecommunications.

Fig. 1. Experimental Setup

109


ID041

Second Harmonic Generation in LiNbO3 nanocrystals: study in terms of

wavelength, polarization angle, incident energy and effective area of excitation

O. Sánchez-Dena 1 , E. V. García-Ramírez 1 , C. D. Fierro-Ruíz 2 , J. R. Farías-Mancilla 2 , and J. A.

Reyes-Esqueda 1,*

1 Instituto de Física, Universidad Nacional Autónoma de México, 04510, México, D. F., México

2 Universidad Autónoma de Ciudad Juárez, Av. Del Charro 450 Norte, Ciudad Juárez, Chihuahua, 32310, México

* reyes@fisica.unam.mx

KEY WORDS: Nonlinear optics, second harmonic generation, lithium niobate, nanostructures.

Second-harmonic generation (SHG) at fundamental wavelengths of 800-1300 nm, in

mechanochemically synthesized lithium niobate (LiNbO3) nanocrystals is reported. For a small

constant energy of 100 μJ, a doubled-frequency converted signal has been detected for all this

range, showing an incident-wavelength-dependent intensity. Such behavior is observed in all the

studied samples. Three different nano-crystalline systems in the form of powders were obtained

by varying the temperature and time parameters in the annealing processes. Samples exposed to

higher temperatures as well as to bigger time intervals in the annealing, show higher intensities

for the doubled-frequency converted signals. A partial conversion efficiency of 1.37% was

determined together with an energy of 9 pJ estimation for the doubled-frequency converted signal

at highest conversion efficiency, which correspond to the harmonic intensity at a fundamental

wavelength of 1070 nm. SHG shows no clear dependency upon polarization angle of the incident

light, and is very sensitive to changes on incident energy and effective area of excitation. It

increases non-lineally with incident energy and decreases non-lineally as the effective diameter

of a spotted convergent beam (effective area of excitation) increases. All optical measurements

were performed in transmission mode and a fixed fundamental wavelength of 1064 nm was used

in the polarization angle, incident energy and effective area of excitation experiments. SHG in

similar systems has been previously reported, however only a fundamental wavelength of 1064

nm and relatively high incident energies (order of milijoules) were employed 1 . In other works,

SHG has also been studied in ABO3 type nano-crystalline ferroelectric materials different from

lithium niobate 2,3 .

Fig. 1. (a) Overlapping of fundamental and harmonic signals detected for various wavelengths of excitations. (b)

SHG response as a function excitation wavelength. (c) SHG response as a function of incident-on-lens light’s energy

for sample S2 and using two different effective beam diameters.

1 S. Lisinski, , L. Ratke, D. Schaniel, T. Jungk, E. Soergel, H. Boysen, and T. Woike, Opt. Mat., 32 (2010) 504-509

2

D. Kip, J. Appl. Phys. B., 67 (1998) 131-150

3 S. E. Skipetrov, Nature, 432 (2004) 285-286

110


ID043

Uniquely Defined 2-D MoS2 and WS2 flakes and Their Size Dependent

Nonlinear Optical Properties.

B. M. Szydłowska 1 , W. Blau 1 ,

Trinity College Dublin, School of Physics, Dublin 1, Ireland.

KEY WORDS: 2D, nanosheets, NLO, flakes, Liquid phase exfoliation,

Since graphene discovery and its presentation as a wonder material scientists started looking for

similar structures. The Liquid Phase Exfoliation (LPE) method enabled creation of 2D

nanomaterials with precise control of size, shape, composition and number of layers.

Investigation of the nonlinear and ultrafast optical properties (NLO) of 2D nanomaterials

considered in that study are indisputably important.

Molybdenum Disulfide and Tungsten disulfide (2D materials representing transitionmetal

dichalcogenides family) dispersions with high population of single and few layers were

prepared by Liquid Phase Exfoliation (LPE) method. High quality of the 2-dimensional structures

was verified with use of techniques like Transmission Electron Microscopy (TEM), Atomic

Force Microscopy (AFM) and spectroscopic techniques (UV-Vis). Applying size selection

procedure, variety of sizes and concentrations of MoS2 nanosheets were prepared.

Ultrafast nonlinear optical (NLO) properties were investigated by Z-scan open aperture

technique. All measurements were performed by 6 ns pulses at wavelength of 532 nm from Q-

switched Nd:Yag laser with pulse repetition rate 10 Hz and few power setups, concentrations and

flake sizes.

Output of the experiment gives deep insight in size and layers dependence of NLO

properties in 2D materials family. TMDs have great chance to enable development of the new

level technology in electronics for photonic devices.

TEM image of single mono anf few layered TMD material.

[1] Jonathan Coleman et all,, Large-Scale Production of Size-Controlled MoS 2 Nanosheets by Shear Exfoliation,

Chem Mater, (2015)

111


ID052

MODELING OF NONLINEAR ABSORPTION OF AR FAMILY

PORPHYRINS IN THE NANOSECOND REGIME

B. Tywoniuk 1 , N. V. Buchete 1 , W. Blau 2

1 University College Dublin, Dublin 4, Belfield, Ireland

2 School of Physics, Trinity College Dublin, College Green, Dublin 1, Ireland

bTywoniuk@gmail.com

KEY WORDS: NLO, Z-Scan, Porphyrins, 1D materials,

Solutions of organic molecules have begun to attract a lot interest for use in optical limiting

devices (O.L.) due to their fast responses to high intensity visible light, which refers to the

use of materials to reduce the transmitted intensity of light, it is often desirable to have sharp and

rapid decrease in transmittance above a certain intensity threshold and or a certain optical wave

length. That means that materials, which exhibit a rapid NLO response, are of interest applications

such as eye protection or Q-switching in lasers!

Porphyrins in general are planar ligands (a molecule with at least one lone electron pair

that form a covalent bond with a metal ion) derived from the Porphyrine molecule. The Porphine

molecule is itself composed of four Pryrole molecule sub-units and so is known as a Tetra–Pyrrole

molecule. A family of Porphyrin molecules is classified by their common macro-cycle and

central metal ion. In this experiment the AR family of Porphyrins whose central metal ion is a

Zinc atoms where used.

Porphyrins from the AR family used in the experiment lead to observe reverse saturable

absorption. Moreover, the NLO effect is sensitive for alternative solvents like NMP or ethanol.

Experiment was performed with use of Z-scan technique with nanosecond laser pulse at 532nm

wavelength.

Fig. 1 AR-family porphirine example, image of the samples measured, z-scan system schema.

[1] J. Mozer et all, " Dichromophoric Zinc Porphyrins: Filling the Absorption Gap between the Soret and Q Bands,

Phys. Chem. C, 2015, 119 (10), pp 5350–5363

[2] David Dolphin, The Porphysins, Academic Press, New York.

112


ID054

Unitary maps between pixelated screens

Alejandro Ricardo Urzúa, Kurt Bernardo Wolf

Instituto de Ciencias Físicas, UNAM

Av. Universidad s/n, Cuernavaca, Morelos 62210

alejandro@fis.unam.mx, bwolf@fis.unam.mx

KEY WORDS: geometric optics, unitary maps, pixelated screens, finite optical systems

We summarize the theoretical framework on which the unitary maps between pixelated

screens is based. The case of a two-dimensional map between square and polar circular screens

with the same number or pixels was done by Vicent and Wolf [1]. Here we show the previous

results and formulate the natural extension of unitary maps between two-dimensional rectangular

and polar annular pixelated screens.

Cartesian square (a) and polar circular (b) arrangements of 11 pixels. Cartesian rectangular (c) and

polar annular (d) arrangements of 11 × 7 pixels.

[1] L.E. Vicent and K.B. Wolf, Unitary transformation between Cartesian- and polar pixelated screens, J.

Opt. Soc. Am. A 25, 1875-1884 (2008)

113


ID055

Polarimetry of light using analysis of the nonlinear voltage-retardance

relationship for liquid-crystal variable retarders

Juan Manuel Lopez-Tellez 1 ,* and Neil C. Bruce 1

1 Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México,

Circuito Exterior S/N, Ciudad Universitaria, Apdo. Postal 70-186, México D.F., 04510, México.

* jmlopez@comunidad.unam.mx

KEY WORDS: Optical instrumentation, Polarimetry, Liquid-crystal devices.

The measurement of the polarization of light is well established 1 . Recently, more use has been

made of variable retarders, for example, liquid crystal retarders or electro-optic cells which have

changes of the retardance depending on the voltage applied to the system. We present a method

for using liquid-crystal variable retarders (LCVR’s) with continually varying voltage to measure

both the Stokes vector of a light beam 2 and the complete Mueller matrix of a general sample 3 .

The LCVR’s are usually employed with fixed retardance values due to the nonlinear voltageretardance

behavior that they show. For the measurement method presented here, the nonlinear

voltage-retardance relationship is first measured 4 and then a linear fit of the known retardance

terms to the detected signal is performed. We use known waveplates (half-wave and quarterwave)

as devices to provide controlled polarization states to the Stokes polarimeter, and we use

the measured Stokes parameters as functions of the orientation of the axes of the waveplates as an

indication of the quality of the polarimeter. In addition, we present results of simulations for

comparison. Also, we have used this technique to measure the complete Mueller matrix of a

general sample.

Fig. 1. Sixteen Mueller-matrix elements of a Glan–Thompson prism polarizer drawn as a function of its

optical angle (in degrees). The dots are the experimental results and the solid curves are the fitted

theoretical curves of an ideal polarizer.

1 D. Goldstein, Polarized Light, 2 nd ed. (Marcel Dekker, Inc., 2003).

2 J.M. López-Téllez and N.C. Bruce, Rev. Sci. Instrum. 85, (2014) 033104.

3 J.M. López-Téllez and N.C. Bruce, Appl. Opt. 53, (2014) 5359-5366.

4 J.M. López-Téllez, N.C. Bruce, J. Delgado-Aguillón, J. Garduño-Mejía and M. Avendaño-Alejo, Am. J. Phys. 83,

(2015) 143-149.

114


ID060

Image transport in Lieb photonic lattices

Camilo Cantillano 1 , Bastián Real 1 , Luis Morales-Inostroza 1 , Mario I. Molina 1 , and Rodrigo A.

Vicencio 1

1 Departamento de Física, MSI-Nucleus on Advanced Optics, and Center for Optics and Photonics (CEFOP), Facultad de

Ciencias, Universidad de Chile. Las Palmeras 3425, Ñuñoa, Santiago, Chile.

cantillano.milo@gmail.com

KEY WORDS: Flat band, localized state, nondiffracting propagation.

Optical lattices are periodic structures that posses different physical properties depending on their

configuration. Specifically, a Lieb lattice [see Figures (a) and (b)] presents, on a discrete approximation,

a linear band structure consisting of two dispersive and one completely-flat bands [see Figure

(c)]. Flat band modes are spatially localized and have only four nonzero amplitudes [see Figure

(d)]. They present nondiffracting propagation 1 along the crystal, due to the absence of dispersion.

This work focuses on the experimental procedure to observe such localized states, using a setup

based on a Spatial Light Modulator (SLM) and a photonic lattice written using a femtosecond-laser

technique 2 . Here, the nearest-neighbors approximation is valid due to the discreteness of the lattice

composed of well separated and weakly interacting waveguides. Localized states, such as Figure

(d) are not symmetric in amplitude (up and down site amplitudes are larger than left and right

site amplitudes), due to the ellipticity of waveguides in the experiment that induces an effective

anisotropy for nearest-neighbors interactions (vertical coupling is larger than horizontal one).

(a) Lieb lattice, where light propagates along the z axis. (b) Microscope image of a lieb lattice with 20 µm of separation

between guides. (c) Band structure for Lieb lattice using nearest-neighbors approximation, where a flat band at l = 0

is present. (d) Localized state for Lieb lattice, where yellow and black sites have a phase difference of p. (e) Output

face of the crystal, showing nondiffracting propagation for a (d)-like input condition.

In the experiment, green light of 532 nm is used to illuminate one half of a transmission SLM

in order to achieve an amplitude modulation that generates a four spots image, which is redirected

to the second half of the SLM. Here, using a combination of two polarizers and two quarter waveplates,

phase modulation is achieved, and a (d)-like input condition is formed. This input condition

is propagated along the photonic crystal, and as a result a four sites ring is obtained at the output of

the lattice 3 [see Figure (e)], demonstrating the nondiffracting propagation of this state. Given that

the sum of two localized states is also a localized state, several ring modes could be propagated

without diffraction, and an image code could be generated.

1 D.L. Bergman, C. Wu and L. Balents, Phys. Rev. B 78 125104 (2008).

2 A. Szameit and S. Nolte, J. Phys. B 43 163001 (2010).

3 Rodrigo A. Vicencio, Camilo Cantillano, Luis Morales-Inostroza, Bastián Real, Mario I. Molina, Steffen

Weimann, and Alexander Szameit, Phys. Rev. Lett. in press (2015).

115


ID061

Band structure of a photonic crystal waveguide that include a

dispersive metamaterial

I. López-López 1 , A. Mendoza-Suárez 1 , H. Pérez-Aguilar 1

1 Avenida Francisco J. Múgica S/N Ciudad Universitaria, C.P. 58030, Morelia, Michoacán, México.

hiperezag@yahoo.com

KEY WORDS: Photonic crystal waveguide, dispersive left-handed material, photonic band

structure, plasmonic surface mode.

In this work we consider an electromagnetic system composed of two flat conductor surfaces and

a periodic array of circular inclusions forming a photonic crystal waveguide. An integral

numerical method was applied to determine the band structure of the system and the intensity

field of its electromagnetic modes 1 . We found that the variation of the filling fraction allow to

control at a certain degree the photonic band structure of the system. We found interesting band

structures that contain regions of nearly zero-dispersion and bandgaps. Although initially we

considered that the medium inside the waveguide is vacuum, we also discuss the case of a

dispersive metamaterial medium. Some numerical results show the presence of a plasmonic

surface mode in the system proposed for TE polarization, as shown in Fig. 1.

Fig. 1. Plasmonic surface mode represented by electric field distribution at the frequency ω r = 0.7519.

1 A. Mendoza-Suárez, F. Villa-Villa, and J. A. Gaspar-Armenta, JOSA B, 24 (2007) 3091-3098.

116


ID063

Near-field Diffraction: Cornu Spiral and the Golden Mean

1. Elizabeth Flores 1 , 2. Haret C. Rosu 1 ,

1. IPICYT (Instituto Potosino de Investigación Científica y Tecnológica)

1.e-mail: elizabeth.flores@ipicyt.edu.mx

2.e-mail: hcr@ipicyt.edu.mx

KEY WORDS: Euler spiral, Cornu spiral, golden mean.

In the theoretical formulation of diffraction, there exists an important treatment that involves the

Fresnel diffraction and thereby his graphical representation through the Cornu spiral or clothoid,

also known as Euler’s spiral, which intrinsically contain the golden mean (φ=1.618),

characteristic of the Fibonacci sequences.

In this work, we present the relation between the clothoid and the golden meanin the field of

diffraction from a geometric point of view.

Spiral of the divine proportion.

[1] Grant R. Fowless, Introduction to the Modern optics, Second Edition, Dover Publication, Inc, New

York, 1975

[2] Victor M. Castaño, The Cornu Spiral as a Golden Mean Construction, Jpn. J. Appl. Phys. 44 5009

(2005)

[3] Ralph Levien, The Euler spiral: a mathematical history, August 30, 2008

117


ID064

A general optical theorem for propagation invariant beams

I.Rondón-Ojeda 1 , B. M. Rodríguez-Lara 1 , and F. Soto-Eguibar 1

1 Instituto Nacional de Astrofísica Óptica y Electrónica, Puebla, México

irondon@inaoep.mx

ABSTRACT

We derive an expression for the optical cross-section theorem, or simply the

optical theorem, for probe sources given in terms of propagation invariant beams

[1, 4]. The optical theorem describes the rate at which energy is taken away

from a probing wavefield by an object, due to both scattering and absorption.

The energy extinction rate, due to scattering and absorption at the scatterer,

is proportional to the imaginary part of the forward scattering amplitude, that

is, the direction of propagation of the incident propagation invariant beams.

Keywords: elastic scattering, far field approximation, propagation invariant beams

Figure 1: A scatter diagram of fields on an arbitrary object [4]

References

[1] D. Jackson, Classical Electrodynamics, Wiley 3Ed (1999)

[2] C. Bohren and D. Huffman, Scattering of light for small particles, Wiley

(1998)

[3] L. Tsang, J. Au Kong and K. H. Dim, Scattering of Electromagnetic Waves,

John Wiley Sons (2000)

[4] Akira Ishimaru, Electromagnetic Wave Propagation, Prentice Hall (1991)

1

118


ID067

STUDY OF ALUMINUM OXIDE DOPED WITH TERBIUM AT

DIFFERENT CONCENTRATIONS.

L. Mariscal 1,2 , C. García 3 , S. Ramírez 3

1. Physics Institute – UNAM, Circuito de la Investigación Científica Ciudad Universitaria CP 04510 México, D.F.

2. CINVESTAV, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, Delegación Gustavo A. Madero, México D.F.

Código Postal 07360

3. Faculty of Science, UNAM. Av. Universidad 3000, Circuito Exterior S/NDelegación Coyoacán, C.P. 04510Ciudad

Universitaria, D.F.México

mariscal2005@gmail.com, miguel.garcia@ciencias.unam.mx, sergio.ramirez@ciencias.unam.mx

KEY WORDS: powders, Energy Dispersive Spectroscopy, doping.

Different emission intensities that occur in aluminum oxide powders correspond to different doping terbium

concentrations, such sample powders were synthesized via evaporation technique. These were characterized

using luminescence techniques, x-ray diffraction and Energy Dispersive Spectroscopy (EDS). The emission

spectra for each of the distinct terbium doping percentages show terbium's typical transitions in 494, 543, 587

and 622nm, these correspond to 5

D 4 → 7 F 6 , 5 D 4 → 7 F 5 , 5 D 4 → 7 F 4 and 5 D 4 → 7 F 3 , respectively. Such powders were

excited at room temperature at λ = 380nm . X-ray diffraction results show the presence of both γ-400 phase and

γ-440 phase at 45.90 degrees and 67.38 degrees for the two hour thermally treated compounds. EDS analyses

indicate 60% of oxygen and 40% of aluminum with presence of terbium doping in the compound.

The powders’ photoluminescence shows their spectrum is associated with terbium characteristic

transitions and that the best intensity efficiency corresponds to a 12% doping.

When excited at l = 380nm, the energy required for luminescence is less EDS analysis show the attainment of

aluminum oxide corresponding to the Al 2 O 3 estequiometric formula. Due to the obtained results, the easy

preparation and the low cost of the compound, terbium-doped alumina can be considered as a good candidate to

attain green light.

In graph are indicated the corresponding different transitions in Terbium Tb 3+ , which are presented in 494, 543, 587 y 622nm, this ones

correspond to 5 D 4→ 7 F 6, 5 D 4→ 7 F 5, 5 D 4→ 7 F 4 and 5 D 4→7F3,

respectively, being excited at l = 380nm at room temperature and the intensity is accord to the doping.

[1] Azorín, J., Esparza, A., Falcony, C., Rivera, T., García M., y Martínez, E. Preparation and thermoluminescence

properties of aluminium oxide doped with europium. Radiation Protection Dosimetry, 100, 277–279 (2002).

[2] Martínez, R., Yescas, E., Álvarez, E., Falcony, C., and Caldiño, U. (2013). White light generation in rare-earth-doped

amorphous films produced by ultrasonic spray pyrolysis aluminium and hafnium oxide films doped with CeCl3/TbCl3/MnCl2,.

Advances in Science and Technology, 82, 19-24 (2013).

119


ID076

Bessel trap at low numerical aperture

Yareni A. Ayala 1 , Alejandro V. Arzola 1 and K. Volke-Sepúlveda 1

1 Instituto de Física, Universidad Nacional Autónoma de México

Corresponding Author: yareni.ayala@gmail.com

KEY WORDS: Optical levitation, Bessel Beam, Low numerical Aperture.

Optical levitation was first demonstrated by A. Ashkin 1 combining the upward force produced by

photon pressure and the downward gravity force of particles suspended. Since then, many other

optical traps has been developed using a variety of configurations 2 . Most of three-dimensional

optical traps depend on the use of high numerical aperture objectives to achieve a strong laser

focusing 3 . We report on three-dimensional trapping using a Bessel beam generated by an axicon

lens and then focused by a low numerical aperture objective. This configuration leads to a stable

levitation optical trapping of solid glass spheres (n = 1.48) of few microns in diameter immerse

in water. We compare the spatial stability of the focused Bessel trap with different Gaussian

levitation traps formed using the same low numerical objective lens.

We observe that in all cases the glass bead is levitated in an axial position above the focal

region that depends on the input power. The figure 1 A) shows the transverse intensity profile of

the focused Bessel beam at the focus region z=0μm and at an axial distance of z=30μm. In B) is

shown the transverse trap stiffness as a function on the incident power P for a glass bead of

diameter (4.9 ± 0.5)μm when trapped by both the Bessel and Gaussian traps. We found that the

Bessel trap provides a transverse trap stiffness per incident power higher than the all Gaussian

traps tested in this work.

Figure 1. A) Transverse intensity profiles of the focused Bessel beam using a low numerical aperture

objective at two different axial positions z. B) Comparison of the transverse stiffness (divided by the

incident power) for the Bessel (●) and Gaussian (▲) traps. The error bars are the standard deviation of

the experimental measurements.

.

1 A. Ashkin, Phys. Rev. Lett.,24 (1970)156-159.

2 D. McGloin, Phil. Trans. R. Soc. A., 364 (2006)3521-3537.

3 A. Ashkin, J.M. Dziedzic, J.E. Bjorkholm, and Steve Chu, Opt. Lett., 11(1986)288-290.

120


ID077

POLARIZATION PROPERTIES OF THE SOLITONS IN THE

SUPERCONTINUUM GENERATION IN TWISTED FIBER PUMPED BY

NS PULSES

A. Flores-Rosas, S. Mendoza-Vazquez, B. Posada-Ramirez, O Diaz-Hernandez and J G

Escalera-Santos

Universidad Autónoma de Chiapas, Facultan en Física y Matemáticas, Carretera Emiliano Zapata Km. 8.5, Rancho San

Francisco, Ciudad Universitaria, Terán, 29050, Tuxtla Gutiérrez, Chiapas

arielf@nucleares.unam.mx

KEY WORDS: Supercontinuum, Soliton, birefringence and Polarization

Common optical fibers are randomly birefringent, which results in random polarization of the

supercontinuum (SC) generated in such fibers. Random polarization is undesirable for many

applications of the SC. One of principal mechanism of generation of supercontinuum is formation of

solitons by Modulation Instability (MI). Pulse break up was observed in conventional fibers [1, 2]. At

pumping by relatively long (> 10 ps) pulses, MI and Stimulated Raman Scattering (SRS) are dominant at

the initial stage of the process broadband spectrum formation, MI results in pulse breakup and

formation of short pulses that evolve finally to a bunch of solitons and dispersive waves. The

solitons are shifted to longer wavelengths by soliton self-frequency shift (SSFS). The solitons with

higher power have a larger wavelength shift. In this work we investigate the polarization of solitons

formed by the pulse breakup process by MI at pumping by ns-long pulses in standard fiber with

circular birefringence introduced by fiber twist, the fiber twist mitigates the random linear

birefringence. We found that a circularly polarized pump pulse introduced to a twisted fiber

produces solitons with a high grade of circular polarization while in the fiber without twist the soliton

polarization was random, Fig. 1 a), and we obtained broadband spectrum covering the range from

1510 nm to 1630 nm. Thus we get a source of ~ 130 nm bandwidth, Fig 1 b).

Fig. 1. a) The ellipticity of the solitons at wavelength of 1570 nm and b) Espectrum of SC

[1] Beaud P, Hodel W, Zysset B, and Weber H P IEEE J. of Quantum Electr., QE-23 (1987) 1938.

[2] Islam N M, Sucha G, Bar-Joseph I, Wegener M, Gordon J P, and Chemla D S, J. Opt. Soc. Am. B 6

(1989) 1149.

121


ID078

Optical resonances in metallic nanostrips

J. G. Calvillo, U. Esparza, E. I. Chaikina and E. R. Méndez

Optics Department, Ensenada Center for Scientific Research and Higher Education (CICESE),

Ensenada-Tijuana Highway 3918, Zona Playitas, Ensenada, B. C., 22860, Mexico.

jcalvill@cicese.edu.mx

KEYWORDS: Localized surface plasmons, light scattering, discrete dipole approximation.

The use of nanoparticles in biological media has had a great impact in cancer treatments, where

they are used as thermal nanosources, and in the diagnostic imaging of tumors using labeled

nanostructures that selectively adhere to specific cells. In both cases, the nanoparticles have to be

illuminated with light of specific wavelengths that excite localized surface plasmon resonances.

