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Principles of optical engineering
282
they impair the pleasure to the subject.
Book reviews
of reading
an otherwise
very good introduction
W. S. Davies Principles of Optical Engineering, by Francis T. S. Yu and I. C. Khoo. John Wiley, Chichester, 1990, 306 pp., X13.50, Pb. ISBN O-471-52751-3. This book sets out to provide the basis for an understanding of optical systems that may comprise source, optics, detectors and modulators; in current practice, such systems multiply daily; in high-density data transmission fibre-optic systems abound; every office has access to a fax machine; most homes have compact disc players, while in industry and in industrial metrology laser gauging is routine; in some quarters, the topic has been dubbed ‘optotronics’, to distinguish it from ‘mechanatronics’. Yu and Khoo’s book will therefore be seen as a timely addition to the literature available to undergraduates who wish to become acquainted with this field. It is natural that much of the text should read like a standard book on optics; since their ultimate aim is towards the systems application, their treatment of topics such as image formation in lenses, or interference, is necessarily to the point rather than encyclopaedic. That is all to the good since it leaves room for a clear and detailed review of spatial and temporal coherence with experimental demonstrations of both concepts. These elements are all the more worthy of detailed consideration since they recur frequently in laser-based systems, and a separate consideration of each is fully justified. In most other respects, Yu and Khoo have developed a competent undergraduate textbook that treats image formation and detection, the mathematics of radiation leading on to diffraction, lasers and holography. The last two chapters on Signal Processing and Fibre Optics are more overtly engineering in their content, but the material is treated in a conceptual manner, rather than discussing real-world case histories. In view of the multiple possible examples that are of current interest this does seem rather a pity. However, what is a thoroughly competent and readable book does have one major drawback in the shape of Chapter 1, in which linear systems transforms are introduced. These, one is certain, are a delight for communications engineers. However, since the concepts are unused for most of the first 250 pages (and in any case electrical engineers will be quite familiar with them), the book will be more readily appreciated if the reader simply omits Chapter 1. Such a criticism may be overly harsh in view of the authors stated target
Book reviews
283
group; it does imply, though, that the book may have limited attraction to students from disciplines outwith electrical engineering. The really creative developments in recent times have arisen from an intimate synthesis of optics, electronics and control; despite their declared aim, Yu and Khoo have progressed only partly along the road towards a unified treatment. C. A. Walker
Photoconductivity,
Marcel Dekker, 8321-2.
Art,
Science
and Technology,
by N. V. Joshi. New York, 1990, 304 pp., US$119.50. ISBN 0-8247-
The phenomena of photoconductivity holds a special place in the history of physics and in this century has been widely exploited, both directly as photodetectors and indirectly in material characterization, development of semiconductor device technology. in the Photoconductivity, Art, Science and Technology covers the subject from viewpoints of physics, material science and electrical and optical engineering, and forms part of the Marcel Decker series on optical engineering. The book is organized in seven chapters. A substantial introduction gives a little of the history of photoconduction and outlines the various mechanisms which produce free charges in a semiconducting material. The introduction also gives a rigorous description of all the terminology used in dealing with photoconductivity. The second chapter covers the techniques for photoconductivity measurement, including advice for making ohmic contact with the test material, the influence of contact configuration on the measurement and a detailed section on the various light sources that are employed. Chapter 3 on transient photoconductivity is a physics-oriented exposition of the time-dependent behaviour of current produced by incident light and the information about charge-carrier kinetics which can be obtained. This is followed by a chapter focusing on the materials in which photoconductivity is observed, detailing its relationship to semiconductor band structure and including the recent diluted magnetic semiconductors and superlattice structures. Chapter 5 discusses the various noise phenomena which limit photoconduction and is followed by a chapter entitled ‘Modern Photodetectors’ which covers the whole range of device structures and even includes a design example for a speculative detector and, furthermore, to compliment the previous chapter, includes a device approach to noise in detectors and detectivity. The final chapter
they impair the pleasure to the subject.
