Nonlinear Optics in Periodic Structures

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Nonlinear Optics in Periodic Structures

Amir Feizpour

Nonlinear Optics Course Presentation

28 April 2009


• Why ... ?

• Introduction and Motivation

• How ... ?

• Photonic Crystals

▪ Definition and properties

Nonlinear Optical Properties

• Then ... ?

• Future

• Summery and Conclusion

28 Apr 2009 Nonlinear Optics Course Presentation 2 / 15


Amir Feizpour

NLO in

Periodic

Structures

Problem with Electronics

•Introduction

•Electronics

•Photonics

•Photonic

Crystals

•Definition

and

properties

•NLO

properties

•Future

• Moore’s Law

• Capacity and computational power doubles

every 18 month

• Electronics becomes less efficinet

• Higher frequencies

▪ More power dissipation

▪ Nodes of optical communiation networks

•Summery

28 Apr 2009 Nonlinear Optics Course Presentation 3 / 15


Amir Feizpour

NLO in

Periodic

Structures

All‐Optical Info Processing

•Introduction

•Electronics

•Photonics

•Photonic

Crystals

•Definition

and

properties

•NLO

properties

•Future

•Summery

• Advantages

• High speed of photons

• Low decoherence rate

• Available at high frequencies

• Problem

• No photon – photon interaction!

▪ Optical nonlinearities

28 Apr 2009 Nonlinear Optics Course Presentation 4 / 15


Amir Feizpour

NLO in

Periodic

Structures

Photon‐Photon Interaction

•Introduction

•Electronics

•Photonics

•Photonic

Crystals

•Definition

and

properties

•NLO

properties

•Future

•Summery

• Weak optical nonlinearities

• Higher optical powers

▪ More loss and damage

• Longer interaction times

▪ Not scalable

• Enhancement approaches

• Material oriented

▪ eg. Chalcogenide glasses, GaAs

• Structure Oriented

▪ eg. micro‐/nano‐ cavities, photonic crystals

28 Apr 2009 Nonlinear Optics Course Presentation 5 / 15


Amir Feizpour

NLO in

Periodic

Structures

Photonic Crystal

•Introduction

•Electronics

•Photonics

• Spatial modulation of susceptibility

• First order (refractive index)

• Higher orders

•Photonic

Crystals

•Definition

and

properties

•NLO

properties

•Future

•Summery

• Dynamic modulation (photorefractive

material)

28 Apr 2009 Nonlinear Optics Course Presentation 6 / 15


Amir Feizpour

NLO in

Periodic

Structures

Band Structure

•Introduction

• Forbidden bands!

•Electronics

•Photonics

•Photonic

Crystals

•Definition

and

properties

•NLO

properties

•Future

•Summery

• Very small group velocity

28 Apr 2009 Nonlinear Optics Course Presentation 7 / 15


Amir Feizpour

NLO in

Periodic

Structures

Optical waveguide

•Introduction

• A 2D PhC and its band structure

•Electronics

•Photonics

•Photonic

Crystals

•Definition

and

properties

•NLO

properties

•Future

•Summery

Less device length

Less intensity

Coupled Resonator Optical Waveguide (can be filled with eg. Chalcogenide glass)

28 Apr 2009 Nonlinear Optics Course Presentation 8 / 15


Amir Feizpour

NLO in

Periodic

Structures

XPM

•Introduction

•Electronics

Signal beam

•Photonics

•Photonic

Crystals

Ultrafast response => Ultra short pulse => Ultra small index change

•Definition

and

properties

•NLO

properties

•Future

•Summery



sn

cL


nc v

g

Effective Length

28 Apr 2009 Nonlinear Optics Course Presentation 9 / 15


Amir Feizpour

NLO in

Periodic

Structures

Intensity

•Introduction

•Electronics

•Photonics

•Photonic

Crystals

•Definition

and

properties

• Second order

• Less length => less volume => less total EM

power needed to produce

• Third Order

•NLO

properties

•Future

•Summery

28 Apr 2009 Nonlinear Optics Course Presentation 10 / 15


Amir Feizpour

NLO in

Periodic

Structures

Future

•Introduction

•Electronics

•Photonics

•Photonic

Crystals

•Definition

and

properties

•NLO

properties

•Future

•Summery

• So far...

• Efficient harmonic generation

• Spatial solitons

• Optical bistability

• ...

• Future Directions

• Further optimization (geometry and materials)

• Observation of proposals experimentally

• Lower intensities

▪ Single photon regime (combined with EIT)

28 Apr 2009 Nonlinear Optics Course Presentation 11 / 15


Amir Feizpour

NLO in

Periodic

Structures

Summary

•Introduction

•Electronics

•Photonics

•Photonic

Crystals

•Definition

and

properties

•NLO

properties

•Future

•Summery

• Limitations on electronics

• All‐optical information processing

• Enhancement of NLO effects

• Photonic crystals having novel optical

properties

• Material independent => one can use

highly nonlinear material in a PhC

• Breakthrough!!

28 Apr 2009 Nonlinear Optics Course Presentation 12 / 15


• Main part

• Enhancement of nonlinear effects using photonic

crystals, M. Soljacic and J. D. Joannapoulos, Nature

Materials, 3, 211 (2004)

• Photonic Lattices

Nonlinear optics and light localization in photonic

lattices, D. N. Neshev et. al., arxiv: 0705.1817v1

• Book on Photonic Crystals

• Photonic Crystals: modeling the flow of light, J. D.

Joannapoulos et. al., Princeton University Press (1 st

edition 1995, 2 nd edition 2008)

• All pictures used are taken from these ref’s and Wikipedia

28 Apr 2009 Nonlinear Optics Course Presentation 13 / 15


A natural photonic crystal!

QUESTION?

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