Dispersion of acoustical activity and anisotropy of acoustical attenuation in Bismuth Silicate Crystals
Abstract
Dispersion of acoustical activity and anisotropy of acoustical attenuation have been studied in bismuth silicate crystals. The measurements were carried out using optical quantum generators with different wavelengths and acoustic waves with frequencies of 0.4 - 1.8 GHz. Acoustical activity was investigated with the help of Bragg diffraction of light on transverse acoustic waves. The specific rotation of the polarization plane of light was determined at different wavelengths of light by the standard method using an analyzer fixing the dependence of the intensity of light passing through the sample on its thickness. It is shown that the acoustic rotation of the polarization plane greatly exceeds optical rotation. It is also ascertained that the dispersion of the acoustic activity of bismuth silicate crystals is well described by the power-law dependence close to the quadratic dependence predicted by the theory. The anisotropy of acoustical attenuation has been studied at the planes (001) and (110).