Laser Based Transduction Of Ultrasound For Practical NDT Applications
Abraham Aharoni, Moshe Tur, K. M. Jassby · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1989
Laser based techniques for the generation and the detection of ultrasonic surface waves (SAW) are described. These methods were motivated by practical ultrasonic non-destructive testing (NDT) applications and are suitable for operation on rough surfaces which are typical to engineering materials. Wide strip laser illumination is used to generate SAW waveforms by means of a thermoelastic mechanism. For detection an holographic method has been developed, achieving sensitivities of the order of 0.1 Å at 10 MHz bandwidth on rough aluminum surfaces.