Electronic speckle pattern interferometry

Abstract: A fast-Fourier-transform method of topography and interferometry is proposed. By computer processing of a noncontour type of fringe pattern, automatic discrimination is achieved between elevation and depression of the object or wave-front form, which has not been possible by the fringe-contour-generation techniques. The method has advantages over moire topography and conventional fringe-contour interferometry in both accuracy and sensitivity. Unlike fringe-scanning techniques, the method is easy to apply because it uses no moving components.

Abstract: Contents: Dainty, J. C.: Introduction. - Goodman, J. W.: Statistical Properties of Laser Speckle Patterns. - Parry, G.: Speckle Patterns in Partially Coherent Light. - McKechnie, T. S.: Speckle Reduction. - Francon, M.: Information Processing Using Speckle Patterns. - Ennos, A. E.: Speckle Interferometry. - Dainty, J. C.: Stellar Speckle Interferometry. - Dainty, J. C.: Recent Developments. - Subject Index.

Abstract: Ultrasound images obtained with a simple linear or sector scan show a granular appearance, called "speckle." This speckle is analyzed. The reduction in speckle that can be obtained with a compound scan with maximum amplitude writing is computed. The reduction in speckle is almost as large as can be obtained with averaging. It depends on the number of independent amplitude values that are measured. The condition for the independence of two amplitude values is derived, and thus a limit is given for the possible reduction in speckle.

Abstract: INTRODUCTION Ultrasonics Lasers Main characteristics of laser light Lasers for ultrasonics ACOUSTO-OPTIC INTERACTIONS The acousto-optic effect The measurement of ultrasonic fields Bragg diffraction Acousto-optic devices Applications of acousto-optic devices The interaction of light with surface waves LASER INTERFEROMETRY Principles of laser interferometry Theory of interference between light beams Reference beam interferometry with rough surfaces Light detection and signal amplification Effects of laser mode structure Signal processing Stabilized interferometers Optical frequency shifting Quadrature interferometers Long path difference and interferometry Fabry-Perot interferometers APPLICATINOS OF LASER INTERFEROMETRY TO ULTRASONIC DISPLACEMENT MEASUREMENT The measurement of acoustic fields Scanned laser interferometry Full field visualisation of surface displacement The measurement of surface waves Calibration of transducers Acoustic emission The measurement of transverse and vector displacement Sensitivity comparison with other ultrasonic detection techniques ULTRASONIC GENERATION BY LASER Absorbtion of electromagnetic radiation Temperature distributions Thermoelastic stresses Other effects Constrained surfaces Ultrasonic wave propagation in unbounded solids Propagation in bounded solids Radiation patterns for laser-ultrasonic sources Ultrasonic bulk waveforms in plates Ultrasonic surface and guided waves Lasers for ultrasonic generation APPLICATIONS USING LASER GENERATION OF ULTRASOUND Applications to flaw detection Applications to materials property measurement APPLICATIONS TO ACOUSTIC MICROSCOPY Calibration Wave propagation studies Medical applications CONCLUSIONS AND FUTURE PROSPECTS FOR LASER TECHNIQUES IN ULTRASONICS Summary and conclusions Future research and development Future prospects for applications REFERENCES INDEX

Abstract: Preface to the first edition Preface to the second edition 1. Basic optical principles 2. Holographic interferometry 3. Speckle pattern interferometry 4. Electronic speckle pattern correlation interferometry 5. Holographic and speckle pattern interferometry techniques for shape measurements 6. Experimental design and technique 7. Applications Appendices References Index.