These resonances are due to the motion of the free electrons in the particle, in combination with

its shape. Thus, the spectral position and amplitude of these resonances depend on the size, shape

and dielectric constant of the nanoparticles as well as the medium in which they are embedded.

In this work, we study the spectral response of rectangular parallelepipeds (nanostrips) of

nanometric dimensions in water, as a function of their geometrical parameters (length L, width W

and thickness H). The work is motivated by the possibility of using such particles as nanosources

of heat in biological experiments. The calculations are based on the discrete-dipole

approximation (DDA) method 1 , which constitutes a flexible and powerful technique for

computing scattering and absorption by particles of arbitrary geometry. The geometry considered

is illustrated in Fig. 1a. The nanostrips are immersed in an aqueous medium (like biological

tissue), and we search for resonances that lie within the spectral regions called the biological

windows, corresponding to the ranges 700-950nm and 1000-1350nm 2 . Some illustrative results

are shown in Fig. 1b.

x

E⃗

k⃗

z

H = 50nm

L = 100nm

y

(a)

(b)

Figure 1. Illustration of the geometry considered (a) and spectral response for a nanostrip with H=50 nm, L=150 nm

and W=50 nm (b).

The results show that the position of the resonance can be tuned by the length L, but that

the other dimensions also play role and can modify the width of the absorption curve. The

fabrication of such particles on flat substrates by electron beam lithography and simulations

considering the substrates using COMSOL will also be described.

[1] B. Draine and P. Flatau. J. Opt. Soc. Am. A., 11, 1491 (1994).

[2] L. Martínez Maestro, et. al. RSC Advances., 4, 54122 (2014).

122


ID081

Achromatic Band-limited Uniform Diffusers Fabricated with Threedimensional

Printers

A. K. González-Alcalde 1 , E. R. Méndez 1 , and A. A. Maradudin 2

1 División de Física Aplicada, Centro de Investigación Científica y de Educación Superior de Ensenada, Ensenada, BC, México.

2 Department of Physics and astronomy, University of California, Irvine CA 92697, USA.

Corresponding author e-mail: alcalde@cicese.edu.mx

KEY WORDS: Diffuse light, optical diffusers, random surfaces.

The control of diffuse light has been a subject of long-standing interest. It is a central problem in

projection and illumination systems. In the case of lamps, for instance, light bulbs and shades are

used for these purposes.

Optical diffusers are optical elements that produce diffuse light by modifying the angular

spread of the incident light. The conventional methods to produce diffuse light are based on

volume and/or surface scattering. As normally applied, these techniques do not provide control

about the angular distribution of the light. Methods based on diffraction have been used to

produce scattering patterns with prescribed angular distributions, but this kind of approach,

produces diffusers whose properties depend on the illumination wavelength and do not work well

for large angles of scattering.

Diffuser designs that base their operation on refraction, rather than diffraction, have also

been studied 1 . These have the advantage of being achromatic and that the designs are not limited

to the paraxial region. Based on the design procedures described in Ref. 1 , we report the

fabrication of two-dimensional random surfaces that scatter light uniformly within a specified

range of angles using three-dimensional printers. The designs were first tested by means of

computer simulations. To illustrate the results, in Fig. 1(a) we present a section of a realization of

a surface designed to scatter light uniformly within a specified range of angles. The mean

scattering pattern estimated by averaging over 5000 realizations of the surface is shown in Fig.

1(b), and a photograph of the scattering pattern obtained with a fabricated surface is shown in

Fig. 1(c). The measurements carried out with the fabricated surfaces validate the design

procedures.

(a) (b) (c)

Fig. 1. (a) Two-dimensional random surface that produces a uniform scattering pattern. (b) Mean differential

transmission coefficient of the optical diffuser. (c) Photograph of the transmission scattering pattern produced by a

fabricated optical diffuser. The angular spread of the pattern is about 10 degrees.

1

A. A. Maradudin, E. R. Méndez, and T. A. Leskova. Designer Surfaces. (Elsevier Science, 2008).

123


ID083

Interaction of Surface Plasmon Polaritons with Grooves of Different Widths

A. Shlyagina 1 , S. de la Cruz 1 , E. E. García-Guerrero 2 , R. Salas-Montiel 3 , E. I. Chaikina 1 , and E. R.

Méndez 1

1

División de Física Aplicada, CICESE, Ensenada, B.C., México.

2

FIAD, Universidad Autónoma de Baja California, Ensenada, B.C., México.

3

LNIO, Université de technologie de Troyes, France.

anna.shlyagina@gmail.com

Key words: Surface plasmon polaritons, Electron beam lithography.

While optical interconnects have a much greater transmission capacity than their electronic

counterparts, the size of the individual elements of electronic circuits is much smaller than optical

waveguides. It has been argued that plasmonics could bridge the gap between these two

technologies. Not surprisingly, the interaction of surface plasmon polaritons (SPPs) with surface

nanostructures, 1 which can be used for their manipulation, has attracted much interest in recent

years.

For nanophotonic applications, it is essential to be able to launch SPPs in small spaces. We

have recently studied the efficiency of excitation of SPPs by simple structures, such as steps and

grooves, and designed compact and efficient grating-like launchers of SPPs. 2 This has allowed us to

design platforms for the study the interaction of SPPs with surface structures.

In this work, we present experimental results on the interaction of SPP with grooves of

various widths ruled on an otherwise planar surface. Using samples fabricated by electron-beam

lithography, we have measured the transmission coefficients of SPPs interacting with the grooves. A

schematic diagram of the experimental setup is shown in figure 1, together with a photograph that

illustrates the sample geometry.

Fig 1. Experimental setup used to study the interaction of SPPs with the grooves (a).

Photograph of a sample (b).

[1] H. Raether, Surface Plasmons on Smooth and Rough Surfaces and Gratings (Springer-Verlag, Berlin,

1988).

[2] S. de la Cruz, E. R. Méndez, D. Macías, R. Salas-Montiel, and P. M. Adam, Phys. Status Solidi B 249

(2012) 1178.

124


ID084

Laguerre-Gauss and Bessel beams, a proper comparison

J. Mendoza-Hernández 1 , M. L. Arroyo Carrasco 1 , M. D. Iturbe Castillo 2 , and S. Chávez-Cerda 2

1 Facultad de Ciencias Físico Matemáticas, BUAP, Puebla, Puebla, 72570, México

2 Instituto Nacional de Astrofísica, Óptica y Electrónica, Luis Enrique # 1, Tonanzintla, Puebla, 72840, México

job.mendoza@alumno.buap.mx

KEY WORDS: Paraxial beams, wave propagation, invariant optical fields.

It is presented a proper comparison of Bessel beams (BB) with the high order Laguerre-Gauss

beams (LGB). We demonstrate that, imposing the right conditions, the Laguerre-Gauss beams

propagate quasi-nondiffracting as Bessel beams within the same conic volume of existence of

Bessel beams. Our investigations reveal that Laguerre-Gauss beams also possess property of selfhealing

showing a better recovery than Bessel beams. The result will be able useful in recent

studies that it has shown that these structured fields can boost classical and quantum

communications as in quantum entanglement and quantum cryptography 1,2 . The similar profiles

of LGB and BB were obtained to follow the procedure described in reference 3 in order to arrive

the formula that relation the index radial and azimuthal with the period of BB

e / () ( (√)

() )|| L || (

() ) ≈ (||)

! ||/ J (2√2N

() ),

where n and m are the index radial and azimuthal of associated Laguerre polynomials L , N =

n + (|m| + 1)/2, J is the Bessel function, and w(z) is the beam width.

With the same transvers transverse section for BBs and LGB, and relation between the

radial frequency the maximum propagation invariant distance is approximately the diffraction

length L to a LGB, see figure, this is very important because the distance L defines the space

which LGB can be considered quasi-collimated, and then quasi-nondiffracting as Bessel beams .

Behavior of the propagation on the plane x − z for a Laguerre-Gauss (top) and Bessel (bottom) beams

with m = 0 and n = 10, in the left image. The conic region for BB and the size of the LGB are

indicated with a white broken line. In the right image, it is shown the profile central of intensity between

LGB and BB at z=0.

1 M. McLaren, M. Agnew, J. Leach, F. S. Roux, M. J. Padgett, R. W. Boyd, and A. Forbes, Opt. Express, 20, (2012)

23589

2 M. McLaren, T. Mhlanga, M. J. Padgett, F. S. Roux and A. Forbes, Nature Commu. 5, (2014) 3248.

3 N. N. Lebedev, Especial functions and their applications, (Dover, 1972), pp 85.

125


ID087

?

?

1

2,3

=

%

%

[ ]

[ ]

[ ]

126


ID089

Waves to study the formation of points or Poisson Fresnel Spot

Beltran González Luis Enrique, Quintero Torres Rafael

Centro de Física Aplicada y Tecnología Avanzada (CFATA), Universidad Nacional Autónoma de México campus Juriquilla,

Boulevard Juriquilla No. 3001, Juriquilla, Querétaro, México. luisebgonzalez@gmail.com

KEY WORDS: Fourier Optics, Simulation Difraction, Spot

Fresnel,

A Fresnel point is a bright spot that appears in the shadow of a

circular object due to Fresnel diffraction. This experiment

contributed to the characterization of the light wave. This

phenomenon is very common in astronomy, where a star can

function as a light source, and the telescope's mirror as the object

generate circular Fresnel point. 1

In the early nineteenth century it was believed that light traveled

only in straight lines, experiments such as Thomas Young

published in 1807 supported this theory further. In 1818 the French

Academy of Sciences launched the call to demonstrate the nature of

light, Augustin-Jean Fresnel civil engineer decided to participate,

submitting experiment Fresnel point. 2

In the wave theory of Fresnel, the Huygens-Fresnel principle states

that all points of a wavefront unobstructed become a source of

spherical waves and the amplitude of the optical field at a point on

the screen you are given by superposition of these waves at a point

where the phases are synchronized. 3

Conducted an experimental arrangement that meets the

characteristics for forming a Fresnel point, these characteristics are

given by the following equation (1).

! = !!

≳ 1!!!d = !diameter!of!the!circular!object, L! =

!!!

!distance!between!object!and!screen!and!!!λ! = !wavelength (1)

This arrangement can be seen in Figure (1).

Where we represent in the central part a CD we use to sustain the

circular obstacle which we remove the coating and add a cap

cardboard the central part which impede the passage of light, on the

right screen and left a light source.

Using a light source and a circular led a radius of 1.75 cm with a

distance between the light source and the object circular 20cm and a

distance between the object and the screen round 10 cm object point

Fresnel find better targeted figure (2).

Figure (1) Diagram of

experiment

Figure (2) Fresnel point on

the screen.

Figure (3). The 1200x1200

graphic matrix representing the

diffraction pattern obtained.

Figure (4) optical intensity

of the diffraction pattern

obtained

Now we try to simulate this result by Matlab using a 1200x1200 matrix screen that will represent

an opening of radius R will have the function of the object that comes between the light source

and the screen for generating diffraction patterns. Figure (3) A graph of current passing through a

symmetric axis of the diffraction pattern of Figure (3) is shown in Figure (4), Fourier optics

provides us with important information on the diffracted objects.

1 Pedrotti, Frank L.; Pedrotti, Leno S.; Pedrotti, Leno M., Introduction to Optics,2007, 3rd ed., p. 315.

2 Young, Thomas, A Course of Lectures on Natural Philosophy and the Mechanical Arts ,1807, 1st ed. p. 10, 11.

3 Sommerfeld, Arnold, Vorlesungen über Theoretische Physik: Optik 4, 1978, 3rd ed., p. 82.

127


ID090

Photonic materials: simulation and modeling prototype photonic structures.

L. Hernandez 1 , R. Quintero 2

1 Student of the Bachelor of Technology, Center for Applied Physics and Advanced Technology. National Autonomous University

of Mexico - Campus Advanced Juriquilla, e-mail addres: luc@comunidad.unam.mx

2 Tutor Project, Center for Applied Physics and Technology. National Autonomous University of Mexico - Campus Juriquilla.

3001 Boulevard Juriquilla, Juriquilla, Qro.76230, Mexico, e-mail addres:rquintero@fata.unam.mx

KEY WORDS: Photonic material, simulation, waveguide, laser micro-fabrication.

ABSTRACT: The photonic materials can control and manipulate the luminous flux due to

the arrangement of microscopic structures [1]. In this work is exposed the simulation of photonic

materials using Comsol software. The model describes wave propagation in photonic crystals and

glasses, which consists of pillars of GaAs placed equidistant from each other and randomly

disordered respectively. As well as the design of a prototype equipment for laser microfabrication

system capable of modeling the photonic materials or waveguides, using laser diode

writing and Optical Pick-up Unit of optical disc recorder.

a) b)

a) Simulation using finite resonant nanocavities in a two-dimensional photonic bandgap structure

elements. The figure shows the electric field in the z to light with 3m wave frequency plane

3.000x10 14 . b) Prototype. Obtained with an electron microscope at 100x images. The diagonal

lines in clockwise direction are factory, perpendicular to these are recorded by the laser.

[1] Joannopoulos J., Johnson S., Winn Joshua. Photonic Crystals. Molding the flow of light. 2° ed. (44-

65pp.), 2008.

128


ID092

INFLUENCE OF THE NOLINEAR ABSORPTION EFFECT ON THE

LIGHT TRANSMITTED IN A LOCAL NONLINEAR MEDIA

B. A. Martínez Irivas, 1,* M. L. Arroyo Carrasco, 1 M. M. Méndez Otero, 1 R. Ramos García, 2 and

M. D. Iturbe Castillo, 2

1 Facultad de Ciencias Físico-Matemáticas, Benemérita Universidad Autónoma de Puebla, Av. San Claudio y 18 Sur.

Col San Manuel, C.P. 72570, Puebla, Puebla, México

2 Instituto Nacional de Astrofísica, Óptica y Electrónica, Luis Enrique Erro # 1, C.P. 72840 Tonantzintla, Puebla,

México

*beatriz_iriv@yahoo.com.mx

KEY WORDS: Nonlinear optics, self-action effects.

Abstract

We show the effects on the far field diffraction patterns and z-scan curves when nonlinear

refraction and absorption are simultaneously present in a local media.

We consider a nonlinear media that it is illuminated with a Gaussian beam of wavelength

λ and beam waist w 0 that propagates along the z-axis, with field amplitude E (r, z). The output

field considering a thin local sample (L


ID093

OPTICAL CHAINING OF TENS OF SILICA BEADS WITH SINGLE TRAP

J.A. Ascencio-Rodríguez 1 , O.G. Rodríguez-Herrera 2 , A. González-Suárez 3 , R. Ávila 3

1 Facultad de Física, Universidad Veracruzana, Xalapa, Veracruz, México. 2 Department of Atmospheric Sciences, University of

Arizona, Tucson, Arizona, USA. 3 Centro de Física Aplicada y Tecnología Avanzada, UNAM, Juriquilla, Querétaro, México

j.albertoar10@gmail.com oscar@email.arizona.edu; aglez.suarez@gmail.com; remy@fata.unam.mx;

KEY WORDS: optical tweezers, optical binding.

Optical confinement of micron-sized particles using a focused laser beam was first demonstrated

by Ashkin 1 in 1970; since then, a whole field in optical sciences, known as optical tweezes, has

emerged. In this technique, a high numerical aperture laser beam is used to trap and manipulate a

microparticle. A particular research topic in this field is the investigation of interactions between

multiple trapped particles. The term optical binding was first introduced by Burns 2 , referring to

interference effects between the light scattered by a single trapped particle and the background

laser trapping light. Optical binding has more generally been used to designate the attraction

between multiple particles trapped by optical means 3 .

Figure 1 shows some of our experimental results of vertical optical confinement of up to

60 2.5-µm-diameter silica beads using a NIR gaussian laser, and two differently corrected

microscope objectives show that the number of bound particles is about 7.5 larger with an

objective corrected for a 160-mm tube-length corrected objective than with an infinity. Our

observations suggest that the confinement geometry is due to the combination of gravitational

forces, optical binding and the beam shape.

Figure 1. Bottom view of the optical trapping: (A) the particles are confined along a vertical axis (B) when laser is

turned off spheres are released and sink quickly. Side view of entrapment: (C) vertical chain of microparticles. (D)

Results of the number of particles trapped with two types of corrected microscope objectives.

[1] Ashkin A., Phys. Rev. Lett. 24 (1970) 156–9.

[2] M. M. Burns, J. -M. Fournier, and J. A. Golovchenko, Phys. Rev. Lett. 63 (1989), 1233–1236.

[3] T. Čižmár, L. C. Dávila Romero, K. Dholakia, and D. L. Andrews, J. Phys. B 43 (2010), 102001.

130


ID096

Second-harmonic generation of nanotubes: First principles studies

R. A. Vázquez-Nava 1 , R. V. Salazar-Aparicio 1 and G. H. Cocoletzi 2

1

Centro de Investigaciones en Optica, León, Guanajuato, México.

2

Instituto de Física, Universidad Autónoma de Puebla, Apartado postal J-48, Puebla 72570, México.

KEY WORDS: Second-harmonic, nanotubes,

We present ab initio calculations to investigate the second harmonic generation (SHG)

response of single wall zigzag nanotubes. Studies have been performed using the density

functional theory (DFT) within the local-density approximation (LDA) together with the GW

Green function method to determine the band gap. A length gauge approach has been used to

calculate the nonlinear optical response with the scissors correction to obtain the nonlinear

susceptibility of the zigzag nanotubes. Our results show that, contrary to reports in the literature,

the (5,0) and (9,0) display non vanishing SHG response.

We acknowledge partial financial support by CONACYT under Grants No. 153930 and

No. 223180.

Nonlineal susceptibility for SiC nanotubes including GW gap correction

throught the scissors operator.

131


ID097

Experimental observation of linear localized state in photonic Sawtooth lattices

Bastián Real 1 , Camilo Cantillano 1 , Luis Morales-Inostroza 1 , and Rodrigo A. Vicencio 1

1 Departamento de Física, MSI-Nucleus on Advanced Optics, and Center for Optics and Photonics (CEFOP), Facultad de

Ciencias, Universidad de Chile. Las Palmeras 3425, Ñuñoa, Santiago, Chile.

bastianreal71@gmail.com

KEY WORDS: Flat band, linear localized state, nondiffracting propagation.

Photonic lattices are spatial periodic structures of the refractive index that posses different physical

properties depending on their configuration. Sawtooth lattice are quasi-1D photonic lattices [see

Figure (a)] that present different transport regimes depending on the coupling between nearestneighbors

waveguides. Specifically, on a discrete approximation, this lattice possesses two linear

bands [see Figure (b)] (with different curvature and different width) where, for a critical value of

couplings, the lower band becomes completely-flat. States belonging to this flat band are spatially

localized 1 and have only three nonzero amplitudes: {...,0,0, 1, p 2, 1,0,0,...}. A flat band has

no dispersion; then, their modes present a non diffracting propagation along the crystal.

(a)

(b)

6

(c)

4


2

0

2

4

⇤ 2 ⇤ 4 0 ⇤ 4 ⇤ 2

kxa

(a) (b) (c)

Fig. 2. Linear spectrum of an infinite Sawtooth lattice for =

0.75 (thin), p Fig. 3. Output intensity versus projected site n and versus

2 (thick), and 2.5 (dashed).

wave vector kx, for : (a) 0.75, (b) p 2, and (c) 2.5. The input

position is indicated with a vertical dashed line.

(a) Experimental Sawtooth lattice. (b) Band structure for Sawtooth lattice using nearest-neighbors approximation,

horizontal distance between nearest A and B sites is a, while

where a flat band in l = 2 isbetween presented

nearest A sites

foris 2a.

a critical

The vertical distance

valueb of

is equal

the coupling.

the other traveling

(c)

to the

Output

left or to the

face

rightof it.

the

We test

crystal,

this

showing

nondiffracting propagation for for a state up and down belonging triangles andto it isflat our control band. parameter to idea by studying the transport of a wide gaussian beam by

modify the ratio effectively.

numerically integrating model (1), with an initial condition

Linear solutions of model (1) are obtained by solving given by

these coupled equations with a stationary ansatz of the

form {un(z),vn(z)} = {A,B}exp(ikxxn)exp(i z); i.e., a wave

un(0)=A0 exp[ (n nc) 2 ]exp[ikxa(n nc)], vn(0)=0 ,

This work focuses on propagating the experimental horizontally across thisprocedure quasi-1D lattice. A and for B observing

where A0 corresponds

such

to the

linear

amplitude and

localized

to the exponent

of a gaussian beam centered position nc ( is such

states. We

are the amplitudes of different sites, kx defines the transversal

propagation vector, and xn determines the horizontal position

use a setup based on a transmission spatial light modulator that the (SLM) beam occupies (to 20 modulate lattice sites). kx corresponds in phase to and amplitude

a wide gaussian beam)

for different lattice sites. By inserting this ansatz in (1), we

the transversal wave vector, what adds a phase structure the

obtain the longitudinal spatial frequency , which defines the

linear spectrum

and

of a Sawtooth

on a

lattice:

Sawtooth lattice wave written front, allowing in the Silica movement by of the wave-packet a femtosecond-laser

across

the lattice. For simplicity, we study transport in the central

(kx)= row where mobility must be enhanced. In Fig. 3 we show a

technique 2 . Here the nearest-neighbors approximation issweep valid on kx, for due three different to discreteness values, plotting the output of the lattice

V1 cos(2kxa) ± 1 + 4( 2 1)cos 2 (kxa)+4cos 4 (kxa) . intensity after propagating a given distance. For simplicity,

composed of well separated and weakly interacting waveguides. In this context, a nearest-neighbors

we projected the quasi-1D lattice to a 1D representation with

The system possesses two linear bands with different curvature

and

period a, and show the output pattern by changing kx. We observe

in

approximation is valid due todifferent the

width.

discreteness

Fig. 2 shows the linear

ofspectrum the lattice,

of a

which

all cases that

isthecomposed input wave packet split

of

into

well

two

separated

Sawtooth lattice, in the first Brillouin zone, for three different wavefronts. For < c [Fig. 3(a)], we observe how the two

values of . We observe how for a small the gap between fronts propagate in the same direction with small velocities

and weakly interacting waveguides. bands is smaller, and the Insystem thetends experiment, to behave as an onedimensional

lattice. For a critical value c = p dueform to the low associated the input curvaturecondition of bands. For = using

we

c [see a green

2, bands reduce

to (kx)=4V1 cos2 (kxa) and 2V1; i.e., the lower band tionthe of flat transmission (static) band while the SLM, other front propagates we modulate in

Fig. 3(b)], one wavefront remains trapped due to the excita-

light laser beam of l = 532nm. By illuminating one half of

becomes constant and completely flat. The states belonging

to this non dispersive band consists of localized profiles separated and possess a similar power content; i.e, a flat band

away. We see how for |kxa| /4, the two fronts are well

amplitude and generate a three-sites (-spots) light image. Then, this image is injected in the second

composed for only three sites: {...,B,A,B,A,B,A,B...} =

{...,0,0, 1, p beam splitter. For > c [see Fig. 3(c)], we observe propagation

of two wave-fronts in opposite directions, due to

2, 1,0,0,...}. These states can be located in

half of the SLM to give itany aposition phase of thestaggered lattice and all possess structure. the same propagation

constant. Therefore, they can be linearly combined to The two fronts are well separated and beams are effectively

We theimage change in the this curvature amplitude of the lower band and (see Fig. phase 2). pattern

at the input facet of the crystal and study its propagation by observing the output facet with a CCD

propagate arbitrary non-diffractive composed images [7, 8]. divided a controlled manner.

At this critical value, we observe that the curvature of the To study general transport properties, we explore the excitation

of individual waveguides at the bulk and surfaces

lower band is inverted. This is an interesting property of Sawtooth

lattices, for < c, and a given kx, waves from both of a Sawtooth lattice. Fig. 4 shows different sweeps for dif-

camera. In Figure (c) we show an experimental image, where we observe a non diffracting propagation

of this flat band velocities. state. For Linear > c therecombinations will be two wave fronts propa-

of these model (1). localised We construct ourstates, lattice with N centered = 100 sites, hav-at different

bands will propagate same direction, but with different ferent input excitations, obtained by numerically integrating

gating in opposite directions for the same value of kx. These ing one A-site end and one B-site end, in order to study the

positions in the lattice, are also a localized state; therefore, properties can be used for controlling wavepackets in any excitation several of different linear images states. Fig. pcould 4(a) and (b) show

physical context. For example, we could use this lattice as the tendency to localization when 2. A single-site

be

input

condition excites strongly the lower band, what is evi-

propagated

a Beam Splitter with two beams traveling in the same direction,

in opposite ones, or one trapped at the input position and dent from the intensity profiles. Close to the critical

without diffraction.

parame-

1 2

D.L. Bergman, C. Wu and L. Balents, Phys. Rev. B 78 125104 (2008).

