ENGINEERING APPLICATIONS OF LASERS AND HOLOGRAPHY
OPTICAL PHYSICS AND ENGINEERING Series Editor: William L. Wolfe Optical Sciences Center, University of Arizona, Tucson, Arizona M. A. Bramson Infrared Radiation: A Handbook for Applications Sol Nudelman and S. S. Mitra, Editors Optical Properties of Solids S. S. Mitra and Sol Nudelman, Editors Far-Infrared Properties of Solids Lucien M. Biberman and Sol Nudelman, Editors Photoelectronic Imaging Devices Volume 1: Physical Processes and Methods of Analysis Volume 2: Devices and Their Evaluation A. M. Ratner Spectral, Spatial, and Temporal Properties of Lasers Lucien M. Biberman, Editor Perception of Displayed Information W. B. Allan Fibre Optics: Theory and Practice Albert Rose Vision: Human and Electronic J. M. Lloyd Thermal Imaging Systems Winston E. Kock Engineering Applications of Lasers and Holography Shashanka S. Mitra and Bernard Bendow, Editors Optical Properties of Highly Transparent Solids A Continuation Order Plan is available for this series. A continuation order will bring delivery of each new volume immediately upon publication. Volumes are billed only upon actual shipment. For further information please contact the publisher.
ENGINEERING APPLICATIONS OF LASERS AND HOLOGRAPHY Winston E. Kock Acting Director The Herman Schneider Laboratory of Basic and Applied Science Research University of Cincinnati Cincinnati, Ohio PLENUM PRESS NEW YORK AND LONDON
Library of Congress Cataloging in Publication Data Kock, Winston E Engineering applications oflasers and holography. (Optical physics and engineering) Edition for 1969 published under title: Lasers and holography. Bibliography: p. Includes index. 1. Holography. 2. Lasers. I. Title. QC449.K6 1975 621.36'6 75-17507 ISBN-13: 978-1-4684-2162-0 DOl: 10.1 007/978-1-4684-2160-6 e-isbn-13: 978-1-4684-2160-6 1975 Plenum Press, New York softcover reprint of the hardcover I st edition 1975 A Division of Plenum Publishing Corporation 227 West 17th Street, New York, N.Y. 10011 United Kingdom edition published by Plenum Press, London A Division of Plenum Publishing Company, Ltd. Davis House (4th Floor), 8 Scrubs Lane, Harlesden, London, NWI0 6SE, England All rights reserved No part of this book may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, microfilming,. recording, or otherwise, without written permission from the publisher
Nobel Laureate Dennis Gabor, who originally conceived of the idea of holography
PREFACE This book is intended for upperclass college students as an introduction to the growing field of coherent optics and to the increasing number of its applications, and also for those versed in other fields who wish to gain perspective and insight without detailed calculations. It is an outgrowth of the author's Science Study Series book Lasers and HolographY. * Besides being an updated and expanded version of that book, it includes discussions of numerous recent applications. It differs in its slightly higher analytical level and in the inclusion oflarge numbers of references, which enable the reader to obtain further information on subjects of interest to him. The level was selected to match the capabilities of students in their middle college years so as to permit them to make an early assessment of possible career interests in any of the many interdisciplinary fields now embracing the technologies of modern optics. It is hoped that the book can be used (as has occurred rather extensively with another of the author's Science Study Series books, Sound Waves and Light Wavest) as an auxiliary reading assignment for students in various disciplines. The author strongly believes that the promise of continued growth in this field, as evidenced by the extensive participation in technology developments by industry, both within the U.S. and abroad, identifies the subject as * Doubleday, 1969 (hard cover and paperback). This book was chosen by Heinemann Education Books, Ltd. for No. 39 in their Science Series (1972, hard cover), by Editorial Universitaria De Buenos Aires (EUDEBA) for No. 42 in their New Science Collection (1972, paperback), by World Publishing (MIR, Moscow) for their Science and Technology Series (1971, paperback), and by Kawade Shobo (Tokyo) for No. 41 in their Science Series (1971, paperback). t Doubleday, 1965, also widely translated: No. 109 in the Springer Verstandliche Wissenschaft series (1971, paperback), No. 17 in the Zanichelli Scientific Monograph series (Rome, 1966, paperback), No. 27 in the Kawade Shobo Science Series, (Tokyo, 1969, paperback), and in the World Publishing Science and Technology Series (MIR, Moscow, 1966, paperback). vii
viii PREFACE one of more than average significance to engineering students, and the auxiliary reading assignment procedure would enable the student to become aware of the future importance of this new technology. Several chapters include an introductory review of the history and growth of the field discussed so as to further permit the reader to recognize the impact that modern optics is making in that area. ACKNOWLEDGMENTS The author is indebted to F. K. Harvey of the Bell Telephone Laboratories for the photographs portraying microwaves and sound waves, to Lowell Rosen and John Rendiero of the NASA Electronics Research Center for various hologram photographs, and to the Bendix Corporation, the Bell Telephone Laboratories, and numerous corporations for various photos of equipment and records. Numerous sections of the book are based on the author's presentations at the three U.S.-Japan Seminars on Holography, held in Tokyo, Washington, D.C., and Honolulu, Hawaii in 1967, 1969, and 1973, respectively, under the auspices of the National Science Foundation and the Japanese Society for the Promotion of Science. The author wishes to thank Professor George Stroke, State University of New York, Head of the U.S. delegations, for the invitations to participate as one of the U.S. delegates and as co-chairman for the last two seminars.
