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Introduction to Fiber Optics
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Introduction to Fiber Optics 2nd Edition
John Crisp
OXFORD AUCKLAND
BOSTON
JOHANNESBURG
MELBOURNE
NEW DELHI
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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
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Contents
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
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Contents
vi
20 Some final thoughts
206
Glossary
210
Quiz time answers
217
Index
227
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Preface
An increasing proportion of the world’s communications are carried by fiber optic cables. It has spread quietly, almost without being noticed into every situation 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 communication. 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
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