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Laser photochemistry, tunable lasers and other topics
BOOKS the University of Tokyo and an ingenious moulded plastic connector developed by Bell Telephone Laboratories for single graded-index fibres.
Second European conference on optical fibre communications Comite du Colloque International Fibres Optiques, 1976, pp 444
sur les Transmissions
par
This volume consists of photocopies of the abstracts submitted to the meeting held in Paris in September 1976. The papers (about seventy in all) thus represent an up-todate cross-section of current work in the field of optical fibres and systems. The survey is international, with 65% of the papers covering the European countries, 2 1% North America, and 14% Japan. The reproduction is clear and for ease of access the papers are indexed into sub-groups by topic: materials and technology (of fibres), propagation, cables and connectors, components, field measurements, long distance systems, and short distance systems. My only criticism of the volume itself was its very poor binding since it nearly fell apart on reading and certainly could not withstand photocopying. The quality of the contributions varies greatly, some being well-prepared and full of new information, others being of dubious value. Among the materials papers were a number of reports of fibres with losses of below 1 dB km-’ at extended wavelengths, 1 .l to 1.4 w region. Also noticeable was the emphasis on graded-index fibres, now clearly the preferred transmission medium, and stemming from this, an increasing interest in the manufacture of fibres with more precisely controlled profiles and larger index-difference (or NA), and the measurement of these properties. The continuing reduction of fibre loss and improvement of bandwidth stimulated a number of papers on the subject of meaningful measurement of fibre parameters since these become critically dependent upon the launched modal power distribution. A number of separate techniques were described with no clear preference emerging for any one. Two sessions of the meeting were devoted to cables and connectors, comprising some twelve papers, but it was not apparent from the reports that any clear theory of optical fibre cable design has yet emerged nor has the ideal connector. Perhaps of greatest interest was the paper on the Bell Telephone 144 fibre guide cable with some statistical information on the yield of complete fibre, the losses, and bandwidths. Also in this field were a number of descriptions of Japanese cables, but in all cases insufficient information was given to allow any clear understanding to emerge of the performance governing factors. Among the many papers on fibre materials and cabling there was surprisingly little mention of strength considerations, although a paper by the British Post Office detailed a fibre coating process and the results obtained therefrom. The sources for systems were well covered in a number of review and submitted papers. The proceedings also include some useful papers on joints and connectors, notably on a tapered fibre coupling for single mode fibres developed at
OPTICS & LASER TECHNOLOGY.
JUNE 1977
The contributions on systems were to me the most disappointing, particularly when compared with the preceeding meeting in this series. A few papers reported operating experience while a number discussed more hypothetical matters. Perhaps it would be fair to conclude that systems work is in a lull, the initial burst of activity leading to many meaty papers in 1975, hopefully to be followed in 1977 by reports of more substantial systems experiments. In summary, then, the volume represents a sizeable collection of material that is generally of good standard, readily accessible and invaluable for quick up-to-date reference. It must be nearly obligatory reading for workers in the field, and for those interested in assessing progress or status at a point in time, it will provide a useful source. In years to come it will form one record out of many of the continuing series of European conferences on optical fibres, London in 1975, Paris in 1976, Munich in 1977, Italy in 1978 and Holland in 1979. This volume will then be of interest in tracing the development in this very rapidly changing and developing field. J. E. Midwinter
Laser photochemistry, tunable lasers and other topics Edited by S. F. Jacobs, M. Sargent, M.O. Scully, C.T. Walker Addison-Wesley,
1976, pp 463, $23.50
This is the fourth volume of a series entitled Physics of Quantum Electronics. It is based on lectures given at a Summer School held in New Mexico in 1975 and deals mainly with laser isotope preparation, light scattering, and spectroscopy. There are 15 chapters in which work currently taking place in American laboratories is described by 2 1 authors. The largest number of contributors come fromLos Alamos, New Mexico and Boulder, Colorado. The first three chapters give, respectively, a review of laser isotope separation, details of the separation programme of the Energy Research and Development Administration, and experimental studies of selective photochemical reactions and energy transfer. Three chapters are devoted to the molecular physics for laser isotope separation. In these are described recent work in Russian and American laboratories, and the applications of Raman spectroscopy. Tunable laser sources for laser isotope separation are considered in the next four chapters. Included here are a review of tunable infrared lasers, experimental work with spin-flip lasers, and do-ityourself instructions for building dye lasers. Chapters 11 and
139
LASER75 OPTO-ELECTRONICS CONFERENCE PROCEEDINGS The LASER 75 OPTO-ELECTRONICS The worldwide interest in the applications of lasers and
opto-electronics was clearly evident at Laser ‘75. More than 800 delegates from 28 countries were present to hear and discuss papers on: Laser systems
($44 .OO) The papers are recorded in the Proceedings, which are edited by Professor Wilhelm Waidelich, Chairman of the Conference Programme Committee.
