The Bragg Diffraction of Light at Acoustophotorefractive Holographic Gratings in Gyrotropic Cubic Crystals

We investigate diffraction of light at phase holographic-type gratings recorded by a piezoactive ultrasonic wave in gyrotropic cubic photorefractive crystals. We show that the efficiency of diffraction at a holographic grating can be increased substantially by applying a d.c. field to a crystal under the conditions of a longitudinal electrooptical effect; elliptical polarization of diffracted light is determined by electrically induced anisotropy of a crystal in the piezofield of a photorefractive grating, by the external electric field, detuning of phase synchronism, gyrotropy of the crystal, ultrasound frequency, and the time of recombination of charge carriers.