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Fiber optic component design, fabrication, testing, operation, reliability and maintainability
Book Reviews background material. As a publication, the presentation is not helped by the choice of unusually small print, particularly for some of the figures accompanying the text. However, a number of references for further reading are provided at the end of each chapter, which should prove useful to the student or researcher intent on following up a particular topic, and the book will no doubt soon find its way to the library shelves, if not the student bookcase.
A. C. Selden Culham Labora tory
Fiber Optic Component Design, Fabrication, Testing, Operation, Reliability and Maintainability N.L. Christian and L.K. Passauer Noyes Data Corp, 1989, ISBN O-8 155 1203- 1, pp xiv + 434, $64
As its title suggests, this is a substantial work which seeks to provide detailed information on the reliability and maintainability of optical and electrooptical components particularly with respect to the support of systems in the field. The book is based on a report prepared by the authors for the US Department of Defense and does therefore have a slight bias towards gruelling operating conditions and requirements for long lifetimes. The bulk of the information presented, however, is equally relevant for non-military applications. The book is well-organized and is divided into six main sections covering basic guidelines for optical fibre systems, a summary of numerical reliability data, an extensive discussion of the characteristics of the basic components, studies of three installed systems, test equipment and procedures, and conclusions. The needs of the non optical fibre specialist have been kept very much in mind, and the differences between optical system practice and that for electrical systems are highlighted. A substantial part of the book (250 pages out of 433) is devoted to seven chapters on the fundamental components, fibre and cable, connectors and splices, emitters and transmitters, detectors and receivers, couplers, multiplexers and demultiplexers, switches, and enclosures and organizers. Each of these chapters consists of a description of the fundamental design and operation of the component, manufacturing processes and typical specifications. This serves as an excellent tutorial for those unfamiliar with the
420
technology, and reaches a sufficiently advanced level to be of real use. A discussion of the failure modes of the component is then presented, backed up with actual reliability data where available. A useful feature of this book is the inclusion of information on the logistics of maintenance, particularly on temporary and permanent repairs to severed cables and the repair kits, tools and personnel required to provide satisfactory support. None of the information presented is novel, but a mass of previously unpublished reliability data has been extracted from manufacturers and presented in a very accessible form. Similarly, it is unusual to find within one volume technical details of the design of a range of optical fibre cables ranging from indoor to submarine, a discussion of the advantages of silicon over InGaAs for the fabrication of avalanche photodiodes, and a review of research on non-linear optical devices for switching. There are occasional minor factual errors, but these do not affect any significant conclusions. A valid point is made that there is too little quantitative reliability data available to allow accurate lifetime calculations to be performed and the reader should take care to note that data provided by one manufacturer of, for example, surface emitting LEDs may not be directly applicable to similar devices from a different source. The section on three military fibre-optic systems is an interesting illustration of the application of these basic principles. For each system the basic requirement and system design are covered, followed by a description of installation, operation and maintenance procedures. Actual failures are reported, an analysis of which shows that destruction of the cable by rodents or by workmen servicing another part of the aeroplane have happened far more frequently than failure of the optoelectronic devices. This indicates a continuing need for training of installation personnel in optical fibre procedures and also for training of optical system designers in the skills of installation practice such as cable routing and rodent-proof manholes. A further useful section covers the types of specialized optical test gear. The operation and use of sources, power meters, and time domain reflectometers is described, together with a well-illustrated guide to recommended test procedures. This gives sound techniques for performing such tests as cutback measurements for fibre attenuation and the measurement of connector insertion loss. Practical aspects such as the requirement for mode scrambling in order to obtain good results from these tests are highlighted, and where available reference is made to relevant published test specifications. A good bibliography is provided with 164 references in all, the numerical reliability data is all referenced, but frequently to private communications rather than to publications. Optics
Et Laser Technology Vol22 No 6 1990
statistical data on the full range of components makes this a valuable source of reference data, and one which provides a good grounding in the basics of the technology for the non-specialist who is confronted with the requirement to procure and maintain an optical fibre system. It is equally useful
BRITE/EURAM
Technological
the factors which must be taken into account before his system can leave the well-equipped laboratory and enter the real world.
