Table Of ContentNonlinear Optics in Signal Processing
Engineering Aspects of
Lasers Series
Series Editor
Dr T. A. Hali
Reader in Physics, University of Essex
SERIES EDITOR'S PREFACE
In thelate 1960sand early 1970sthelaser wasstillsomethingofascientiticcuriosity
with only alimited practical use.The extent ofthefour volumesinthis seriesshows
the enormous change that has happened since that time. The laser is now an
indispensableadditiontothetoolboxoftheengineerandscientist.The progress from
thetimewhenthelaserwasoftendubbed'asolutioninsearchofaproblem'to today,
when engineers of aII disciplines frequently use lasers as a matter of course, is a
remarkabletransformation.Evenso,the useoflasersinengineering and other walks
ofIifeisstillinitsinfancyand has beenheld back partly bytheir relatively highcost
and in some cases by their inconvenience in use. The cost of many laser systems
has been falling for several years,they are becoming much more convenient to use
andnolongerneedtrainedpersonnel tooperatethem.Astheseproblemsareovercome
laserswilltind widerand wider applications and there isan everincreasingneed for
engineers andscientists,who perhaps haveIittleinterestinlasers themselvesto have
access to an authoritative source which not only acts as an introduction but also
takes the reader up to the latest developments inlaser applications.
The four books ofthe series'Engineering Aspects ofLasers'arose from a seriesof
laser workshop courses which have been held annually at the University of Essex
since 1979.These courses have evolved veryconsiderably since their inception but
aspects of their organization have not changed - the contents of the courses have
always been coordinated by the recognized international authority in each subject
areaand thelecturesgivenbyexpertsintheparticulartieldfromindustry,government
laboratoriesoruniversities.When theideaofpublishing aseriesofbooks based upon
thecontentsofthesecourses wastirstsuggested,thecoursecoordinatorsat thattime
became the editors ofeach volume and the lecturers wereasked to contribute.
Theworkshopcoursesareself-supportingcourseswhichalsoformpartofthe MSc
degreeinLasersand theirApplications.Therearemanypeoplewhohavecontributed
much to thesecourses overthe yearsand havemade them thesuccessthat they have
been. I would Iiketo express my gratitude to them ali. The courses and the MSc
were the brainchild of T.P. Hughes who was then Reader in Physics at Essex
University. Without his foresight, hard work and determination in setting up the
courses,this seriesofbooks would not have been written.
Othertitles in series
Laser Processing in Manufacturing
Edited by R.C.Crafer and P.J.Oakley
Optical Methods in Engineering Metrology
Edited by D.C.Williams
Advances in OpticalCommunications
Edited by N.Doran and 1.Garrett
Nonlinear Optics
in Signal Processing
Edited by
Robert W. Eason
Senior Lecturer in Optics
University ofSouthampton
UK
and
Alan Miller
Professor ofPhysicsand Electrical Engineering
Center for Research in Electro-Optics and Lasers
University ofCentral Florida
Orlando
USA
SPRINGER-SCIENCE+BUSINESS MEDIA, B.V.
ISBN978-94-010-4681-7 ISBN978-94-011-1560-5(eBook)
DOI10.1007/978-94-011-1560-5
First edition 1993
©1993SpringerScience+BusinessMediaDordrecht
Originally publishedbyChapman& Haliin1993
Softcoverreprintofthehardcover 1stedition
Apart from any fairdealingforthe purposesofresearch or private study, or
criticismorreview,aspermittedunder theUK CopyrightDesignsand Patents
Act, 1988,this publicationmay not be reproduced,stored,or transmitted, in
any form or by any means, without the prior permission in writing of the
publishers, or in the case of reprographic reproduction only in accordance
withthetermsofthelicencesissued bytheCoyprightLicensingAgencyinthe
UK,or in aeeordanee with the terms oflieenees issued by the appropriate
Rcproduetion Rights Organization outsidc the UK. Enquirics conecrning
reproduetion outside the termsstated here should be sent to the publishers
at the Londonaddress printed on this page.
