Introduction to Wave Optics

Introduction to Fourier Optics McGraw-Hill Series in Electrical and Computer Engineering SENIOR CONSULTING EDITOR Stephen W. Director, Carnegie Mellon University Circuits and Systems Communications and Signal Processing Computer Engineering Control Theory Electromagnetics Electronics and VLSI Circuits Introductory Power and Energy Radar and Antennas PREVIOUS CONSULTING EDITORS Ronald N. Bracewell, Colin Cherry, James F. Gibbons, Willis W. Harman, Hubert Heffner, Edward W. Herold, John G. Linvill, Simon Ramo, Ronald A. Rohrer, Anthony E. Siegman, Charles Susskind, Frederick E. Terman, John G. Truxal, Ernst Weber, and John R. Whinnery Elec tromagnetics SENIOR CONSULTING EDITOR Stephen W. Director, Carnegie Mellon University Dearhold and McSpadden: Electromagnetic Wave Propagation Goodman: Introduction to Fourier Optics Harrington: Time - Harmonic Electromagnetic Fields Hayt: Engineering Electromagnetics Kraus: Electromagnetics Paul and Nasar: Introduction to Electromagnetic Fields Plonus: Applied Electromagnetics Introduction to Fourier Optics SECOND EDITION Joseph W. Goodman Stanford University THE McGRAW-HILL COMPANIES, INC. New York St. Louis San Francisco Auckland Bogot6 Caracas Lisbon London Madrid Mexico City Milan Montreal New Delhi San Juan Singapore Sydney Tokyo Toronto [...]... angle 8 (with respect to the x axis) given by In addition, the spatial period (i.e the distance between zero-phase lines) is given by 8 Introduction to Fourier Optics \ \ FIGURE 2.1 - - - - - Lines of zero phase for the fur exp[j2.rr(fxn + fry)] - In conclusion, then, we may again regard the inverse Fourier transform as providing a means for decomposing mathematical functions The Fourier spectrum G of... of Photographic Emulsions 7.2 Spatial Light Modulators 7.2.1 Properties of Liquid Crystals / 7.2.2 Spatial Light Modulators Based on Liquid Crystals / 7.2.3 Magneto-Optic Spatial Light Modulators / 7.2.4 Deformable Mirror Spatial Light Modulators / 7.2.5 Multiple Quantum Well Spatial Light Modulators / 7.2.6 Acousto-Optic Spatial Light Modulators 7.3 Diffractive Optical Elements 7.3.1 Binary Optics. .. decomposition are, of course, just these 6 functions To find the response of the system to the input gl, substitute ( 2-4 3) in ( 2-4 1): Now, regarding the number gl(5, q ) as simply a weighting factor applied to the elementary function 6(x1 - 5, yl - q), the linearity property ( 2-4 2) is invoked to allow S { )to operate on the individual elementary functions; thus the operator S{} brought is within the integral, yielding... functions separable in rectangular coordinates Function e x - ( a +2 2 Transform ?- exp y 2 lab1 [ (2+ 2 )] -n - - I 6(ax,by) - exp[j.rr(ax+ by)] sgn(ax) sgn(by) ab 1 - 1 comb(ax) comb(by) -comb(fxla) comb(fylb) exp[jn(a 2 x 2+ b2y2)] - exp [-( alxl + blyl)l Circle function lab1 6(fx - al2, f~ - bl2) 1 lab1 1 circ( ) / , lab1 jnfx jnfy 1 lab1 2 / , = 2 + ( 2 nf ~ l a )1 ~ (27rfylb)2 + = 1 ( 0 otherwise... also like to thank the students in my 1995 Fourier Optics class, who competed fiercely to see who could find the most mistakes Undoubtedly there are others to whom I owe thanks, and I apologize for not mentioning them explicitly here Finally, I thank Hon Mai, without whose patience, encouragement and support this book would not have have been possible Joseph W GoodmIntroduction to Wave Optics Introduction to Wave Optics Bởi: OpenStaxCollege 1/2 Introduction to Wave Optics The colors reflected by this compact disc vary with angle and are not caused by pigments Colors such as these are direct evidence of the wave character of light (credit: Infopro, Wikimedia Commons) Examine a compact disc under white light, noting the colors observed and locations of the colors Determine if the spectra are formed by diffraction from circular lines centered at the middle of the disc and, if so, what is their spacing If not, determine the type of spacing Also with the CD, explore the spectra of a few light sources, such as a candle flame, incandescent