R. Jones Optical Sensors Ltd
Days
21-22 May 1990, Brussels, Belgium One of the consequences of the expansion of both the size and influence of the European Community (EC) is its increasing impact on the Technological field. The Community dictates policy on a wide range of activities involving citizens of the various member states and through the promotion of a number of directives with relevance to the scientific activities within the Community, its influence is felt. Funding from the EC has become big business, especially in view of the large size programmes that can be supported from Brussels. As the requirements to be met for grants from the SERC and the other research councils in the UK become more and more stringent, the EC offers a real alternative, providing certain rules on programme nature and consortium membership are met. The BRITE Technological days were the third ‘shop window’ for one of the larger of these programmes with genuine industrial relevance, the BRITE/EURAM funding scheme. It has reached the stage where the acronyms BRITE and EURAM are now so well established that their original meanings are somewhat lost - save to say that the theme of the programme is ‘Manufacturing Technologies for the 199Os’, and from a review of the projects funded, the breadth of activity encompassed by that sub-title is indeed wide. The delegates met at the Palais de Congres, to attend a meeting comprising three main parts - a Conference, an Exhibition and a Proposers’ Forum. However, in order to receive the admission badge that indicated you were a fully paid-up attendee (with appropriate colour coding to denote Industry,University, Research Institute or other origins of the delegates, and a special coding for Commission Staff) the hurdle of registration had to be overcome. Here the organization really had broken down. The Conference was oversubscribed but to ask delegates to have to queue for nearly two hours at a hopelessly undermanned registration desk does not make for the best of humour with even the most enthusiastic of them. This arose Optics Et Laser Technology Vol22 No 6 1990
because late registrations were effectively impossible due to the specified method of payment of the registration fee - I do not know any administrative system in a British company or University which can produce a foreign currency banker’s draft quickly enough. There is still much to learn from the smooth efficiency of the typical American meeting, and the simple charging of a registration cost to a company or personal credit card. It is vital that action on this basic matter is taken before the next meeting. That having been said, over 1500 people managed (eventually) to acquire registered status and access to the events. Thus, the third ‘Technological Days’ had seen an increase in attendance of about 20-25% at each meeting since the first, with about 1000 delegates, a few years ago, showing a clear indication of the current degree of interest, This included a number of senior figures from UK industry whose faces could be recognized in the crowd, an assortment of University Industrial liaison officers and other academics and a number of ‘match-making’consultants whose experience in treading softly through the apparent minefield of programme regulations is invaluable to project proposers. The Conference itself consisted of an opening and closing session where the speakers were senior policy makers and administrators from the programme encompassing a number of parallel sessions where representatives of projects in various stages of completion gave reports of a technical (and managerial) nature. For the average delegate this latter part of the programme was only of limited interest as the session titles ranged from ‘New Materials’, ‘Design’, Production Control’ and ‘Manufacturing Techniques’ to ‘Biomaterials’, Chemical Engineering’ and ‘Jointing of Materials’, too wide a range for all except those with the most eclectic of interests. However for the average delegate what was of real interest was to see the scale of a typical programme in
421
A. C. Selden Culham Labora tory
Fiber Optic Component Design, Fabrication, Testing, Operation, Reliability and Maintainability N.L. Christian and L.K. Passauer Noyes Data Corp, 1989, ISBN O-8 155 1203- 1, pp xiv + 434, $64
As its title suggests, this is a substantial work which seeks to provide detailed information on the reliability and maintainability of optical and electrooptical components particularly with respect to the support of systems in the field. The book is based on a report prepared by the authors for the US Department of Defense and does therefore have a slight bias towards gruelling operating conditions and requirements for long lifetimes. The bulk of the information presented, however, is equally relevant for non-military applications. The book is well-organized and is divided into six main sections covering basic guidelines for optical fibre systems, a summary of numerical reliability data, an extensive discussion of the characteristics of the basic components, studies of three installed systems, test equipment and procedures, and conclusions. The needs of the non optical fibre specialist have been kept very much in mind, and the differences between optical system practice and that for electrical systems are highlighted. A substantial part of the book (250 pages out of 433) is devoted to seven chapters on the fundamental components, fibre and cable, connectors and splices, emitters and transmitters, detectors and receivers, couplers, multiplexers and demultiplexers, switches, and enclosures and organizers. Each of these chapters consists of a description of the fundamental design and operation of the component, manufacturing processes and typical specifications. This serves as an excellent tutorial for those unfamiliar with the
420
