book of abstracts - IM2NP

A B S T R A C T S TUESDAY, JUNE 29 N A N O S E A 2 0 1 0
18H00-18H20
High refractive index modification inside Si02 by femtosecond laser created
self-ordered planar nanostructures.
David Grojo1,2, Thomas Barillot1, Marina Gertsvorlf1,3, Shuting Lei4, David
M. Rayner1 and Paul B. Corkum1,3 (1National Research Council of Canada, Steacie Institute for
Molecular Sciences, Ottawa, Canada 2LP3 –UMR 6182, CNRS-Univ. Méditerranée, Marseille, France 3University
of Ottawa, Ottawa, Ontario, Canada 4Kansas State University, 2012 Durland Hall, Manhattan, Kansas, USA)
Illumination with intense femtosecond optical pulses focused to small focal spots modifies dielectrics in such
a way that the refractive-index can be locally adjusted. This represents today an attractive microfabrication
method for photonic applications. Here, we investigate the non-uniform nature of the strong laser field
ionisation in amorphous silica (a-SiO2) which translates in material cracking at a subwavelength scale.
Under repeated illumination, the cracks migrate to form beautifully-ordered arrays of ~8-nm planar
nanocracks with a crack-to-crack spacing of λ/2 in the medium. These are extending through the focal region
with no defect and are oriented perpendicular to the laser polarization [1,2]. The material transport is
amazingly driven by the strong laser field making possible to change the writing orientation at anytime with
the polarization. We show the nanotructures are characterized by a very large refractive index change (up to
Δn/n=1.8%) and form birefringence (ns-np ~0.01 at 800 nm). This offers unprecedented control over the
linear optical properties of a-SiO2 anywhere in 3-D space. The local change in the focal region leads
progressively to the self-generation of a polarization dependent biconvex defocusing microlens (Fig). The
refractive feedback effect on the light that creates the microlens ascribes a self-limited character on the
writing process that is attractive for technological considerations. This is achieved without any noticeable
increase in linear losses and opens a route to adding new functionality inside optical fibers or bulk materials.
[1] V. R. Bhardwaj, E. Simova, P. P. Rajeev, C. Hnatovsky, R. S. Taylor, D. M. Rayner, and P. B. Corkum, Phys. Rev. Lett. 96, (2006)057404
[2] D. Grojo, M. Gertsvolf, H. Jean-Ruel, S. Lei, L. Ramunno, D. M. Rayner, and P. B. Corkum, Appl. Phys. Lett. 93 (2008) 243118.
18H20-18H40
Fabrication of an IR emitting ErQ3-based distributed feedback laser by X-ray
Interference Lithography.
S. Prezioso1, P. De Marco1, F. Bisti1, M. Donarelli1, S. Penna2, A. Reale2, S.
Santucci1, and L.Ottaviano1 (1Dipartimento di Fisica, Università dell‟Aquila, gc-LNGS INFN, Via
Vetoio, 67100, L‟Aquila, Italy 2Dip. di Ingegneria Elettronica, Univ. degli studi di Roma “Tor Vergata”, Viale
Politecnico 1, 00133 Roma, Italy)
1 – Introduction
Modern telecommunication technology requires to process large volumes of information for scientific,
military and civil purposes. IR light is the most suitable radiation to sustain petabyte-per-year traffics. IR
optical fiber technology is sufficiently mature as well as the micro-electronics industry to accept this
challenge. The bottleneck is represented by the optical interconnection between fiber and chip. The onchip
collection of the optical information is one of the most promising strategies.
In this work we propose the fabrication of an IR emitting ErQ3-based distributed feedback laser as the
onchip light source in charge of transferring the information collected from the chip directly into the optical
fiber. Using ErQ3 as the active medium, we can combine the perfect adaptability of amorphous organic
materials to any kind of surface, periodically modulated surfaces included, with the perfect match of Er
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