The publishermakes no representation,expressor implied, with regard to
thcaeeuraey ofthcinformationcontaincdinthisbook and eannotaccept any
legalresponsibilityorliabilityforanyerrorsoromissionsthatmaybemade.
Acataloguerecord forthis book isavailable from the British Library
LibraryofCongress Cataloging-in-Publicationdata
Nonlincaroptics insignal proccssing / cditcd by R.W.Eason and A.
Miller.- Ist ed.
p. em.
Includcs bibliographicalrcfcrencesand index.
1. Signal processing. 2. Nonlinearoptics. 1. Eason, R.W.
II. Miller, A.
TK5102.5.N564 1993
621.382'2-dc20 92-31149
CIP
@;
Printedon permanentacid-free text paper,manufacturedinaccordancewith
thc proposcd ANSljNISOZ39.48-199Xand ANSIZ39.4-1984
Nonlinear Optics in Signal Processing
Engineering Aspects of
Lasers Series
Series Editor
Dr T. A. Hall
Reader in Physics, University of Essex
SERIES EDITOR'S PREFACE
In the late 1960s and early 1970s the laser was still something of a scientific curiosity
with only a limited practical use. The extent of the four volumes in this series shows
the enormous change that has happened since that time. The laser is now an
indispensable addition to the toolbox of the engineer and scientist. The progress from
the time when the laser was often dubbed 'a solution in search of a problem' to today,
when engineers of all disciplines frequently use lasers as a matter of course, is a
remarkable transformation. Even so, the use of lasers in engineering and other walks
of life is still in its infancy and has been held back partly by their relatively high cost
and in some cases by their inconvenience in use. The cost of many laser systems
has been falling for several years, they are becoming much more convenient to use
and no longer need trained personnel to operate them. As these problems are overcome
lasers will find wider and wider applications and there is an ever increasing need for
engineers and scientists, who perhaps have little interest in lasers themselves to have
access to an authoritative source which not only acts as an introduction but also
takes the reader up to the latest developments in laser applications.
The four books of the series 'Engineering Aspects of Lasers' arose from a series of
laser workshop courses which have been held annually at the University of Essex
since 1979. These courses have evolved very considerably since their inception but
aspects of their organization have not changed - the contents of the courses have
always been coordinated by the recognized international authority in each subject
area and the lectures given by experts in the particular field from industry, government
laboratories or universities. When the idea of publishing a series of books based upon
the contents of these courses was first suggested, the course coordinators at that time
became the editors of each volume and the lecturers were asked to contribute.
The workshop courses are self-supporting courses which also form part of the MSc
degree in Lasers and their Applications. There are many people who have contributed
much to these courses over the years and have made them the success that they have
been. I would like to express my gratitude to them all. The courses and the MSc
were the brainchild of T. P. Hughes who was then Reader in Physics at Essex
University. Without his foresight, hard work and determination in setting up the
courses, this series of books would not have been written.
Other titles in series
Laser Processing in Manufacturing
Edited by R. C. Crafer and P. J. Oakley
Optical Methods in Engineering Metrology
Edited by D. C. Williams
Advances in Optical Communications
Edited by N. Doran and I. Garrett
Nonlinear Optics
in Signal Processing
Edited by
Robert W. Eason
Senior Lecturer in Optics
University of Southampton
UK
and
Alan Miller
Professor of Physics and Electrical Engineering
Center for Research in Electro-Optics and Lasers
University of Central Florida
Orlando
USA
CHAPMAN & HALL
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Published by Chapman & Hall, 2-6 Boundary Row, London SEI 8HN
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First edition 1993
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Typeset in 10/12 Times by Thomson Press (India) Ltd, New Delhi
ISBN 0 412 39560 6 044231658 5 (USA)
Apart from any fair dealing for the purposes of research or private study, or
criticism or review, as permitted under the UK Copyright Designs and Patents
Act, 1988, this publication may not be reproduced, stored, or transmitted, in
any form or by any means, without the prior permission in writing of the
publishers, or in the case of reprographic reproduction only in accordance
with the terms of the licences issued by the Coypright Licensing Agency in the
UK, or in accordance with the terms of licences issued by the appropriate
Reproduction Rights Organization outside the UK. Enquiries concerning
reproduction outside the terms stated here should be sent to the publishers
al the London address printed on this page.