2 A. Szameit and S. Nolte, J. Phys. B 43 163001 (2010).

132


ID0102

Thin Film Coatings for Cylindrical Photonic Devices

Amado. M. Velázquez-Benítez, Ivan B. Ramírez-Ortega, Juan Hernández-Cordero

Instituto de Investigación en Materiales, UNAM, Cd. Universitaria. D. F., 04510, Postal Code 70-360, México

amadovelb@gmail.com

KEY WORDS: Thin films, fiber optics, polymeric materials, photonic devices.

We demonstrate a simple procedure for coating of photonic cylindrical devices with thin films of

fluidic materials. Photonic devices of circular cross-sectional area and small dimensions are

desirable for several applications offering axial symmetry in light propagation and interaction

with its surrounding environment. Uniform functional coatings with controlled thickness are

required for fabrication of photonic devices. Deposition of coating layers is achieved by an

automated system using the wire coating technique, in which the layer thickness is determined by

the rheological properties of the fluid, viscosity and surface tension, and the speed of process 1,2 .

Experimental results coating optical fibers, bare and tapered sections, as well as glass

capillaries are demonstrated. Uniform coating thicknesses ranging from 0.5 to 50 µm were

achieved for a single layer and being scalable to multiple layers 2 . Two different materials were

employed: silicon-based and acrylate-based polymers. Coating of thin films over tapered sections

of optical fibers was performed resulting in attenuation losses less than 1 dB. Fabrication of fiber

optic devices using functional polymers has been demonstrated on tapered sections of fibers, i.e.

small length lasers, microresonators, fiber gratings, and tunable attenuators 3-6 . Applications in the

field of fluidics has been also proposed by deposition of optically activated layers on glass

capillaries 7 , showing their capability for the creation of low cost photonic devices.

a) b)

Polymeric thin film coatings on: a) optical fiber and b) glass capillary.

1 D. Quéré, “Fluid coating on a fiber,” Annu. Rev. Fluid Mech., vol. 31, pp. 347–384, (1999).

2 Amado M. Velázquez-Benítez, Moisés Reyes-Medrano, J. Rodrigo Vélez-Cordero, and Juan Hernández-Cordero,

"Controlled Deposition of Polymer Coatings on Cylindrical Photonic Devices," J. Lightwave Technol. 33, 176-182

(2015)

3 G. Kakarantzas, S. G. Leon-Saval, T. A. Birks, and P. St. J. Russell, “Low-loss deposition of sol gel-derived silica

films on tapered fibers,” Opt. Lett., vol. 29, no. 7, pp. 694–696, (2004).

4 T. A. Birks and Y. W. Li, “The shape of fiber tapers,” J. Lightw. Technol., vol. 10, no. 4, pp. 432–438, 1992.

5 A. Velázquez-Benítez and J. Hernández-Cordero, “Optically controlled wavelength tunable fused fiber coupler,”

presented at the Workshop Specialty Opt. Fibers Appl., Sigtuna, Sweden, W3.25, (2015).

6 Z. Y. Xu, Y. H. Li, and L. J. Wang, "Versatile technique to functionalize optical microfibers via a modified sol-gel

dip-coating method," Opt. Lett. 39, 34-36 (2014)

7 J. R. Vélez-Cordero, A. M. Velázquez-Benítez, and J. Hernández-Cordero, “Thermocapillary flow in glass tubes

coated with photoresponsive layers,” Langmuir, vol. 30, no. 18, pp. 5326–5336, (2014).

133


ID0103

Active Control for Polarization State of Spectral Components of Femtosecond

Pulses.

Delgado-Aguillón Jesús 1 , Garduño-Mejía Jesús 1 , Rosete-Aguilar Martha 1 , Román-Moreno

Carlos J. 1

Centro de Ciencias Aplicadas y Desarrollo Tecnológico – UNAM, Avenida Universidad No. 3000, Colonia. Ciudad

Universitaria, Delegación Coyoacán, C.P. 04510, México, D.F.

Corresponding Author’s e-mail address and URL: cucho.del@hotmail.com

KEY WORDS: Pulse shaping, femtosecond, polarization, soft computing, SLM.

In this work, we developed a femtosecond polarization pulse shaping based on Spatial Light

Modulator (SLM) controlled by an iterative algorithm. The polarization shaper includes a 1200

lines/mm diffraction-grating, achromatic doublet with 410 mm focal length and a 128-pixel

SLM-LCD arranged in a 2-F configuration, achieving 0.15 nm/pixel resolution [1]. We applied

soft computing algorithm to control the SLM-LCD for polarization shaping on spectral

components. The soft computing algorithm is based in genetic algorithm and fuzzy logic [2], the

algorithm modifies the applied voltage on the SLM-LCD to modulate the retardance on each

wavelength of the spectrum of the femtosecond pulses. We present preliminary results on 200 fs

@ 800 nm pulses (Coherent MIRA 900) in terms of the capability and efficiency of different

optical components, as retarders and birefringent plates, to modifying the polarization state of the

pulse as a function of the wavelength (Figure 1). The system is capable to retrieve the actual

retardance as a function of the pulse spectral components. Some results are presented in figure 1.

Figure 1: Spectral retardance of a femtosecond pulse. Right: initial retardance of femtosecond pulse. Left:

retardance of the pulse after be transmitted trough a half-wave plate oriented at 45 degrees.

Acknowledgements

The authors gratefully acknowledge sponsorship for this work by DGAPA-UNAM PAPIIT

IG100615.

[1] Jesús Delgado-Aguillón, et al., Direct inversion methods for spectral amplitud modultaion of

femtosecond pulses, RSI 85, 043105, 2014. (RSI paper)

[2] Castro-Olvera Gustavo, Garduño-Mejía Jesus, Rosete-Aguilar Martha, “Soft computing for

adaptive control polarization state with a liquid-crystal spatial light modulator”, International

Comission for Optics 2014 (ICO-2014).

134


ID0105

TUNING OF LIQUID CRYSTALS BY ELECTRIC FIELDS

M. Clark 1 , P. Castro-Garay 2 , J. Lizola 3

Centro de Investigación en Física de la Universidad de Sonora 1, 2, 3 , Hermosillo, Sonora, México.

MarielenaClarkR@gmail.com 1 , paola@cifus.uson.mx 2 .

KEY WORDS: liquid crystal, Electric fields, Organic molecules, Optical response.

Students find fascinating the subject of liquid crystals but unfortunately there are few organic

chemistry texts dealing with these subjects. The study of liquid crystals gives the opportunity for

students to visualize the organic molecules as real physical objects and relate the molecular

behavior with the physical properties observed. In this paper simple activities in which students

can use mixtures of different liquid cristal, align molecules and tune the optical response using an

electric field is developed. Besides they can visualizing the samples in the optical microscope

through crossed polarizers.

Liquid crystals are used in optoelectronic devices such as flat screen where information is

displayed so this technology can be an interface between man and machine.

The experiments were designed to demonstrate the relationship between molecular order

and the optical and dielectric properties of the liquid crystalline state and the application of these

properties to create a working display device. 1

Figure 1. Liquid crystal display.

1. P. Hale, J. Shapter, N. Voelcker, M. Ford and E. Waclawik, Liquid-Crystal Displays: Fabrication and

Measurement of a Twisted Nematic Liquid-Crystal Cell, Journal of Chemical Education 81 (6), 854 (2004).

135


ID0111

Light scattering by arrays of silicon posts on a planar surface

V. Pérez-Chávez 1* , E. R. Méndez 1 , S. Blaize 2 , A. A. Maradudin 3

1

Departamento de Óptica, Centro de Investigación Científica y de Educación Superior de

Ensenada, Ensenada, Baja California 22800, México

2

Laboratoire de Nanotechnologie et d’Instrumentation Optique, UTT, Troyes 10010, France

3

Department of Physics and Astronomy

University of California, Irvine CA 92697, U.S.A.

*

Corresponding Author: veperez@cicese.edu.mx

KEY WORDS: Conformal mapping, silicon optics, Rayleigh equations.

Conformal mapping uses functions of complex variables to transform complicated boundaries

into simpler ones. Due to the change in geometry, the medium in the transformed space becomes

inhomogeneous, presenting spatial variations in its refractive index. This required spatially

varying refractive index can be then obtained, in principle, by structuring the medium with in

homogeneities that are much smaller than the wavelength 1 . Motivated by the possibility of

applying conformal mapping techniques to the design of integrated optical components in a

silicon platform, we have fabricated samples consisting of isolated, periodic, and random arrays

of silicon posts on a planar substrate as the one shown in the Figure.

Figure 1. SEM images of the isolated pillars sample after lithography (right), and after the etching process (left).

To provide a theoretical framework for the structures modeled on our samples, we have

developed programs that enable us to carry out calculations of the light scattered by them. These

calculations were carried out on the basis of the reduced Rayleigh equations 2 . In this method, one

obtains integral equations that depend on the kind of structure considered (isolated posts or

periodic arrays) that need to be solved numerically. The solutions can be then compared with

experimental results. Such comparisons are made in this work.

____________________

1

L. H. Gabrielli and M. Lipson, “Transformation optics on a silicon platform,” J. Opt. 13, 024010 (2011).

2

R. E. Arias and A. A. Maradudin, “Scattering of a surface plasmon polariton by a localized dielectric surface

defect” Opt. Express 21, 9734-9756 (2013).

136


ID0112

Visible-frequency hyperbolic metasurface

Robert C. Devlin 3* , Alexander High 1,2* , Alan Dibos 3 , Mark Polking 1 , Dominik Wild 2 , Janos Perczel 2 ,

Nathalie P. de Leon 1,2 , Mikhail Lukin 2 , Hongkun Park 1,2

*These authors contributed equally to this work.

1 Department of Chemistry and Chemical Biology, 2 Department of Physics, and 3 School of Engineering and Applied Sciences,

Harvard Unviersity, 9 Oxford St, Cambridge MA 02139

devlin@fas.harvard.edu

KEY WORDS: Single-crystal silver, plasmonics, hyperbolic metamaterial, metasurface

Metamaterials are artificial optical media that produce optical phenomena not present in naturally

occurring materials. However, 3D metamaterials suffer from extreme propagation losses, limiting

their utility. 2D metasurfaces and, in particular, hyperbolic metasurfaces (HMSs) for propagating

surface plasmon polaritons, have the potential to alleviate this problem. Because SPPs are guided

at a metal-dielectric interface (rather than passing through metals), these HMSs have been

predicted to have lower loss while still exhibiting phenomena observed in 3D metamaterials.

(a) TEM image showing low defect, single crystal silver film. (b) Top-down fabricated HMS in singlecrystal

silver. (c) Measured negative refraction of SPPs in HMS. (d) Concave, flat and hyperbolic isofrequency

contours realized in the HMS at different wavelengths. (d) Frequency-dependent, spin-orbit coupling in HMS.

We report the first experimental realization of a visible-frequency HMS 1 by lithography

and etching nanostructures into sputter-deposited, single crystalline films. The resulting devices

display broadband negative refraction and diffraction-free propagation. Moreover, HMSs exhibit

strong, dispersion-dependent spin-orbit coupling, enabling polarization- and wavelengthdependent

routing of chiral SPPs. Because we begin with extremely low-loss silver films 1,2 , the

measured propagation distances of up to 30 µm indicate that the low-loss, 2D nature of our

devices offers a substantial, one to two orders of magnitude improvement over 3D metamaterials.

These results open the door for a wide array of high-performance plasmonic nanostructures with

widespread conventional and quantum optics applications.

[1] Alexander High*, Robert C. Devlin*, Alan Dibos, et al. Visible-frequency hyperbolic metasurface.

Nature (in press) . *equal contribution.

[2] S. Kolkowitz*, A. Safira*, A. A. High, R. C. Devlin, et al. Probing Johnson noise and ballistic

transport in normal metals with a single-spin qubit. Science 347, 1129 (2015)

137


ID0114

INTEGRATED PHOTOCONDUCTIVE ANTENNA-PROBE DESIGN FOR

NEAR FIELD THZ IMAGING

Joel Pérez-Urquizo 1 , Gaudencio Paz-Martínez 1 , Lucio Barralaes-Morales 1 , Jesús Garduño-Mejía 1

and Naser Qureshi 1

1 CCADET, Universidad Nacional Autónoma de México, Cd. Universitaria, México DF, ZIP 04510

joel4x4urquiz@hotmail.com

KEY WORDS: Terahertz, Near-Field Imaging, Photoconductive antenna.

THz imaging has gained attention due to the potential applications in biomedical imaging,

security, inspections on semiconductor devices, etc. Until now, systems devoted to Near Field

THz imaging consist of two basic parts 1 : generation of THz radiation and a sensing probe system.

In this work we present the design of a novel device capable of integrate in a single chip the

generation of THz radiation with the sensing system required to do imaging for Near Field

Microscopy. The device is fabricated in a GaAs substrate. On one side of the substrate a

photoconductive antenna is printed using micro photolithography. On the other side a specifically

designed antenna-based sub-μm wavelength sized aperture is placed in the center of the substrate.

According to our simulations, when the antenna is excited with a laser pulse, it will generate THz

radiation and will concentrate a good part of this radiation at the aperture. This concentrated

electromagnetic field can be used as a sensing probe for imaging. Putting a sample very close to

the probe will produce a measurable change in the intensity of the THz electric field. When the

whole sample is scanned in the close proximity of the probe, a THz image is obtained as a result

of the sample-probe interaction per pixel.

In the figure below, a THz image of a metallic sample is presented. With this result we

confirm experimentally that the device is capable of detecting and differentiating between

different dielectric media and of imaging in the near field.

At the left: Sample tested with the aperture probe. The region scanned with the probe is squared in red.

At the right, the image obtained..

Resolution of the system depends on both the dimension of the aperture and the correct alignment

of the entire system. Imaging and sensing is still possible when making the aperture as small as

an nm-sized structure. Thus, great resolution is achievable at nanometer scales.

1 W.-L. Chan, J. Deibel and Daniel M Mittleman, “Imaging with terahertz radiation,” Reports on Progress in Physics

70, 1325-1379 (2007).

138


ID0115

Control of the local TEM polarization state of femtosecond laser pulses

Castro- Olvera Gustavo 1 , Garduño-Mejía Jesús 1 , Rosete-Aguilar Martha 1

Centro de Ciencias Aplicadas y Desarrollo Tecnológico – UNAM, Avenida Universidad No. 3000, Colonia. Ciudad

Universitaria, Delegación Coyoacán, C.P. 04510, México, D.F.

Corresponding Author’s e-mail address and URL: gustavo.castro@ccadet.unam.mx

KEY WORDS: Spatial light modulator, ultrafast optics, polarization control, TEM.

In this paper we present a method for analysis and control the polarization sate of the transversal

electromagnetic mode (TEM) of femtosecond laser beam. The control of femtosecond pulses was

performed using a spatial light modulator 1 (SLM) than consist in 127 elements in a hexagonal

array which introduces a local retardance in the pulse phase. The system works in a closed-loop,

drived by a soft computing algorithm, with the task to control the local phase shift and then the

polarization state introduced by different optical systems, for instance a focusing lens.

To test our system, it was designed an experiment with the aim to control the intensity of the

Second Harmonic Generation (SHG) generated by a Type 1 BBO. In this process peak power,

angle of incidence and incident light polarization state are variables that affect the Phase-

Matching condition.

Left: Final polarizer state necessary to minimize the SGH intensity of a BBO, Center: Initial condition,

Right: Final condition.

The local phase shifts differences can be attributed to the focusing optical system or some local

variations of input polarization state.

The technique can be used for the quantitative study of polarization or phase shift induced by

different optical systems on the TEM of femtosecond pulses 2 .

The authors gratefully acknowledge sponsorship for this work by DGAPA-UNAM PAPIIT

IG100615

[1] Boyd, Robert W., Nonlinear optics, Academic Press, (1992).

[2] Goldstein, Dennis H., Polarized light, second Edition, Marcel Dekker, (2003).

1

D3128 Spatial Light Modulator, User Manual, Meadowlark Optics., (USA, 2014).

2

Castro-Olvera G. Optica adaptativa para el control del modo transversal electromagnético (TEM) de pulsos de

femtosegundos, Tesis de Maestria, (UNAM, 2014).

139


ID0116

Mid-infrared Multi-Mode Absorption Spectroscopy (MUMAS) using

Interband Cascade Lasers (ICLs)

Seamus O'Hagan a , Henry Northern a , Paul Ewart a and Jerry Meyer b

a Department of Physics, University of Oxford, UK

b Naval Research Laboratory, Washington, USA

KEY WORDS: Spectroscopy, multi-mode laser, interband cascade laser, gas sensing.

Multi-mode Absorption Spectroscopy, MUMAS, is a recently developed technique suited to the simultaneous

detection of multiple gas-phase species, and measurement of concentration, temperature and pressure 1,2 . Tunable

diode laser absorption spectroscopy (TDLAS), using single mode lasers, allows a lower minimum detection

limit, MDL, but requires multiplexing of several lasers to detect multiple species if their absorption transitions

are separated by more than the typical mode-hop-free tuning range of a single mode diode laser. Although

alternative approaches using wavelength agile lasers, broadband sources such as superluminescent diodes or

supercontinua generated in optical fibres, and wide bandwidth frequency combs emitted by mode-locked femtosecond

laser sources have been developed for spectroscopic gas sensing, the high dispersion instruments often

required tend to make these systems more complex, bulky and expensive and generally unsuited to field

applications. In addition, the higher precision afforded by “frequency comb spectroscopy” is often unnecessary

since the spectral lines used in gas sensing typically have widths in the GHz range. There remains a need for a

simple, robust and reliable multiple-species sensor for applications such as industrial process control, chemical

analysis, leak detection, remote detection of explosives and environmental monitoring.

MUMAS operates by detecting the small change in total transmitted intensity of a laser beam, as the

laser’s mode-comb is scanned in frequency, when any one of the modes comes into resonance with a molecular

absorption line. The resulting time-dependent signal is a unique signature of the absorbing species interacting

with the particular multi-mode laser output. This MUMAS signature can be modeled when the spectral

characteristics of the laser output are known or measured, and the absorption properties of the species present are

available from a database such as HITRAN. Concentrations of individual species, temperature and pressure,

may be derived by fitting the calculated MUMAS signature to experimental data.

Figure 1. (a) MUMAS signature of CH 4 in

the region of 3.7 µm, experimental (red

dashed line), modeled fit (black solid line).

(b) Residual, on expanded scale, between data

and fit. (c) A reconstructed CH 4 absorption

spectrum of lines contributing to the

MUMAS signature is shown (upper part

black lines) with a simulation of the ICL’s

mode spectrum, containing over 65 modes

under the experimentally determined

envelope over a range of 30 nm, (lower part

red lines).

The MUMAS signature of CH 4 is shown in Figure 1(a) (red dashed line) with the modelled MUMAS fit

(black solid line). The modelled signature allows identification of the transitions in CH 4 that contribute to each

feature in the experimental signature. For illustrative purposes, these transitions are displayed as a more

conventional spectrum in Figure 1(c), which is shown together with a schematic representation of the multimode

ICL spectrum used to record the signature. This laser spectrum, covering a range of 30 nm illustrates the

ability of MUMAS to acquire data on widely separated spectral features, a property that allows detection of

multiple species having absorption lines spanning a wide range.

1. Arita, Y., Stevens, R. & Ewart, P. Multi-mode absorption spectroscopy of oxygen for measurement of concentration, temperature

and pressure. Appl. Phys. B 90, 205–211 (2008).

2. Northern, H., Thompson, A., Hamilton, M. & Ewart, P. Multi-species detection using multi-mode

absorption spectroscopy (MUMAS). Appl. Phys. B 111, 627–635 (2013).

140


ID0122

Fresnel Off-Axis Digital Holography Without Zero-Order Diffraction and Without

Speckle Noise.

Bermúdez Luis Carlos 1 and Mosquera Julio Cesar 2

1

Instituto de Astronomía UNAM, Km 103 Carretera Tijuana – Ensenada C.P. 22860. Ensenada Baja California, México.

luisb@astro.unam.mx

2

Universidad del Quindío, Carrera 15 Calle 12 Norte Armenia, Quindío, Colombia

jcmosquera@uniquindio.edu.co

KEY WORDS: digital holography, diffraction, interference, image reconstruction, Fresnel transform,

speckle free reconstruction, zero-order diffraction.

Holography is a two-step imaging process. The first step is the recording of the interference pattern

between a collimated beam of monochromatic light and the light scattered by an object (object

wavefront). The second step involves the reconstruction of the object wavefront by diffraction of a

similar collimated beam passing throughout the interference pattern 1 . The result is a three-dimensional

image of the original object.

In digital holography, a CCD camera captures the interference pattern which is send to a

computer for its processing while eluding any trouble caused by chemical recording medium used in

the analog holography. The wavefront reconstructed numerically using Fresnel transform contains not

just the main information about the object but also the zero order diffraction and speckle noise that

altogether degrade the image quality. Although there are various types of experimental and digital

processing methods for producing quality digital holograms, is not clear how to choice one method

over other 2 .

In this paper, we evaluated the most wide know experimental setups for the production of

digital holograms and different digital processes in order to obtain high quality holographic images

without the zero-order and the speckle noise. Comparing the principal experimental techniques and

some digital processing methods allowed us to choose the best conditions to get Fresnel off-axis digital

holograms. The research showed that the wavefront recording using diffused light and numerical

addition of multiple decorrelated holograms presents the higher quality of holographic images.

Left: Original reconstructed wavefront. Middle: Addition of 4 decorrelated images. Right: Addition of 32 decorrelated

images.

The wavefront was recorded with diffused light.

1 E. N. Leith and J. Upatnieks, Wavefront reconstruction and communication theory, J. Opt. Soc. Am. 52, 1123-1130 (1962).

2

Garcia-Sucerquia, J., Ramirez, J. A. H., Improvement of the signal-to-noise ratio in digital holography, Revista Mexicana

de Física 51 (1), 76-81 (2005).

141


ID0126

Deformation of an aperture contained in laminated metal, due mechanical

stress or heat influence

H. Valenzuela-Loubet 1 , E. Andrés-Zárate 2 , Q. Angulo-Córdova 3

1,2,3 Universidad Juárez Autónoma de Tabasco, DACB, Carr. Cunduacán-Jalpa, Km. 1.5, Tabasco, C.P. 86680 México.

1 vajhe@live.com.mx, 2 esteban.zarate@ujat.mx, 3 quintiliano.angulo@ujat.mx

KEY WORDS: Heat, Mechanical stress, Deformation, diffraction patterns.

In this work it will be presented the study of deformations by the method of diffraction patterns 1 ,

of an aperture subject to mechanical stress and heat, contained in laminated metal. The obtained

models allowed to define a new transmittance function and establish that the Fourier Transform

diffraction pattern of the Fraunhofer's plane it's generated as an especial case of convolution

The experimental results allowed to identify in a simpler way, in the Fresnel regions, the

effect of the deformation caused by mechanical stress and heat.

Optical arrangement to study the apertures in solids.

[1] E. Andrés-Zárate, A. Cornejo-Rodríguez,, Influence of the mechanical stress and heat parameter into

the transmittance function of the integrals of the diffraction phenomena, Proc. SPIE 8011, 22 nd Congress of

the International Commission for Optics: Lights for the Development of the World, 801169 (2011).

142


ID0130

ANALISYS OF PULSE PROPAGATION IN OPTICAL FIBERS AND NON LINEAR

OPTICAL LOOP MIRROR

Ing. Marisol Billión Reyes 1 Dr. Miguel A. Bello Jiménez 2 ; Dr. Gustavo Ramírez Flores,

Dr. Alfonso Lastras 3 , Dr. Raúl Balderas 4 .

Instituto de Investigación enComunicaciones Opticas (IICO)

1

ing_billionreyes@hotmail.com, 2 miguel_bello@hotmail.com, 3 alastras@gmail.com,

4

raul.balderas@gmail.com,

KEY WORDS: Optical fiber, Split-Step Fourier Method (SSFM), dispersion, self phase

modulation (SPM), nonlinearity, refractive index, solitons, modulation inestability (MI), Nonlinear

Optical Loop Mirror (NOLM), ultra-short pulses.

Light transmission confined to very small cores is a process of great interest in the field of nonlinear

optics. This work analyzes the effects that primarily affect single-mode fibers, which currently

dominate communication systems.

A simulation will be performed by Method Split Step Fourier (SSFM), which uses algorithms of

finite Fourier transforms, separating the nonlinear Schrödinger equation in a differential part (D),

which works in frequency domain and other nonlinear (N), which works in time domain.

Simulating SSFM in Matlab, the effects of losses and dispersion in optical fibers were analyzed.

