FIBRE OPTICS Theory and Practice
OPTICAL PHYSICS AND ENGINEERING Series Editor: William L. Wolfe Optical Sciences Center University of Arizona Tucson, Arizona 1968: M. A. Bramson Infrared Radiation: A Handbook for Applications 1969: Sol Nudelman and S. S. Mitra, Editors Optical Properties of Solids 1970: S. S. Mitra and Sol Nudelman, Editors Far-Infrared Properties of Solids 1971: Lucien M. Biberman and Sol Nudelman, Editors Photoelectronic Imaging Devices Volume I: Physical Processes and Methods of Analysis Volume 2: Devices and Their Evaluation 1972: A. M. Ratner Spectral, Spatial, and Temporal Properties of Lasers 1973: Lucien M. Biberman, Editor Perception of Displayed Information W. B, Allan Fibre Optics: Theory and Practice'
FIBRE OPTICS Theory and Practice by W. B. Allan Ministry of Defence Fort Halstead Sevenoaks Kent PLENUM PRESS LONDON AND NEW YORK 1973
Library of Congress Catalog Card Number: 72-95066 ISBN-13: 978-1-4684-2042-5 e-isbn-13: 978-1-4684-2040-1 DOl: 10.1007/978-1-4684-2040-1 Copyright 1973 by Plenum Publishing Company Ltd Sof'tcover reprint of the hardcover 1 st edition 1973 Plenum Publishing Company Ltd Davis House 8 Scrubs Lane Harlesden London NWIO 6SE Telephone 01-969 4727 US edition published by Plenum Publishing Corporation 227 West 17th Street New York, New York 10011 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
Preface The emergence of fibre optics as a commercially viable technology occurred barely ten years ago; in this time it has become an established field with a variety of applications. This book has been written in an attempt to review the entire field with an emphasis on the practical applications of the technology. This approach has been adopted since it was felt that there was a need for a work which could be referred to by non -specialists in the field who were interested in, or who wished to make use of, fibre optics. With this readership in mind, the theory has been presented in as simple a manner as possible and emphasis has been placed on the description of typical applications and the manufacturing techniques of the technology. It is hoped that this mode of presentation will enable the reader to form an appreciation of both its advantages and its limitations. In Chapter I, a brief historical introduction is presented of the technology. In Chapters 2 and 3, the theory and practice of the optical fibre is outlined. Chapters 4 and 5 describe the manufacture and applications of the simplest type of component met in fibre optics, namely the light guide. Chapters 6, 7 and 8 provide, respectively, the theory, manufacture and applications of coherent bundles of optical fibres. Chapter 9 deals with the optical fibre regarded as a waveguide for electromagnetic energy. Chapter 10 is a pot-pourri of topics which are of secondary importance (at present!), and includes: fibre optics outside the visible spectrum, active optical fibres and optical fibres with a graded index. Chapter 11 is a review of the technology as it is applied in the medical field. It is always difficult in a work of this nature to single out people who have influenced the author, since many of the developments described were team efforts; however, I would like to acknowledge the help and advice which I received from Mr J. M. Ballantine and Dr A. J. W orral, both of Barr and Stroud Ltd, during my stay with that firm. In addition, I had many stimulating discussions with the former regarding the structure of a book on fibre optics, and he has also kindly read and commented on the manuscript. I also feel that I must acknowledge the encouragement I received from Dr T. Flitcroft while he was General Manager at Rank Kershaw (Rank Precision Industries Ltd), during which time a number of commercially successful developments
VI Fibre Optics were initiated, some of which are described in the book. Finally, I must thank my wife who undertook the arduous task of typing and correcting the manuscript, and without whose moral support the book would not have been written. W. B. Allan
Contents Preface v Historical Introduction 2 Fibre Optics - Basic Theory 4 3 The Optical Fibre 39 4 Non-Coherent Bundles - Manufacture and Properties 59 5 Non-Coherent Bundles - Applications 72 6 Coherent tlundles - Basic Theory 101 7 Coherent Bundles - Manufacture and Properties 116 8 Coherent Bundles - Applications 148 9 Waveguide Properties of Optical Fibres 175 10 Miscelianeous Topics 202 11 Fibre Optics in Medicine 218 Bibiiography 235 Subject ihdex 243