Lasers in nuclear energy technology Television
pick-up
Lasers in material processing Lasers in medicine
Order your copy now from:
Opto-electronic displays Lasers in optical communications Lasers in measuring
PROCEEDINGS provide an essential summary of the latest applications of lasers and optoelectronics. 305 x 210 mm / viii + 293 pages 1976 / Cloth / ISBN 0 902852 56 6 / Price L22.00 net
iw
engineering
and testing practice
Infra red and ultra violet techniques Lasers in data processing Lasers in environmental measuring techniques
science and
technobY press
Department APlA, IPC Science and Technology Press Limited IPC House, 3; High Street, Guildford, Surrey, %$~n~~~4%~ 166 1 Telex: Scitec Gd 859556
ELECTRO-OPTICS/LASER INTERNATIONAL’Z5dJK CONFERENCE PROCEEDINGS Edited by l-i. G. Jerrard Electra-Optics/Laser International ‘76 was held at the Metropole Convention Centre, Brighton, England from 9 to 11 March 1976. The topics covered were: Laser developments Optical instrument evaluation and special techniques Optical waveguides and fibre optics Applications of lasers to holography and interferometry: laser optics Electra-optical properties of materials and techniques Visible and infra-red technology Applications of lasers to-material processing and inspection Low-light-level techniques Optical information processing ipc
science and
technology press
140
TheProceedings
are edited for publication by the Conference Chairman, Dr H.G. Jerrard 304 x 210 mm / 208 pages test) Cloth / ISBN 0 902852 63 9 / Price f 18.00 net (536.00) Order your copy now from : IPC Science and Technology Press Limited IPC House, 32 High Street, Guildford, Surrey, England GUl 3EW Telephone: 0483-71661 Telex: Scitec Gd 859556
OPTICS & LASER TECHNOLOGY.
JUNE 1977
12 deal with light scattering and spectroscopy and in these chapters results of recent experiments on critical fluids and dense optical systems are described. The last three chapters, grouped under the heading ‘More’, cover the use of density matrices in quantum electronics, quantum electrodynamics, and superradiance - which is defined as a process in which a gas of identical atoms is radiating strongly because of coherence. The lectures tend to be of a tutorial nature,but, although the editors say they present recent developments in quantum electronics from first principles, the book is really only suited to those whose basic knowledge is good and who are working in the fields covered.
comparative technical evaluation of four primary solar collecting configurations. The studies of materials which constitute the fourth group deal almost exclusively with coatings for surfaces for the thermal conversion of solar energy. The proceedings give a useful insight into the studies of solar energy utilization which are currently in progress. There are author and subject indexes. H. G. Jerrard
Tunable lasers and applications
Edited by A. Mooradian, T. Jaeger, P. Stokseth
H. G. Jerrard
Springer-Verlag,
Optics in solar energy utilization
Edited by Y.H. Katz Proceedings of the Society of Photo-Optical Engineers, Volume 68,1975, $35.00
Instrumentation
Energy requirements on earth are estimated to amount to about 1% of that radiated from the sun to the earth and the availability of this energy source is infinite in time. National energy research programmes are being conducted in the United States with the aim of developing methods for harnessing some of this solar energy. The present publication gives the proceedings of a seminar held in California during August 1975. The contents are grouped under four broad headings: the solar radiation data base, instrumentation for solar radiation measurements, solar radiation collectors, materials and materials research. In the first group there are five papers. The first is introductory in nature and sets out the goals for solar energy, the second is tutorial in form in which the units and nomenclature used are defined. In the third paper the National Oceanic and Atmospheric Administration solar radiation programme is discussed. Paper four deals with the variability of solar energy in space and time as determined from satellite observations, and paper live covers the data available on hourly solar radiation (insolation). The papers of the second group, except for one dealing with the high altitude calibration of solar cells using rockets, are all concerned with some aspect of radiation measurement. In general the instruments described are variants of pyrheliometers for the measurement of the direct solar beam and pyranometers which detect all the radiation from the direct solar beam and the diffuse sky components falling on a horizontal surface. One paper deals with the measurements of the flux of the energy from the sun and the small angle region (the circumsolar region) around it. Eight papers make up the group on solar radiation collectors. There is a review of the state of the art of the non-tracking solar collectors and a paper which is a speculative concept for an advanced solar thermal power conversion plant. A theoretical aspect is introduced by a paper in which a mathematical model is derived from the design of an optimum stationary solar energy collector. Descriptions and performances of various collectors are the subject matter of the other papers, finally finishing with an article giving a
OPTICS & LASER TECHNOLOGY.
