Second EditionOptoelectronicsand Photonics:Principles and PracticesS.O. KasapUniversity of SaskatchewanCanadaBoston Columbus Indianapolis New York San Francisco Upper Saddle RiverAmsterdam Cape Town Dubai London Madrid Milan Munich Paris Montréal TorontoDelhi Mexico City São Paulo Sydney Hong Kong Seoul Singapore Taipei Tokyo Pearson Education, Inc., Upper Saddle River, NJ 07458. All Rights ReservedA01 KASA1498 02 SE FM.INDD 118/09/12 6:45 PM

Vice President and Editorial Director, ECS: Marcia J. HortonExecutive Editor: Andrew GilfillanSponsoring Editor: Alice DworkinEditorial Assistant: William OpaluchMarketing Manager: Tim GalliganMarketing Assistant: Jon BryantPermissions Project Manager: Karen SanatarSenior Managing Editor: Scott DisannoProduction Project Manager: Clare RomeoCreative Director: Jayne ConteCover Design: Suzanne BehnkeCover Illustration/Photo: Courtesy of Teledyne-DALSAImage Permission Coordinator: Karen SanatarFull-Service Project Management/Composition: Integra Software Services, Pvt. Ltd.Printer/Binder: Courier/WestfordTypeface: 10/12 Times LT StdCredits and acknowledgments borrowed from other sources and reproduced, with permission, in this textbook appear onappropriate page within text. Printed in the United States of America. This publication is protected by Copyright and permission should be obtainedfrom the publisher prior to any prohibited reproduction, storage in a retrieval system, or transmission in any form or byany means, electronic, mechanical, photocopying, recording, or likewise. For information regarding permission(s), writeto: Rights and Permissions Department.Library of Congress Cataloging-in-Publication DataKasap, S. O. (Safa O.)Optoelectronics and photonics: principles and practices/S.O. Kasap.—2nd ed.p. cm.Includes bibliographical references and index.ISBN-13: 978-0-13-215149-8ISBN-10: 0-13-215149-91. Optoelectronic devices. 2. Photonics. I. Title.TK8304.K37 621.381'045—dc23201201941010 9 8 7 6 5 4 3 2 1ISBN-10:0-13-215149-9ISBN-13: 978-0-13-215149-8 Pearson Education, Inc., Upper Saddle River, NJ 07458. A01 KASA1498 02 SE FM.INDD 218/09/12 6:45 PM

We have a habit in writing articles published in scientific journals to makethe work as finished as possible, to cover up all the tracks, to not worryabout the blind alleys or describe how you had the wrong idea first,and so on. So there isn’t any place to publish, in a dignified manner,what you actually did in order to get to do the work.—Richard P. FeynmanNobel Lecture, 1966Philip Russell led a team of researchers at the University Bath in the 1990s where photonic crystal fibers weredrawn. Thin hollow capillary tubes were stacked together and then fused to make a preform as shown on the left.A photonic crystal fiber was then drawn at a high temperature from this preform. Photonic crystal fibers havethe ability to guide light endlessly in a single mode, and have highly desirable nonlinear properties for variousphotonics applications in the manipulation of light, such as the generation of supercontinuum light. (Courtesyof Professor Philip Russell.) Pearson Education, Inc., Upper Saddle River, NJ 07458. All Rights ReservedA01 KASA1498 02 SE FM.INDD 318/09/12 6:45 PM

Peter Schultz, Donald Keck, and Bob Maurer (left to right) at Corning were the first to produce low-loss optical fibers in the 1970s by using the outside vapor deposition methodfor the fabrication of preforms, which were then used to draw fibers with low losses.(Courtesy of Corning.)To Nicolette, who brightens my every dayand makes me smile with joy every time I see her. Pearson Education, Inc., Upper Saddle River, NJ 07458. All Rights ReservedA01 KASA1498 02 SE FM.INDD 418/09/12 6:45 PM

