Propagation of acoustic waves in strongly anisotropic crystals: Theory and experiment

The paper examines unique cases of propagation and reflection of acoustic waves in the single crystal tellurium dioxide. The investigation was carried out using acousto-optic methods. We observed in a cell, a simultaneous generation of two elastic waves provided by a single piezoelectric transducer. Maximum transformation of elastic energy into a quasi shear elastic wave with the efficiency about 100% was obtained during a process of reflection of a quasi longitudinal wave from a free crystalline surface. The reflected quasi shear wave propagated with an extremely large acoustic walkoff angle. A close to back reflection of elastic waves was also observed in the crystal. This reflection was accompanied by a compression of the reflected beam to a factor of 8. Acousto-optic figure of merit of paralellurite was calculated along various directions in the crystal for different polarization of the optic and the acoustic waves.