Amazing Light: A Volume Dedicated To Charles Hard Townes On His 80th Birthday

674 Pages·1996·15.35 MB·English

by  Arthur L. Schawlow (auth.)

Amazing Light
Springer
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Charles Hard Townes
Raymond Y. Chiao, Editor
Amazing Light
A Volume Dedicated To
Charles Hard Townes On
His 80th Birthday
With 189 illustrations
Springer
Raymond Y. Chiao
Department of Physics
University of California at Berkeley
Berkeley, CA 94720
USA
Library of Congress Cataloging-in-Publication Data
Chiao, Raymond Y.
Amazing light: a volume dedicated to Charles Hard Townes on his
80th birthday / Raymond Y. Chiao.
p. cm.
Includes bibliographical references and index.
ISBN-I3: 978-1-4612-7521-3 e-ISBN-13: 978-1-4612-2378-8
DOl: 10.1007/978-1-4612-2378-8
1. Quantum electronics-Congresses. 2. Lasers-Congresses.
3. Masers-Congresses. 4. Astrophysics-Congresses. 5. Townes,
Charles H.-Congresses. 6. Physicists-United States-Biography
-Congresses. I.T itle.
QC685.C45 1996
537.5--<1c20 95-49220
Printed on acid-free paper.
© 1996 Springer-Verlag New York, Inc.
Softcover reprint of the hardcover 1s t edition 1996
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987654321
To Charles Hard Townes
Preface
This Festschrift is a collection of essays contributed by students, colleagues, and ad
mirers to honor an eminent scholar on a special anniversary: Charles Hard Townes
on the occasion of his 80th birthday, July 28, 1995. In 1964, Townes shared the
Nobel Prize in physics with Alexander Mikhailovich Prokhorov and Nikolai Gen
nadyevich Basov "for fundamental work in the field of quantum electronics, which
has led to the construction of oscillators and amplifiers based on the maser-laser
principle." His contributions have covered a much wider area, however. His fruitful
interests spanning several decades have included many scientific subjects, includ
ing, microwave spectroscopy and astrophysics (other articles in this volume will
expand further on this point). He has also contributed to public service, having
served as the chairman of the Science and Technology Advisory Committee for
NASA's Apollo program, and as a member and vice chairman of the President's
Science Advisory Committee. As the enormous breadth of contributions from his
students shows, he has educated scholars who are now in a wide range of fields.
The contributions from his many admirers, among whom are nine fellow Nobel
laureates, attest to his impact on many disciplines ranging from electrical engi
neering to medicine. His influence extends even to theology, as is indicated by
one essay. The broadly international character of this Festschrift reflects his deep
belief in the international, universal nature of science. Contributors have come
from Australia, Canada, England, France, Germany, Italy, Japan, Russia, Switzer
land, and the United States. His students have also come from countries all over
the globe, which, in addition to the above, include China, Greece, India, Iran, and
Israel. In light of the breadth of these contributions, it was difficult to decide on
their order. In the end, to be as impartial as possible, I have decided to present
them in alphabetical order by first author, apart from the Introduction by Arthur
Schawlow.
This book would have been impossible without the hard work and assistance
of Mamie McElhiney, who helped type, organize, compile, and proofread the
manuscripts, and the help of Grant McKinney and David E. Johnson, who assisted
in compiling the manuscripts into IbTpc. They made many valuable suggestions
viii Preface
along the way while I edited the manuscripts. Many thanks also go to my neighbors
in Birge Hall, Dr. Norbert Geis and Paul McEuen, for their expert advice on the
editing of some manuscripts. I would especially like to thank Arthur Schawlow for
his wise advice and friendly encouragement. I gratefully acknowledge the support
of the Office of Naval Research under ONR Grant No. NOOOI4-90-J-1259 during
my editorship. Also, the support and encouragement from the Berkeley physics
department through its chairman, Roger Falcone, and through its staff, was essen
tial for the production of this volume. Moreover, this Festschrift would not have
been possible without the generous donations of the supporters and contributors
listed below. Finally, I would like to thank my dear wife Florence for her patience
and wise advice during this labor.
R.Y.C.
Berkeley, July 28, 1995
o o o
Many thanks go to the following societies, corporations, and persons, whose
generous donations have made the production of this Festschrift possible:
Supporters: Contributors:
Optical Society of America Burleigh Instruments, Inc.
AT&T Cleveland Crystals, Inc.
Mr. and Mrs. S. D. Bechtel Mr. and Mrs. David R. Dunlap
Carnegie Institution of Washington Prof. Thomas E. Everhart
Coherent Laser Group Mr. Richard C. Gerstenberg
NEC Research Institute, Inc. Lambda Physik
Optical Coating Laboratory, Inc. Mr. and Mrs. F. James McDonald