technology, and reaches a sufficiently advanced level to be of real use. A discussion of the failure modes of the component is then presented, backed up with actual reliability data where available. A useful feature of this book is the inclusion of information on the logistics of maintenance, particularly on temporary and permanent repairs to severed cables and the repair kits, tools and personnel required to provide satisfactory support. None of the information presented is novel, but a mass of previously unpublished reliability data has been extracted from manufacturers and presented in a very accessible form. Similarly, it is unusual to find within one volume technical details of the design of a range of optical fibre cables ranging from indoor to submarine, a discussion of the advantages of silicon over InGaAs for the fabrication of avalanche photodiodes, and a review of research on non-linear optical devices for switching. There are occasional minor factual errors, but these do not affect any significant conclusions. A valid point is made that there is too little quantitative reliability data available to allow accurate lifetime calculations to be performed and the reader should take care to note that data provided by one manufacturer of, for example, surface emitting LEDs may not be directly applicable to similar devices from a different source. The section on three military fibre-optic systems is an interesting illustration of the application of these basic principles. For each system the basic requirement and system design are covered, followed by a description of installation, operation and maintenance procedures. Actual failures are reported, an analysis of which shows that destruction of the cable by rodents or by workmen servicing another part of the aeroplane have happened far more frequently than failure of the optoelectronic devices. This indicates a continuing need for training of installation personnel in optical fibre procedures and also for training of optical system designers in the skills of installation practice such as cable routing and rodent-proof manholes. A further useful section covers the types of specialized optical test gear. The operation and use of sources, power meters, and time domain reflectometers is described, together with a well-illustrated guide to recommended test procedures. This gives sound techniques for performing such tests as cutback measurements for fibre attenuation and the measurement of connector insertion loss. Practical aspects such as the requirement for mode scrambling in order to obtain good results from these tests are highlighted, and where available reference is made to relevant published test specifications. A good bibliography is provided with 164 references in all, the numerical reliability data is all referenced, but frequently to private communications rather than to publications. Optics
Et Laser Technology Vol22 No 6 1990
statistical data on the full range of components makes this a valuable source of reference data, and one which provides a good grounding in the basics of the technology for the non-specialist who is confronted with the requirement to procure and maintain an optical fibre system. It is equally useful
BRITE/EURAM
Technological
the factors which must be taken into account before his system can leave the well-equipped laboratory and enter the real world.
R. Jones Optical Sensors Ltd
Days
21-22 May 1990, Brussels, Belgium One of the consequences of the expansion of both the size and influence of the European Community (EC) is its increasing impact on the Technological field. The Community dictates policy on a wide range of activities involving citizens of the various member states and through the promotion of a number of directives with relevance to the scientific activities within the Community, its influence is felt. Funding from the EC has become big business, especially in view of the large size programmes that can be supported from Brussels. As the requirements to be met for grants from the SERC and the other research councils in the UK become more and more stringent, the EC offers a real alternative, providing certain rules on programme nature and consortium membership are met. The BRITE Technological days were the third ‘shop window’ for one of the larger of these programmes with genuine industrial relevance, the BRITE/EURAM funding scheme. It has reached the stage where the acronyms BRITE and EURAM are now so well established that their original meanings are somewhat lost - save to say that the theme of the programme is ‘Manufacturing Technologies for the 199Os’, and from a review of the projects funded, the breadth of activity encompassed by that sub-title is indeed wide. The delegates met at the Palais de Congres, to attend a meeting comprising three main parts - a Conference, an Exhibition and a Proposers’ Forum. However, in order to receive the admission badge that indicated you were a fully paid-up attendee (with appropriate colour coding to denote Industry,University, Research Institute or other origins of the delegates, and a special coding for Commission Staff) the hurdle of registration had to be overcome. Here the organization really had broken down. The Conference was oversubscribed but to ask delegates to have to queue for nearly two hours at a hopelessly undermanned registration desk does not make for the best of humour with even the most enthusiastic of them. This arose Optics Et Laser Technology Vol22 No 6 1990
because late registrations were effectively impossible due to the specified method of payment of the registration fee - I do not know any administrative system in a British company or University which can produce a foreign currency banker’s draft quickly enough. There is still much to learn from the smooth efficiency of the typical American meeting, and the simple charging of a registration cost to a company or personal credit card. It is vital that action on this basic matter is taken before the next meeting. That having been said, over 1500 people managed (eventually) to acquire registered status and access to the events. Thus, the third ‘Technological Days’ had seen an increase in attendance of about 20-25% at each meeting since the first, with about 1000 delegates, a few years ago, showing a clear indication of the current degree of interest, This included a number of senior figures from UK industry whose faces could be recognized in the crowd, an assortment of University Industrial liaison officers and other academics and a number of ‘match-making’consultants whose experience in treading softly through the apparent minefield of programme regulations is invaluable to project proposers. The Conference itself consisted of an opening and closing session where the speakers were senior policy makers and administrators from the programme encompassing a number of parallel sessions where representatives of projects in various stages of completion gave reports of a technical (and managerial) nature. For the average delegate this latter part of the programme was only of limited interest as the session titles ranged from ‘New Materials’, ‘Design’, Production Control’ and ‘Manufacturing Techniques’ to ‘Biomaterials’, Chemical Engineering’ and ‘Jointing of Materials’, too wide a range for all except those with the most eclectic of interests. However for the average delegate what was of real interest was to see the scale of a typical programme in
421