Another simulated effect is self-phase modulation (SPM). Produced by nonlinearity, which is

induced by dependence on intensity of the refractive index and causing a nonlinear phase versus

time, increasing with length (LNL) and producing an instantaneous change in the optical frequency,

manifesting as a spectral broadening and pulse compression.

If dispersion and self-modulation act simultaneously, it is possible to propagate light pulses stable

over long distances, called solitons. Pulses widen due to group velocity dispersion (GVD) and

compressed due to SPM.

In addition, modulation inestability (MI) was reproduced, which occurs in the anomalous

dispersion region (β2


ID0134

THIRD ORDER NONLINEAR PROPERTIES OF COLLOIDAL AU

NANORODS SYSTEMS

E. V. García-Ramírez 1* , S. Almaguer-Valenzuela 2 , O. Sánchez-Dena 1 , O. Baldovino-Pantaleón 2 , and J. A.

Reyes-Esqueda 1

1 Instituto de Física, Universidad Nacional Autónoma de México, México D.F. 04510

2 Unidad Académica Multidisciplinaria Reynosa – Rodhe, Universidad Autónoma de Tamaulipas. Reynosa, Tamaulipas, 88779

México.

e-mail address:* emma_vgr@fisica.unam.mx

KEY WORDS: Nonlinear absorption, nanomaterials, resonance plasmon.

This work presents a study of third order nonlinear optical properties for four different colloidal

Au nanorods (NRs) systems. The NRs were prepared with the bottom-up method by seed

growth 1 , using Ag + ions and CTAB as surfactant, obtaining aspect ratio between 3 and 5. Third

order nonlinear properties were measured with the Z-scan technique for open (OA) and closed

aperture (CA) at 532 and 1064 nm with laser pulse of 26 ps for vertical and horizontal

polarization.

The experimental results show saturable absorption for all samples in both wavelengths and a

small nonlinear refraction for some of them. Small changes in the nonlinear absorption

coefficients were obtained modifying the incident polarization of light. The samples were

studied for several irradiances; in the case 1064nm, the increase in the irradiance causes a

decrease in the response and the possible presence of the reverse absorption in this case the

increase in irradiance produces a structural modification in the samples; which is manifested in

the behavior of nonlinear absorption and refraction curves, these modifications can be observed

in micrographs obtained with microscopy SEM. These results were used for determinate the

irradiances to which NRs can be modified by photodegradation.

a)

normalized transmittance

2.8

2.4

2.0

1.6

1.2

1ml

2ml

3ml

4ml

b) 5

4

3

2

1

normalized transmittance

1st experiment

2nd experiment

3rd experiment

4th experiment

0.8

-2.5 -2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5

z/Z 0

0

-2.5 -2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5

z/Z 0

Figure 1.-a) NLO responses at =532nm for Au nanorods in colloidal solution; growth with 1,2,3 and 4 ml

concentration of AgNO 3 , a) nonlinear absorption at I 0 = 0.400GW/cm 2 b) nonlinear absorption for 2ml sample

after of several measurements at I 0 =4.991GW/cm 2 .

1. [1] N. R. Jana, L. Gearheart and C. J. Murphy, “Wet Chemical Synthesis of High Aspect Ratio

Cylindrical Gold Nanorods,” J. Phys. Chem B. 105(19), 4065-4067 (2001).

144


ID0135

Physical systems arising from projections

between the sphere and the plane

Cristina Salto-Alegre

Instituto de Ciencias Físicas, Universidad Autónoma de México, Av. Universidad s/n, Cuernavaca, Morelos 62210, México

E-mail: salto.alegre@gmail.com

KEY WORDS: Stereographic projection, gnomonic projection and physical systems.

Projections from the sphere into the plane, and viceversa, give rise to correspondences between a

compact and a non-compact physical systems and their phase spaces with comatic aberration 1 .

We will discuss this correspondence for the stereographic and the gnomonic projections.

Physical systems that are naturally bound through these projections are: the free motion on the

sphere with the Maxwell fish-eye 23 , and the harmonic oscillator with the Pöschl-Teller potential,

among others.

a) Stereographic projection, b) Gnomonic projection.

1

V.I. Man’ko and K.B. Wolf, The map between Heisenberg-Weyl and Euclidean optics is comatic, Lie Methods in

Optics, II, Lecture Notes in Physics, Vol. 352 (Springer Verlag, Heidelberg, 1989). Chap. 7, pp. 163–197.

2

C. Salto-Alegre and K.B. Wolf, Position and momentum bases for the monochromatic Maxwell fish-eye and the

sphere, J. Phys. A: Math. Theor. 48 (2015) 195202.

3

C. Salto-Alegre and K.B. Wolf, Position and momentum bases on the sphere for the monochromatic Maxwell fisheye,

J. Phys.: Conference Series 597 (2015) 012067.

145


ID0139

Fabrication of Long-Period Fiber Gratings whit Polymeric Materials

Ivan B. Ramírez-Ortega 1 , Amado M. Velázquez-Benítez 1 , Juan A. Hernández-Cordero 1

1 Instituto de Investigación en Materiales, UNAM, Cd. Universitaria. D. F., 04510, Postal Code 70-360, México.

tek_01_3@hotmail.com

KEY WORDS: long-period fiber gratings, Rayleigh-Plateau instability, azopolymers, fiber optics.

We present a simple and cost effective fabrication process of long-period fiber gratings (LPFGs)

by coating tapered fibers whit polymeric materials. Formation of periodic polymer drops along the

uniform diameter section of a tapered fiber is generated in a quasi-uniform distribution by the

Rayleigh-Plateau instability phenomenon 1, 2 . Key parameters for instabilities generation are

optical fiber diameter, fluid viscosity and surface tension, and speed of the coating process 3,4 .

Fabrication of the LPFGs is experimentally demonstrated coating a symmetrically tapered optical

fiber with a uniform waist of 13.72 mm in length and 18 µm diameter. Coating process was

performed by a homemade coating station 4 using polydimethyl siloxane (PDMS) due its suitability

for optical applications. The obtained periodicity of the LPFGs are 77.89 m, resulting in an

attenuation of more than 20 dB at the 1562 nm wavelength.

a) b)

Fig 1. LPFG fabricated on PDMS coated tapered fiber: a) camera picture (bar represents 500 m), and

b) transmission spectra.

Fabrication materials can be extended to optically reconfigurable polymers. Azopolymers have the

capability of modify their molecular structure via an optical signal generating birrefringence 5 ,

resulting in an optically tunable LPFG.

[1] M. S. Cano-Velázquez, et al “Functional polymer coatings for photonic devices,” en 3rd Latin American Optics

and Photonics Conference, Cancún, México, OSA Technical Digest (2014).

[2] Rodrigo Vélez-Cordero, A. M. Velázquez-Benítez, J. Hernández-Cordero, “Thermocapillary Flow in Glass Tubes

Coated with Photoresponsive Layers,” Langmuir, Vol. 30, No. 18, pp. 5326-5336 (2014).

[3] D. Quéré, “Fluid coating on a fiber,” Annu. Rev. Fluid Mech., vol. 31, pp. 347–384, 1999.

[4] Amado M. Velázquez-Benítez, et al., "Controlled Deposition of Polymer Coatings on Cylindrical Photonic

Devices," J. Lightwave Technol. 33, 176-182 (2015).

[5] A. Velázquez-Benítez, J. Hernández-Cordero, “Optically driven all-fiber polarization rotator,” Journal of

Lightwave Technology, Vol. 29, No. 11, pp. 1672-1677 (2011).

146


ID0142

Wood anomalies in diffraction gratings with defects

Iván C. Avilés and E.R. Méndez

Departamento de Óptica,

Centro de Investigación Científica y de Educación Superior de Ensenada

Carretera Ensenada-Tijuana 3918, Ensenada, BC 22860, México

iaviles@cicese.edu.mx

KEY WORDS: Scattering of light by periodic metallic surfaces with localized defects

In 1902, while observing the continuous spectrum of a light source, Wood observed some

misterious bright and dark bands that could not be associated with the source spectrum1.

Moreover, these anomalies were only present in p polarization. We now know that the Wood

anomalies, as they are called, are associated with the excitation of surface plasmon polaritons

(SPPs). In this work, we consider the scattering of light by periodic metallic surfaces with

localized defects, illuminated, under illumination conditions for the observation of the Wood

anomalies. In such a situation, the light scattered outside the orders of the grating has two

contributions, one corresponding to the interaction of incident light with the defect and the other

corresponding to the scattering of surface plasmon polaritons by the defects. The proposed

configuration constitutes, then, a way of studying the interaction of surface plasmon polaritons

with surface defects.

For the experiments, suitable samples were fabricated with a combination of optical lithography

(for the periodic component) and mechanical methods (for the isolated defects). Measurements of

the angular ditribution of scattered light will be presented, together with rigorous computer

simulations of the problem.

Figure 1: Example of a surface profile and scattering patterns calculated with and without the defect. The

curve obtained by subtracting the results in amplitude is also shown.

1

R. W. Wood, “On a remarkable case of uneven distribution of light in a diffraction grating spectrum.”

Philos. Mag. 4, 396-402 (1902).

147


ID0143

Design of an Optical Filter based on Photonic Crystals using Transmission

Line Theory.

Gómez Bravo, Gerzon 1 and Gutiérrez Arenas, Rodrigo Alejandro 2

Undergraduate Program on Telecommunications 1 , Faculty of Engineering 1, 2 , National Autonomous University of Mexico,

Coyoacán, Mexico City, Mexico

ggomezb@comunidad.unam.mx

KEY WORDS: Photonic crystals, filters, transmission lines, photonic bandgap.

The success of optical communications technologies has stimulated the development of photonic

integrated circuits based on Photonic Crystals, these devices possess the property of inhibiting

certain frequencies of light due to the presence of a photonic bandgap. That property leads to

successful filtering of desired wavelengths of light. 1

Our goal in this work is to design a high-order band-rejection filter with Photonic Crystals. The

method proposed is based on Transmission Line, being a simple way to start the designing of

photonic devices without the need of have advance knowledge of condensed matter, through its

representation as bi-ports.

We also evaluate the parameters and the behavior of the filter using Circuit Theory in order to

compare the advantages and disadvantages of each methodology.

2

Photonic bandgap diagram

1.8

1.6

1.4


1.2

1

0.8

Photonic bandgap diagram for n 2

=2

Photonic bandgap diagram for n 2

=1.5

Photonic bandgap diagram for n 2

=1.25

0.6

0.4

0.2

0

-3 -2 -1 0 1 2 3


Photonic band gap diagram obtained using the method proposed.

[1] Pratik Al Islam, Nameeza Sultan, Seefath Nayeem, Belal Bhuian , “Optimization of photonic crystal

waveguide based optical filter”, 2014 IEEE Region 10 Symposium, pp.162-167, (2014).

148


ID0145

Nonlinear optical properties of gold nanoparticles embedded in sapphire

A. Peña R. 1 , R. Rangel Rojo 1

1 Departamento de Óptica, Centro de Investigación Científica y de Educación Superior de Ensenada, Apartado Postal 2732,

Ensenada BC 22860, México.

aldopena@cicese.edu.mx

KEY WORDS: gold-sapphire composite, optical properties, Z-scan, third-order response.

Composites materials possess fascinating electromagnetic properties which differ greatly from

those of ordinary bulk materials and they are likely to become ever more important with a

miniaturization of electronic and optoelectronic components 1 . Composite materials containing

metallic nanoparticles in a dielectric media have attracted a considerable amount of attention due

to their linear and particularly their nonlinear optical properties. Recently a lot of work has been

done using different size, shape and composition of nanoparticles embedded in different host

matrices. Changes in the host material result in different dielectric contrast that can greatly

enhance the nonlinearity of the composite. In this work we study the third-order nonlinear

response of a composite material consisting of spherical gold nanoparticles contained in sapphire.

The composite material was fabricated by ion implantation, and we expect to have a higher

nonlinearity than the one that can be achieved in samples with silicon as the host.

We present a study of the absorptive and refractive nonlinear response of the composite,

performed using the Z-scan technique with fs pulses at 749 nm. Regarding the nonlinear optical

response, the composite presents a positive nonlinear refraction and induced absorption at this

wavelength.

1.01

Au nanoparticles in sapphire at 749 nm

Open-aperture Z-scan

1.01

Au nanoparticles in sapphire at 749 nm

Closed-aperture Z-scan

1.005

1.005

Normalized Trasmittance

1

0.995

Normalized Trasmittance

1

0.995

0.99

(a)

0.99

(b)

0.985

-60 -40 -20 0 20 40 60

Sample position (mm)

0.985

-60 -40 -20 0 20 40 60

Sample position (mm)

Open (a), and closed-aperture (b) Z-scan results for the spherical nanoparticles in sapphire. The results were

obtained for a pulse energy E p = 3.03 nJ.

1 A. L. Stepanov, Rev. Adv. Mater. Sci., 27 (2011) 115-145.

149


ID0147

Simplified Bond-Hyperpolarizability Model in Terahertz Range with

Electronic Non-linear Effects for InN

E. S. Jatirian-Foltides, J. J. Escobedo-Alatorre, A. Alejo-Molina

Instituto de Investigación en Ciencias Básicas y Aplicadas (IICBA): Centro de Investigación en Ingeniería y Ciencias Aplicadas

(CIICAp), UAEM, Cuernavaca, Mor. 62160, Mexico

adalberto.alejo@uaem.mx

KEY WORDS: Harmonic Generation, polarizabilities, hyper polarizabilities, bond model

In this work we propose an extension of the Simplified Bond-Hyperpolarizability Model (SBHM)

to Terahertz range and for including some electronic nonlinear effects. Originally, this model was

developed by Aspnes and his group some years ago for nonlinear optical excitations 1 . SBHM is a

classical phenomenological description of the nonlinear response of the electrons along the bonds

in a material. Originally, the mean contribution was considered only along the bonds but later a

correction was done and transversal contribution also added to the calculation 2 . First proposed for

surfaces, where reconstruction was neglected and later also adapted to bulk, SBHM has shown to

be an acceptable model to describe nonlinear phenomena as for example second harmonic

generation (SHG), sum frequency generation (SFG), difference frequency generation (DFG) third

harmonic generation (THG) and recently in a previous work was shown that also describes

accurately electric field induced optical second harmonic (EFISH) generation 3 .

Now, our proposal consist on the extension of the concepts developed for crystalline

silicon 4 to a semiconductor crystal with two different species in the conventional cell and taking

account of the nonlinear phenomena originated for free electrons in the semiconductor at the

Terahertz range. The idea is very simple, according to SBHM, the nonlinear polarization is

calculated as follows:

1

P

2

ˆ ˆ ˆ


j

bj bj bj EE

(1)

V

where V is the volume, 2 j

j

are the hyperpolarizabilities and b ˆj are the unit vectors in the direction

of the atomic bonds, E is the electric field and the summation is going over all the bonds in the

conventional cell. Thus, for taking account of the nonlinear effect due to the free electrons, it is

only needed to add this extra contribution as a new hyperpolarizability in the direction of the

electric field. Our calculations will be compared with the numerical results from solving directly

the differential equations in terms of amplitudes of the field for de particular case of difference

frequency generation with the amplification of the signal due to the contribution of the free

electrons.

2 f

1

G. D. Powell, J. F. Wang, and D. E. Aspnes, Phys. Rev. B 65 (2002), 205320.

2

H. S. Peng and D. E. Aspnes, Phys. Rev. B 70 (2004), 165312.

3

A. Alejo-Molina, K. Hingerl, and H. Hardhienata, J. Opt. Soc. Am. B 32 (2015), 562–570.

4

A. Alejo-Molina, H. Hardhienata, and K. Hingerl, J. Opt. Soc. Am. B 31 (2014), 526–533.

150


ID0160

Calculation of Group Delay Dispersion in Femtosecond Pulses Propagating

Through a Parallel-Plane Plate and a Pair of Wedges

B. Sanchez-Padilla*, M. Rosete-Aguilar, J. Garduño-Mejia

Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México

Cd. Universitaria, Circuito Exterior S/N, Apdo. Postal 70-186, D.F. 04510, México

*benjamin_sanchez@ciencias.unam.mx

KEY WORDS: Group velocity dispersion, third order dispersion, femtosecond pulse, wedges,

In this work we calculate the group delay dispersion (GDD) and the third-order dispersion (TOD)

of a parallel-plane plate and a pair of wedges. These calculations were used to model de

dispersion of a z-fold cavity in order to support pulses of less than 10fs with a central wavelength

of 810nm.

The dispersive elements in the cavity were the Ti:Sapphire (gain medium), double chirped

mirrors (DCM) and a pair of wedges 1 . In a z-fold laser cavity with a pair of identical isosceles

prisms the dispersion in one roundtrip is 0 fs 2 of GDD and about 180 fs 3 of TOD. In the

configuration presented in this paper, the dispersion in one roundtrip is about -0.5327 fs 2 of GDD

and -5.266 fs 3 of TOD. The correction of TOD in this laser cavity allows increasing the

bandwidth inside the cavity for the generation of sub-10 femtosecond pulses. In figure 1 we

show a pulse of 5 fs before and after propagating through the cavity.

Figure 1: 5 fs pulse before and after propagating through the laser cavity. As we can see, the pulse is barely

broadened before one roundtrip in the cavity.

Acknowledgments. We gratefully acknowledge sponsorship of this work from the Dirección

General de Asuntos del Personal Académico (DGAPA) of the Universidad Nacional Autónoma

de México (UNAM), project PAPIIT-IG100615 and PAPIIT-IN104112.

1 F. X. Kartner, Few-Cycle Laser Pulse Generation and Its Applications, 1st. Edition, (Springer-Verlag, Berlin

Heidelberg, Germany, 2010).

151


ID0164

Comparing efficiency and accuracy of the kinoform

and the helical axicon as Bessel-Gauss beam

generators

Dilia Aguirre-Olivas ∗ , David Sánchez-de-la-Llave, Ulises Ruiz and Victor Arrizón

Instituto Nacional de Astrofísica, Óptica y Electrónica.

Luis Enrique Erro #1, 72840 Tonantzintla, Puebla, México. Tel: (222) 266.31.00

∗ dilia.aguirre@gmail.com

KEY WORDS: Diffraction, Waves, Computer holography, Optical vortex.

The study of Bessel beams (BBs) has become an attractive topic of research in optics 1 . Because

of BBs are invariant under propagation and have orbital angular momentum, they have become

increasingly important in the manipulation techniques and optical tweezers 2 . The BBs have been

generated with different techniques, 3,4,5 . We compare two phase optical elements that are employed

to generate approximate Bessel-Gauss beams.

The elements are the helical axicon (HA) given by HA(r,θ) = exp(−i2πr/r 0 )exp(iqθ)circ(r/R)

that generates a Bessel beam (BB) by free propagation, and the kinoform (BBK) defined as

BBK(r,θ) = sgn[J q (2πr/r 0 )]exp(iqθ)circ(r/R) that is employed in a Fourier spatial filtering optical

setup.

Representative intensity profiles of the approximate first-order BGBs generated with the two

methods are displayed in Fig.1.

Fig. 1: Transverse intensity profiles of a theoretical BGB and of the approximate BGBs generated

by a HA and a BBK.

Comparison in performance of the different techniques were made through the efficiency, i.e. the

optical power of the generated beam, normalized by the optical power transmitted (or reflected)

by the optical element, and the accurancy using the Root Mean Square Deviation (RMSD). The

results proved that the BBKs allow the generation of BGBs more accurately than the HAs. On the

other hand, it is obtained that the efficiencies of the methods are approximately 1.0 (HA) and 0.7

(kinoform).

1 D. McGloin and K. Dholakia, Contemp. Phys. 46, (2005)15-28.

2 V. Garcés-Chávez, D. McGloin, H. Melville, W. Sibbett, and K. Dholakia, Nature 419, (2002)145-147.

3 J. Durnin, J. J. Miceli, Jr., and J. H. Eberly, Phys. Rev. Lett. 58, (1987)1499-1501.

4 C. Paterson and R. Smith, Opt. Commun. 124, (1996)121-130.

5 V. Arrizón, D. Sánchez-de-la-Llave, U. Ruiz, and G. Méndez, Opt. Lett. 324, (2009)1456-1458.

152


ID0165

Optimum Generation of Annular Vortices

using Phase Diffractive Optical Elements

Gabriel Mellado-Villaseñor ∗ , Victor Arrizón, Ulises Ruiz and David Sánchez-de-la-Llave.

Instituto Nacional de Astrofísica, Óptica y Electrónica.

Luis Enrique Erro #1, 72840 Tonantzintla, Puebla, México, Telefono: (222) 266.31.00.

∗ gmelladv@inaoep.mx

KEY WORDS: Optical vortices, Computer holography, Diffractive optics,

An Optical Vortex (OV) is a dark hollow in an optical field, surrounded by a bright area which

possesses a certain amount of Orbital Angular Momentum 1,2 . We propose a method for efficient

generation of an annular OV with arbitrary integer topological charge q, based on a diffractive

optical element (DOE), whose transmittance coincides with the phase modulation of a qth order

Bessel beam (BB). This DOE, which is here referred to as Bessel beam kinoform (BBK), was

previously proposed as an efficient generator of such a beam 3,4 . Also, we prove that the BBK is the

phase DOE that allows the generation of an annular OV with the maximum possible peak intensity.

This optimum intensity propitiates a narrow bright annular section and a high intensity gradient

in the generated annular OV. Fig. 1 shows (a) the experimentally recorded intensities and (b) the

transverse intensity profiles of annular OVs, of topological charges q = 0 (top) and q = 4 (button).

(a)

(b)

Fig. 1: (a) Experimental recorder intensities and (b) transversal intensities profiles of annular OVs,

of topological charges q = 0 (top) and q = 4 (bottom), generated by a BBK.

1 L. Allen, M. W. Beijersbergen, R. J. C. Spreeuw, and J. P. Woerdman, Phys. Rev. A 45, 8185 (1992).

2 K. Volke-Sepulveda, V. Garcés-Chávez, S. Chávez-Cerda, J. Arlt, and K. Dholakia, J. Opt. B 4, S82 (2002).

3 V. Arrizón, D. Sánchez-de-la-Llave, U. Ruiz, and G. Méndez, Opt. Lett. 34, 1456 (2009).

4 M. McLaren, J. Romero, M. J. Padgett, F. S. Roux, and A. Forbes, Phys. Rev. A 88, 033818 (2013).

153


ID0167

Selectively Magnetic Fluid Infiltrated Dual-Core Photonic Crystal Fiber based

Magnetic Field Sensor

Rahul Kumar Gangwar and Vinod Kumar singh

Department of Applied Physics, Indian School of Mines, Dhanbad-826004, Jharkhand, India

Corresponding Author’s e-mail address: rahul0889@ap.ism.ac.in

KEY WORDS: Photonic crystal fiber, Magnetic field sensor, Magnetic fluid, Mode coupling.

In this article, we propose selectively magnetic fluid infiltrated dual-core photonic crystal fiber

based magnetic field sensor. Inside the cross section of the designed photonic crystal fiber, the

two fiber cores filled with magnetic fluid (Fe 3 O 4 ) are separated by an air hole which forms two

independent waveguides with mode coupling 1 . The mode coupling under different magnetic field

strengths is investigated theoretically. The result shows that proposed sensing device with 1 cm

photonic crystal fiber length have larger sensing range and higher sensitivity of 1.23 nm/Oe in

comparison to previously reported work 2 .

Fig.1. (a) Cross section of the designed magnetic fluids infiltrated dual-core PCFs magnetic field sensor, and (b)

Wavelength shift of the transmission spectrum of 1 cm dual core PCF with different magnetic field strength at

different air hole diameter d 2 .

References:

[1] W. P. Huang, J. Opt. Soc. Am. A, 11 (1994) 963-983.

[2] Jianhua Li, Rong Wang, Jingyuan Wang, Baofu Zhang, Zhiyong Xu and Huali Wang, Opt. Fiber

Technol., 20 (2014) 100–105.

154


ID0181

Spiral optical vortices generated by a Mach-Zehnder interferometer

A. Montes-Pérez 1 , A. Martínez-García 2 , C.I. Robledo-Sánchez 1 , G. Rodríguez-Zurita 1

1 Facultad de Ciencias Físico Matemáticas BUAP,Av. San Claudio y 18 Sur, Colonia San Manuel Edificio 111A-109B, Ciudad

Universitaria, Puebla México C.P. 72570

2 Centro de Investigaciones en Óptica A.C. Loma del Bosque 115, Colonia Lomas del Campestre León Gto. México C.P. 37150

Corresponding Author’s e-mail address and URL: arelimp@fcfm.buap.mx,

http://www.fcfm.buap.mx/nosotros/directorio/investigadores-asociados.html

KEY WORDS: Interferometry, spiral phase, spatial Light Modulator, optical vortices

In interferometry, one of the interesting properties related to vortices and of interest in this work

is the possibility of creating interference patterns that carry information on the sign of the phase.

