Acoustic-Field Distribution Within A Fan-Shaped Filter

We have investigated the surfaceacoustic wave field variation in a fan-shaped filter on a 112degrees LiTaO3 substrate as a function of position and frequency. The acoustic field has been measured with the help of a scanning laser interferometer and the SAW-field distribution in the complete filter has also been numerically simulated in detail. Our modelling scheme utilizes a discretization of the filter into elementary cells. The simulations serve to render features of the acoustic-field distribution in astonishing quantitative agreement with the laser-interferometric detections.