Polarization reversal of the wavefront of light beams in photorefractive crystals

A theoretical study is made of the possibility of reversal of the wavefront of a light beam in respect of the phase and polarization by degenerate four-wave interactions in photorefractive ferroelectric crystals. It is shown that the polarizations of the signal and reversed waves can be conjugate only under certain conditions which must be satisfied by the intensity, phase, and polarization of the pump beams, and also by the orientation of the optic axis of a crystal. Specific situations when these conditions are satisfied are considered in the case of photorefractive ferroelectric crystals of the 3m and 4mm symmetries.