This information is recognizable in the direction of rotation of the spiral strips in the vicinity of a

vortex. The spiral fringes arise from the superposition of a wavefront with vortices and a

spherical wavefront. In this paper, experimental and numerical results show the generation of

optical vortices with a SLM (spatial light modulator) in a Mach-Zehnder interferometer.

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patterns spiral, negative and 67:I7'4232;MI567'' positive, with topological 67:I7'4232;MI567'' V'' charge 'R'' m = ±1,2,3.

V'' -' 'R'' -'

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'

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SUMMER

SCHOOL

L

i S c

i

2 0 1 5

POSTER SESSION

3Th


Poster Session 3Th

Title Presenting Author ID

Characterization of FEOM to generate Raman beam

for its use on atomic interferometry

Direct Digital Synthesis for atomic interferometry

Memory Manipulation in a Λ-System

Quantitative Characterization of the Interaction

between Optical Spatial Solitons in Colloidal Media

Single particle scattering detection for velocity estimation based on

Edge Filter Enhanced Self-Mixing Interferometry

Integrated Cold Atoms Source for Portable Atomic Clocks

and Quantum Gas Experiments

Photonic and Phononic band structure in helical media

Spatial optical solitons in bidisperse fluorescent nanocolloids

Compressive Ghost Imaging

Pure heralded single-photon sources generated in uniaxial and

biaxial crystals

Nanoautonomous Solitons in Optical Fibers

Study of Monochromatic Aberrations Introduced by Perfectly

Conducting Spherical Mirrors in the Focusing of Ultrashort Light

Pulses

Astigmatism Compensation in a off-axis Laser Cavity

N. Arias

Instituto de Física, UASLP

Daniel Matínez-Arias

Instituto de Física, UASLP

R. Gutierrez-Cuevas

Centre for Coherence and

Quantum Optics

Univeristy of Rochester, USA

Emma C. Brambila

Instituto de Física, UNAM

Victor Ulises Contreras

Tampere University of

Technology

N. Garrido-Gonzalez

University or Nottingham

England

A. Villegas-Juarez

Instituto de Física, UNAM

M. Yadira Salazar-

Romero

Instituto de Investigaciones en

Materiales, UNAM

Peter A. Morris

School of Physics and

Astronomy

University of Glasgow, UK

Kalo Traslosheros

Departamento de Óptica,

CICESE

M. Perez-Maldonado

Instituto Potosino de Investigación

Científica y Tecnológica, México

S. Anaya-Vera

Centro de Ciencias Aplicadas y

Desarrollo Tecnológico, UNAM

A. Moreno-Larios

Centro de Ciencias

Aplicadas y Desarrollo

tecnológico, UNAM

025

027

028

044

033

045

046

049

053

056

062

065

066

157


Title Presenting Author ID

Ray Tracing and Polarization for Uniaxial Birrefringent Lenses

Using Huygens

Quadrupolar second harmonic generation by helical beams and

vectorial vortices

Optimal randomness generation from optical Bell experiments

Observation of secondary ionization by photon feedback in a

Townsend discharge

How random are random numbers generated using photons?

Quantum efficiencies in finite disordered networks connected by

many-body interactions

Comparison of the pattern of light scattering from 1D rough

surfaces

using focused illumination

Transient-Thermo-Reflectance to study carrier dynamics on Thz

antennas

Classical chaos in atom-field systems

Transverse amplitud transfer of optical vortex to a single photon

by the process of SPDC

Photon pair generation in birrefringent optical fiber

by Spontaneous Four Wave Mixing

Defocusing effect of laser pulse on THz radiation

from an photoconductive antenna source

Characterization of the VOLC channel for indoor applications

Luis A. Alemán-

Castañeda

Centro de Ciencias Aplicadas y

Desarrollo Tecnológico, UNAM

Miguel G. Mandujano

División de Física Aplicada,

CICESE

A. Máttar

The Institute of Photonic

Sciences-ICFO

Eduardo Basurto

Departamento de Ciencias

Básicas, UAM, Azcapotzalco

Ali M. Anglo M.

Instituto de Ciencias Nucleares,

UNAM

Adrian Ortega

Instituto de Ciencias Físicas,

UNAM

O. Rodriguez-Nuñez

Centro de Ciencias Aplicadas y

Desarrollo Tecnológico, UNAM

Catalina Ramirez-Guerra

Centro de Ciencias Aplicadas y

Desarrollo Tecnológico, UNAM

Jorge Chavez Carlos

Instituto de Ciencias Nucleares,

UNAM

Verónica Vicuña-

Hernandez

Instituto de Ciencias Nucleares,

UNAM

Daniel Cruz-Delgado

Instituto de Ciencias Nucleares,

UNAM

Gaudencia Paz-Martinez

Centro de Ciencias Aplicadas y

Desarrollo Tecnológico, UNAM

A. M. Ramirez-

Aguilera

Facultad de Ciencias

UASLP

070

071

072

074

080

086

088

100

101

107

108

113

121

158


Title Presenting Author ID

Proposal for studying electric quadrupole transitions using

structures light beams

Statistical Properties of the Diffraction Pattern Produced by a

Speckle Field

Design and contruction of ultrashort pulse Erbium doped fiber

optic laser with broad spectrum

Adaptive Control of Group Velocity Dispersion of ultrashort

pulses.

Development of video-rate spectral phase interferometry

for direct electric field reconstruction (SPIDER)

High-stability Electronic Control for ECDL Applied in

Spectroscopy

Transverse amplitude transfer of optical vortex to a single photon

by the process of spontaneous parametric down conversion.

Measurement and control of the frequency of the light of trapped

and control

from magnetic fields of a magneto-optical trap of atoms of

rubidium.

Laser frequency modulation for polarization spectroscopy in

rubidium

Photoelasticity

Design of the Vacuum System for 6Li and 7Li Fermi and Bose

Gases Experiments

Synthesis of Ag and Au nanoparticles by laser ablation in ethanol:

a pulsed photoacoustic study.

Experimental system for the measurement of an electric dipole

forbidden transition in atomic rubidium

S. Hernández-Gómez

Instituto de Ciencias Nucleares,

UNAM

Laura Perez García

Instituto de Física, UNAM

P. Castro-Marín

Centro de Ciencias Aplicadas y

Desarrollo Tecnológico, UNAM

Itzel Reyna Morales

Universidad Nacional

Autónoma de México

Ramiro Contreras

Martinez

Universidad Nacional

Autónoma de México

Manuel Cerna Larenas

Universidad de La Frontera,

Universidad de São Paulo

José Tomás Santiago Cruz

Instituto de Ciencias Nucleares,

UNAM

Luis Armando Vieyra

Reboyo

Instituto de Ciencias Nucleares,

UNAM

Oscar López Hernández

Instituto de Ciencias Nucleares,

UNAM

Alitzel López Sánchez

Universidad Nacional

Autónoma de México

Eduardo Ibarra García

Padlla

Instituto de Física, UNAM

Enrique Esparza Alegria

Facultad de Ciencias UNAM

Francisco Sebastián

Ponciano Ojeda

Instituto de Ciencias Nucleares,

UNAM

123

125

127

129

138

140

146

156

157

158

159

161

162

159


Title Presenting Author ID

Lasing/amplifying properties of phosphate glass containing silver

nanoparticles

Quantum Tomography via Non-orthogonal basis and Weak values

Quantum correlations in semiclassical approximation

Swapping of Quantum Discord

Quantifying Chaos in the Dicke model: IPR of a coherent state

An experimental setup for cold atom spectroscopy

Development and Characterization of a Tuneable Laser Diode

System

for Doppler Cooling of Ba+

Theoretical analysis for the 5P3/2 → 6P3/2 electric quadrupole

transition.

A Compact 1049 nm Littrow External Cavity Diode Laser

María Alejandrina

Martinez Gamez

Centro de Investigaciones en

Óptica

Juan Jesús Díaz Guevara

Universidad de Guadalajara

Iván Fernando Valtierra

Carranza

Universidad de Guadalajara

Ariana Scarlet Muñoz

Espinoza

Universidad de Guadalajara

(CUCEI)

Miguel Angel

Bastarrachea Magnani

Universidad Nacional

Autónoma de México

Oscar Gerardo Lazo

Arjona

Instituto de Ciencias Nucleares,

UNAM

Luis Alberto Nava

Rodríguez

Universidad Autońoma

Metropolitana-Iztapalapa

Cristian Mojica Casique

Instituto de Ciencias Nucleares,

UNAM

José Eduardo Navarro

Navarrete

Instituto de Ciencias Nucleares,

UNAM

163

170

171

173

175

189

192

194

195

160


ID025

Characterization of FEOM to generate Raman beams for its use on atomic

interferometry

N. Arias, V. Avediyeh and E. Gomez

Instituto de Física, UASLP, San Luis Potosí 78290, México

ntellez.005@gmail.com

Raman transitions are one of the most useful techniques to make atomic interferometry 1 . The

applications of Raman transitions on interferometry include determination of the fine structure

constant, tests of general relativity, the study of the 1/r 2 dependence in Newton’s law or short

range forces such as the Casimir-Polder force. Nowadays there are more techniques but the best

sensitivity known until today was based on Raman transitions 2 .

There are different methods to generate Raman beams, typically are generated by an optical

phase lock loop of two independent lasers. This is technically challenging and introduces phase

noise both due to the laser locking and to the vibrations of the mirrors along the beam paths 3 .

Alternatively, the two beams can be generated by amplitude or phase modulation 4 . Here we

present the characterization of an electro-optical phase modulator (FEOM) for its use on atomic

interferometry. The phase modulation produces a series of sidebands that we use as the phase

locked beams for the Raman transition.

In this work we measured the phase noise with different methods and compare them: the first

method was using a spectrum analyzer, or mixing the signal with the reference one to access

directly to the phase in an FFT analyzer or an oscilloscope. We obtain a phase noise of 0.07 rad,

0.047 and 0.031 with each method respectively. The phase noise is good enough for our initial

interferometric needs and can be improved with better microwave sources. The setup that we use

is sown in figure 1.

Figure 1. Setup to measure the phase noise of the FEOM.

On the other hand, there is a cancellation when using pure phase modulation and in order to generate the

Raman transitions it becomes necessary to eliminate one of the sidebands or play with the polarization, in

this part we are working.

1 M. Kasevich and S. Chu, Phys. Rev. Lett. 67(1991).

2 S. Dickerson, J. Hogan, A. Sugarbaker, S. Johnson, and M. Kasevich, Phys. Rev. Lett., 111 (2013).

3 V. Ménoret, R. Geiger, G. Stern, N. Zahzam, B. Battelier, A. Bresson, A. Landragin and P. Bouyer,

arXiv:1108.2453v1 (2011).

4 S.M. Dickerson, J.M. Hogan, A. Sugarbaker, D.M.S. Johnson, and M.A. Kasevich, Phys. Rev. Lett. 111 (2013).

161


ID027

Direct Digital Synthesis for atomic interferometry

Daniel Martínez-Arias 1 , V. Abediyeh 1 , J.R. Martínez 1 , E. Gomez 1

Instituto de Física, Universidad Autónoma de San Luis Potosí

Av. Manuel Nava 6, Zona Universitaria 78290, San Luis Potosí, San Luis Potosí México

dmtz@ifisica.uaslp.mx

KEY WORDS: Direct Digital Synthesis, atomic interferometry, Zeeman effect, Raman effect.

Precision measurements have increased their sensitivity considerably over the last years. The

classical techniques have been superseded by the interferometric methods. The atomic

interferometry uses Ramsey’s separated fields method where two p/2 pulses are separated by a

free evolution time in darkness. Phase control of all the applied fields is a requirement for these

purposes.

In our laboratory we are interested in applying atomic interferometry to improve

gravitational measurements, in particular, at short distances. We are exploring different ways to

exploit the spin of the atoms as an additional degree of freedom to improve the measurements 1 .

The present work focuses in three different methods that we use for synthesis with controllable

phase.

The first modulator is the 409-B AC from Novatech. This Direct Digital Synthesis (DDS)

generator has four output channels that work up to 170 MHz in 0.1 Hz steps. The synthesizer

accepts an external trigger to follow a list of values previously recorded. This makes it

compatible with our control system and very useful for experimental sequences where we need to

change between frequencies at particular times. The synthesizer can operate in phase continuous

mode, something that is required for keeping track of the phase in coherent measurements. We

use a LabView program to control the synthesizer.

The second modulator is the Rigol DG5071. This is an arbitrary wave synthesizer that we

use to program complex patterns. It reaches frequencies up to 70 MHz with 128 M points.

Combining this synthesizer with the fiber modulator we can produce complicated Raman

excitation sequences that would be impossible to do with the traditional setup of two independent

phase locked lasers. We combine the frequency of the synthesizer with a fixed microwave source

using a single sideband modulator to produce radiation at the hyperfine splitting of 87Rb (6.8

GHz).

The third modulator is based on a Field Programable Gate Array (FPGA) and a Digital to

Analog Converter (DAC). Using a simple program we achieve a frequency resolution of 10 mHz.

This system has the advantage that the phase of the output signal can be adjusted in real time and

it is useful for implementing feedback to reduce any phase deviations introduced by

environmental factors.

Acknowledgements. We thank CONACYT, UASLP and Fundación Marcos Moshinsky

for support.

1 L.O. Castaños and E. Gomez. “Model for a phase-space selector using microwave transitions,” Phys. Rev. A. 89,

013406 (2014).

162


ID028

Memory Manipulation -System

R. Gutierrez-Cuevas 1, 2 and J. H. Eberly 1, 3

1 Centre for Coherence and Quantum Optics, University of Rochester, Rochester, NY 14627, USA

2 Institute of Optics, University of Rochester, Rochester, NY 14627, USA

3 Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627, USA

Corresponding Author e-mail address and URL: rgutier2@ur.rochester.edu

KEY WORDS: Memory manipulation, Maxwell--system, solitons, Darboux

transformation

We examine the coherent memory manipulation in a -type medium, using the novel second

order solution derived by Groves et al. as a guide 1 . This solution for the interaction of two fields

with a -system in two-photon resonance (see Figure a) describes complicated soliton-pulse

dynamics. But by an appropriate choice of parameters, this intricate solution can be reduced to a

well-defined sequence of pulses interacting with the medium, transferring information back and

forth (see Figure b). The information of the initial signal pulse is encoded in the ground state

density matrix elements as it transfers its energy to a control pulse, and is subsequently displaced

by a second control pulse (see Figure c).

The analytical solution obtained using the Darboux transformation and a nonlinear

superposition principle is reviewed and put to test by means of a series of numerical simulations,

encompassing all the parameter space and adding the effects of homogeneous broadening due to

spontaneous emission. We find that even though the decohered results deviate from the analytical

prediction they do follow a similar trend that could be used as a guide for future experiments.

Additionally we show that the finiteness of the medium can be used to our advantage as a means

to recover the initially stored signal pulse.

a) Three level atom in -configuration, with spontaneous emission 3 from the excited

state interacting with two fields in two-photon resonance, b) pulse evolution dictated by the

second order analytical solution and c) corresponding imprint of the initial signal pulse as it

has been encoded in the ground state density matrix elements before (continuous line) and

after the displacement (dashed lines).

1

E. Groves, B. D. Clader, J. H. Eberly, J. Phys. B: At. Mol. Opt. Phys., 46 (2013) 224005.

163


ID033

Single particle scattering detection for velocity estimation based on

Edge Filter Enhanced Self-Mixing Interferometry

Victor Contreras 1 , Jan Lonnqvist 2 , Juha Toivonen 1

1. Department of Physics, Tampere University of Technology, P. O. Box 692, FI-33101 Tampere, Finland

2. Vaisala Oyj, P. O. Box 26, FI-00421 Helsinki, Finland

Corresponding Author’s e-mail address and URL: ulev22@gmail.com

KEY WORDS: Interference, Frequency modulation, Semiconductor Lasers.

Self-Mixing Interferometry has been proved to be a low-cost and practical self-aligned

alternative to the conventional interferometers for distance, displacement, velocity and vibration

measurements with successful operation on diffusive targets [1]. We present an enhanced and

more sensitive approach than conventional self-mixing interferometer based on the detection of

the FM signal [2]. The FM signal detection is achieved using an acetylene edge filter that maps

laser FM into intensity modulation (IM) as the laser wavelength is tuned to the steep edge of the

absorption profile. The new Enhanced Self-Mixing Interferometry (ESMI) is based on a

commercial Distributed Feedback (DFB) laser monolithically integrated with a Master Oscillator

Power Amplifier (MOPA) emitting a maximum power output in the order of 1 W in the near-IR

band at 1532 nm. Theoretical and experimental evidence of the signal enhancement is presented.

The ESMI technique yields to about two orders of magnitude larger signal-to-noise ratio and

extends the applicability of SMI into new fields allowing longer detection ranges and the use of

more diffusive targets. To demonstrate the signal enhancement, we tested the ESMI technique as

a laser Doppler anemometer for the detection of single particle scattering events using

polystyrene microspheres. Preliminary results on single-particle detection suggest the ESMI

technique can be used as a robust and inexpensive laser Doppler anemometer based on the

detection of micro-particles present in the atmosphere.

Doppler signal (a. u.)

×10 -3

6

5

4

3

2

1

1.0µm

1.5µm

2.0µm

3.0µm

10µm

0

1 1.5 2 2.5 3 3.5 4

Frequency (MHz)

ESMI%Doppler%frequency%signal%from%single%polystyrene%spheres%of%different%sizes.%The%scattering%signals%come%

from%moving%particles%located%on%the%laser%focal%point%at%3m.%The%bigger%the%particle,%the%stronger%the%signal.

[1] S. Donati, Developing self-mixing interferometry for instrumentation and measurements, Laser &

Photon. Rev. 6, 393 (2011).

[2] V. Contreras, J. Lonnqvist, J. Toivonen, Edge Filter Enhanced Self-Mixing Interferometry, Optics

Letters, submitted and accepted (2015).

164


ID044

Quantitative Characterization of the Interaction between

Optical Spatial Solitons in Colloidal Media

Emma C. Brambila 1* , Yareni A. Ayala 1 , Yadira Salazar-Romero 1,2 , Luke Sciberras 3 ,

Antonmaria A. Minzoni 3 , Karen Volke-Sepúlveda 1

1

Instituto de Física, Universidad Nacional Autónoma de México

Apdo. Postal 20-364, 01000 México D.F., México.

2

Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México

Apdo. Postal 70-360, México D.F., México.

3

Instituto de Investigaciones en Matemáticas Aplicadas y Sistemas

Apdo. Postal 70-543, México D.F., México.

E-mail*: emma_brambila@ciencias.unam.mx

KEY WORDS: Optical spatial soliton, soliton interactions, nonlinear medium.

It has been shown that when a gaussian beam (CW laser) travel through a colloidal

suspension of dielectric nanoparticles with a power above a critical value, the colloid

behaves like a nonlinear medium that supports stable optical spatial solitons (OSS) in two

transverse dimensions 1,2 . The origin of the nonlinear properties of these media is attributed

to the optical gradient force that pulls the particles towards the most intense part of the

beam 1 .

In this work, we describe in detail the interaction of two OSS in terms of the angle

between them and their relative power. We find experimentally three different regimes. For

small angles (11º), we observe two separated beams that are not selffocused.

However, when one of the beams is blocked, the other does form a soliton. The

three regimes are quantitatively characterized in the experiments. Moreover, the first regime

is successfully described with a theoretical model 3 .

Two-OSS interaction for the regime of the small relative angles.

Angle of the resulting soliton vs relative power between the interacting beams.

[1] A. Ashkin, Opt. Lett. 7 (1982) 276-278.

[2] L.A. López-Peña, et. al. Proceedings of SPIE 9164, Art. No. 916429 (2014).

[3] M.Matuszewski, W. Krolikowski and Y. S. Kivshar. Optic Express. 16 2 (2008) 1371-1376.

165


ID045

Integrated Cold Atoms Source for Portable Atomic Clocks

And Quantum Gas Experiments

N. Garrido-Gonzalez 1,2 , F. Orucevic, P.Kruger 1

1 University Of Nottingham, School of Physics and Astronomy, Nottingham, England. NG7 2RD

2 falgargon@gmail.com

KEY WORDS: Cold Atoms, Atomic Clocks, Quantum Devices, Quantum Optics

This project presents the development of a set of tools to capture, cool and manipulate 87 Rb

atoms to provide a cold atom source for portable Atomic Clocks and experiments. The design

follows closely the design presented in the reference 1 which makes use of a Magneto Optical

Trap and atom chip to cool and confine the atoms.

General design rules for the establishment of integrated trapping systems based on atom

chip technology were assessed and a new experimental system which captured more than 10 8

atoms at temperatures below 25 µK is presented. The final objective is the implementation of a

novel, low-power, low-current atom chip assembly that can function as a portable and efficient

cold atom source for use on the future atomic clocks.

This work is realized under the framework of the Marie-Curie Actions Project “Future

Atomic Clock Technology” (FACT), funded by the European Commission, which focuses

technological developments enhancing the technology readiness level of the new optical atomic

clocks, enhancing the chance that they are picked up by the commercial sector 2 . This project

involves 14 universities from 5 different countries in close collaboration.

1 Piccardo-Selg A. (2013). Cold Atom Sources for Portable Quantum Sensors. Ph.D. Thesis. The University of

Nottingham.

2 'European Commission : CORDIS : Projects And Results : FUTURE ATOMIC CLOCK TECHNOLOGY'. N.p.,

2015. URL: http://cordis.europa.eu/project/rcn/109147_en.html. Consulted 8 May 2015.

166


ID046

Photonic and Phononic band structure in helical media

A. Villegas-Juárez 1,2* , J. A. Reyes-Cervantes 1

1 Instituto de Física, UNAM, Circuito de la Investigación Científica S/N, Ciudad Universitaria, México D.F., México, 04510

2 Facultad de Ciencias, UNAM, Av. Universidad 300, Circuito Exterior S/N, Ciudad Universitaria, México D.F., México, 04510

*avillegas@ciencias.unam.mx

KEY WORDS: Cholesteric Liquid Crystals, Anisotropic Media, Elastic waves, Band structure

We study the propagation of monochromatic electromagnetic waves in cholesteric liquid crystals

as anisotropic non-magnetic media in which the permittivity tensor depends only on the helical

axis direction coordinate 1 . Solving Maxwell equations for this problem, using Marcuvitz-

Schwigner equations, the problem is reduced to !"

= !"#, where ! is a four dimensional vector

!"

that contains the components of the Electric and Magnetic fields, and ! is a 4×4 matrix 2 . The

solution of these equations gives the photonic band structure for frequency (!) as a function of

the wave number (!) of the electromagnetic wave.

In analogy, we study the propagation of elastic monochromatic waves in a helical

structured solid. In this case !! is a six dimensional vector that contains the independent

components of the strain tensor and the components of the displacement vector. By a similar

procedure we get to the phononic band structure for frequency (!) as a function of the wave

number (!) of the elastic wave.

Planar electromagnetic wave propagating in a cholesteric liquid

crystal that induces a reflection band.

[1] P. G. de Gennes and J. Prost, The Physics of Liquid Crystals, Second edition, Clarendon Press.

Oxford(1993)

[2] M. Becchi, S. Ponti, J. A. Reyes, Defect modes in helical photonic crystals: An nalytic approach,

Physical Review B 70, 033103 (2004)

1 P. G. de Gennes and J. Prost, The Physics of Liquid Crystals, , 2 nd . ed., (Clarendon Press, Oxford, 1993).

2 M. Becchi, S. Ponti, J. A. Reyes*, Phys. Rev. 70, 033103 (2004).

167


ID049

Spatial optical solitons in bidisperse fluorescent nanocolloids

M. Yadira Salazar-­‐Romero 1, * , Yareni Aguilar-Ayala 2 , Alejandro V. Arzola 2 , Juan Hernández-

Cordero 1 , and K. Volke-Sepúlveda 2, *

1

Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México

Apdo. Postal 70-360, México D.F., México

2

Instituto de Física, Universidad Nacional Autónoma de México

Apdo. Postal 20-364, 01000 México D.F., México

*E-mails: yayafisica@gmail.com, karen@fisica.unam.mx

Keywords: soliton, self-focusing, nanoparticles, fluorescence.

ABSTRACT :

The nonlinear optical properties of colloids were discovered in the 1980’s [1,2]. The origin of

the nonlinear optical properties of this media is attributed to optical gradient force. In colloidal

media it can be produce the self-focusing effect [3] and induce waveguides [4]. In this work we

report the nonlinear effects of light propagation through a fluorescent nanocolloid. The medium

was formed by a bidisperse suspension of fluorescent and nonfluorescent nanospheres of similar

diameters (60nm and 57nm, respectively) in distilled water. A CW laser beam (532 nm

wavelenght) was focused into the nano-suspension, generating a spatial optical soliton of few

millimeters in length figure 1. The rings surrounding the spot beam are atribute to thermal effects.

