Excitation of high frequency surface acoustic waves by phase velocity scanning of a laser interference fringe

Abstract

We present a novel method for generating 100 MHz band surface acoustic wave (SAW) by using a scanning interference fringe at the phase velocity of the SAW. The scanning interference fringe is obtained by intersecting two laser beams with different frequencies, and used as a thermoelastic source. The principle of this method is described, and experimentally demonstrated in the 110 MHz Rayleigh waves on an aluminum specimen generated by a long-pulse (140 ns) Q-switched Nd:YAG laser.