bulb, halogen light, and fluorescent light Knowing the spacing of the rows of pits in the compact disc, estimate the maximum spacing that will allow the given number of megabytes of information to be stored If you have ever looked at the reds, blues, and greens in a sunlit soap bubble and wondered how straw-colored soapy water could produce them, you have hit upon one of the many phenomena that can only be explained by the wave character of light (see [link]) The same is true for the colors seen in an oil slick or in the light reflected from a compact disc These and other interesting phenomena, such as the dispersion of white light into a rainbow of colors when passed through a narrow slit, cannot be explained fully by geometric optics In these cases, light interacts with small objects and exhibits its wave characteristics The branch of optics that considers the behavior of light when it exhibits wave characteristics (particularly when it interacts with small objects) is called wave optics (sometimes called physical optics) It is the topic of this chapter These soap bubbles exhibit brilliant colors when exposed to sunlight How are the colors produced if they are not pigments in the soap? (credit: Scott Robinson, Flickr) 2/2 [...]... 3-D Optical Storage 8.4.6 Photochemical Hole-Burning 3-D Storage 8.5 Holographic Optical Storage 8.5.1 Principle of Holography 8.5.2 Plane Holographic Storage 8.5.3 Stacked Holograms for 3-D Optical Storage 8.5.4 Volume Holographic 3-D Optical Storage 8.6 Near Field Optical Storage 8.7 Concluding Remarks References Exercises Chapter 9 9.1 9.2 9.3 9.4 9.5 9.6 9.7 Computing with Optics Introduction Parallel... application of which can range from very abstract artistic interpretations to very efficient scientific usages This chapter discusses the relationship between entropy information and optics Our intention is not to provide a detailed discussion, however, but to cover the basic fundamentals that are easily applied to optics We note that entropy information was not originated by optical scientists, but rather by... entropy information, interest in its application has never totally been absent from the optical standpoint As a result of the recent development of optical communication, signal processing, and computing, among other discoveries, the relationship between optics and entropy information has grown more profound than ever 2 1 Entropy Information and Optics 1.1 INFORMATION TRANSMISSION Although we seem to know... (1.28) where H(A/B) represents the amount of information loss (e.g., due to noise) or the equivocation of the channel, which is the average amount of information needed to specify the noise disturbance in the channel And H(B/A) is referred to as the noise entropy of the channel To conclude this section, we note that the entropy information can be easily extended to continuous product space, such as p(a)log2p(a)da,... Sensors 10.4 Summary References Exercises 589 589 600 612 613 615 Chapter 11 617 Information Display with Optics 11.1 I ntrod action 11.2 Information Display Using Acousto-optic Spatial Light Modulators 11.2.1 The Acousto-optic Effect 11.2.2 Intensity Modulation of Laser 11.2.3 Deflection of Laser 11.2.4 Laser TV Display Using Acousto-optic Devices 11.3 3-D Holographic Display 11.3.1 Principles of Holography... not only the source of energy necessary to live — plants grow up by drawing energy from sunlight; light is also the source of energy for information - our vision is based on light detected by our eyes (but we do not grow up by drawing energy from light to our body through our eyes) Furthermore, applications of optics to information technology are not limited to vision and can be found almost everywhere... interests in optical applications to information technology In view of the great number of contributions in this area, we have not been able to include all of them in this book Chapter 1 Entropy Information and Optics Francis T.S Yu THE PENNSYLVANIA STATE UNIVERSITY Light is not only the mainstream