The threshold power and focusing conditions to create the soliton were analyzed as a function of

the pump power and hysteresis effects were observed. We also varied the concentration of both

types of particles and the size of the nonfluorescent nanospheres and studied their effect in the

soliton formation.

Figure 1: a) top view of the beam propagation in to the colloid, c) front view of beam. In picture b) it can be seen the

propagation of soliton through the colloidal media and d) front view of the soliton.

[1] A. Ashkin, et al. “Continuous-wave self-focusing and self-trapping of light in artificial Kerr

media,”Opt. Lett. 7, 276 (1982).

[2] Smith, P. W., Ashkin, A., Biorkholm, J. E., and Eilenberger, D. J., “Studies of self-focusing bistable

devices using liquid suspensions of dielectric particles,” Opt. Lett. 9, 131 (1984).

[3] Roland A. Terborg, et al. “Guiding and Steering Light With Nanocolloids,” OPTICS LETTERS / Vol.

38, No. 24 / December 15, 2013

[4] Luis A. López-Peña et al. “Beam-splitting waveguides induced in nanocolloids.” Proc. SPIE,

Conference: Optical Trapping and Optical Micromanipulation.

168


ID053

Compressive Ghost Imaging

Peter A. Morris,* a , Reuben S. Aspden a , Jessica Bell a , Daniel S. Tasca b , Robert W. Boyd a, c, d ,

Miles J. Padgett a

a

School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, UK;

b

Institute of Physics, Federal University of Rio de Janeiro, Rio de Janeiro, RJ 21941-972, Brazil

c

Institute of Optics, University of Rochester, Rochester, NY 14627, USA

d

Dept. of Physics, University of Ottawa, Ottawa, ON K1N 6N5, Canada

Email: p.morris.1@resaerch.gla.ac.uk

KEY WORDS: Quantum imaging, compressive sampling, image optimization, detector arrays.

Although a single photon can encode carry large amounts of information, real images require

many photons to discern them. Our latest approach 1 all but eliminates noise events by use of a

time-gated, intensified camera and heralded single-photons from a parametric down-conversion

(SPDC) source. One photon from the pair interacts with the object and is subsequently detected

with a single-pixel detector. The signal from this detector triggers the camera, which records the

position of the correlated photon. The maximum number of photons per pixel is


ID056

Pure heralded single-photon sources generated in uniaxial and biaxial crystals

Kalo Traslosheros, Karina Garay-Palmett

Departamento de Óptica, Centro de Investigación Científica y de Educación Superior de Ensenada

Carretera Ensenada-Tijuana 3918, Zona Playitas, 22860 Ensenada, B.C.

ktraslos@cicese.edu.mx, kgaray-palmett@cicese.edu.mx

KEY WORDS: Quantum optics, quantum entanglement, heralded single photons

From quantum computation to quantum communication protocols there is a growing demand of

pure single photon sources 1 . Single photon states can be produced from photon pair sources

generated by spontaneous nonlinear processes such as parametric down conversion, in which

detection of one photon in a pair announces the presence in the conjugate mode. Even though

there are theoretical and experimental studies (especially in uniaxial crystals) that already have

manage the implementation of this kind of sources 2 , there is still a compromise among heralding

efficiency, photon rate flux (brightness) and purity. The ideal scenario would be the one in which

these three quantities are maximized.

The present work comprises a theoretical and numerical study of the process of

spontaneous parametric down conversion (SPDC) in uniaxial and biaxial crystals, considering the

coupling to single mode fibers after generation. The projection of the two-photon state into the

fiber mode suppresses the spatial correlations in the two-photon state, which is desirable in this

kind of sources since attaining the suppression of correlations in all continuous variable degrees

of freedom is a requirement for increasing the purity of the heralded single photon state. Biaxial

crystals such as BiBO and KTP exhibit a high nonlinear coefficient, which suggests that the

improvement in the three characteristic quantities of this type of non-classical light sources is

possible.

The figure below shows the behavior of heralding efficiency, coincidence photon counts

and purity with respect to one experimental variable of the source: the pump bandwidth.

0.5

8

1

η H

0.4

0.3

0.2

N (1x10 3 photons/sec)

7

6

5

4

3

Purity = Tr(ρ 2 )

0.8

0.6

0.4

λ i (µm)

0.77

0.81

0.85

Coupled JSI

0.85 0.81 0.77

λ s (µm)

0.1

5 10 15 20 25

∆ λ (nm)

2

5 10 15 20 25

∆ λ (nm)

5 10 15 20 25

∆ λ (nm)

Figure1. Dependence of heralding efficiency, coincidence photon counts and purity of the source on pump

bandwidth.

1 Knill, R. Laflamme, and G. J. Milburn, Nature 409, 46–52 (2001).

2 L.E. Vicent, A.B. U'Ren, R. Rangarajan, C.I. Osorio, J.P. Torres, L. Zhang and I.A. Walmsley, New J.Phys. 12

093027 (2010).

170


ID062

Nonautonomous Solitons in Optical Fibers

M. Pérez-Maldonado 1 , Haret C. Rosu 2

1 IPICYT, Instituto Potosino de Investigación Científica y Tecnológica. Departamento de Matemáticas Aplicada.

Camino a la presa San José 2055. Lomas 4ª. Sección, C.P. 78216, San Luis Potosí, S.L.P. México.

maximino.perez@ipicyt.edu.mx

2 IPICYT, Instituto Potosino de Investigación Científica y Tecnológica. Departamento de Materiales Avanzados.

Camino a la presa San José 2055. Lomas 4ª. Sección, C.P. 78216, San Luis Potosí, S.L.P. México.

htc@ipicyt.edu.mx

KEY WORDS: Nonlinear Optics, Nonlinear Schröndiger equation, Solitons, Fiber optics, Optical

Amplifiers in Optical fibers.

In the particular case of optical fibers, the nonlinearity and dispersion, as physical properties, are

serious sources of signal distortion 1-3 . An analytical solution of the nonlinear Schrödinger equation

of variable coefficients, describing the transfer of information through an optical fiber, is obtained

by mapping it to the standard nonlinear Schrödinger equation of constant coefficients using the

similar transformations 4,5 . We use the analytical solution to describe the behavior of the pulse

during the propagation with the amplitude ansatz similar of Talanov 6 .

Periodic solution of nonlinear Schrödinger equation of variable coefficients, with anomalous dispersion, and

contour plot of the pulse evolution.

[1] A. Hasegawa and M. Matsumoto, “Optical Solitons in Fibers”, Third Edition, Springer-Verlag, (2003).

[2] G. P. Agrawal, “Nonlinear Fiber Optics”, Third Edition. Academic Press, (1995).

[3] M. J. Ablowitz, B. Prinari and A.D. Trubatch, “Discrete and Continuous Nonlinear Schrödinger

Systems”, Cambrige University Press, (2004).

[4] L.W. Liou, G.P. Agrawal. “Solitons in fiber amplifiers beyond the parabolic-gain and rate-equation

approximations”, Optics Commun. 124, 500-504 (1996).

[5] J. He and Y. Li, “Designable integrability of the variable coefficient nonlinear Schrödinger equations”,

Studies in Appl. Math. 126, 1-15 (2011).

[6] V.I. Talanov “Focusing of light in cubic media”, JETP Lett. 11, 199-201 (1970).

[7] Y. V. Katyshev, N. V. Makhaldiani, V. G. Makhankov, “On the stability of solutions to the Schrödinger

equation with nonlinear term of the form φ|φ| ”, Phys. Lett. 66A, 456-458 (1978).

[8] Z. Y. Yang, L. Y. Zhao, T. Zhang, and R. H. Yue, J. Opt. Soc. Am. B. Vol. 28. No. 2. (2011).

[9] V. N. Serkin, A. Hasegawa, and T. L. Belyaeva, “Nonautonomous solitons in external potentials”, Phys.

Rev. Lett. 98, 074102 (2007).

171


ID065

Study of Monochromatic Aberrations Introduced by Perfectly Conducting

Spherical Mirrors in the Focusing of Ultrashort Light Pulses.

S. Anaya-Vera*, M. Rosete-Aguilar, J. Garduño-Mejía, N.C. Bruce.

Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México

Cd. Universitaria, Circuito Exterior S/N, Apdo. Postal 70-186, D.F. 04510, México

*sergio_anayavera@yahoo.com.mx

KEY WORDS: Aberrations, mirrors, pulse shaping, nonlinear microscopy.

By using mirrors to focus ultra-short pulses the dispersive effects, which are introduced by lenses,

are avoided but aberrations are not. In the present work we analyze the effects of the

monochromatic aberrations on the spatial-temporal pulse focusing. The scalar diffraction theory is

used to model the focusing of ultrashort pulses near the focal region of the mirror. We will study

two cases: in the first one, the mirror introduces no aberrations; in the second case, the mirror does

introduce aberrations. For the ideal mirror we assume incident pulses with an initial temporal

duration of 2.7, 4.5 and 10fs for a carrier wavelength of 810nm. In the second case, the pulses

have initial durations of 20 and 200fs, and the incident beam makes an angle of incidence between

0° and 8°, with respect to the optical axis of the mirror, to induce the aberrations.

When the mirror is aberration-free, the focused pulse is wider in time than the incident

pulse. This temporal widening is generated by the diffraction introduced by the mirror 1 . We show

that monochromatic aberrations do not change the duration of the pulse, however, they introduce

a large spatial spreading.

A 20fs pulse in the focal plane of a mirror. The pulse suffers spatial spreading by the monochromatic aberrations.

The incident pulse beam makes an angle of 5° measured from the optical axis of the mirror.

Acknowledgments. We gratefully acknowledge sponsorship of this work from the

Dirección General de Asuntos del Personal Académico (DGAPA) of the Universidad Nacional

Autónoma de México (UNAM), project PAPIIT-IG100615.

1

S. Anaya-Vera, L. García-Martínez, M. Rosete-Aguilar, N.C. Bruce, and J. Garduño-Mejía, J. Opt. Soc. Am. A, 30,

8 (2013) 1620-1626.

172


ID066

Astigmatism Compensation in an off-axis Laser Cavity.

A. Moreno-Larios*, M. Rosete-Aguilar, J. Garduño-Mejía.

Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México

Cd. Universitaria, Circuito Exterior S/N, Apdo. Postal 70-186, D.F. 04510, México

*agustin90m@gmail.com

KEY WORDS: Aberrations, Astigmatism, laser cavity.

A laser cavity designed for mode-locked operation requires a well-defined mode structure 1 . A pair

of spherical mirrors is used within the laser cavity to focus the light into the non-linear gain

medium. In this work we present the design and analysis of a laser cavity shown in Figure (1),

which uses a titanium-doped sapphire crystal rod with faces cut at Brewster´s angle. In such a

system the optical axes of the mirrors are not collinear introducing astigmatism into the focusing

spot within the crystal rod. We discuss how to compensate the astigmatism introduced by the offaxis

operation of the spherical mirrors. The coupling between the pump beam and the focusing

beam within the crystal rod is critical for the stability of the mode-locked operation. The ABCD

matrix method is used to evaluate the stability of this laser cavity.

Figure 1. Astigmatism-compensated laser cavity.

Acknowledgments. We gratefully acknowledge sponsorship of this work from the Dirección General de

Asuntos del Personal Académico (DGAPA) of the Universidad Nacional Autónoma de México (UNAM),

project PAPIIT-IG100615.

1 J. C. Diels and W. Rudolph, Ultrashort Laser Pulse Phenomena, 2 nd . Edition, (Elsevier, London,

2006).

173


ID070

Ray Tracing and Polarization for Uniaxial Birefringent Lenses Using Huygens

Principle

!

Luis A. Alemán-Castañeda 1 , Martha Rosete-Aguilar 1

Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, Apartado Postal 70-186,

C.P. 04510, México D.F., México

laleman.k@ciencias.unam.mx, martha.rosete@ccadet.unam.mx

!

KEY WORDS: Uniaxial birefringent lenses and parallel plane plates, Huygens principle,

ordinary and extraordinary polarization, computational ray tracing, paraxial aproximation.

!

Birefringent lenses and crystals are important due to their different applications, particularly in

second harmonic generation. There are two types of birefringent crystals: uniaxial and biaxial.

Huygens’ principle can be used to model refraction in the former ones

1

to compute the wave and

Poynting vectors, which are in general no longer parallel. According to Huygens’ principle, each

point in a wavefront can be seen as a secondary spheric (ordinary ray) or ellipsoidal

(extraordinary) point source, and the envelope of the each type of wavelets will conform the new

wavefront.

This model is a geometrical one, and although its equations

2

are rather complex, they are

easy to implement with numerical computation. A ray tracing program for lenses and parallel

plane plates was written in C++ to compare it with our own experimental data and results in the

literature

3. Furthermore, a paraxial analysis was carried out to find the foci of a calcite lens and

correct the paraxial approximation already calculated by M. Avendaño and M. Rosete

4, as well as

a study of optical aberrations focusing on the extraordinary ray. Lastly, polarization can be

included in the model computing it from the wave vectors and the crystal axis orientation. Our

aim is to show possible applications particularly for non-colimated rays, which are used in

second harmonic generation. We gratefully acknowledge sponsorship of this work from the

General Directorate of Academic Staff Affairs at the National Autonomous University of Mexico

(DGAPA-UNAM), project PAPIIT-IG100615.

!

!

!

Spot diagram at the ordinary focal distance, showing the optical aberration in a convex-plane lens with

an angle θ between the crystal axis and the optical axis. In green the extraordinary, in red the ordinary.

1

F. Jenkins, H. White, Fundamentals of optics, 3 rd . ed., (McGraww-Hill, 1957). .

2

M. Avendaño, O. Stavroudis, J. Opt. Soc. Am. A. 19 (2002) 1674-1679.

3

J. Lesso, A. Duncan, et al, Applied Optics, 39 (2000) 592-598

4

M. Avendaño, M. Rosete, J. Opt. Soc. Am. A. 22 (2005) 881-891.

174


ID071

Quadrupolar second harmonic generation by helical beams and vectorial

vortices

Miguel G. Mandujano 1 , and Jesús A. Maytorena 2

1. Applied Physics Division, CICESE, Ensenada, B. C., México.

2. Centro de Nanociencias y Nanotecnología, UNAM, Ensenada, B. C., México.

mangel.gmandujano@gmail.com, jesusm@cnyn.unam.mx

KEY WORDS: Second harmonic, Orbital Angular Momentum of Light, Nonlinear Optics.

We study the optical second-harmonic generation by scattering from a homogeneous

centrosymmetric thin composite material when is illuminated with higher-order Gaussian beams.

It is considered that the induced polarization is of the second order quadrupolar type

which depends on the inhomoheneity of the incident electric field . We calculate the angular

patterns of second-harmonic radiation to different cases of illumination with transverse spatial

structure and arbitrary polarization beams. In particular, it is considered that the beam consist of

Hermite-Gauss (HG) modes or Laguerre-Gauss (LG) modes. We analize combinations of HG

modes called doughnut modes with radial or azimuthal polarization and LG helical modes with

optical orbital angular momentum of linear or circular polarization. We found that the quadrupole

second harmonic generation (SHG) depends sensitively on the transverse structure and

polarization of the fundamental field. The responds to introduces a factor for the

Fourier component of the scattering amplitude in the second harmonic absent in the dipole case.

This new factor may give rise to zero lines intensity or rings patterns of second-harmonic

radiation, changes in polarization or a change in the azimuthal phase radiation. For circularly

polarized beams ( ) and a helical wavefront orbital angular momentum , it was found

that the beam generated at the second harmonic acquires a helical phase (Fig. 1),

in contrast to the case of dipolar second harmonic which the orbital angular momentum doubles.

These characteristics could be used to identify SHG processes quadrupole type or produce a

beam in with angular and polarization pattern desired. In particular, one could use the

inhomogeneity of the new beams and the polarization changes in areas such as nano-optics,

photonics and optical tweezers 1 .

Fig 1. Intensity distribution of a fundamental field TEM0,0 and the corresponding intensity pattern of the

scattered second harmonic field for linearly and circularly polarization..

1 . Miguel G. Mandujano and Jesús A. Maytorena, Phys. Rev. A 88, 0238111 (2013).

175


ID072

Optimal randomness generation

from optical Bell experiments

!

A.Máttar 1 , P.Skrzypczyk 1 , J.Bohr-Brask 2 , D. Cavalcanti 1 and A. Acín 1,3

1

ICFO - Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona), Spain

2

Department of Theoretical Physics, University of Geneva, 1211 Geneva, Switzerland

3

ICREA-Institució Catalana de Recerca i Estudis Avançats, Lluis Companys 23, 08010 Barcelona, Spain

!

Alejandro.Mattar@icfo.es

!

KEY WORDS: Quantum optics, Entanglement, Nonlocality, Random processes.

!

Quantum systems have the potential to provide a strong form of randomness which cannot be

attributed to incomplete knowledge of any classical variable of the system. At the basis of such

genuine randomness lies a quantitative relation between the amount by which a Bell inequality is

violated [1] and the degree of predictability of the results of the test [2]. Intuitively, the violation

of a Bell inequality certifies the presence of nonlocal correlations, and in turn, this guarantees that

the outcomes of the measurements cannot be determined in advance. Furthermore, this genuine

randomness can be certified without any detailed assumptions about the internal working of the

devices used, that is, in a device-independent fashion [3].

A few years ago, Pironio et al. [2] implemented the first device-independent random

number generation (DIRNG) proof-of-principle experiment. It involved light-matter interaction

and managed to certify 42 genuinely random bits over a period of one month. More recently,

DIRNG has been observed in entirely optical setups, based on polarisation measurements of

entangled photons distributed from a spontaneous parametric down-conversion (SPDC) source.

These optical setups represent an important achievement as they enable much higher rates of

genuine random bits per time unit.

Here we construct a general method for optimal randomness generation and apply it to

such all-optical setups. We certify up to four times more randomness than previous methods.

!

! !

Fig. 1. Setup for DIRNG within an all optical Bell experiment based on SPDC.

[1] Bell J 1964 Physics 1 195–200

[2] Pironio S, Acin A, Massar S, de la Giroday A B, Matsukevich D N, Maunz P, Olmschenk S,FHayes D, Luo L,

Manning T A and Monroe C 2010 Nature 464.

[3] Masanes Ll, Pironio S and Acin A 2011 Nature Communications 2.

176


ID074

Observation of secondary ionization by photon feedback in a

Townsend discharge

Eduardo Basurto 1 , Laura N. Serkovic Loli 2 , Jaime De Urquijo 2

1

Departamento de Ciencias Básicas, Universidad Autónoma Metropolitana-Azcapotzalco,

Av. San Pablo 180, 02200, México D.F., México.

2

Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México,

PO Box 48-3, 62251, Cuernavaca, Mor., México

lauraserkovic@gmail.com

KEY WORDS: Ionization, photon feedback, metastables, nitrogen.

The secondary ionization process due to the decay of N 2 metastables that emit UV light reaching

the cathode (also known as photon feedback 1 ) has been observed under pre-breakdown conditions

in a pulsed Townsend discharge from the electron avalanche for E/N=180-260 Td. A reaction

scheme has been proposed and simulations have been compared with the measurements. Good

agreement between simulation and measurement has been found. Reaction rates for metastable

N 2 * formation and decay have been derived. Our findings indicate that the photon feedback

processes plays an important role in the N 2 discharge with an aluminium cathode.

Measured and simulated electron avalanches in N 2 at E/N=250 Td.

[1] H. Raether, Electron avalanches and Breakdown in Gases; Butterworts:London, (1964).

177


ID080

How random are random numbers generated using photons?

Ali M. Angulo M ., Aldo Solis, Roberto Ramírez Alarcón, Héctor Cruz Ramírez, Alfred B. U'ren,

Jorge G. Hirsch

Authors’ affiliation and full address (9-point type, centered, italics)

Corresponding Author’s e-mail address and URL: (9-point type, centered, italics)

KEY W ORDS: Quantum Randomness, algorithmic information, Borel normality, SPDC pairs

Randomness is fundamental in quantum theory, with many philosophical and

practical implications. In this paper we discuss the concept of algorithmic

randomness, which provides a quantitative method to assess the Borel normality

of a given sequence of numbers, a necessary condition for it to be considered

random. We use Borel normality as a tool to investigate the randomness of ten

sequences of bits generated from the differences between detection times of

photon pairs generated by spontaneous parametric downconversion. These

sequences are shown to fulfil the randomness criteria without difficulties. As

deviations from Borel normality for photon-generated random number sequences

have been reported in previous work, a strategy to understand these diverging

findings is outlined 1 .

In the figure we present, for each of the ten sequences, their deviations from the expected mean

value. The box-and-whisker plots, display in short horizontal lines, from bottom to top, the

minimum value, first quantile, median, third quantile and maximum value, of the difference

|P(i)− (½) m |, including the results for m =2, 3 and 4. More information can be consulted at ref 1.

Deviations from the mean value for each of the ten sequences. The red line represents the maximum

deviation allowed by Borel normality.

1 Citation of a journal article: Ali M. Angulo M ., Aldo Solis, Roberto Ramírez Alarcón, Héctor Cruz Ramírez,

Alfred B. U'ren, Jorge G. Hirsch kin, to be published in Physica Scripta as invited article (2015).

178


ID086

Quantum efficiencies in finite disordered networks

connected by many-body interactions

Adrian Ortega, Manan Vyas, Luis Benet

ABSTRACT

The quantum efficiency in the transfer of an initial excitation in disordered finite

networks, modeled by the k -body embedded Gaussian ensembles of random matrices,

is studied for bosons and fermions. The influence of the presence or absence of timereversal

symmetry and centrosymmetry/centrohermiticity are addressed. For bosons

and fermions, the best efficiencies of the realizations of the ensemble are dramatically

enhanced when centrosymmetry (centrohermiticity) is imposed. For few bosons distributed

in two single-particle levels this permits perfect state transfer for almost all

realizations when one-particle interactions are considered. For fermionic systems the

enhancement is found to be maximal for cases when all but one single particle levels

are occupied.

Reference

[1] arXiv:1503.02027. Submitted to Annalen der Physik.

1

179


ID088





Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México,

Circuito Exterior S/N, Ciudad Universitaria AP 70-186, C.P. 04510

*e-mail: omar.rodriguez@ccadet.unam.mx

**e-mail: neil.bruce@ccadet.unam.mx





















Effect of line and trench profile variation on specular and diffuse reflectance from a

periodic structure,


Characterization of chemically etched Indium Phosphide surfaces with light scattering,


Multiple scatter of vector electromagnetic waves from rough metal surfaces with infinite

slopes using the Kirchhoff approximation

180


ID0100

Transient-Thermo-Reflectance to study carrier dynamics on THz antennas

Ramírez-Guerra Catalina and Garduño-Mejía Jesús and Rosete-Aguilar Martha

Centro de Ciencias Aplicadas y Desarrollo Tecnológico, UNAM

Avenida Universidad No. 3000, Col. Universidad Nacional Autónoma de México, C.U., Delegación Coyoacán, C.P. 04510,

México, D.F.

catalina.ramirez@ciencias.unam.mx

KEY WORDS: Time Resolved Spectroscopy, Ultrafast Charge Carrier Dynamics, Transient

Thermo-Reflectance, THz Anthenas.

In this work a Time Resolved Spectroscopy technique based on Transient-Thermo-Reflectance

was implemented to characterize the ultrafast of carrier dynamics in an arrangement of coplanar

transmission lines, fabricated on GaAs working as THz antenna. The experimental setup is a

pump-probe system which consists on an array of non-collinear autocorrelator using a ultrashortpulsed

laser with a time duration of ~200 femtoseconds. Pump pulses reach excitation fluence

capable to disturb the sample to induce a transient process. With a probe pulse we detect the

change in the reflectance associated with the transient processes of carrier dynamics and energy

transfer between THz antenna electrodes on time scales of picosecond and subpicosecond. The

developed instrument has a sensitivity of about 10 -6 .

Variations on the relaxation times, immediately after the optical excitation, were found: respect

to: external bias voltage, excitation fluence and focussing incidence position of pump beam. This

changes are mainly attributed to the low density of electric field between the electrodes 1 , due to

the large separation between the anthena transmission lines (300 um).

Left. Time resolved spectrometer experimental setup with sensitivity of about 10 -6 . Right Differential Transient

Thermo-Reflectance response of an antenna as a function of optical excitation fluence.

Aknowlegements

The authors gratefully acknowledge sponsorship for this work by DGAPA-UNAM PAPIIT

IG100615

_______________________

1

Stephen E. Ralph and D. Grischkowsky. Appl. Phys. Lett., 59 (1991) 1972-1974.

