Measurement of piezoelectric constants using an optical heterodyne interferometer

Abstract

Piezoelectric constants of crystals (SiO2, LiNbO3, LiTaO3) and polymers (PVDF) have been determined by using an optical heterodyne interferometer to measure the strains. With this setup, the minimum detectable displacement is 10−3 Å and the accuracy is 5%. The effect of the bonding to the support has been analysed and experimentally checked. The well established value of the modulus d11 of quartz (2.31 × 10−12 m/V) has been confirmed. For LiNbO3, the controversial value of d33 was determined to be 9.5 × 10−12 m/V.