Books recieved

Book Reviews that the multiple-beam interference fringes that are usually generated when using a laser can be eliminated by spatial filtering. Furthermore, by projecting the fringes on to a coarse grating, moire contours of flatness are produced, and enhanced precision of measurement obtained by translating the grating to perform phase-stepping. A novel method for on-line measurement of optical fibres is presented by a group from the Technical University of Budapest. Laser light back-scattered from the fibre has an intensity that is a periodic function of fibre diameter. By monitoring the reflectivity at two different angles of incidence a continuous measurement of diameter can be made to 0.1 pm. A much lower sensitivity instrument (for industrial measurement of tubing) uses an oscillating mirror to scan the object, a fraction of the scan beam falling on to a coarse grating for calibration (MIKI Instrumentation, Budapest). The remainder of the papers dealing with metrology cover a wide range of applications. Schubert (Hamburg, FRG) uses the diffraction of light between a straight edge brought up close to a surface to study transient shock waves induced in it. An automatic diffractometer for analysing blood cells for abnormality has been developed at Tianjin University, where the cells are ‘smeared’ in a viscometer to investigate their deformability. At the same institution precision measurement of wire meshes are similarly studied, and at the University of Szczecin, Poland, magneto-optic films of garnet are also examined by diffraction. An original paper from the University of Tokyo describes a mobile robot that can ‘walk down corridors at 30 cm s-l by ranging the walls with a swept laser beam range finder. The on-board computer is programmed to make decisions on which way to turn when intersections, for example, are encountered. Industrial applications of holography and laser speckle are represented by papers from the Universities of Budapest and Sczczecin. The former qualitatively shows vibration patterns on a car engine block and body panel by double pulse holography, while the latter presents careful measurements of the deformation of a piston ring using speckle photography. Data acquisition and computer processing are of increasing importance in laser metrology. Five papers deal with various aspects of converting optical fringe patterns into numerical data. The majority use Fourier Transform analysis, and in particular Kreis and Juptner (BIAS, Bremen) describe a process whereby optical and displacement can be extracted phase unambiguously from one holographic interferogram. Automatic analysis is also achieved by Hofling and Osten (Academy of Sciences, DDR, Berlin) by generating an optical reference grid which is moired with the interferogram, to enable phase-stepping to be carried out for improved analysis accuracy. The book provides an interesting coverage of the state of the art of precision laser metrology, especially of work in the eastern bloc countries and China, which 348

otherwise might not be available. Some strictures, however, must be directed at the manner of publication and editing, which illustrates all too well the lowered standards of book production that are now accepted by the scientific community. The printing of ‘camera-ready copy’, allegedly for speed of publication, has not allowed editors to correct misprints or to demand clarification of the text, which is occasionally necessary, and the imperfections of a multitude of typewriters leads to an uneven appearance. The (American) publisher of this book has merely provided hard covers and a printed frontispiece, and not even checked that pages are all in correct order. With all the modern print technology now available it should no longer be necessary to rely upon self-editing alone.

A.E. Ennos

Books received The following books have been received at the editorial office. Their inclusion in this column does not preclude publication of a review at a later date. Principles of Lasers (3rd Edition) 0. Svelto (translated by D.C. Hanna) Plenum Press, $39.50, pp xiii + 494 Metal Vapor and Metal Halide Vapor Lasers

Edited by G.G. Petrash

Nova Science, $87.00 US/Canada, $104.00 Elsewhere, pp ix + 297 Introduction to the Optical Transfer Function C.S. Williams and O.A. Becklund Wiley Interscience, 233.35, pp xi + 412 High Power Lasers

Edited by A. Niku-Lari and B.L. Mordike Pergamon Press, $10500, pp xiii + 335

Principles of Modem Optical Systems I. Andonovic and D. Uttamchandani Artech House, $85.00, pp xv + 608 Optical Electronics

A.K. Ghatak and K. Thyagarajan

Cambridge University Press, f25.00, pp xii + 624

Fiber Optic Component Design, Fabrication, Testing, Operation, Reliability and Maintainability

N.L. Christian and L.K. Passauer Noyes Publications, $64.00, pp xiv + 434 Optics Et Laser Technology Vol21 No 5 1989