181


ID0101

Classical chaos in atom-field systems

Jorge Chávez Carlos 1 , M. A. Bastarrachea Magnani 1 , Sergio Lerma Hernández 2 , Jorge Hirsch G. 1

1 Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Apdo. Postal 70-543, México D.F.,C.P. 04510

2 Facultad de Física, Universidad Veracruzana, Circuito Aguirre Beltrán s/n, Xalapa, Veracruz, México, C.P. 91000

E-mail’s: jorge.chavez@correo.nucleares.unam.mx

mamigre4008@gmail.com

slerma@uv.mx

hirsch@nucleares.unam.mx

KEY WORDS: Classical chaos, quantum chaos, atom-field interaction, Dicke model, Lyapunov

exponent.

The emergence of chaos in an atom-field system is studied employing both semiclassical and

numerical quantum techniques, taking advantage of the character of the Hamiltonian. The

semiclassical Hamiltonian is calculated as the expectation value of the quantum Hamiltonian of

Dicke 1 between Glauber (for the field) and Bloch (for the atoms) coherent states 2 , its Poincaré

sections exhibit regular and chaotic regions 3 . An analytical expression for the semiclassical

energy density of states is obtained by the available phase space which provides an exact

unfolding to extract the Lyapunov exponent. If the maximal Lyapunov exponent for the orbits is

positive, the reference orbit is chaotic, if the Lyapunov exponent is zero, the orbit is regular 4 . The

Poincaré section are a powerful visual tool to identify individual states belonging to a regular or

chaotic region and the Lyapunov exponent provide a measure quantitative to describe this.

Lyapunov exponent for the Dicke model in parametric space for energy vs interaction parameter atomfield,

Lyapunov exponent cero or positive describes regular or chaotic region respectively.

1

R. H. Dicke, Phys. Rev., 93, 99(1954).

2 Eduardo Nahamad Achar, Octavio Castaños, Ramón Lopez Peña and Jorge G. Hirsch, Phys. Scr., 87, (2013)

038114.

3

M. A. Bastarrachea Magnani, S. Lerma Hernández and J. G. Hirsch, Phys. Rev. A 89, 032101(2014).

4 Pavel Cejnar and Pavel Stransky, AIP Conference Proceedings, 1575, 23 (2014); doi: 10.1063/1.4861698.

182


-0.125 0 0.125

ID0107

Transverse amplitude transfer of optical vortex to a single photon

by the process of spontaneous parametric down conversion

Verónica Vicuña-Hernández 1∗ , José Tomás Santiago-Cruz 1 ,Roberto

Ramírez-Alarcón 1 , Héctor Cruz-Ramírez1, andAlfredB.U’Ren 1

1 Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México Apdo. Postal 70-543, 04510 México

Distrito Federal, México.

∗ veronica.vicuna@correonucleares.unam.mx

KEY WORDS: SPDC,OAM, optical vortex

In this work we study, for the spontaneous parametric downconversion process, how the

transverse amplitude of the pump may be transferred to one of the emitted photons in a given

pair when heralded by the detection of the remaining photon. We present the description of

this process with a discussion of the short-crystal regime within which faithful transfer of the

transverse amplitude occurs. We show experimental results for Bessel-Gauss pump beams of

orders l =1and l =2and we verify that the transverse amplitude mechanism occurs. We

show that our heralded single photons exhibit a non-diffractive behavior, and we show that

these heralded single photons are in fact vortices with orbital angular momentum transferred

from the pump. An optical vortex beam, implemented classically, can be transferred to the

transverse amplitude of a heralded single photon. The experiments are based on the process

of spontaneous parametric downconversion (SPDC) for the generation of signal and idler

photon pairs, using a pump in the form of a Bessel-Gauss (BG) beam with orbital angular

momentum (specifically, with topological charge l =1and l =2). In order to verify the

vortex nature of our heralded single photon, we have shown that the conditional angular

spectrum and the transverse intensity at the single-photon level match similar measurements

carried out for the pump. In addition, we have shown that when our heralded single photon

is diffracted through a triangular aperture, the far-field single- photon transverse intensity

exhibits the expected triangular arrangement of intensity lobes associated with the presence

of orbital angular momentum.

y(mm)

a)

-0.125 0

x(mm)

0.125

16

14

12

10

8

6

4

2

0

x10

coinc. counts per 120s

y(mm)

-0.15 0 0.15

-0.15 0

0.15

x(mm)

b)

3.5

3

2.5

2

1.5

1

0.5

x10 2

coinc.counts per 300s

Measured far-field, single-photon diffraction pattern through a triangular aperture, obtained

for a BG pump beam of order l =1(panel a) and l =2(panel b).

183


ID0108

1⇤ 1 1

1

1 2

1

1

2















coincidence counts per 10s

2500

2000

1500

1000

500

A(01)

B(11)

G(21)

C(11)

F(21)

e

C(01)

F(01)

G(11)

B(11)

A(01)

0

590 610 630 650 770 790 810 830 850

idler wavelength (nm)

signal wavelength (nm)

f






184


ID0113

Defocusing effect of laser pulse on terahertz radiation from an

photoconductive antenna source

Gaudencio Paz-Martínez 1 , Naser Qureshi 1 , Jesus Garduño-Mejía 1 , Oleg Kolokolsev 1 , Carlos G.

Treviño-Palacios 2

1 Centro de Ciencias Aplicadas y Desarrollo Tecnológico, UNAM, DF, Mexico.

2 Instituto Nacional de Astrofísica, Optica y Electrónica, Puebla, Mexico.

KEY WORDS: Terahertz, photoconductive source, defocusing tolerance, Rayleigh length.

We present a study of the effect of defocusing the excitation laser pulse when it hits the

semiconductor in a hertzian dipole with H-shape structure. The experiment was carried out by

moving the antenna structure in two dimensions, while the laser was fixed in the same position. A

second antenna was used to measure the terahertz pulse radiated with the laser spot at each point,

and this measurement was repeated at different defocusing distances perpendicular to plane xy,

until 2.5 Rayleigh lengths. The objective is quantify the tolerance of a terahertz time domain

spectroscopy system, and we study the variation of peak amplitude, spectrum, phase and energy

distribution as a function of excitation position and defocus. We find that although the terahertz

spectrum is sensitive to alignment, at certain values, a terahertz source can be made relatively

tolerant to variations in focus, alignment and details of the geometry of the photoelectric system,

providing a window for a more robust field operation.

Normalized map of the distribution of peak THz amplitude along the H-shape structure for selected

distances of defocus in the optical excitation, in a range of about five Raleigh lengths. Red indicates high

amplitude and blue low.

185


ID0121

CHARACTERIZATION OF THE VLC CHANNEL FOR INDOOR

APPLICATIONS

A.M. Ramirez-Aguilera 1,* , J.M. Luna-Rivera 1 , R. Perez-Jimenez 2

1 Facultad de Ciencias, UASLP, Av. Salvador Nava s/n, Zona Universitaria, San Luis Potosí,

S.L.P., CP 78290, México

2 IDeTIC, Universidad de Las Palmas de Gran Canaria

Las Palmas de Gran Canaria, 35017, Spain

*atziry@fc.uaslp.mx

KEY WORDS: Visible Light Communications, channel model.

With today’s growing demand for bandwidth-intensive applications, network technologies face

important challenges to provide services with the adequate quality of service. In this context, the

use of LED-based lighting systems as a short range communication technology has attracted

much attention from the research community in recent years. Unlike most communication

systems, a VLC link is not designed exclusively for data transmission but also for illumination.

Since VLC deployment is based on exploiting the existing LED lighting infrastructure, the

technology must demonstrate the advantage of having a VLC system integrated in the lighting

system of a room.

In order to meet specific illumination conditions for an indoor environment, the lighting

design must consider several factors such as the LED luminaries available in the market, their

power and emmission angle, room geometry, spatial arrangement of the luminaries, among other

factors. We remark that these requirements are, in general, ignored or not related to the

performance and needs of a VLC communication link. Therefore, this research work aims to

study the resulting VLC communication channel under the conditions imposed by the

commercial multi-lamp design, guaranteeing the lighting functionality and its aesthetic appeal.

A simulation-based environment is utilized to characterize the VLC channel on the basis

of a practical indoor scenario. We consider a typical room (Figure 1) with common material for

the application scenario where the lighting layout has been calculated with the assistance of a

professional lighting design software. The results show that the VLC system performance is

affected by the spatial distribution of the multi-lamp layout and the physical characetristics of

each luminaire. Moreover, we have unveiled the importance of time synchronization in the

performance of VLC systems for indoor scenarios. While high-speed VLC link may be possible

in practical indoor environments, they come with the need of a hardware-assisted

synchronization approach which will challenge the implementation of the VLC technology.

L 2 L 3

L 1

LOS

L 4

τ 2

τ 4 τ 3

τ 1

NLOS

Figure 1. Example of scenario, signal path and effect of synchronization in algorithm.

186


ID0123

Proposal for studying electric quadrupole transitions using

structured light beams.

S. Hernández-Gómez 1 , P. Ortega Escorza 1 , F. Ponciano-Ojeda 1 , C. Mojica Casique 1 ,

F. Ramírez-Martínez 1 , J. Flores-Mijangos 1 , K. Volke-Sepúlveda 2 , R. Jáuregui 2 ,J.

Jiménez-Mier 1

1 Instituto de Ciencias Nucleares, UNAM, 04510 México. D.F., México

2 Instituto de Física, UNAM, 04510 México D.F., México

Contact shgaeo@ciencias.unam.mx

KEY WORDS: Electric quadrupole transition, SLM, phase structured beams.

The aim of this project is to perform an experimental study of the interaction between

an electric quadrupole (E2) transition 1 and an spatially-structured light beam, a problem

that has previously been theoretically studied by Dra. R. Juregui 2 . For this purpose, the

5P 3/2 ! 6P 3/2 E2 transition in atomic rubidium shown schematically in Figure 1 will be

probed with a 911 nm spatially-structured light beam. In the present work the progress

towards the generation of 911 nm spatially-structured beams by using a liquid crystal-spatial

light modulator LC-SLM (Hamamatsu X10468) is presented together with a proposal for the

experimental setup that will be used for performing the study of the interaction between the

structured light and the E2 atomic transition.

The structured beams are generated using a Julia 3 based program that allows to send

images to the SLM in the proper format (800 ⇥ 600 size, black&white, 8-bit resolution).

The program also have functions that make a set of di↵erent patterns and send them to the

modulator. For example these patterns can be used for generating Bessel beams.

As shown in Figure 1 (A), the experimental setup is formed by a TiS laser operating

at 911 nm, the LC-SLM that gives structure to the beam, an atomic rubidium cell and a

detection system for the 420 nm light resulting from the 6P 3/2 ! 5S 1/2 spontaneous decay.

The main components of this detection system are a photomultiplier tube and a Lock-In

amplifier.

SLM

6 p 3 /2

Spatial

Filter

Rb cell

Phototube

420 nm

911 nm

5 p 3/2

780 nm

911 nm

780 nm

5 s 1/2

(A) (B)

Figure 1: (A) Experimental setup. (B) Level scheme for the excitation of rubidium atoms.

1 Citation of a journal article: Colín-Rodríguez et al. Polarization e↵ects in the interaction between

multi-level atoms and two optical fields. Physica Scripta, 90(6):068017, 2015.

2 Citation of a journal article: R. Jáuregui. Control of atomic transition rates via laser-light shaping.

Phys. Rev. A, 91:043842, Apr 2015.

3 julialang.org

187


ID0125

Statistical Properties of the Diffraction Pattern Produced by a Speckle Field

Laura Pérez García 1⇤ , Santiago López Huidobro 2 Alejandro V. Arzola 1 Karen Volke-Sepúlveda 1

1 Instituto de Física, Universidad Nacional Autónoma de México, Apdo. Postal 20-364, 01000 México D. F., México.

2 Facultad de Ciencias, Universidad Nacional Autónoma de México, Apdo. Postal 20-364, 01000 México D. F., México.

⇤ laup@ciencias.unam.mx

KEY WORDS: Speckle, Diffraction, Statistical Distribution.

The speckle phenomenon arises whenever a coherent wave field is transmitted through or reflected

by a rough surface, and in optics, it also appears as a result of propagation through multimode

optical fibers. Speckle has been extensively studied and it has important applications in many

areas, from medicine 1 to quantum phenomena 2 .

We study the diffraction pattern produced by a speckle field impinging on a rectangular aperture

of dimensions L x ⇥ L y . As the initial condition, we consider a plane wave passing through the

aperture and a rough surface represented by a normal distribution of phases with standard deviation

s. For s = 0 we get a surface without roughness and the increase of the standard deviation means

a rougher surface. We study the evolution of the propagation for a distance z by solving the Fresnel

integral with a standard algorithm based on the FFT (Fast Fourier Transform).

Numerical results for energy distribution and the correlation in respect to the diffraction pattern

without speckle are discussed in terms of different control parameters, such as the aperture size,

the propagation distance and s.

(a)

Speckle Pattern in far-field for an aperture of 4mm ⇥ 8mm at a distance of z = 100m for s = 1.4 (left) and s = 0.3

(right) .

The analysis of the resulting diffraction patterns was divided in two parts. On the one hand

we calculated the cross-correlation between diffraction patterns with and without speckle. On the

other hand we analyzed the integrated energy as a function of the detection area, in order to extract

information about the distribution of energy.

We have observed that in the near field, the diffraction pattern for large s resembles the geometrical

shadow of the object, but it expands very rapidly with the propagation distance in comparison with

the diffraction pattern without speckle. In the far field the correlation between the diffraction pattern

with and without speckle is completely lost for large values of s. For small values of s there is a

large correlation and both patterns remain basically confined within the same region, as it can be

seen in the figure.

With the availability of light modulation technology with liquid crystal devices, experimental

studies can be done to verify the numerical results. This is the next step in our research.

We acknowledge support of DGAPA-UNAM, project IN-115614.

(b)

References

[1] A. F. Fercher, et al., Optical coherence tomography: principles and applications. Reports on Progress in Physics,

66: 239-303,(2003).

[2] L. Levi et al., “Hyper-transport of light and stochastic acceleration by evolving disorder”, Nature Physics ,8,

912 (2012) .

188


ID0127

Design and construction of ultrashort pulse Erbium doped fiber optic laser

with broad spectrum.

P. Castro-Marín [A] , J Garuño-Méjia [A] , M. Rosete-Aguilar [A]

[A] Centro de Ciencias Aplicadas y Desarrollo Tecnológico (CCADET), U NAM

Apdo, Postal 70-186, CP 04510. Coyoacán Cd. Universitaria, México D.F.

Corresponding Author’s e-mail address and URL: jesus.garduno@ccadet.unam.mx , martha.rosete@ccadet.unam.mx

pablo.castro@ccadet.unam.mx

KEY WORDS: Ultrashort Pulse, Erbium Doped Fiber Laser,

In this work we present the design and construction of an Erbium Doped Optical Fiber Laser

(EDFL), with the capacity to generate femtosecond pulses at the middle IR region @1550nm

with a broad band spectrum.

This laser consist in a ring cavity in which the active medium is the Erbium doped fiber optic,

and operate under the principle of “additive pulse-mode locking” to generate the pulses 1,2,3 .

Stable operation has been achieved with a broad spectrum of about 170 nm (20Thz) capable to

generate pulses up to 30fs pulse with a compressor. The laser system is currently applied in the

characterization of optical systems.

Actual FRAC 4 (Frecuency-Resolved AutoCorrelation) of the pulse.

Actual Laser Pulse Spectrum.

Aknowlegements

The authors gratefully acknowledge sponsorship for this work by DGAPA-UNAM

PAPIIT IG100615.

[1] H. A. Haus, E. P. Ippen y K. Tamura, «Additive-pulse modelocking in fiber lasers,» IEEE

journal of quantum electronics, vol. 30, nº 1, pp. 200-208, 1994.

[3] L. E. Nelson, D. J. Jones, K. Tamura, H. A. Haus y E. P. Ippen, «Ultrashort-pulse fiber ring

lasers, Applied Physics B lasers and optics, vol. 65, pp. 277-294, 1997

[4] R. Trebino, Frequency-Resolved Optical Gating: the measurement of ultrashort laser pulses,

Massachusetts: Kluwer Academic Publishers, 2000.

189


ID0129

Adaptive Control of Group Velocity Dispersion of ultrashort pulses.

Reyna-Morales Itzel, Garduño-Mejía Jesús, Rosete-Aguilar Martha , Castro-Olvera Gustavo.

Centro de Ciencias Aplicadas y Desarrollo Tecnológico – UNAM, Avenida Universidad No.

3000, Colonia. Ciudad Universitaria, Delegación Coyoacán, C.P. 04510, México, D.F.

Corresponding Author’s e-mail address and URL: shice@comunidad.unam.mx

Keywords: Deformable Mirror, ultrashorts Pulses, Group Velocity Dispersion, Genetic

Algorithms.

In the present work, we use adaptive control to compensate the Group Velocity Dispersion

(GVD) of Ultrashort Pulses using a Pulse Shaper based on a Micromachining Deformable

Mirror (MMDM)1. The Pulse Shaper produce a Spectral Phase correction to compensate the

GVD introduced for the output coupler of the laser cavity and the rest of the optics which

delivers and focus the femtosecond pulses in a BBO crystal. The shaper was drived with

Genetic Algorithms using as a target the Second Harmonic Generation (SHG) intensity,

measured with a Photo-Multiplier-Tube (PMT).

Fig.Influence Matrix, we retrieve the shape of the mirror surface and the pulse Spectral Phase.

We were able to maximize the SHG, which indicates an increment on the peak power and

corresponding pulse shortening, and calculate the introduced pulse spectral phase and determine

the shape of the actual mirror surface, trough the Influence Matrix 2 of the MMDM, fig. 1

Acknowledgements

The authors gratefully acknowledge sponsorship for this work by DGAPA-UNAM PAPIIT

IG100615.

References:

[1] J. Garduño-Mejía, A. H. Greenaway and D.T. Reid (2003), Designer femtosecond pulses

using adaptive optics, Optical Society of America.

[2]

. Garduño-Mejía, A. Greenaway and D.T. Reid, (2004), Programmable spectral

phase control of femtosecond pulses using adaptive optics and real-time pulse

measurement, Journal of the Optical Society of America B, 21, p 833.

190


ID0138

Development of video-rate spectral phase interferometry for direct electric

field reconstruction (SPIDER)

Contreras Martinez, R. 1 , Garduño Mejía, J. 1 , Rosete Aguilar, M. 1 Román Moreno, C.J. 1

1 Centro de Ciencias Aplicadas y Desarrollo Tecnológico (CCADET), U NAM Apdo, Postal 70-186, CP 04510. Coyoacán Cd.

Universitaria, México D.F.

ramiro.contreras@ccadet.unam.mx, jesus.garduno@ccadet.unam.mx, martha.rosete@ccadet.unam.mmx,

carlos.roman@ccadet.unam.mx

KEY WORDS: Pulse characterization, femtosecond, SPIDER, ultrafast, video-rate.

In this work we present a femtosecond characterization system based on a Spectral Phase

Interferometry for Direct Electric-field Reconstruction (SPIDER) 1 system. Since the calibration

and the measurement itself needed a high dynamic range and a high resolution spectrometer we

designed and manufactured a spectrometer that works both in the visible and infrared region with

a resolution of 0.06 nm per pixel and a limited bandwidth of 220 nm using a linear CCD array. The

instrument relies on both spectral interferometry and spectral shearing and is capable of

reconstructing the spectral phase, spectral profile and the temporal profile of a 258 femtosecond

laser pulse from a Ti:Sapphire laser (Coherent MIRA 900) at a minimum refresh rate of 24 Hz

(video- rate).

Figure 1: SPIDER interferogran and the reconstructed pulse with its phase.

Aknowlegements:

The authors gratefully acknowledge sponsorship for this work by DGAPA-UNAM PAPIIT

IG100615

1

C. Iaconis, I.A. Walmsley, Spectral phase interferometry for direct electric-field reconstruction of ultrashort optical

pulses, Optics Letters 23, 792 (1998)

191


ID0140

High-stability Electronic Control for ECDL Applied in Spectroscopy

Cerna Larenas. M 1, 2 , Guzmán Estrada. R 1 , Varela Magalhães, Daniel 3

1 Departamento de Ciencias Físicas, Universidad de La Frontera, Temuco, Chile

2 Programa de Doutorado em Engenharia Mecânica, EESC, Universidade de São Paulo, Brasil

3 Departamento de Engenharia Mecânica, EESC, Universidade de São Paulo, Brasil

1 manuel.cerna@usp.br

KEY WORDS: ECDL, temperature controller, current controller, espectroscopy

An extended cavity diode laser (ECDL) is a kind of coherent optical source which is able to

generate a signal whose power and wavelength are highly stable. Due to its characteristics a

ECDL has multiple applications in diverse areas of the science and engineering, highlighting its

use in atomic physics and spectroscopy.

The ECDL is composed by four essential components: the laser diode; a dispersive

element which usually is a diffraction grating that is responsible for providing an optical feedback

to the laser diode; a controller of the current supplied to the diodo; and a temperature control of

the laser diode junction. Additionally it is posible to control the position of the dispersive element

in order to obtain an optical signal with selectable wavelength, in this case the system is enhanced

and denominated as tunable ECDL. Thus, the quality of the obtained signal depends directly on

the performance of the systems responsible for controlling temperature and current.

Left, obtaining fluorescence spectrum of the fungus Botrytis cinerea.

Center, CAD model of ECDL implemented. Right, Rubidium fluorescence in line D 2.

This work exposes the reached results from the implementation of high-stability current

and temperature control systems applied to a ECDL using readily available electronic

components. Additionally, the ECDL was applied in Rubidium absorption spectroscopy, as well

as in fluorescence spectroscopy in the fungus pathogenic Botrytis cinerea.

Under the conditions of the study, it was posible powering the laser diode with a current

of 50mA with variations less than 0.2μA, maintaining a temperature of 18ºC with variations less

than 0.5mºC. In contrast, the commercial system Thorlabs LDC201CU, current controller, and

Thorlabs TED200C, temperature controller, showed higher variations. The implemented system

was validated by obtaining the absorption spectrum of the Rubidium in the D 2 line, and

additionally, the fluorescence of Botrytis cinerea was recorded as a first step in spectroscopic

characterization of this fungus for assess their possible early detection using this technique.

[1] Cunyun Ye. Tunable external cavity diode lasers. 2004. World Scientific Publishing Co.

[2] MacAdam K, Steinbach A, Wieman C. A narrow-band tunable diode laser system with grating

feedback, (1992). American Journal of Physics 60, 1098-1111.

[3] Wieman C, Hollberg L. Using diode lasers for atomic physics. Rev. Sci. Instrum. 62, Jan 1991. 1-20.

192


ID0156

Measurement and control of the frequency of the light of

trapped and control from magnetic elds of a magnetooptical

trap of atoms of rubidium.

L. Vieyra Reboyo 1 , F. Ramírez Martínez 1 , J.I. Jiménez 1

1 Instituto de Ciencias Nucleares, UNAM

Circuito Exterior s/n, Ciduad Universitaria, Zip 70-543, Coyoacan México D.F.

Email: hiperboreus@ciencias.unam.mx URL: www.nucleares.unam.mx/~atomosfrios/J30/

Key words: cold atoms, magneto-optical trap, acusto-optic modulator, time of flight.

The main tool for the diagnostic of atoms clouds confined in a Magneto-Optical Trap (MOT) is

take a photograph of them through a CCD camera. This can be done in two ways, by recording

absorption caused by the cloud of trapped atoms induced on a beam of resonant light beam or

recording the fluorescence emitted by the cloud when interacts with a field of resonant light. For

the first of these two cases is necessary to interrupt suddenly the power of trapped for take image

of the cloud of atoms in the moment it is released or even dome few miliseconds later (Time of

Flight tecnique, TOF) to record the way down and is dissipated when it is set free. To implement

this techniques is then necessary off quickly both the magnetic field and the field of radiation

laser with which we caught cloud. 1

-We present a detailed description of the system issue that have been implemented in the

Laboratory of Cold Atoms from the Instituto de Ciencias Nucleares for the fast interruption of

the magnetic field so as components of the light’s laser used in our MOT. We performed the

design, construction and characterization of a circuit of control the magnetic fields generated by

the coils that make up the MOT. Also, we designed and built a system for sealing a quick laser

beam through the use of a acusto-optic modulator (AOM) in double-pass configuration and a

study of the performance of the system was performed. This system gives us a tool for fine and

quick control of the frequency of radiation laser which interacts whit the atoms. 2

[1] C. J.Foot, Atomic Physics, Oxford University Press (2002)

[2] E. A. Donley, T.P. Heavner, Double-pass Acusto-Optic Modulator, Review of Instrument Scientific 76

063112 (2005)

193


ID0157

Laser frequency modulation for polarization spectroscopy in rubidium

O. López Hernández 1 , J. Jiménez-Mier 1 , F. Ramírez-Martínez 1 , J. Flores-Mijangos 1 , L. Vieyra-

Reboyo 1

1

Instituto de Ciencias Nucleares, Circuito Exterior s/n, Ciudad Universitaria, Apartado Postal 70-543, Coyoacán, C. P.

