Springer Series in Optical Sciences Volume 54 Springer Series in Optical Sciences Editorial Board: D.L. MacAdam A.L. Schawlow K. Shimoda A. E. Siegman T. Tamir Volume 42 Principles of Phase Conjugation By B. Ya. Zel'dovich, N. F. Pilipetsky, and V. V. Shkunov Volume 43 X-Ray Microscopy Editors: G. Schmahl and D. Rudolph Volume 44 Introduction to Laser Physics By K. Shimoda 2nd Edition Volume 45 Scanning Electron Microscopy Physics of Image Formation and Microanalysis By L. Reimer Volume 46 Holography and Deformation Analysis By W. Schumann, J.-P. Zürcher, and D. Cuche Volume 47 Thnable Solid State Lasers Editors: P. Hammerling, A.B. Budgor, and A. Pinto Volume 48 Integrated Optics Editors: H. P. Nolting and R. Ulrich Volume 49 Laser Spectroscopy VII Editors: T. W. Hänsch and Y. R. Shen Volume 50 Laser-Induced Dynamic Gratings By H.J. Eichler, P. Günter, and D. W. Pohl Volume 51 Tunable Solid State Lasers for Remote Sensing Editors: R. L. Byer, E. K. Gustafson,.and R. Trebino Volume 52 Tunable Solid-State Lasers 11 Editors: A. B. Budgor, L. Esterowitz, and L. G. DeShazer Volume 53 The CO Laser 2 By W. J. Witteman Volume 54 Lasers, Spectroscopy and New Ideas A Tribute to Arthur L. Schawlow Editors: W. M. Yen and M. D. Levenson Volumes 1-41 are listed on the back inside cover Lasers, Spectroscopy and New Ideas A Tribute to Arthur L. Schawlow Editors: W. M. Yen and M. D. Levenson With 161 Figures Springer-Verlag Berlin Heidelberg GmbH Professor William M. Yen Department of Physics and Astronomy, The University of Georgia, Athens, GA 30602, USA Dr. Mare D. Levenson K69/803(E), IBM Almaden Research Center, 650 Harry Rd., San Jose, CA 95120, USA Editorial Board Professor KOICHI SHIMODA Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku Yokohama 223, Japan Professor ANTHONY E. SIEGMAN DAVID L. MAcADAM, Ph. D. Electrical Engineering, 68 Hammond Street E. L. Gintzton Laboratory, Stanford University Rochester, NY 14615, USA Stanford, CA 94305, USA THEODOR TAMIR, Ph. D. ARTHUR L. SCHAWLOW, Ph. D. Polytechnic University Department of Physics, Stanford University 333 Jay Street Stanford, CA 94305, USA Brooklyn, NY 11201, USA ISBN 978-3-662-13608-9 ISBN 978-3-540-47872-0 (eBook) (Springer series in DOI 10.1007/978-3-540-47872-0 Library of Congress Cataloging·in-Publication Data. Lasers, spectroscopy, and new ideas. optical sciences ; v. 54) Inc1udes index. 1. Lasers. 2. Spectrum analysis. 3. Schawlow, Arthur L., 1921-. 1. Levenson, Marc D. 11. Yen, W.M. (William M.) III. Schawlow, Arthur L., 1921-. IV. Series. QC688.L37 1987 535.5'8 87-23332 This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in other ways, and storage in data banks. Duplication of this publication or parts thereof is only permitted under the provisions of the German Copyright Law of September 9, 1965, in its version of June 24, 1985, and a copyright fee must always be paid. Violations fall under the prosecution act of the German Copyright Law. © Springer· Verlag Berlin Heidelberg 1987 Originally published by Springer-Verlag Berlin Heidelberg New York in \987. Softcover reprint of the hardcover \ st edition \987 The use of registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. 2153/3150-543210 To Do Successful Research, You Don't Need to Know Everything. You Just Need to Know of One Thing That Isn't Known. A.L. Schawlow Arthur L. Schawlow v Foreword This volume originated in a happy event honoring Arthur Schawlow on his 65th birthday. As a research physicist, Schawlow has been a major infiuence on the present nature of physics and of high technology. He has also had a role, through the American Physical Society and other organizations, in shaping policy for the world of physicists. Important as these professional activities have been, the contributions to this volume were not prepared just for these reasons, but more for Art Schawlow the friend, colleague, and teacher. I am one who has had the privilege of knowing and collaborating with Art, probably over a longer period of time than others participating in this volume, and in a number of different enterprises; his friendship and stimulating scientific abilities are a very significant part of my own life. It is hence a pleasure to take part in this volume celebrating his contributions to science and to scientists. Schawlow's career has been geographically centered at the University of Toronto, Columbia University, the Bell Telephone Laboratories, and Stan ford University. But, as is illustrated by the papers of this volume, its effects and his personal infiuence have diffused widely. In his own work, Art Schawlow is noted for thoughtful imagination, keen physical intuition, and what might be thought an interest in gadgets - not just any gadgets, but beautiful and innovative mechanisms or new techniques in which he charac teristically recognizes important potentials. One can say that he has always been a spectroscopist - from a thesis at Toronto in optical spectroscopy, to his work and book on microwave spectroscopy, the first.publication on the laser, and most recently his part in the inventive development of laser spectroscopy to remarkable refinement, precision, and power. Prom this brief list it is ob vious that his work has also had great breadth and touched many fields. Art has also touched many people, and always with consideration, friend ship, adelight in scientific discovery, and an infectious sense of humor. I be lieve the inspiration and motivation for this volume spring largely from these latter warm personal qualities. The contributions it contains will illustrate some of the many fields and individuals indebted to Arthur Schawlow, and it is hoped that here and there the authors will have captured at least some approximation of his almost inimitable humor. Berkeley, California March, 1987 Charles H. Townes VII Preface It occurred to some of us as the occasion of Art Schawlow's sixty-fifth birthday approached in 1986 that we needed to make an appropriate ges ture to honor this man, not only for his weIl-recognized scientific contri butions, but also for the personal legacy which he is leaving to, and the influence he has exerted on, everyone who has had the privilege of coming into contact with hirn through the years. After some false starts, it was decided that a collection of artides and reminiscences would serve as an appropriate vehide for such a tribute, and it is thus