Mr. David Packard Mr. and Mrs. Thomas A. Murphy
The Perkin-Elmer Corp. Mr. and Mrs. James M. Roche
Rudolph Research Corp. Prof. and Mrs. Arthur Rosenfeld
Prof. Arthur L. Schawlow Mr. and Mrs. Marian O. Scully
Mr. Casper W. Weinberger
Mr. and Mrs. Warren L. Wolfson
Mr. Timothy F. Wullger
Contents
Preface vii
List of Contributors xxiii
1 Introduction: Charles Townes as I Have Known Him 1
Arthur L. Schawlow
2 Methane Optical Frequency Standard 7
Nicolai G. Basov, Vladimir A. Alekseev, and Mikhail A. Gubin
2.1 Introduction........................ 7
2.2 Two-mode He-Ne Laser with a Methane Absorption Cell. 8
2.3 Absolute Frequency Measurements. . . . . . . . . . . . 10
2.4 Determination of the Unperturbed Transition Frequency
(). = 3.39 J,tm) ........ . . . . . . . . . . . . 14
2.5 Theoretical Estimates of Methane Standard Accuracy .. 16
2.5.1 Second-order Doppler Effect . . . . . . . . . . . 16
2.5.2 Detuning of the Active and Absorption Line Centers . 18
2.5.3 Transverse Inhomogeneity of the Gain 18
2.6 Future Possibilities . . . . . . . . . . . . . . . . . . . . . . 19
3 Mid-infrared Lines as Astrophysical Diagnostics: Two Decades of
Problems and Promise 21
SaraC. Beck
3.1 Youthful Enthusiasm . . . . . . . . . . . . . 21
3.2 General Confusion . . . . . . . . . . . . . . 22
3.3 Maybe We Know What We're Doing After All 23
3.4 Conclusion.................. 26
x Contents
4 The Laser Stabilitron 27
William R. Bennett, Jr. and Vieniamin P. Chebotayev
4.1 Background . . . . . . . . . . . . . . . . . 27
4.2 Method of Intensity Stabilization . . . . . . 28
4.3 Coupled Field Equations and Photon Noise . 32
4.4 Possible Systems for Realizing a Stabilitron 38
5 Self-Regulated Star Formation in Molecular Clouds 41
Frank Bertoldi and Christopher F. McKee
5.1 Introduction................. 41
5.2 Structure and Stability of Molecular Clouds 42
5.2.1 Gravitational Stability 43
5.2.2 The Dissipation Problem ..... . 44
5.3 Self-Regulated Star Formation . . . . . . . 45
5.3.1 Energy Gain: Low-Mass Star Formation 45
5.3.2 Equilibrium Star Formation Rate .... 46
5.3.3 Photoionization-regulated Star Formation 47
5.3.4 Self-regulated Equilibrium States. 48
5.4 Discussion.... 50
5.5 Summary ..... 52
5.6 Acknowledgments 53
6 Long-baseline Interferometric Imaging at 11 Microns with 30
Milliarcsecond Resolution 55
Manfred Bester and William C. Danchi
6.1 Introduction................ 55
6.2 The Infrared Spatial Interferometer . . . . 57
6.3 Highlights of Recent Results from the lSI 58
6.3.1 Broad Conclusions on Dust Shell Characteristics . 60
6.3.2 Masers ......... . 62
6.4 Direct Inversion of Visibility Data 63
6.4.1 Methodology 63
6.4.2 Results.. 65
6.5 Conclusions.... 70
6.6 Acknowledgments 70
7 Ammonia in the Giant Planets 73
Albert L. Betz
7.1 Introduction....................... 73
7.2 The Upper Atmospheres of Jupiter and Saturn ..... 73
7.3 The Collision of Comet Shoemaker-Levy 9 with Jupiter 75
7.4 Acknowledgments .................. . 78
Contents xi
8 Collision Broadening and Radio-frequency Spectroscopy 79
Brebis Bleaney
8.1 Prehistory . . . . . . . . . . . . . . . . . . . . . . . 79
8.2 Emission Spectroscopy . . . . . . . . . . . . . . . . 79
8.3 Laboratory Measurements of Microwave Absorption . 80
8.4 The Inversion Spectrum of Ammonia. . . . . . . 80
8.5 Further Studies of Collision Broadening at Oxford 82
8.6 High Resolution Microwave Spectroscopy . . . . 83
8.7 The Switch to Electron Paramagnetic Resonance. 83
8.8 Atomic and Molecular Beams 84
8.9 Conclusion 84
8.10 Postscript....... 84
9 Meeting Charles H. Townes 87
Nicolaas Bloembergen
10 Population Inversion and Superluminality 91
Raymond Y. Chiao
10.1 Introduction: The Ammonia Maser Revisited. . . . . . . 91
10.2 Historical Review of Some Faster-than-Light Phenomena 94
10.3 Theory of Wave Packet Propagation in Transparent,
Population-inverted Media . . . . . . . . . . . . . . . . 97
10.4 The Kramers-Kronig Relations Necessitate Superluminality 99
10.5 Considerations of Energy and of Superposition . . . . . . . 100
10.6 Einstein Causality, and Sommerfeld and Brillouin's Wave
Velocities . . . . . . . . . . . . . . . . . . . . . . . . . . 102
10.7 An Experiment in an Optically Pumped Rubidium Vapor Cell 104
10.8 Concluding Personal Remarks 106
10.9 Acknowledgments ...... 107
11 The Autler-Townes Effect Revisited 109
Claude N. Cohen-Tannoudji
11.1 Introduction...................... 109
11.2 Dressed-atom Approach to the Autler-Townes Effect . 109
11.3 The Autler- Townes Effect in the Optical Domain . . . 113
11.3.1 Case of Two Optical Transitions Sharing a Common
Level . . . . . . . . . . . . . . . . . . . . . . . .. 113
11.3.2 Single Optical Transition-The Mollow Triplet ... 114
11.4 The Autler-Townes Effect in Cavity Quantum Electrodynamics 115
11.5 Doublets of Dressed States with a Position-dependent Rabi
Frequency. . . . . . . . . . . . . . . 117
11.5.1 Gradient (or Dipole) Forces . 117
11.5.2 High Intensity Sisyphus Effect 119