JUNE 1977
1976, pp 404, $25.70
This is the third volume of the Springer Series in Optical Sciences and is the proceedings of the international conference ‘Tunable lasers and applications’ held in Loen, Norway, in June 1976. It is a collection of 35 invited papers covering a broad range of disciplines. The topics dealt with are the technology of tunable lasers from the vacuum ultra-violet to the far infrared and their applications in the areas of photochemistry, chemical kinetics, isotope separation, atmospheric photochemistry and environmental studies, photobiology, and spectroscopy. On casually glancing through this book one may obtain the impression that tunable lasers are understood and developed to such a high technical expertise that one must just crank the handle and new physics and chemistry will automatically evolve. A word of caution is sounded by J.L. Hall and S.A. Lee who comment on how notoriously easy it is for enthusiasm to influence the reliable estimation of difficulties still to be overcome before each new potential laser capability can really be widely applied in other areas of research. Indeed, they notice a significant leading phase angle between the discussion and wide spread application of widely tunable lasers. For example, they air some of the typical problems and pitfalls of operating a single frequency cw dye laser for spectroscopy. Certainly, as evidenced in this book, a number of experimental groups have had notable success in the field of applications but many have found themselves involved in tunable laser research per se. Another manifestation of the difficulties involved is the complexity of control techniques which have to be applied, many costing more than the average small laboratory can afford; a computer controlled parametric oscillator is just one example (Byer, Stanford). Let all of this not dismay those of us in this field but act as a stimulus to solve the problems. This book is a must as it admirably illustrates the type of success achievable and also highlights the problems to be faced. The utopian requirements are a simple to operate, inexpensive, broadly tunable source with pulsed and moderately high output power (several watts), and a high resolution capability. Rather than attempt to review the individual contributions separately I wiIl just emphasise the areas of great current interest. A major preoccupation amongst laser spectroscopists is the achievement of efficient uranium isotope separation. This represents a new area for laser researchers in that they are now asked to invent a laser to order with respect to wavelength, energy and efficiency. (For example, of the
141
Second European conference on optical fibre communications Comite du Colloque International Fibres Optiques, 1976, pp 444
sur les Transmissions
par
This volume consists of photocopies of the abstracts submitted to the meeting held in Paris in September 1976. The papers (about seventy in all) thus represent an up-todate cross-section of current work in the field of optical fibres and systems. The survey is international, with 65% of the papers covering the European countries, 2 1% North America, and 14% Japan. The reproduction is clear and for ease of access the papers are indexed into sub-groups by topic: materials and technology (of fibres), propagation, cables and connectors, components, field measurements, long distance systems, and short distance systems. My only criticism of the volume itself was its very poor binding since it nearly fell apart on reading and certainly could not withstand photocopying. The quality of the contributions varies greatly, some being well-prepared and full of new information, others being of dubious value. Among the materials papers were a number of reports of fibres with losses of below 1 dB km-’ at extended wavelengths, 1 .l to 1.4 w region. Also noticeable was the emphasis on graded-index fibres, now clearly the preferred transmission medium, and stemming from this, an increasing interest in the manufacture of fibres with more precisely controlled profiles and larger index-difference (or NA), and the measurement of these properties. The continuing reduction of fibre loss and improvement of bandwidth stimulated a number of papers on the subject of meaningful measurement of fibre parameters since these become critically dependent upon the launched modal power distribution. A number of separate techniques were described with no clear preference emerging for any one. Two sessions of the meeting were devoted to cables and connectors, comprising some twelve papers, but it was not apparent from the reports that any clear theory of optical fibre cable design has yet emerged nor has the ideal connector. Perhaps of greatest interest was the paper on the Bell Telephone 144 fibre guide cable with some statistical information on the yield of complete fibre, the losses, and bandwidths. Also in this field were a number of descriptions of Japanese cables, but in all cases insufficient information was given to allow any clear understanding to emerge of the performance governing factors. Among the many papers on fibre materials and cabling there was surprisingly little mention of strength considerations, although a paper by the British Post Office detailed a fibre coating process and the results obtained therefrom. The sources for systems were well covered in a number of review and submitted papers. The proceedings also include some useful papers on joints and connectors, notably on a tapered fibre coupling for single mode fibres developed at
OPTICS & LASER TECHNOLOGY.
