Optical Measurement of Surface-Wave Scatter Losses in Piezoelectric Ceramics

Abstract

Direct experimental measurement of surface‐wave scatter losses of several ceramics is reported, as well as verification of the fourth‐power frequency dependence of scatter losses per wavelength predicted by Steg and Klemens. Laser measurements of surface‐wave amplitude vs position exhibit interference due to scattered waves. The statistical analysis of such measurements allows separation of scatter losses from true dissipative losses. Scatter losses for Honeywell Type S material are found to be 0.027 dB/wavelength at 46.8 MHz, and increase with the fourth power of frequency. A limiting frequency for a given ceramic for surface‐wave applications might be the frequency at which scatter losses overtake dissipative losses; for Honeywell S, this occurs at 73 MHz.