Lasers and Optical Engineering

488 Pages·1991·14.91 MB·English

by  P. Das (auth.)

Lasers and Optical Engineering
Springer
New York
Berlin
Heidelberg
Barcelona
Budapest
Hong Kong
London
Milan
Paris
Santa Clara
Singapore
Tokyo
P. Das
Lasers and
Optical Engineering
With 391 Illustrations
, Springer
P. Das
Electrical, Computer, and
Systems Engineering Department
Rensselaer Polytechnic Institute
Troy, NY 12180-3590
U.S.A.
Cover illustration: Photograph of the optical processor for real-time spectrum analysis. This figure
appears on p. 315 of the text.
Library of Congress Cataloging-in-Publication Data
Das. P.
Lasers and optical engineering I P. Das.
p. cm.
Includes bibliographical references.
ISBN-13: 978-1-4612-8764-3 e-ISBN-13: 978-1-4612-4424-0
DOl: 10.1007/978-1-4612-4424-0
1. Lasers. 2. Optics. 1. Title.
TA1677.D37 1990
621.36'6-dc20 89-26312
CIP
Printed on acid-free paper.
© 1991 Springer-Verlag New York Inc.
Softcover reprint of the hardcover 1st edition 1991
All rights reserved. This work may not be translated or copied in whole or in part without the
written permission of the publisher (Springer-Verlag, 175 Fifth Avenue, New York, NY 10010,
U.S.A.), except for brief excerpts in connection with reviews or scholarly analysis. Use in connec
tion with any form of information storage and retrieval, electronic adaptation, computer software,
or by similar or dissimilar methodology now known or hereafter developed is forbidden.
The use of general descriptive names, trade names, trademarks, etc., in this publication, even if
the former are not especially identified, is not to be taken as a sign that such names, as understood
by the Trade Marks and Merchandise Marks Act, may accordingly be used freely by anyone.
Typeset by Asco Trade Typesetting Ltd., Hong Kong.
9 8 7 6 543 2
To
Virginia, Andrea, Joshua and the memory of Susama
and Upendra
Preface
A textbook on lasers and optical engineering should include all aspects of
lasers and optics; however, this is a large undertaking. The objective of this
book is to give an introduction to the subject on a level such that under
graduate students (mostly juniors/seniors), from disciplines like electrical
engineering, physics, and optical engineering, can use the book. To achieve
this goal, a lot of basic background material, central to the subject, has been
covered in optics and laser physics. Students with an elementary knowledge
of freshman physics and with no formal courses in electromagnetic theory
should be able to follow the book, although for some sections, knowledge of
electromagnetic theory, the Fourier transform, and linear systems would be
highly beneficial.
There are excellent books on optics, laser physics, and optical engineering.
Actually, most of my knowledge was acquired through these. However, when
I started teaching an undergraduate course in 1974, under the same heading
as the title of this book, I had to use four books to cover the material I thought
an electrical engineer needed for his introduction to the world of lasers and
optical engineering. In my sabbatical year, 1980-1981, I started writing class
notes for my students, so that they could get through the course by possibly
buying only one book. Eventually, these notes grew with the help of my
undergraduate and graduate students, and the final result is this book.
It is a pleasure to thank Janet Tomkins for typing the class notes, over and
over again. Without her patience and efforts, this book would not have been
possible. Also, I would like to thank many of my students who helped improve
the manuscript by criticizing, finding mistakes and correcting them, and
editing and writing projects reports which I have freely used.
Contents
Some Fundamental Constants xiii
Chronology of Optical Discoveries xv
Introduction xvii
PART I
Geometrical Optics
1.1. Fundamentals of Geometrical Optics 1
1.1.1. Discussion of Waves 1
1.1.2. Snell's Laws 4
1.2. Matrix Formulation of Geometrical Optics 7
1.2.1. Some Properties of Matrices 8
1.2.2. The Translational Matrix 9
1.2.3. The Matrix for Refraction 11
1.2.4. Matrix for a Simple Lens 13
1.3. Image Formation 15
1.3.1. Image Formation by a Thin Lens in Air 18
1.4. Complex Systems 22
1.4.1. Image Formation Using an Equivalent Thin-Lens Formulation 26
1.5. The Telescoping System 29
1.6. Some Comments About the Matrix Method 30
1.7. Apertures and Stops 33
1.7.1. The Aperture Stop 33
1.7.2. The Field Stop 38
1.7.3. Field of View 41
1.8. Radiometry and Photometry 41
1.8.1. Radiometry 41
1.8.2. Photometric Unit 45
1.9. Exact Matrices and Aberration 48
