Wavefront reversal of optical beams in anisotropic media

An analysis of wavefront reversal (WFR) of optical beams in anisotropic media (class 3m electrooptic crystals, such as LiNbO₃ and LiTaO₃) is used to show that WFR depends strongly on the crystal orientation and on the predominant nonlinearity mechanism. A new type of WFR of parallel beams is proposed, this being due to intermode scattering between ordinary and extraordinary waves in holographic gratings.