that this venture came into existence. To quantify or enumerate Art 's contributions to the scientific litera ture is a relatively easy task, and his articles and reviews, many of which are dassics, are dear, concise and numerous. He has co-authored pa pers with almost one hundred different people and he has worked with nearly seventy-five collaborators with varying functions during his period at Stanford. The range of topics to which his contributions are addressed is impressively wide-ranging and spans subjects as diverse as Doppler-free atomic spectroscopy and the properties of xenon flash lamp discharges. Needless to say, this volume of scientific work has had undeniable influence and impact in a number of areas of scientific and technical importance, which we need not belabor here. The nature of Art's influence is sampled in the articles presented here and is evinced by the accomplishments of the many researchers he has trained. It is much more difficult to provide an adequate measure of Art's other contributions, especially those concerned with the fostering of scientific ideas and scientific talent and attitudes. Indeed, it is because of the very positive influence he exerted on many of us with respect to our professional growth that we decided to organize this celebratory volume. For those of us who have had the privilege of falling under his tutelage, it is generally agreed that he attempted to teach us (sometimes successfully, many times not) that very simple concepts are normally sufficient to explain even the most complex observations. This principle has served us all weIl in our subsequent careers. In addition to developing and encouraging new scientific ideas and approaches, Art has always provided a personal touch in his interactions; in these he reveals without fail his patience, his intrinsic kindness, his humanism, and his humor. This touch was most welcome as IX it nurtured self-confidence in the many raw and inexperienced graduate students and postdocs that joined his effort at Stanford, including the two editors of this volume. It was the humanistic side of his infiuence that led us to choose the general tone of this collection of writings. The authors who graciously agreed to participate in this effort represent a sampIe of the many scientific areas in which Art has left a legacy or made an impact. We suggested to all the contributors that they write their articles in such a way as to include not only some description of some phase of their present area of scientific endeavors but also to include impressions as to how their personal attitudes and development were affected by interactions with Art. Some of the contributions describe work in which the authors are currently engaged, while others are archival, as they are concerned with the evolution of areas in which Art has made seminal contributions. By and large, we are pleased by the results of the effort, and we believe that in this collection a number of the contributions will remain relevant weIl into the future, especially those which were designed to be historical. We have incorporated, between parts, anecdotes and other items which address only the humanistic side and are exemplary of the joy and humor which normally prevail in any association with Art. Indeed, we would also have liked to provide recordings of his jazz clarinet playing dating from his graduate school days, but unfortunately he would not allow their release for circulation. The volume is organized as follows: The contributed articles are di vided into four areas. The first three parts include material devoted to areas in which Art has had an undeniable role, either in establishing a field of endeavor or in exercising exceptionalleadership. These are, in sequence, lasers and laser spectroscopy, spectroscopy of atomic and molecular sys tems, and spectroscopy in the condensed phases. Each of these parts contain four to six papers from authors who have made recognizable con tribut ions in each of the respective areas and who, following their contact with Art, have gone on to distinguished careers of their own. The fourth part consists of three contributions which are illustrative of areas where Art has had an indirect infiuence, in these cases by training a cadre of scientists who have advanced other frontiers by utilizing those attitudes which are so characteristic of "The Boss". The picture we have succeeded in presenting in this sampling does not totally summarize all the accom plishments of Art Schawlow. Many of us are cognizant of the fact that Art made a pioneering attempt at laser isotope separation in the early 1960s, that he played a principal role in interpreting the spectra of magnetically ordered materials, and that methods to induce cooling in atoms with lasers were suggested by hirn in the early 1970s. Regardless of the shortcomings of this collection, for which we, the editors, assurne full responsibility, we believe that each of the contributions has its own worth; in some instances x the articles are important reviews in their own right, albeit softened some what from the usual austere scientific format because of the nature of this enterprise. The advantage in return is that the majority of the contribu tions are eminently readable and will be understood by a wide range of readers not directly involved in the specific areas of scientific endeavor. It is always difficult to take time out from the many pursuits which normally engage our time to participate in extracurricular ventures. It is indeed gratifying that so many people readily agreed to contribute to this volume and, for the most part, produced their manuscripts on time. The editors would thus like to take this opportunity to express their thanks to all who participated in this worthwhile cause and also to Dr. Helmut Lotsch and Springer-Verlag for their cooperation, which made this volume possible. Ms. Nancy Bachman of the University of Georgia is thankfully acknowledged for her assistance in sundry editorial tasks. And, of course, Mrs. Fred-a Jurian is acknowledged to be the true "boss of bosses" of the operations at Stanford, and she bears direct responsibility for many of us having survived the vicissitudes of our youth, perhaps at times to her regret. Indeed, this volume is also a tribute to her wisdom, concern and kindness. San Jose, California W.M. Yen April 1987 ]VI.D. Levenson XI