1.9.1. Exact Matrices 48
1.9.2. Exact Matrices for Skew Rays 53
1.9.3. Aberration 55
1.9.4. Spherical Aberration 61
1.9.5. Coma 64
1.9.6. Astigmatism 66
x Contents
1.9.7. Curvature of Field 68
1.9.8. Distortion 68
1.9.9. Chromatic Aberration 69
References 73
PART II
Physical Optics, Wave Optics, and Fourier Optics 74
2.1. Fundamentals of Diffraction 74
2.1.1. Maxwell's Equations 74
2.2. Radiation from a Source 78
2.3. The Diffraction Problem 79
2.4. Different Regions of Diffraction 81
2.4.1. The Fresnel Approximation 82
2.4.2. The Fraunhofer Approximation 83
2.4.3. The Spatial Frequency 85
2.4.4. Summary of Formulas 87
2.5. The Fourier Transform 88
2.5.1. Physical Interpretation of the Fourier Transform 91
2.5.2. The Two-Dimensional Fourier Transform 93
2.6. Some Examples of Fraunhofer Diffraction 95
2.6.1. The One-Dimensional Rectangular Aperture 95
2.6.2. The Two-Dimensional Rectangular Aperture 97
2.6.3. One-Dimensional Aperture Centered at x = xo 99
2.6.4. One-Dimensional Rectangular Aperture with Uniform Light
e
Shining at an Angle with Respect to the Optical Axis 100
2.6.5. Some Discussion About the Free Space Propagation of Waves. 102
2.7. Phase Transmission Functions and Lens 103
2.8. Fresnel Diffraction 106
2.8.1. Fresnel Diffraction and Lens 106
2.8.2. Diffraction Grating 109
2.8.3. Sinusoidal Gratings 117
2.8.4. Fresnel Diffraction Without Lens 119
2.9. Detection and Coherence 124
2.9.1. Detection 124
2.9.2. Coherency 131
2.10. Interference 133
2.10.1. Young's Experiment 134
2.10.2. Interference due to the Dielectric Layer 136
2.10.3. Michaelson's Interferometer 139
2.10.4. Interference by Multiple Reflections and the Fabry-Perot
Interferometer 141
2.11. Holography 148
2.11.1. Photography 148
2.11.2. The Making of a Hologram 150
2.11.3. Reconstruction of a Hologram 151
2.11.4. The Gabor Hologram 154
2.11.5. Analogy with Radio and Information Storage 155
2.11.6. Some Comments About Holograms 156
2.11.7. Hologram Using Point-Source References 157
Contents Xl
2.12. Physical Optics 159
2.12.1. Total Internal Reflection and Optical Tunneling 159
2.12.2. Reflection and Transmission Coefficients 161
2.12.3. Polarization 164
2.12.4. Phase Velocity, Group Velocity, and Ray Velocity 165
2.12.5. Propagation in Anisotropic Media 166
2.12.6. Double Refraction and Polarizers 168
2.12.7. The Electro-Optic Effect 172
2.12.8. The Acousto-Optic Effect 175
2.12.9. Optical Activity and Magneto-Optics 183
References 184
PART III
Lasers 187
3.1. Introduction 189
3.2. Amplifier and Oscillator 190
3.3. The Fabry-Perot Laser 192
3.4. Laser Cavity 197
3.4.1. Cavity Stability Using Geometrical Optics 198
3.5. Gaussian Beam Optics 204
3.5.1. Gaussian Optics Including Lenses 209
3.6. Solution of the Cavity Problem 211
3.6.1. Frequency of Oscillation 214
3.6.2. Unstable Resonators 217
3.7. Photon, Stimulated, and Spontaneous Emission, and the Einstein
Relationship 221
3.8. Light Amplifier~Population Inversion 226
3.9. Different Types of Light Amplifiers and Quantum Efficiency 229
3.10. Rate Dynamics of Four-Level Lasers 231
3.10.1. Optimum Output Power 235
3.11. Properties of Laser Light 237
3.12. Q-Switching and Mode Locking 240
3.12.1. Single-Mode and Multimode Lasers: Lamb Dip 240
3.12.2. Mode Locking of Multimode Lasers 243
3.12.3. Q-Switching 246
3.13. Lasers 254
3.13.1. The Gas Laser 254
3.13.2. Solid State Lasers 266
3.13.3. Dye Lasers 269
3.13.4. Semiconductor Lasers 273
3.13.5. Free-Electron Lasers and Cyclotron Resonance Masers 290
References 293
PART IV
Applications 294
4.1. Introduction 294
4.2. Optical Instruments 294
4.2.1. The Lens Magnifier 294
4.2.2. The Telescope 296
XII Contents
4.2.3. Binoculars 299
4.2.4. Compound Microscopy 300
4.2.5. Beam Expanders 302
4.2.6. Photographic Lens Systems 302
4.3. Fiber-Optics and Integrated Optics 314
4.3.1. Introduction 314
4.3.2. Guided Light 319
4.3.3. Integrated Optics 325
4.3.4. Fiber-Optic Cables 335
4.3.5. Applications 340
4.4. Optical Signal Processing 344
4.4.1. Introduction 344
4.4.2. Optical Signal Processing Devices 348
4.4.3. Optical Matrix Processor 376
4.4.4. Fourier Optics and Spatial Filtering 385
4.4.5. Some Examples of Matched Filtering or Correlation 395
4.5. Laser Applications 408
4.5.1. Lower Power Laser Applications 408
4.5.2. Material Processing with Lasers 408
4.5.3. The Medical Applications of Lasers 428
4.6. Recent Advances 438
4.6.1. Optical Interconnections for Integrated Circuits 438
4.6.2. Optical Computing 439
4.6.3. Star War 450
References 452
APPENDIX
Delta Function 455
Supplemental References 459
Index 463