of energy that supports life; it also provides us with an important source of information One can easily imagine... therefore able to advance themselves above the rest of the animals on this planet Earth It is undoubtedly true that if humans did not have eyes, they would not have evolved into their present form In the presence of Introduction to Fiber Optics Prelims 3/5/01 11:48 Page i Prelims 3/5/01 11:48 Page ii Introduction to Fiber Optics 2nd Edition John Crisp OXFORD AUCKLAND BOSTON JOHANNESBURG MELBOURNE NEW DELHI Prelims 3/5/01 11:48 Page iii Newnes An imprint of Butterworth–Heinemann Linacre House, Jordan Hill, Oxford OX2 8DP A division of Reed Educational and Professional Publishing Ltd A member of the Reed Elsevier plc group First published 1996 Reprinted 1997, 1998, 1999, 2000 (three times), 2001 Second edition 2001 © John Crisp 1996, 2001 All rights reserved. No part of this publication may be reproduced in any material form (including photocopying or storing in any medium by electronic means and whether or not transiently or incidentally to some other use of this publication) without the written permission of the copyright holder except in accordance with the provisions of the Copyright, Designs and Patents Act 1988 or under the terms of a licence issued by the Copyright Licensing Agency Ltd, 90 Tottenham Court Road, London, England W1P 0LP. Applications for the copyright holder’s written permission to reproduce any part of this publication should be addressed to the publishers. British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library ISBN 07506 50303 Composition by Scribe Design, Gillingham, Kent Printed and bound in Great Britain by Biddles Ltd, www.biddles.co.uk Prelims 3/5/01 11:48 Page iv Preface vii 1 Optic fiber and light — a brilliant combination 1 2 What makes the light stay in the fiber? 9 3 The choice of frequency 17 4 Propagation of light along the fiber 22 5 Decibels 39 6 Losses in optic fibers 50 7 Dispersion and our attempts to prevent it 59 8 Real cables 68 9 Connecting optic fibers — the problems 82 10 Fusion splicing 92 11 Mechanical splices 103 12 Connectors 108 13 Couplers 126 14 Light sources and detectors 139 15 Testing a system 147 16 System design — or, will it work? 166 17 The transmission of signals 183 18 Organizing optic fiber within a building 192 19 LANs and topology 200 Contents Prelims 3/5/01 11:48 Page v 20 Some final thoughts 206 Glossary 210 Quiz time answers 217 Index 227 Contents vi Prelims 3/5/01 11:48 Page vi An increasing proportion of the world’s communications are carried by fiber optic cables. It has spread quietly, almost without being noticed into every situa- tion in which information is being transmitted whether it is within the home hi-fi system, cable television or telecommunication cables under the oceans. The purpose of this book is to provide a worry-free introduction to the subject. It starts at the beginning and does not assume any previous knowledge of the subject and, in gentle steps, it introduces the theory and practical knowledge that is necessary to use and understand this new technology. In learning any new subject jargon is a real problem. When the words are understood by all parties they make an efficient shorthand form of communi- cation. Herein lies the snag. If not understood, jargon can create an almost impenetrable barrier to keep us out. In this book jargon is introduced only when required and in easily digested snacks. John Crisp Preface Prelims 3/5/01 11:48 Page vii Prelims 3/5/01 11:48 Page viii The starting point For thousands of years we have used light to communicate. The welcoming camp fire guided us home and kept wild animals at bay. Signal bonfires were lit on hilltops to warn of invasion. Even in these high-tech days of satellite communications, ships still carry powerful lamps for signaling at sea, signaling mirrors are standard issue in survival packs. It was a well known ‘fact’ that, as light travels in straight lines, it is impossible to make it follow