Library of Congress Cataloging-in-Publication Data

Powers, Peter E.

Field guide to nonlinear optics / Peter E. Powers.

pages cm. – (The field guide series; FG29)

Includes bibliographical references and index.

ISBN 978-0-8194-9635-5—ISBN 978-0-8194-9636-2—ISBN 978-0-8194-9637-9

1. Nonlinear optics. I. Title.

QC446.2.P688 2013

621.36'94−dc23

2013014471

Published by

SPIE

P.O. Box 10

Bellingham, Washington 98227-0010 USA

Phone: +1.360.676.3290

Fax: +1.360.647.1445

Email: books@spie.org

www.spie.org

The content of this book reflects the work and thought of the author(s). Every effort has been made to publish reliable and accurate information herein, but the publisher is not responsible for the validity of the information or for any outcomes resulting from reliance thereon.

Printed in the United States of America.

First printing

Introduction to the Series

Welcome to the SPIE Field Guides—a series of publications written directly for the practicing engineer or scientist. Many textbooks and professional reference books cover optical principles and techniques in depth. The aim of the SPIE Field Guides is to distill this information, providing readers with a handy desk or briefcase reference that provides basic, essential information about optical principles, techniques, or phenomena, including definitions and descriptions, key equations, illustrations, application examples, design considerations, and additional resources. A significant effort will be made to provide a consistent notation and style between volumes in the series.

Each SPIE Field Guide addresses a major field of optical science and technology. The concept of these Field Guides is a format-intensive presentation based on figures and equations supplemented by concise explanations. In most cases, this modular approach places a single topic on a page, and provides full coverage of that topic on that page. Highlights, insights, and rules of thumb are displayed in sidebars to the main text. The appendices at the end of each Field Guide provide additional information such as related material outside the main scope of the volume, key mathematical relationships, and alternative methods. While complete in their coverage, the concise presentation may not be appropriate for those new to the field.

The SPIE Field Guides are intended to be living documents. The modular page-based presentation format allows them to be updated and expanded. We are interested in your suggestions for new Field Guide topics as well as what material should be added to an individual volume to make these Field Guides more useful to you. Please contact us at fieldguides@SPIE.org.

John E. Greivenkamp, Series Editor

College of Optical Sciences

The University of Arizona

The Field Guide Series

Field Guide to Nonlinear Optics

This Field Guide is designed for those looking for a condensed and concise source of key concepts, equations, and techniques for nonlinear optics. Topics covered include technologically important effects, recent developments in nonlinear optics, and linear optical properties central to nonlinear phenomena. The focus of each section is based on my research, my interactions with colleagues in the field, and my experiences teaching nonlinear optics.

Examples throughout this Field Guide illustrate fundamental concepts while demonstrating the application of key equations. Equations are presented without proof or derivation; however, the interested reader may refer to the bibliography for a list of resources that go into greater detail. In addition to the overview of nonlinear phenomena, this Field Guide includes an appendix of material properties for some commonly used nonlinear crystals.

This Field Guide features notations commonly encountered in nonlinear optics literature. All equations are written in SI units for convenience when comparing calculations to laboratory measurements. The formalism of writing equations using complex variable notation introduces ambiguity in defining the electric field’s complex amplitude. Though one convention is used throughout this text, conventions and conversions are presented as part of the first topic. Equations in terms of experimentally measured quantities such as power, intensity, and energy, have no ambiguity.

Peter E. Powers

University of Dayton

March 2013

Table of Contents

Glossary of Terms and Acronyms x

Electromagnetic Waves and Crystal Optics 1

Conventions and Conversions 1

Maxwell’s Equations and the Wave Equation 2

Uniaxial Crystals 3

Biaxial Crystals 4

Nonlinear Susceptibility 5

Nonlinear Polarization for Parametric Interactions 5

Classical Expressions for Nonlinear Susceptibility 6

Nonlinear Susceptibilities 7

d Matrices 8

Working with d Matrices and SHG 9

Effective Nonlinearities 10

Tabulation of d Matrices 11

Electro-optic Effect 13

Electro-optic Effect 13

r Matrices 14

Electro-optic Waveplates 16

Q Switches 17

Amplitude and Phase Modulators 18

Electro-optic Sampling for Terahertz Detection 19

Photorefraction 20

χ⁽²⁾ Parametric Processes 21

χ⁽²⁾ Coupled Amplitude Equations 21

χ⁽²⁾ Processes with Focused Gaussian Beams 22

DFG and OPA 23

Sum-Frequency Generation 24

Second-Harmonic Generation 25

Three-Wave Mixing Processes with Depletion 26

Optical Parametric Generation 27

Optical Parametric Oscillator 28

Singly Resonant Optical Parametric Oscillator 29

Phase Matching 30

Birefringent Phase Matching 30

e- and o-Wave Phase Matching 31

DFG and SFG Phase Matching for Uniaxial Crystals 32

SHG Phase Matching for Uniaxial Crystals 33

Biaxial Crystals in the XY Plane 34

Biaxial Crystals in the YZ Plane 35

Biaxial Crystals in the XZ Plane 36

Quasi-phase-matching 37

Birefringent versus Quasi-phase-matching 38

Noncollinear Phase Matching 39

Tuning Curves 40

Phase Matching Bandwidth 41

Bandwidths for DFG and SFG 41

Bandwidth Calculation Aids 42

SFG and DFG Bandwidth Formulae 43

SHG Bandwidth Formulae 46

Graphical Approach for Bandwidths 48

Noncollinear Bandwidth 49

χ⁽²⁾ Waveguides 50

χ⁽²⁾ Waveguide Interactions 50

χ⁽²⁾ Waveguide Devices 51

Waveguide Phase Matching 52

χ⁽³⁾ Parametric Processes 53

Four-Wave Mixing 53

Degenerate Four-Wave Mixing 54

Third-Harmonic Generation 55

χ⁽³⁾ Parametric Amplifier 56

Noncollinear Phase Matching for χ⁽³⁾ Processes 57

Nonlinear Refractive Index 58

Nonlinear Refractive Index 58

Nonlinear Absorption 59

Calculations of Nonlinear Index 60

Self-Phase Modulation 61

z Scan 62

Optical Bistability 63

Raman and Brillouin Processes 64

Spontaneous Raman Scattering 64

Stimulated Raman Scattering 65

Anti-Stokes Raman Scattering 66

Raman Microscopy 67

Photo-acoustic Interactions 68

Stimulated Brillouin Scattering 69

Ultrafast Nonlinear Effects 70

Saturable Absorption 70

Temporal Solitons 71

Spatial Solitons 72

High Harmonic Generation 73

Ultrashort-Pulse Measurement 74

Appendices 75

Gaussian Beams 75

Sellmeier Equations for Selected χ⁽²⁾ Crystals 76

Properties of Selected χ⁽²⁾ Crystals 78

References for Selected χ⁽²⁾ Crystals Tables 79

Equation Summary 81

Bibliography 90

Index 93