OPTICAL MEASUREMENT OF ACOUSTIC VELOCITY AND POISSON RATIO IN DISK PIEZOELECTRIC TRANSDUCER

The fiber-optic measurement of piezoelectric vibration in a disk transducer and the evaluation of acoustic velocity and Poisson's ratio are described. The amplitude and phase of the vibration can be measured locally by means of the optical method. The phase can change by pi radians at both resonance frequencies independent of the position in the resonator and other frequencies dependent on the position. The latter frequencies can be measured only by means of the optical method, and the acoustic velocity and the Poisson's ratio can be calculated through measurement.