a curved path to shine around corners. Boston, Mass., USA, 1870. An Irish NONRESIDENT TRAINING COURSE SEPTEMBER 1998 Navy Electricity and Electronics Training Series Module 10—Introduction to Wave Propagation, Transmission Lines, and Antennas NAVEDTRA 14182 DISTRIBUTION STATEMENT A: Approved for public release; distribution is unlimited. Although the words “he,” “him,” and “his” are used sparingly in this course to enhance communication, they are not intended to be gender driven or to affront or discriminate against anyone. DISTRIBUTION STATEMENT A: Approved for public release; distribution is unlimited. PREFACE By enrolling in this self-study course, you have demonstrated a desire to improve yourself and the Navy. Remember, however, this self-study course is only one part of the total Navy training program. Practical experience, schools, selected reading, and your desire to succeed are also necessary to successfully round out a fully meaningful training program. COURSE OVERVIEW: To introduce the student to the subject of Wave Propagation, Transmission Lines, and Antennas who needs such a background in accomplishing daily work and/or in preparing for further study. THE COURSE: This self-study course is organized into subject matter areas, each containing learning objectives to help you determine what you should learn along with text and illustrations to help you understand the information. The subject matter reflects day-to-day requirements and experiences of personnel in the rating or skill area. It also reflects guidance provided by Enlisted Community Managers (ECMs) and other senior personnel, technical references, instructions, etc., and either the occupational or naval standards, which are listed in the Manual of Navy Enlisted Manpower Personnel Classifications and Occupational Standards, NAVPERS 18068. THE QUESTIONS: The questions that appear in this course are designed to help you understand the material in the text. VALUE: In completing this course, you will improve your military and professional knowledge. Importantly, it can also help you study for the Navy-wide advancement in rate examination. If you are studying and discover a reference in the text to another publication for further information, look it up. 1998 Edition Prepared by FCC(SW) R. Stephen Howard and CWO3 Harvey D. Vaughan Published by NAVAL EDUCATION AND TRAINING PROFESSIONAL DEVELOPMENT AND TECHNOLOGY CENTER NAVSUP Logistics Tracking Number 0504-LP-026-8350 i Sailor’s Creed “I am a United States Sailor. I will support and defend the Constitution of the United States of America and I will obey the orders of those appointed over me. I represent the fighting spirit of the Navy and those who have gone before me to defend freedom and democracy around the world. I proudly serve my country’s Navy combat team with honor, courage and commitment. I am committed to excellence and the fair treatment of all.” ii TABLE OF CONTENTS CHAPTER PAGE 1. Wave Propagation .................................................................................................... 1-1 2. Radio Wave Propagation.......................................................................................... 2-1 3. Principles of Transmission Lines ............................................................................. 3-1 4. Antennas ................................................................................................................... 