PrefaceThe first edition of this book was written more than 12 years ago. At the time it was meantas an easy-to-read book for third-year engineering or applied physics undergraduate students;it emphasized qualitative explanations and relied heavily on intuitive derivations. As thingsturned out, the first edition ended up being used in fourth-year elective classes, and even ingraduate courses on optoelectronics. Many of the instructors teaching at that level rightly needed better derivations, more rigor, better explanations, and, of course, many more topics andproblems. We have all at one time or another suffered from how wrong some intuitive short-cutderivations can be. The second edition was therefore prepared by essentially rewriting the textalmost from scratch with much better rigor and explanations, but without necessarily dwelling on mathematical details. Many new exciting practical examples have been introduced, and numerous new problems have been added. The book also had to be totally modernized giventhat much had happened in the intervening 12 years that deserved being covered in an undergraduate course.Features, Changes, and Revisionsin the Second EditionThe second edition represents a total revision of the first edition, with numerous additional features and enhancements. All chapters have been totally revised and extended. Numerous modern topics in photonics have been added to all the chapters. There are Additional Topics that can be covered in more advanced courses, or in coursesthat run over two semesters. There are many more new examples and solved problems within chapters, and manymore practical end-of-chapter problems that start from basic concepts and build up ontoadvanced applications. Nearly all the illustrations and artwork in the first edition have been revised and redrawnto better reflect the concepts. Numerous new illustrations have been added to convey the concepts as clearly as possible. Photographs have been added, where appropriate, to enhance the readability of the bookand to illustrate typical modern photonic/optoelectronic devices. The previous edition’s Chapter 7 on photovoltaics has been incorporated into this edition’sChapter 5 as an Additional Topic, thus allowing more photonics-related topics to be covered. Advanced or complicated mathematical derivations are avoided and, instead, the emphasisis placed on concepts and engineering applications. Useful and essential equations in photonics are given with explanations and are used inexamples and problems to give the student a sense of what typical values are. Cross referencing in the second edition has been avoided as much as possible, without toomuch repetition, to allow various sections and chapters to be skipped as desired by the reader. There is greater emphasis on practical or engineering examples; care has been taken toconsider various photonics/optoelectronics courses at the undergraduate level across majoruniversities.v Pearson Education, Inc., Upper Saddle River, NJ 07458. All Rights ReservedA01 KASA1498 02 SE FM.INDD 518/09/12 6:45 PM

viPreface The second edition is supported by an extensive PowerPoint presentation for instructorswho have adopted the book for their course. The PowerPoint slides have all the illustrations in color, and include additional color photos. The basic concepts and equations arealso highlighted in additional slides. There are also numerous slides with examples andsolved problems. Instructors should contact the publisher to access the PowerPoint. The second edition is also supported by an extensive Solutions Manual for instructorsonly. This is available from the publisher.The second edition continues to represent a first course in optoelectronic materials anddevices suitable for a half- or one-semester course at the undergraduate level either at the thirdor fourth-year level in electrical engineering, engineering physics, and materials science andengineering departments. With its additional topics, it can also be used as an introductory textbook at the graduate level. Normally the students would not have covered Maxwell’s equations.Although Maxwell’s equations are mentioned in the text to alert the student, they are not usedin developing the principles. It is assumed that the students would have taken a basic first- orsecond-year physics course, with modern physics, and would have seen rudimentary concepts ingeometrical optics, interference, and diffraction, but not Fresnel’s equations and concepts suchas group velocity and group index. Typically an optoelectronics course would be given eitherafter a semiconductor devices course or concurrently with it. Students would have been exposedto elementary quantum mechanics concepts, perhaps in conjunction with a basic semiconductorscience course.Most topics are initially introduced through qualitative explanations to allow the conceptto be grasped first before any mathematical development. The mathematical level is assumed toinclude vectors, complex numbers, and partial differentiation but excludes reliance on Fouriertransforms. On the one hand, we are required to cover as much as possible and, on the otherhand, professional engineering accreditation requires students to solve numerical problemsand carry out “design calculations.” In preparing the text, I tried to satisfy engineering degreeaccreditation requirements in as much breadth as possible. Obviously one cannot solve numerical problems, carry out design calculations, and at the same time derive each equation withoutexpanding the size of the text to an intolerable level. I have missed many topics but I have alsocovered many, though, undoubtedly, it is my own very biased selection.I would like to thank two very special colleagues, whom I have known for a very longtime, for their comments and help: Harry Ruda (University of Toronto) and Raman Kashyap(École Polytechnique de Montréal)—two perfect gentlemen who read some of the manuscriptand made valuable criticisms toward this final version.No textbook is perfect and I can only improve the text with your input. Please feel freeto write to me with your comments. Although I may not be able to reply to each individualcomment and suggestion, I do read all my email messages and take good note of suggestionsand comments. Many instructors did, in fact, write to me on the first edition, pointed out howthings could have been done better, and various mistakes one never seems to be able to eliminatetotally. I hope that the second edition will at least go far in satisfying some of their criticisms.There is an important old adage that goes something like this (somewhat paraphrased), “a gooddiagram is worth a thousand words, but a bad diagram takes a thousand words to explain.” I useda software package called Canvas to draw nearly all the line-art in the second edition as clearlyas possible, and errors are all mea culpa; feel free to email me the errors you notice in the figures.All third-party artwork and photographs have been used with permission; and I’m grateful to Pearson Education, Inc., Upper Saddle River, NJ 07458. All Rights ReservedA01 KASA1498 02 SE FM.INDD 618/09/12 6:45 PM