JUNE 1977
The contributions on systems were to me the most disappointing, particularly when compared with the preceeding meeting in this series. A few papers reported operating experience while a number discussed more hypothetical matters. Perhaps it would be fair to conclude that systems work is in a lull, the initial burst of activity leading to many meaty papers in 1975, hopefully to be followed in 1977 by reports of more substantial systems experiments. In summary, then, the volume represents a sizeable collection of material that is generally of good standard, readily accessible and invaluable for quick up-to-date reference. It must be nearly obligatory reading for workers in the field, and for those interested in assessing progress or status at a point in time, it will provide a useful source. In years to come it will form one record out of many of the continuing series of European conferences on optical fibres, London in 1975, Paris in 1976, Munich in 1977, Italy in 1978 and Holland in 1979. This volume will then be of interest in tracing the development in this very rapidly changing and developing field. J. E. Midwinter
Laser photochemistry, tunable lasers and other topics Edited by S. F. Jacobs, M. Sargent, M.O. Scully, C.T. Walker Addison-Wesley,
1976, pp 463, $23.50
This is the fourth volume of a series entitled Physics of Quantum Electronics. It is based on lectures given at a Summer School held in New Mexico in 1975 and deals mainly with laser isotope preparation, light scattering, and spectroscopy. There are 15 chapters in which work currently taking place in American laboratories is described by 2 1 authors. The largest number of contributors come fromLos Alamos, New Mexico and Boulder, Colorado. The first three chapters give, respectively, a review of laser isotope separation, details of the separation programme of the Energy Research and Development Administration, and experimental studies of selective photochemical reactions and energy transfer. Three chapters are devoted to the molecular physics for laser isotope separation. In these are described recent work in Russian and American laboratories, and the applications of Raman spectroscopy. Tunable laser sources for laser isotope separation are considered in the next four chapters. Included here are a review of tunable infrared lasers, experimental work with spin-flip lasers, and do-ityourself instructions for building dye lasers. Chapters 11 and
139
LASER75 OPTO-ELECTRONICS CONFERENCE PROCEEDINGS The LASER 75 OPTO-ELECTRONICS The worldwide interest in the applications of lasers and
opto-electronics was clearly evident at Laser ‘75. More than 800 delegates from 28 countries were present to hear and discuss papers on: Laser systems
($44 .OO) The papers are recorded in the Proceedings, which are edited by Professor Wilhelm Waidelich, Chairman of the Conference Programme Committee.
Lasers in nuclear energy technology Television
pick-up
Lasers in material processing Lasers in medicine
Order your copy now from:
Opto-electronic displays Lasers in optical communications Lasers in measuring
PROCEEDINGS provide an essential summary of the latest applications of lasers and optoelectronics. 305 x 210 mm / viii + 293 pages 1976 / Cloth / ISBN 0 902852 56 6 / Price L22.00 net
iw
engineering
and testing practice
Infra red and ultra violet techniques Lasers in data processing Lasers in environmental measuring techniques
science and
technobY press
Department APlA, IPC Science and Technology Press Limited IPC House, 3; High Street, Guildford, Surrey, %$~n~~~4%~ 166 1 Telex: Scitec Gd 859556
ELECTRO-OPTICS/LASER INTERNATIONAL’Z5dJK CONFERENCE PROCEEDINGS Edited by l-i. G. Jerrard Electra-Optics/Laser International ‘76 was held at the Metropole Convention Centre, Brighton, England from 9 to 11 March 1976. The topics covered were: Laser developments Optical instrument evaluation and special techniques Optical waveguides and fibre optics Applications of lasers to holography and interferometry: laser optics Electra-optical properties of materials and techniques Visible and infra-red technology Applications of lasers to-material processing and inspection Low-light-level techniques Optical information processing ipc
science and
technology press
140
TheProceedings
are edited for publication by the Conference Chairman, Dr H.G. Jerrard 304 x 210 mm / 208 pages test) Cloth / ISBN 0 902852 63 9 / Price f 18.00 net (536.00) Order your copy now from : IPC Science and Technology Press Limited IPC House, 32 High Street, Guildford, Surrey, England GUl 3EW Telephone: 0483-71661 Telex: Scitec Gd 859556
OPTICS & LASER TECHNOLOGY.
