Two light beams diffraction by a surface acoustic wave in an anisotropic solid

The results of a theoretical investigation of simultaneous two light beams diffraction by a surface acoustic wave (SAW) in crystals are considered. They form the theoretical basis of descriptive work of a new acoustooptic method of SAW velocity measurement based on a two optical beams interferometer. The influence of elastic anisotropy of a solid on the diffraction and interference of light beams and accuracy of measurement of phase and group SAW velocities in anisotropic mediums are considered. It is shown how to realize direct measurement of a SAW steering beam angle. The obtained results considerably increase possibilities of the given method for measurement of the basic characteristics of acoustic waves in crystals.