4E-4 Laser Interferometric Measurements and Simulations of Waves Transmitted Through the Acoustic Mirror in Thin Film BAW Resonator

Acoustic wave fields excited in a 932 MHz ZnO solidly mounted BAW resonator manufactured onto a glass substrate have been studied in detail with our heterodyne laser interferometer. The glass substrate allows for optical probing directly from the bottom of the mirror stack and hence enables comparison of wave amplitudes on top of the resonator with those at the bottom of the acoustic mirror. Dispersion curves are calculated from the experimental data and compared to simulations. Transmission characteristics of the mirror stack are determined from the experimental data and compared to simulations. Furthermore, the relation between the electrical response of the device and its acoustical behavior is discussed