CONTENTS INTRODUCTION Chapter 1 FUNDAMENTAL WAVE PROPERTIES 3 1.1. Wave Interference 4 1.2. Phase. 5 1.3. Wave Visualization 5 1.4. Diffraction 8 1.5. Diffraction by a Slit. 10 1.6. The Near (Fresnel), Far (Fraunhofer), and Transition Fields 13 1.7. Diffraction by Two Slits. 13 1.8. Dependence of Diffraction on Wavelength 16 1.9. Wave Polarization 16 1.10. Refraction 18 1.11. Prisms 19 1.12. References 21 Chapter 2 WAVE COHERENCE 23 2.1. Frequency Coherence 2.2. Frequency Stability. 2.3. Spatial Coherence 2.4. Coherent Waves from Small Sources 2.5. The Extremely Short Wavelengths of Light. ix 23 25 27 28 30
x Chapter 3 GRATINGS AND ZONE PLATES 3.1. The Optical Grating. 3.2. Slit Gratings and Photographic Gratings 3.3. A Prism Grating 3.4. A Double-Prism Grat~ng. 3.5. Volume Effects. 3.6. The Classical Zone Plate. 3.7. Zone Plates with Areas Interchanged 3.8. A Photographic Zone Plate 3.9. Offset Zone Plates 3.10. Zone Plates as Lenses 3.11. Volume Zone Plates. 3.12. Standing-Wave Patterns 3.l3. Lattice Reflectors 3.14. Reflection Zone Plates 3.15. References. CONTENTS 31 31 32 35 36 38 39 41 43 48 49 50 50 54 56 57 Chapter 4 HOLOGRAM FUNDAMENTALS. 4.1. Two Simple Holograms. 4.2. The Complete Hologram Process 4.3. The Hologram of a Scene 4.4. Parallax in Holograms 4.5. Single-Wavelength Nature of Holograms 4.6. Nonoptical Holograms 4.7. Microwave Holograms 4.8. Acoustic Holograms 4.9. Microwave Holograms and Liquid Crystals 4.10. Liquid-Surface Acoustic Holograms 4.11. Hologram Equations 4.12. References. 59 59 61 64 65 67 68 69 70 71 72 74 75 Chapter 5 PROPERTIES OF HOLOGRAMS 5.1. Three-Dimensional Realism 5.2. Holograms and Photographs 77 77 84
CONTENTS xi 5.3. Lens Action 84 5.4. A Stereohologram 85 5.5. Focused-Image Holography 88 5.6. Reconstruction with a Small Portion of a Hologram. 90 5.7. Pseudoscopy in the Real Image of a Hologram 93 5.8. Image Inversion 94 5.9. Color Holograms 97 5.10. Requirements on Film Properties 98 5.11. Information Content 99 5.12. Holograms and Coherent Radar 101 5.13. References. 101 Chapter 6 LASER FUNDAMENTALS 103 6.1. The Metastable State 6.2. The Two-Step Process 6.3. Energy Conservation with Reflectors 6.4. Reflectors and Spatial Coherence 6.5. Energy Concentration 6.6. Q-Spoiling. 6.7. Gas Lasers. 6.8. Reflectors and Resonators 6.9. The Natural Line Width 6.10. Coherence Length 6.11. Semiconductor Lasers 6.12. Other-Level Lasers 6.13. References. 106 106 108 109 110 112 114 115 117 118 119 120 121 Chapter 7 RECENT DEVELOPMENTS IN LASERS. 7.1. Laser Units 7.2. Solid Lasers 7.3. Solid Laser Amplifiers 7.4. Gas Lasers. 7.5. Semiconductor Lasers 7.6. Liquid Lasers 7.7. Mode Locking 7.8. References. 123 123 124 126 128 136 139 140 142
xii Chapter 8 LASERS IN MEASUREMENT 8.1. Alignment. 8.2. Distance and Length Measurements 8.3. Velocity Measurements. 8.4. Measurement of Acceleration. 8.5. Atmospheric Effects. 8.6. Sonic Boom 8.7. Measurement of Pollutants 8.8. Lasers in Machine-Tool Measurements 8.9. Holographic Microscopy. 8.10. Saturation Spectroscopy. 8.11. Raman and Brillouin Spectroscopy 8.12. Mass Spectroscopy. 8.13. Holographic Interferometry 8.14. Interferometric Structure Analysis. 8.15. Interferometric Detection of Footprints 8.16. Interferometric Testing of Rocket Components 8.17. Nonoptical Holographic Interferometry 8.18. Laser Speckle 8.19. Measurement Techniques Employing Speckle 8.20. References. CONTENTS 145 145 148 151 154 156 157 157 158 163 164 164 165 166 167 168 169 171 171 175 176 Chapter 9 MICROWAVE HOLOGRAPHY 9.1. Early Developments. 9.2. Detection Devices 9.3. Microwave-Hologram Antennas 9.4. Liquid Crystal Holograms 9.5. Holographic Signal Processing 9.6. The Synthetic-Aperture Concept 9.7. Stationary Synthetic-Aperture Systems. 9.8. Forward-Scatter Hologram Radars 9.9. Bistatic Hologram Radars 9.10. Passive and End-Fire Radars. 9.11. Synthetic-Interferometer Radars 9.12. Radar Range Acquisition by Holography 9.13. References. 179 179 182 186 189 191 196 209 211 215 216 218 219 221