04510, México D. F

oscar.lopez@ciencias.unam.mx

KEY WORDS: Rubidium, polarization spectroscopy, acousto-optic modulator

Using an acousto-optic modulator in double-pass configuration, the frequency of a laser beam is

controlled 1 . This frequency control allows to tune a 780 nm laser in the 85 Rb and 87 Rb D2 line

(5S1/2→5P3/2). In the reported spectra it will be measured the hyperfine splitting of the 5P3/2 level

in 85 Rb and 87 Rb using Doppler free polarization spectroscopy.

Polarization spectrum in 85 Rb for the 5S 1/2→5P 3/2 transition.

[1] E. A. Donley et al., Double-pass acousto-optic modulator system, Rev. Sci. Instrum., 76 (2005) 063112

[2] C.P. Pearman et al., Polarization spectroscopy of a closed atomic transition: applications to laser frequency

locking, J. Phys. B: At. Mol. Opt. Phys. . (2002) 35 5141

194


ID0158

Photoelasticity

A. López 1 , R. Quintero 2

Centro de Física Aplicada y Tecnología Avanzada. Universidad Nacional Autónoma de México. Boulevard Juriquilla 3001

Juriquilla Querétaro 76230.México.

Email: 1 lopez.alitzel@gmail.com, 2 rquintero@fata.unam.mx

KEY WORDS: Stress measurement, photoelasticity, instrumentation, photoelastic effect.

In commemoration of the International Year of Light and Light-Based Technologies, this paper

presents a brief description of the photoelastic analysis as well as its applications, effects and

associated fundamental concepts.

Photoelasticity (or photoelastic analysis) is an experimental technique for analyzing stress

distributions in loaded structures 1 . Polarized light reveals stress patterns in clear plastic. When

certain plastics are placed between two pieces of polarized material, their stress patterns become

dramatically visible in a brightly colored display. This technique along with strain gages are the

most widely used tools not only for mechanical engineering and design, but also in medicine for

measuring stress in bones and implants.

Figure I: Piece of cd cover exposing the photoelastic effect

1

1 Khan, Akhtar S. & Wang Xinwei "Strain Measurements and Stress Analysis" (2001) Prentice Hall. Chapter 4:

Photoelasticity pp 94-149.

195


ID0159

Design of the Vacuum System for

6 Li and 7 Li Fermi and Bose Gases Experiments

Eduardo Ibarra-GarcíaPadilla 1 , J. A. Seman 1

1 Instituto de Física, Universidad Nacional Autónoma de México,

Apartado Postal 20-364, 01000, México, D.F., México.

Corresponding Author’s e-mail address and URL: ibarragp92@gmail.com

KEY WORDS: Vacuum, Magneto-Optical Trapping, Quantum Fluids

We designed the ultra-high vacuum system necessary for Fermi and Bose Gases

Experiments. This design will be implemented in the National Laboratory of Quantum Matter at

Instituto de Fisica, UNAM. We were able to find an analogy between vacuum systems and

electrical systems, allowing us to model the response of our system under different pipes, pumps

and chambers characteristics. We were able to reproduce the values of known systems and we

also designed the cell needed for Lithium spectroscopy.

Schematics of the Vacuum System. In red the pumps, in purple the main chamber.

At the right the ovens and the mixing chamber.

[1] J.M. Lafferty. Foundations of Vacuum Science and Technology. John Wiley and Sons, Inc., 1998.

[2] A.N. Nesmeyanov. Vapour Pressure of the Elements. Academic Press, 1963.

196


ID0161

Synthesis of Ag and Au nanoparticles by laser ablation in ethanol: a pulsed

photoacoustic study.

1 M. A. Valverde-Alva,*, 2 T. García-Fernándezb, 3 M. Villagrán-Muniz, 3 C. Sánchez-Aké, R.

3 Castañeda-Guzmán, 4 E. Esparza-Alegría, 5 C. F. Sánchez Valdés, 5 J. L. Sánchez Llamazares and 6 C.

E. Márquez Herrera.

1 Posgrado en Ciencia e Ingeniería de Materiales, Universidad Nacional Autónoma de México (UNAM), México D.F., C.P.

04510, México.

2 Universidad Autónoma de la Ciudad de México (UACM), Prolongación San Isidro 151, Col. San Lorenzo Tezonco, México D.F.,

C.P. 09790, México.

3 CCADET Universidad Nacional Autónoma de México (UNAM), México D.F., C.P. 04510, México.

4 Facultad de Ciencias, Universidad Nacional Autónoma de México (UNAM), México D.F., C.P. 04510, México.

5 Instituto Potosino de Investigación Científica y Tecnológica A.C., Camino a la Presa San José 2055 Col. Lomas 4ª sección, San

Luis Potosí, S.L.P. C.P. 78216, México.

6 Departamento de Ingeniería Metarlurgica, Facultad de Química, Universidad Autónoma de México (UNAM), México D.F., C.P.

04510, México.

KEY WORDS: pulsed photoacoustic analysis; laser ablation in liquid; synthesis of nanoparticles

With the experimental setup of Figure 1 the pulsed photoacoustic (PA) technique was used to

study the synthesis by laser ablation of gold and silver nanoparticles (NPs) in ethanol. Using this

technique was possible to determine the concentration and the production rate of the colloidal

NPs. A Nd:YAG laser with nanoseconds pulse duration was used.

The energy of the laser pulses varied from 10 to 100 mJ. The effect of the wavelength of

the laser pulses on the PA signals was studied. Using transmission electron microscopy the shape

and distribution of the NPs were determined. The absorption spectra of the colloids showed

plasmon absorption peaks around nm for the silver NPs and 520 nm for gold NPs. The root

mean square (RMS) of the PA signal amplitude resulted proportional to the laser pulse fluence on

the target surface.

Figure 1 The figure show the experimental setup used to the PA studies of the synthesis of the NPs.

197


ID0162

Experimental system for the measurement of an electric dipole forbidden

transition in atomic rubidium.

F. Ponciano-Ojeda 1 † , S. Hernández-Gómez 1 , O. López-Hernández 2 , C. Mojica-Casique 1 , F.

Ramírez-Martínez 1 , J. Flores-Mijangos 1 , J. Jiménez-Mier 1

Instituto de Ciencias Nucleares, UNAM. Circuito Exterior, Ciudad Universitaria, 04510, México, D.F., México


fsponciano@ciencias.unam.mx

KEY WORDS: Electric dipole forbidden transition, Doppler-free spectroscopy, rubidium.

We present an experimental system to measure the 5P3/2→6P3/2 electric quadrupole transition in

atomic rubidium at room temperature. This system allows Doppler-free measurements of the

fluorescence produced by the decay of the 6P3/2 state to the 5S1/2 ground state in both isotopes.

The spectra obtained also allow for the hyperfine splitting of the 6P3/2 state to be measured.

The system consists of two homemade CW lasers

1 , 2

used to excite the Rb atoms to the

5P3/2 state at 780nm (D2 line) and then to the 6P3/2 state at 911nm. The first laser’s frequency was

locked using polarization spectroscopy

3

to the cyclic transition. The frequency of a counterpropagating

laser tuned to 911 nm was then swept across the hyperfine structure of the

5P3/2→6P3/2 transition. The second laser needed a high output power (~100mW) in order to

compensate for low transition probabilities. The two-step excitation was done in a rubidium cell

shielded from ambient light and stray magnetic fields. The detection of the atoms in the 6P3/2

state was done by measurement of the fluorescence at 420nm produced in the decay to the ground

state. The blue photons produced were collected using an optical system consisting of two lenses

and a bandpass filter that focused the fluorescence onto the cathode of a photomultiplier tube.

This signal was then passed through a lock-in amplifier to extract the fluorescence spectrum from

the signal’s background noise.

Figure 1: Sample spectra of the 5P3/2→6P3/2 transition obtained with our system for both 87 Rb and 85 Rb. The

fluoresence peaks correspond to the hyperfine levels of the 6P3/2 state.

1

A. S. Arnold et al., A simple extended-cavity diode laser, Rev. Sci. Instrum. 69, 1236 (1998)

2

C. J. Hawthorn et al., Littrow configuration tunable external cavity diode laser with fixed direction output beam,

Rev. Sci. Instrum. 72, 4477 (2001)

3

C. P. Pearman et al., Polarization spectroscopy of a closed atomic transition: applications to laser frequency

locking, J. Phys. B 35, 5141 (2002)

198


ID0163

Lasing/amplifying properties of phosphate

glass containing silver nanoparticles

M. Alejandrina Martínez Gámez 1, *, José L. Lucio Martínez 3 , Alexander V. Kir’yanov 1 , Liliana

Licea Jiménez 2 , Sergio A. Pérez García 2 and Miguel A. Vallejo Hernandez 3

1 Centro de Investigaciones en Óptica, Loma del Bosque 115, Col. Lomas del Campestre, León 37150, Guanajuato, México.

2 Centro de Investigaciones en Materiales Avanzados (CIMAV), Unidad Motenrrey, Alianza Nte. 202, Apodaca N.L. 66600

México.

3 División de Ciencias e Ingenierías del Campus León de la Universidad de Guanajuato. Loma del Bosque 103, Col. Lomas del

Campestre 37150, León Guanajuato, México.

*Corresponding author: mamg@cio.mx (M. Alejandrina Martínez Gámez).

Keywords: Fluorescence, Laser materials, Nanoparticles.

We report the fabrication of Yb 3+ - Er 3+ co-doped phosphate glasses with enhanced lasing

properties in the infrared region (1060 and 1550 nm). We report evidence indicating the central

role played by the Silver Nanoparticles (SN) formed during the manufacturing process.

We prepared three Yb 3+ - Er 3+ co-doped sample phosphate glasses containing 0%, 4% an 8% of

silver nitrate. Transmission electron microscopy and X-ray photoelectron spectroscopy analyses

are used to evidence the nucleation and presence of silver nanoparticles (SN) in the glasses. The

basic parameters of the glasses are inspected in function of SN concentration, including

absorption and fluorescence spectra as well as fluorescence kinetics under excitation at 916 nm

(in-band of the Yb 3+ ion) and 406 nm (in-band of the surface plasmon[1] resonance given by the

presence of SN).

We also report the absorption and emission cross-sections at 916 nm, which is obtained from the

fluorescence lifetime τ and the spontaneous emission intensity as a function of the emission

wavelength. These results allow us to assess the potential of the fabricated glasses as laser /

amplifying materials.

1.0

0.9

0.8

0.7

S ample A

S ample B

S ample C

0.6

Intensity

0.5

0.4

0.3

0.2

0.1

0.0

400 600 800 1000 1200 1400 1600

Wavelength, nm

Fluorescence under excitation at 406-nm. The structure in the 450-750 nm range is due to the SN.

[1] M. Eichelbaum and K. Rademann , Plasmonic enhancement or energy transfer on the luminescence of

gold silver-, and lanthanide-doped glass silicate glasses and its potential for light-emitting devices. Adv.

Funct. Mater. 12(13), 2045 (2009)

199


ID0170

Quantum Tomography via Non-orthogonal basis and Weak values

J. J. Díaz 1 , I. Sainz 1 , A. B. Klimov 1

1 Dept. de Física. Universidad de Guadalajara, Revolución 1500. 44420 Guadalajara, Jal, México.

jjdiaz789@gmail.com

KEY WORDS: Weak values, weak measurement, MUBs, bi-orthogonal basis, quantum

tomography, equidistant basis.

Due to its nature, quantum states cannot be determined precisely through quantum

measurements. Nevertheless, it has been proved that an optimal way to characterize

tomographically an a priori unknown state can be achieved using a certain kind of

measurement basis called MUBs (mutually unbiased basis) 1 .

In this work, we propose a new set of equidistant measurement basis, which allows

us to perform quantum state tomography using the weak values of the density matrix. We

derive an explicit formula for its tomographic reconstruction completely analogous to the

standard mutually unbiased bases expansion.

!!!!!!!!!!!!!!!!!!!!!!!!!!!(a)!Compatible!aspects!are!combined!in!classical!physics,!

(b)!while!complementary!aspects!are!combined!in!quantum!physics.!

!

!

[1] W. K. Wootters, Annals of Physics 176, 1 (1988).

200


ID0171

Quantum correlations in semiclassical approximation

I F Valtierra, JL Romero, A B Klimov

Departamento de Física, Universidad de Guadalajara

Av. Revolución 1500, C.P; 44430, Guadalajara, Jalisco, México

fernando11.valtierra@gmail.com

KEY WORDS: Phase transiton, Wigner function, semiclassical limit

It is shown that the quantum dynamics of spin coherent states governed by spin-like

Hamiltonians, in large spin limit presents quantum phase transistions (QPT). Two non-linear

effects: (a) spin squeezing and (b) spin entanglement are analysed using Wigner function

approach in the quasiclassical limit and numerically compared with the exact solution.

Different parts of the initial distribution rotate with different velocities, which leads to a deformation of

the initial distribution and eventually to spin squeezing.

201


ID0173

Swapping of Quantum Discord

Ariana Muñoz 1,2 , Luis Roa 1

Departamento de Física, Universidad de Concepción, Casilla 160-C, Concepción, Chile

Departamento de Física, Universidad de Guadalajara, Guadalajara, Jalisco, Mexico

arianamunoz@udec.cl

KEY WORDS: Quamtum discord, entanglement, von Neumann measurement

Quantum discord 1 , a kind of quantum correlation, is defined as the difference between quantum

mutual information and classical correlation in a bipartite system. In general, this correlation is

different from entanglement, and quantum discord may be different from zero even for a wide type

of separable states.

One the other hand, the basic entanglement-swapping scheme 2 can be seen as a process which

allows one to redistribute the Bell states properties between different pairs of a four-qubit system.

We analyze a similar scheme, discord-swapping, by performing a Bell–von Neumann measurement

over two local qubits, each one initially correlated through an X state with a spatially distant qubit.

Analogous to entanglement-swapping scheme this process swaps the X feature without conditions.

When the probability distribution is homogeneous our inhomogenoeus we find that the quantum

discord in the four outcomes depends of the initial entanglement. In particular if the input

entanglement is different the zero and the probability distribution is inhomogenoeus we obtain an

outcome with quantum discord higher that or equal to initial one.

[1] H. Ollivier and W. H. Zurek, Quantum Discord: A Measure of the Quantumness of Correlations, Phys.

Rev. Lett. 88, 017901 (2001).

[2] L. Roa, A. Muñoz and G. Grüning, Entanglement swapping for X states demands threshold values, Phys.

Rev. A 89, 064301 (2014).

1

Citation of a journal: H. Ollivier and W. H. Zurek, Phys. Rev. Lett. 88, 017901 (2001).

2

Citation of a journal: L. Roa, A. Muñoz and G. Grüning, Phys. Rev. A 89 064301 (2014)

202


ID0175

Quantifying Chaos in the Dicke model: IPR of a coherent state

M. A. Bastarrachea-Magnani1, J. Chávez-Carlos1, S. A. Lerma-Hernández2 and J. G. Hirsch1.

1 Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Apdo. Postal 70.543, México D. F., C. P. 04510.

2. Facultad de Física, Universidad Veracruzana, Circuito Aguirre Beltrán s/n, Xalapa, Veracruz, México C. P. 91000.

miguel.bastarrachea@nucleares.unam.mx

KEY WORDS: Dicke model, quantum chaos, quantum phase transitions, coherent states.

The Dicke model1 describes a set of N two-level systems interacting with a resonator. It has been

used to model atoms within a cavity, superconducting qubits and polaritons among other systems.

Even though the Hamiltonian seems to be quite simple thanks to its algebraic properties as a spinboson

model, it has a theoretical richness which continuously drives research unto its properties.

For example, besides its well-known quantum phase transition (QPT), it has been shown the

model presents an excited-state quantum phase transition (ESQPT) which is related to the onset

of chaos in the spectrum2,3,4. The relation between them is far from clear.

In this work we explore the connection between the ESQPT and the early onset of chaos in the

spectrum. We employ de inverse participation ratio (IPR) of a coherent state expressed in

the eigen-states of the Hamiltonian, whose values are determined by the energy of the

semiclassical surface associated with the energy levels for the quantum case, in order to explore

the energy regions close to the ESQPT. In figure 1, we show some results for numerical

calculations employing a few atoms. By comparison with the corresponding Poincaré section of

the associated semiclassical system we can identify regions of chaos and regularity and quantify

them at some extent.

Figure 1. (Right) Poincaré section for the semiclassical Dicke model and energy E/j=-1.4, in

resonance, in the superradiant phase (coupling γ=2.0γc). We recall that in γc the QPT occurs and

the ESQPT occur in E/j=-1.0. (Left) Numerical calculations of the IPR in the eigenstates basis of a

coherent state defined for the energy in the same regions of the Poincaré section. We can observe

a correspondence between regions of chaos in both the IPR and the Poincaré section. With N=25

atoms. y=jz/j, 2j=N and ϕ are the semiclassical atomic variables.

[1] R. H. Dicke, Phys. Rev. 93, 99 (1954).

[2] T. Brandes T, Phys. Rev. E 88, 032133 (2013).

[3] M. A. Bastarrachea-Magnani, S. Lerma-Hernández, and J. G. Hirsch, Phys. Rev. A 89, 032101 (2014).

[4] M. A. Bastarrachea-Magnani, S. Lerma-Hernández, and J. G. Hirsch, Phys. Rev. A 89, 032102 (2014).

203


ID0179

Analysis of Epitaxial Layers Grown by LPE in Contact of InAs Liquid Phase

with InP Substrate

U. Zavala 1 , A. Yu. Gorbatchev 2 , V. A. Mishournyi 3 , F. de Anda 4

Instituto de Investigación en Comunicaciones Ópticas – UASLP, Av. Karakurum 1470, Lomas 4a. Secc, 78210 S.L.P., México

ulyzavala@gmail.com 1 , andre@cactus.iico.uaslp.mx 2 , slava@cactus.iico.uaslp.mx 3 , Francisco.deanda@gmail.com 1

KEY WORDS: quantum dot, LPE, density, crystallization

The main objective of this project is the growth InAs quantum dots on InP(100) substrates by the

Liquid Phase Epitaxy (LPE) technique. The samples were formed at two different temperatures

(350 ° C and 400 ° C) with contact times of 1, 2 and 5 seconds.

The morphological analysis with atomic force microscopy (AFM) showed that in each process

there were nanoislands formed. The growth at 350 ° C showed a higher number of nanoislands

compared to the growth at 400 ° C. The highest densities obtained were 10.7 x10 QD ∗ cm

on the samples grown at 350°C and 6.0 x10 QD ∗ cm on the samples grown at 350 °C , The

contact time was 2’ in both cases. The size distribution of the nanostructures had a bimodal

behavior.

The rotation spectra analysis HRXDR of samples grown at 400 ° C with 2 and 5 seconds showed

that the epitaxial layers contained a definite amount of P which allows us to conclude that the

formation of quantum dots by LPE is the result of two simultaneous processes: dissolution and

crystallization.

204


ID0189

An experimental setup for cold atom spectroscopy

O. Lazo-Arjona 1 , G. Domínguez 1 , C. Mojica-Casique 1 , J. Flores-Mijangos, F. Ramírez-Martínez 1 ,

J. Jiménez-Mier 1

1 Instituto de Ciencias Nucleares Universidad Nacional Autónoma de México Circuito Esterior s/n Ciudad Universitaria, Deleg.

Coyoacán México D.F. Contact author: oscar.lazo@correo.nucleares.unam.mx

KEY WORDS: cold atoms, spectroscopy, density matrix

An experimental setup for recording one and two-photon spectra by detecting the fluorescence

emitted by rubidium atoms trapped in a magneto-optical trap (MOT) is presented. Atoms are

excited using either one or two light components generated by tunable lasers. As shown in the

figure, the fluorescence generated by the spontaneous emission of radiation as the atoms decay

from the upper states involved in the excitation scheme is captured and directed towards a

photodetector using a set of lenses. The spectra are constructed by recording the amount of

fluorescence as a function of the frequency of the lasers as they are tuned across the atomic

resonances. The resulting spectra are compared with a model simulating the density matrix

dynamics of the atomic states.

Energy levels diagram for rubidium. Laser excitations and spontaneous decay are shown as solid and

wavy lines respectively. Observed decays are indicated with an eye.

205


ID0192

DEVELOPMENT AND CHARACTERIZATION OF A TUNEABLE LASER

DIODE SYSTEM FOR DOPPLER COOLING OF Ba +

Luis Alberto Nava Rodríguez 1 , Heliodoro Osuna Villegas, José Luis Hernández Pozos 3

Universidad Autónoma Metropolitana-Iztapalapa. Av. San Rafael Atlixco No 186. Col. Vicentina. México. D.F.

1 xxl_db_lxx@hotmail.com

3 jlhp@xanum.uam.mx

KEY WORDS: Tunable laser diodes, saturation spectroscopy.

At UAM-I we are building two tunable diode laser systems in Littman configuration for cooling

Ba+ ions, the necesary wavelenghts are 493.4 nm (cooling transition 6 2 S 1/2 -> 6 2 P 1/2 ) and 649.9

nm (re-pumping transition 5 2 D 3/2 -> 6 2 P 1/2 ).

Here we report results for the prototype at 649.9 nm, and testing absortion in a iodine cell

(figure 1). Here we report results in the interval of 657.5 to 659 nm (≈1040 GHz). Currently, we

are implementing Doppler free saturation spectroscopy with this system with the aim of

provinding locking to the laser.

Figure 1. Prototype of tunable diode laser system in Littman configuration.

206


ID0194

Theoretical analysis for the 5P 3/2 ! 6P 3/2 electric quadrupole

transition.

C. Mojica Casique 1 , O. Lazo-Arjona 1 , F. Ponciano-Ojeda 1 ,S. Hernández-Gómez 1 ,

F. Ramírez-Martínez 1 , J. Flores-Mijangos 1 , K. Volke-Sepúlveda 2 , R. Jáuregui 2 ,J.

Jiménez-Mier 1

1 Instituto de Ciencias Nucleares, UNAM, 04510 México. D.F., México

2 Instituto de Física, UNAM, 04510 México D.F., México

Contact xtianadan@gmail.com

KEY WORDS: Electric quadrupole transition, laser spectroscopy.

Theoretical analysis for the 5P 3/2 ! 6P 3/2 electric quadrupole transition. We present

a theoretical analysis for studying the experimental results of the 5P ! 6P electric dipole

forbidden transition in rubidium atoms. The aim is to compare the results with experimental

spectra corresponding to the 5S 1/2 ! 5P 3/2 ! 6P 3/2 ladder excitation obtained by detecting

the 420 nm fluorescence from the 6P 3/2 ! 5S 1/2 spontaneous emission.

Amodelisusedtocalculatetherelativeintensitiesofthefluorescencecomponentsoriginating

from each of the 6P 3/2 hyperfine states. It has been found that each relative intensity is

proportional to the 6P 3/2 state population. Hence, it is necessary to consider the time

evolution of the atomic populations for the first step transition caused by optical pumping

e↵ects within the sublevels (F, m). For the second step it is su cient to consider only

the geometric probabilities. The calculation results are in very good agreement with the

experimental data.

Figure 1: Energy level diagram for quadrupole transitions model.

207


ID0195

A Compact 1049 nm Littrow External Cavity Diode Laser

E. Navarro-Navarrete 1 , J. Flores-Mijangos, 2 , F. Ramírez-Martínez 3 , J. Jiménez-Mier 4

1 Instituto de Ciencias Nucleares Universidad Nacional Autónoma de México Leonardo Da Vinci 216, Col. Nonoalco Deleg.

Benito Juárez, México D.F. Contact author: rssi_2nava@ciencias.unam.mx

KEY WORDS: Diffraction Grating, frequency selective-feedback, Mode-hop-free

A suitable compact external cavity diode laser of 1049 nm employing Littrow configuration is

presented. A large mode-hop-free tuning range and an excellent stability of laser frequency are

important features for laser spectroscopy. This design uses diffraction grating for wavelength

selection, providing frequency selective-feedback, reducing the wavelength linewidth and

improving single mode tunability. Moreover, its compactness moves the mechanical resonances,

due to external vibrations, above higher frequencies. Two piezo discs, one mounted on the

horizontal axis of the grating pivot and the other between the 1200 grooves/mm dispersive

diffraction grating and the wedge at 39°, are synchronized to minimize the likelihood of modehop,

related to mechanical coupling of cavity length and angle variations, while scanning the

frequency over a range of several Gigahertz.

An external cavity diode laser. It shows the diffraction grating mounted on a 39° wedge and the

redirected output beam mirror parallel to the grating.

208


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SUMMER

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