Thermal acousto-optic excitation for non-contacting NDE.

This paper describes experiments designed to generate acoustic waves by using a laser pulse, transmitted through fiber optics, to thermally shock the surface of a steel specimen. The purpose of this effort was to explore the non-contacting generation of Rayleigh surface waves appropriate to the interrogation of structures for the detection of subcritical defects, with the ultimate goal of developing an efficient nondestructive evaluation technique that does not require any mechanical couplings to transducers.