Book reviews
of reading
an otherwise
very good introduction
W. S. Davies Principles of Optical Engineering, by Francis T. S. Yu and I. C. Khoo. John Wiley, Chichester, 1990, 306 pp., X13.50, Pb. ISBN O-471-52751-3. This book sets out to provide the basis for an understanding of optical systems that may comprise source, optics, detectors and modulators; in current practice, such systems multiply daily; in high-density data transmission fibre-optic systems abound; every office has access to a fax machine; most homes have compact disc players, while in industry and in industrial metrology laser gauging is routine; in some quarters, the topic has been dubbed ‘optotronics’, to distinguish it from ‘mechanatronics’. Yu and Khoo’s book will therefore be seen as a timely addition to the literature available to undergraduates who wish to become acquainted with this field. It is natural that much of the text should read like a standard book on optics; since their ultimate aim is towards the systems application, their treatment of topics such as image formation in lenses, or interference, is necessarily to the point rather than encyclopaedic. That is all to the good since it leaves room for a clear and detailed review of spatial and temporal coherence with experimental demonstrations of both concepts. These elements are all the more worthy of detailed consideration since they recur frequently in laser-based systems, and a separate consideration of each is fully justified. In most other respects, Yu and Khoo have developed a competent undergraduate textbook that treats image formation and detection, the mathematics of radiation leading on to diffraction, lasers and holography. The last two chapters on Signal Processing and Fibre Optics are more overtly engineering in their content, but the material is treated in a conceptual manner, rather than discussing real-world case histories. In view of the multiple possible examples that are of current interest this does seem rather a pity. However, what is a thoroughly competent and readable book does have one major drawback in the shape of Chapter 1, in which linear systems transforms are introduced. These, one is certain, are a delight for communications engineers. However, since the concepts are unused for most of the first 250 pages (and in any case electrical engineers will be quite familiar with them), the book will be more readily appreciated if the reader simply omits Chapter 1. Such a criticism may be overly harsh in view of the authors stated target
Book reviews
283
group; it does imply, though, that the book may have limited attraction to students from disciplines outwith electrical engineering. The really creative developments in recent times have arisen from an intimate synthesis of optics, electronics and control; despite their declared aim, Yu and Khoo have progressed only partly along the road towards a unified treatment. C. A. Walker
Photoconductivity,
Marcel Dekker, 8321-2.
Art,
Science
and Technology,
by N. V. Joshi. New York, 1990, 304 pp., US$119.50. ISBN 0-8247-
The phenomena of photoconductivity holds a special place in the history of physics and in this century has been widely exploited, both directly as photodetectors and indirectly in material characterization, development of semiconductor device technology. in the Photoconductivity, Art, Science and Technology covers the subject from viewpoints of physics, material science and electrical and optical engineering, and forms part of the Marcel Decker series on optical engineering. The book is organized in seven chapters. A substantial introduction gives a little of the history of photoconduction and outlines the various mechanisms which produce free charges in a semiconducting material. The introduction also gives a rigorous description of all the terminology used in dealing with photoconductivity. The second chapter covers the techniques for photoconductivity measurement, including advice for making ohmic contact with the test material, the influence of contact configuration on the measurement and a detailed section on the various light sources that are employed. Chapter 3 on transient photoconductivity is a physics-oriented exposition of the time-dependent behaviour of current produced by incident light and the information about charge-carrier kinetics which can be obtained. This is followed by a chapter focusing on the materials in which photoconductivity is observed, detailing its relationship to semiconductor band structure and including the recent diluted magnetic semiconductors and superlattice structures. Chapter 5 discusses the various noise phenomena which limit photoconduction and is followed by a chapter entitled ‘Modern Photodetectors’ which covers the whole range of device structures and even includes a design example for a speculative detector and, furthermore, to compliment the previous chapter, includes a device approach to noise in detectors and detectivity. The final chapter