A process for the excitation impulsfoermiger ultrasonic waves in the surface strongly a light absorbing materials

摘要

A method and apparatus for producing on the surface of a workpiece an ultrasonic pulse wave without physical contact comprise the use of a laser beam illuminating a small, striplike, portion of the workpiece surface and such portion being moved with uniform motion along a linear axis over a predetermined distance. The angle of propagation of the resulting ultrasonic wave is a function of the propagation velocity of sound in the workpiece and the velocity of the illuminated portion along the linear axis.