JUNE 1977
12 deal with light scattering and spectroscopy and in these chapters results of recent experiments on critical fluids and dense optical systems are described. The last three chapters, grouped under the heading ‘More’, cover the use of density matrices in quantum electronics, quantum electrodynamics, and superradiance - which is defined as a process in which a gas of identical atoms is radiating strongly because of coherence. The lectures tend to be of a tutorial nature,but, although the editors say they present recent developments in quantum electronics from first principles, the book is really only suited to those whose basic knowledge is good and who are working in the fields covered.
comparative technical evaluation of four primary solar collecting configurations. The studies of materials which constitute the fourth group deal almost exclusively with coatings for surfaces for the thermal conversion of solar energy. The proceedings give a useful insight into the studies of solar energy utilization which are currently in progress. There are author and subject indexes. H. G. Jerrard
Tunable lasers and applications
Edited by A. Mooradian, T. Jaeger, P. Stokseth
H. G. Jerrard
Springer-Verlag,
Optics in solar energy utilization
Edited by Y.H. Katz Proceedings of the Society of Photo-Optical Engineers, Volume 68,1975, $35.00
Instrumentation
Energy requirements on earth are estimated to amount to about 1% of that radiated from the sun to the earth and the availability of this energy source is infinite in time. National energy research programmes are being conducted in the United States with the aim of developing methods for harnessing some of this solar energy. The present publication gives the proceedings of a seminar held in California during August 1975. The contents are grouped under four broad headings: the solar radiation data base, instrumentation for solar radiation measurements, solar radiation collectors, materials and materials research. In the first group there are five papers. The first is introductory in nature and sets out the goals for solar energy, the second is tutorial in form in which the units and nomenclature used are defined. In the third paper the National Oceanic and Atmospheric Administration solar radiation programme is discussed. Paper four deals with the variability of solar energy in space and time as determined from satellite observations, and paper live covers the data available on hourly solar radiation (insolation). The papers of the second group, except for one dealing with the high altitude calibration of solar cells using rockets, are all concerned with some aspect of radiation measurement. In general the instruments described are variants of pyrheliometers for the measurement of the direct solar beam and pyranometers which detect all the radiation from the direct solar beam and the diffuse sky components falling on a horizontal surface. One paper deals with the measurements of the flux of the energy from the sun and the small angle region (the circumsolar region) around it. Eight papers make up the group on solar radiation collectors. There is a review of the state of the art of the non-tracking solar collectors and a paper which is a speculative concept for an advanced solar thermal power conversion plant. A theoretical aspect is introduced by a paper in which a mathematical model is derived from the design of an optimum stationary solar energy collector. Descriptions and performances of various collectors are the subject matter of the other papers, finally finishing with an article giving a
OPTICS & LASER TECHNOLOGY.
JUNE 1977
1976, pp 404, $25.70
This is the third volume of the Springer Series in Optical Sciences and is the proceedings of the international conference ‘Tunable lasers and applications’ held in Loen, Norway, in June 1976. It is a collection of 35 invited papers covering a broad range of disciplines. The topics dealt with are the technology of tunable lasers from the vacuum ultra-violet to the far infrared and their applications in the areas of photochemistry, chemical kinetics, isotope separation, atmospheric photochemistry and environmental studies, photobiology, and spectroscopy. On casually glancing through this book one may obtain the impression that tunable lasers are understood and developed to such a high technical expertise that one must just crank the handle and new physics and chemistry will automatically evolve. A word of caution is sounded by J.L. Hall and S.A. Lee who comment on how notoriously easy it is for enthusiasm to influence the reliable estimation of difficulties still to be overcome before each new potential laser capability can really be widely applied in other areas of research. Indeed, they notice a significant leading phase angle between the discussion and wide spread application of widely tunable lasers. For example, they air some of the typical problems and pitfalls of operating a single frequency cw dye laser for spectroscopy. Certainly, as evidenced in this book, a number of experimental groups have had notable success in the field of applications but many have found themselves involved in tunable laser research per se. Another manifestation of the difficulties involved is the complexity of control techniques which have to be applied, many costing more than the average small laboratory can afford; a computer controlled parametric oscillator is just one example (Byer, Stanford). Let all of this not dismay those of us in this field but act as a stimulus to solve the problems. This book is a must as it admirably illustrates the type of success achievable and also highlights the problems to be faced. The utopian requirements are a simple to operate, inexpensive, broadly tunable source with pulsed and moderately high output power (several watts), and a high resolution capability. Rather than attempt to review the individual contributions separately I wiIl just emphasise the areas of great current interest. A major preoccupation amongst laser spectroscopists is the achievement of efficient uranium isotope separation. This represents a new area for laser researchers in that they are now asked to invent a laser to order with respect to wavelength, energy and efficiency. (For example, of the
141