PrefaceviiPearson Education for meticulously obtaining permission from copyright holders. If you likethe second edition, and cannot wait for the third, you can always write your comments andrecommendations directly to the Sponsoring Editor for Electrical Engineering, Pearson HigherEducation, One Lake Street, Upper Saddle River, NJ 07458, USA. This is the best way to haveyour input heard.Resources for Instructors Instructor’s Solutions Manual. An instructor’s solutions manual was prepared by theauthor. Presentation Resources. All art from the text is available in PowerPoint slide and JPEGformat.These files are available for download from the instructor Resource Center. (March)Gordon Gould obtained his BSc in Physics from Union College in Schenectady and MScfrom Yale University. Gould came up with the idea of an optically pumped laser during his PhD work at ColumbiaUniversity around 1957—he is now recognized for the invention of optical pumping as a means of exciting masersand lasers. He has been also credited for collisional pumping as in gas lasers, and a variety of application-relatedlaser patents. After nearly three decades of legal disputes, in 1987, he eventually won rights to the invention ofthe laser. Gould’s laboratory logbook even had an entry with the heading “Some rough calculations on the feasibility of a LASER: Light Amplification by Stimulated Emission of Radiation,” which is the first time that thisacronym appears. Union College awarded Gould an honorary Doctor of Sciences in 1978 and the Eliphalet NottMedal in 1995. (Courtesy of Union College Alumni Office.) Pearson Education, Inc., Upper Saddle River, NJ 07458. All Rights ReservedA01 KASA1498 02 SE FM.INDD 79/27/12 12:22 PM

viiiPrefaceFiber-coupled phase and amplitude modulators. The Pockels effect in lithium niobate is used to modulatethe refractive index and hence the phase of an optical signal. In amplitude modulators, the Pockels effectis used to modulate the refractive indices of the two arms of a Mach–Zehnder interferometer, and hencethe optical output. ( JENOPTIK Optical System GmbH.)Fiber-coupled optical isolators: fiber isolators. The signal is allowed to propagate in one direction only,along the arrow shown on the device. The principle is based on Faraday rotation. (Courtesy of Thorlabs.) Pearson Education, Inc., Upper Saddle River, NJ 07458. All Rights ReservedA01 KASA1498 02 SE FM.INDD 818/09/12 6:45 PM

ContentsChapter 1 Wave Nature of Light31.1 Light Waves in a Homogeneous Medium 3A. Plane Electromagnetic Wave 3B. Maxwell’s Wave Equation and Diverging Waves 6Example 1.1.1 A diverging laser beam 101.2 Refractive Index and Dispersion 10Example 1.2.1 Sellmeier equ