The publisher makes no representation, express or implied, with regard 10
the accuracy of the information contained in this book and cannot accept any
legal responsibility or liability for any errors or omissions that may be made.
A catalogue record for this book is available from the British Library
Library of Congress Cataloging-in-Publication data
Nonlinear optics in signal processing / edited by R. W. Eason and A.
Miller. - 1s t ed.
p. cm.
Includes bibliographical references and index.
ISBN 0-442-31658-5
1. Signal processing. 2. Nonlinear optics. I. Eason, R. W.
II. Miller, A.
TK5102.5.N564 1993
621.382'2-dc20 92-31149
CIP
§
Printed on permanent acid-free text paper, manufactured in accordance with
the proposed ANSI/NISOZ39.48-199X and ANSIZ39.4-1984
-------------------~
Contents
Preface xi
Contributor's xiii
1 Introduction (Alan Miller) 1
1.1 Initial comments 1
1.2 Nonlinear optical interactions 2
1.3 A sketch history of nonlinear optics in dielectric materials 10
1.4 Optical signal processing 14
1.5 Conclusions 17
References 17
2 Nonlinearities in organic solids (Simon Allen) 18
2.1 A comparison of organic and inorganic materials 20
2.1.1 Second-order nonlinearities 20
2.1.2 Third-order nonlinearities 22
2.2 Molecular properties 23
2.2.1 The origin of molecular nonlinearities p and 'Y 23
2.2.2 Measurement of molecular nonlinearities 26
2.2.3 Calculation of molecular nonlinearities 27
2.3 Single crystals 32
2.4 Polymers 42
2.4.1 Poled polymers for second-order nonlinearities 42
2.4.2 Third-order nonlinearities in polymer films 51
2.5 Langmuir-Blodgett films 54
2.6 Conclusions 61
References 62
3 Semiconductors (Alan Miller) 66
3.1 Introduction 66
3.2 Experimental techniques 69
v
I
VI I CONTENTS
3.3 Optical excitation 71
3.3.1 Linear absorption 71
3.3.2 Multiphoton absorption 74
3.3.3 Carrier dynamics 77
3.4 Bound electron nonlinearities 78
3.5 Free carriers 81
3.5.1 Dynamic nonlinear absorption 82
3.5.2 Dynamic nonlinear refraction 86
3.6 Optothermal effects 94
3.7 Conclusions 96
References 97
4 The photorefractive effect (Andrew K. Powell, Trevor J. Hall, 100
Hussain Iman and David A. Fish)
4.1 Introduction 100
4.2 The basic physics of the photorefractive effect 102
4.2.1 The photoconductive interaction 103
4.2.2 The electro-optic interaction 109
4.3 Techniques for space charge field enhancement 120
4.3.1 Static fields and moving fringes 120
4.3.2 Alternating electric field enhancement techniques 124
4.3.3 Effects at large modulation 129
4.4 The photo refractive time response 133
4.4.1 The photoconductive response 134
4.4.2 The electro-optic response critical slowing down 136
4.4.3 Relative merits of some nonlinear materials 139
4.5 Conclusions 141
References 142
5 Optical bistability (Brian S. Wherrett and David C. Hutchings) 145
5.1 Introduction 145
5.2 The linear Fabry-Perot etalon 148
5.3 Nonlinear refraction 151
5.3.1 Electronic nonlinearities 152
5.3.2 Thermal nonlinearities 155
5.4 Dynamics and steady state solutions ofthe nonlinear etalon 156
5.5 Characteristic switching conditions 159
5.5.1 The critical switching irradiance 159
5.5.2 Optimization 161
5.6 Switching powers and power-time products 163
5.6.1 Powers and energies 163
5.6.2 The ideal two-level system 164
5.6.3 Semiconductor, electronic nonlinearities 165
5.6.4 Thermal nonlinearities 165
