The Klein-Cook parameter in analyzing acousto-optic interaction in acoustically anisotropic media

A theoretical study of acousto-optic interaction in acoustically anisotropic media is performed. A new criterion for estimating the Raman-Nath and Bragg regimes of light diffraction by means of ultrasound in acoustic crystals is proposed. The modified Klein-Cook parameter is found to consider the walkoff of ultrasonic wave energy as a result of the elastic anisotropy of a medium.