4-1 APPENDIX I. Glossary.................................................................................................................. INDEX ......................................................................................................................... iii AI-1 INDEX-1 NAVY ELECTRICITY AND ELECTRONICS TRAINING SERIES The Navy Electricity and Electronics Training Series (NEETS) was developed for use by personnel in many electrical- and electronic-related Navy ratings. Written by, and with the advice of, senior technicians in these ratings, this series provides beginners CAMERAPhân tíchảnhNhận dạngThu nhận ảnhSố hoáHệ thốngThu nhận ảnhChương Một: NHẬP MÔN XỬ LÝ ẢNH NHẬP MÔN XỬ LÝ ẢNH INTRODUCTION TO DIGITAL IMAGE PROCESSING1.1 TỔNG QUAN VỀ MỘT HỆ THỐNG XỬ LÝ ẢNHXử lý ảnh là một khoa học còn tương đối mới mẻ so với nhiều ngành khoa học khác, nhất là trên qui mô công nghiệp, song trong xử lý ảnh đã bắt đầu xuất hiện những máy tính chuyên dụng. Để có thể hình dung cấu hình một hệ thống xử lý ảnh chuyên dụng hay một hệ thống xử lý ảnh dùng trong nghiên cứu, đào tạo, trước hết chúng ta sẽ xem xét các bước cần thiết trong xử lý ảnh.Trước hết là quá trình thu nhận ảnh. Ảnh có thể thu nhận qua camera. Thường ảnh thu nhận qua camera là tín hiệu tương tự (loại camera ống kiểu CCIR), nhưng cũng có thể là tín hiệu số hoá (loại CCD - Charge Coupled Device). Lưu trữ SENSOR Lưu trữ Hệ Q.Định Hình 1.1.a. Các giai đoạn chính trong xử lý ảnhẢnh cũng có thể thu nhận từ vệ tinh qua các bộ cảm ứng (sensor), hay ảnh, tranh được quét trên scanner. Chi tiết về quá trình thu nhận ảnh sẽ được mô tả trong chương 2. Tiếp theo là quá trình số hoá (Digitalizer) để biến đổi tín hiệu tương tự sang tín hiệu rời rạc (lấy mẫu) và số hoá bằng lượng hoá, trước khi chuyển sang giai đoạn xử lý, phân tích hay lưu trữ lại.Qúa trình phân tích ảnh thực chất bao gồm nhiều công đoạn nhỏ. Trước hết là công việc tăng cường ảnh để nâng cao chất lượng ảnh. Do những nguyên nhân khác nhau: có thể do chất lượng thiết bị thu nhận ảnh, do nguồn sáng hay do nhiễu, ảnh có thể bị suy biến. Do vậy cần phải tăng cường và khôi phục lại ảnh để làm nổi bật một số đặc tính chính của ảnh, hay làm cho ảnh gần giống nhất với trạng thái gốc- trạng thái trước khi ảnh bị biến dạng. Giai đoạn tiếp theo là phát hiện các đặc tính như biên, phân vùng ảnh, trích chọn các đặc tính, v.v .Nhập môn xử lý ảnh số - ĐHBK Hà nội 11 Chương Một: NHẬP MÔN XỬ LÝ ẢNH Cuối cùng, tuỳ theo mục đích của ứng dụng, sẽ là giai đoạn nhận dạng, phân lớp hay các quyết định khác. Các giai đoạn chính của quá trình xử lý ảnh có thể mô tả ở hình 1.1.a.Với các giai đoạn trên, một hệ thống xử lý ảnh (cấu trúc phần cứng theo chức năng) gồm các thành phần tối thiểu như hình 1.1.b. Đối với một hệ thống xử lý ảnh thu nhận qua camera-camera như là con mắt của hệ thống. Có 2 loại camera: camera ống loại CCIR và camera CCD. Loại camera ứng với chuẩn CCIR quét ảnh với tần số 1/25 và mỗi ảnh gồm 625 dòng. Loại CCD gồm các photo điốt và làm tương ứng một cường độ sáng tại một điểm ảnh ứng với một phần tử ảnh (pixel). Như vậy, ảnh là tập hợp các điểm ảnh. Số pixel tạo nên một ảnh gọi là độ phân giải (resolution). Bộ xử lý tương tự (analog processor). Bộ phận này thực hiện các chức năng sau:- Chọn camera thích hợp nếu hệ thống có nhiều camera.- Chọn màn hình hiển thị tín hiệu- Thu nhận tín hiệu video thu nhận bởi bộ số hoá(digitalizer). Thực hiện lấy mẫu và mã hoá.- Tiền xử lý Introduction to Geometric Optics Introduction to Geometric Optics Bởi: OpenStaxCollege Geometric Optics Light from this page or screen is formed into an image by the lens of your eye, much as the lens of the camera that made this photograph Mirrors, like lenses, can also form images that in turn are captured by your eye 1/3 Introduction to Geometric Optics Image seen as a result of reflection of light on a plane smooth surface (credit: NASA Goddard Photo and Video, via Flickr) Our lives are filled with light Through vision, the most valued of our senses, light can evoke spiritual .. .Introduction to Wave Optics The colors reflected by this compact disc vary with angle and are not caused by pigments Colors such as these are direct evidence of the wave character... branch of optics that considers the behavior of light when it exhibits wave characteristics (particularly when it interacts with small objects) is called wave optics (sometimes called physical optics) ... white light into a rainbow of colors when passed through a narrow slit, cannot be explained fully by geometric optics In these cases, light interacts with small objects and exhibits its wave characteristics