Abstract
Measurements of surface acoustic wave losses of thin‐film gratings on piezoelectric substrates have been made by a real‐time laser probe technique. For a 130‐line chrome‐aluminum shorted grating on Y‐cut Z‐propagating LiNbO3, 70% of the power incident on the grating was reflected, 4% was transmitted, and 26% was lost at the resonant grating frequency of 308.5 MHz. A transmission‐line model applied to the measurements indicates an impedance discontinuity ratio between the film and substrate of Z = 1.018.