CONTENTS Chapter 10 ACOUSTIC HOLOGRAPHY APPLICATIONS. 10.1. Early Developments 10.2. Acoustic Synthetic-Aperture Systems 10.3. Underwater Applications 10.4. Acoustic Kinoforms 10.5. Holographic Pulse Compression 10.6. Hologram Sonar Using Incoherent Illumination 10.7. Seismic Holography 10.8. References xiii 225 226 231 240 246 255 260 262 266 Chapter II LASERS IN INDUSTRY 11.1. Welding and Metalworking 11.2. Micromachining 11.3. Solid-State Trimming 11.4. Laser Scribers for Substrates 11.5. Microdrilling. 11.6. Fabric Cutting 11. 7. Checkout Systems for Supermarkets 11.8. Display Applications 11.9. Cable Insulation Stripping 11.10. Control of Crystal Growth 11.11. Chromatograph-Analysis Use 11.12. Weather Analysis 11.13. References 269 269 272 274 277 277 280 281 283 287 287 288 288 289 Chapter 12 COMMUNICATIONS 12.1. The Constant Demand for Bandwidth 12.2. Coaxial Cable. 12.3. Microwave Systems 12.4. Radio Relay Circuits 12.5. Satellite Communications 12.6. Orbiting Satellites. 12.7. Synchronous Satellites 12.8. Domestic Systems. 12.9. Early Laser Research 12.10. Basic Laser Communication Considerations 291 291 291 292 292 293 296 297 298 299 300
xiv CONTENTS 12.11. Line-of-Sight Laser Communications 12.12. Satellite Laser Communications 12.13. Wires of Glass 12.14. A Long-Distance Fiber Circuit 12.15. Short-Length Fiber Circuits. 12.16. Optical Film Devices 12.17. Lasers in Microfilm Transmission 12.18. Television Recording 12.19. References 301 303 304 306 307 308 308 309 310 Chapter 13 MEDICAL APPLICATIONS 313 13.1. The Development of Ultrasonics in Medical Imaging 313 13.2. Recent Developments 314 13.3. Details of Recent Ultrasonic Techniques. 316 13.4. Synthetic-Aperture Techniques in Medicine 317 13.5. Real-Time Synthetic Aperture 318 13.6. Liquid-Surface Holography for Medical Diagnostics 318 13.7. Concern About Acoustic Intensity in Holography. 324 13.8. Holography and Three-Dimensional X-Ray Pictures 325 13.9. Holography and Three-Dimensional Gamma-Ray Images 329 13.10. Applications in Ophthalmic Fields 331 13.11. Dental Applications 333 13.12. References 334 Chapter 14 COMPUTING APPLICATIONS 337 14.1. Fourier Series. 337 14.2. Discrete Fourier Analysis 340 14.3. Discrete Analysis Tables 341 14.4. Fourier Integrals 344 14.5. Fourier Transforms 344 14.6. Fast Fourier Transforms (FFT) 344 14.7. Distant-Field Patterns. 345 14.8. Near-Field Patterns 346 14.9. Space-Frequency Equivalence 348 14.10. Two-Dimensional Fourier Transforms 348 14.11. The History of Optical Processing 351 14.12. Optical Filtering 353
CONTENTS xv 14.13. Seismic Applications 355 14.14. Complex Optical Filters 356 14.15. Complex-Filter Applications 357 14.16. Optical Processing in Radar 359 14.17. Parallel Optical Processing: The Accepting Function 360 14. 18. Parallel Optical Processing: The Processing and Display Function. 361 14.19. Real-Time Optical Computing 361 14.20. Computer-Generated Holograms. 362 14.21. Holographic Computer Memories 363 14.22. Flying-Spot Scanning 364 14.23. Read-Only Memories 365 14.24. Volume Hologram Memories 367 14.25. Erasable Memories. 367 14.26. One-Dimensional Hologram Memories 371 14.27. References 372 Chapter 15 NUCLEAR FUSION. 375 15.1. Power Needs 376 15.2. Atomic Energy Development 377 15.3. Nuclear Weapons. 378 15.4. Fission Reactors 379 15.5. The Breeder Reactor 381 15.6. Controlled Fusion. 382 15.7. Amplifying the Laser Pulses. 383 15.8. Laser-Fusion Experiments 384 15.9. Pulse Tailoring 385 15.10. Uranium Enrichment by Lasers 386 15.11. References 386 FURTHER READING SUGGESTIONS 389 AUTHOR INDEX 391 SUBJECT INDEX 395