Optical Metrology and Optoacoustics in Nondestructive Evaluation of Materials

This book includes the description, modeling and realization of new optical metrology techniques for technical diagnostics of materials. Special attention is paid to multi-step phase shifting interferometry with arbitrary phase shifts between interferograms, phase shifting and correlation digital speckle pattern interferometry, optical-digital speckle correlation, and digital image correlation, as well as dynamic speckle patterns analysis. Optoacoustic techniques can be treated as a separate branch of optical metrology and can solve many problems of technical diagnostics, including detection and localization of subsurface defects in laminated composite materials. The utility of such techniques can be increased by illumination of the object via acoustic waves at certain frequencies. Hence, an effective theoretical approach to the modeling of an elastic wave field interaction with an interphase defect, and to defect visualization using dynamic speckle patterns, is also includedin this book. The experimental proof of the proposed approaches was achieved using a specially created hybrid optical-digital system for detection of different subsurface defects. This book is intended for engineers, researchers and students engaged in the field of nondestructive evaluation of materials and technical diagnostics of structural elements, hybrid optical systems, speckle metrology and optoacoustic imaging techniques.