UV Laser Irradiation Effects on Frequency of Surface Acoustic Wave (SAW) Filters Coated with Titanium Oxide Films

Abstract
Effects of ultraviolet (UV) light irradiation on the frequency of surface acoustic wave (SAW) filters coated with amorphous Ti–O thin films have been investigated by use of a pulsed KrF excimer laser. The frequency was abruptly changed by the irradiation. From the experimental results, it is concluded that the elastic properties of the Ti–O films are improved by the UV laser irradiation, and the frequency shift is dependent on a change in the velocity of SAWs propagating in the Ti–O film.