A Remote, Non-destructive Laser Ultrasonic Material Evaluation System with Simplified Optical Fibre Interferometer Detection
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- Wang, HC., Fleming, S. & Lee, YC. J Nondestruct Eval (2009) 28: 75. doi:10.1007/s10921-009-0049-5
An optical non-contact ultrasonic testing system is presented. It uses broadband surface acoustic wave impulses generated with a cylindrical lens focused laser line source. The detection of the ultrasound is achieved by a simple and yet effective design of optical fibre interferometer which provides good sensitivity and manoeuvrability. The effectiveness of the fibre interferometer is demonstrated by accurately measuring the broadband surface waves on various common metal structures. The measurement system’s ability for surface material evaluation is also demonstrated from fitting experimental surface wave dispersion curves with theoretical simulations. This measurement system can test small localised areas and miniature samples that were previously difficult to examine.