Two-dimensional Perturbative Analysis of Slant Grating in Photorefractive Crystals in an External Electric Field

A slant grating was recorded with two laser beams incident on photorefractive crystal in an external dc electric field. Two-dimensional perturbative analytical solution for the first two-order space-charge field for steady-state photorefractive slant grating recording has been obtained. It is shown that the inclusion of the longitudinal component of the space-charge field during photorefractive two-wave coupling can predict reduction of the fundamental harmonic and enhancement or reduction of the second-order harmonic for various applied field strength and various grating slant angles. The dependence of the first two-order harmonics on the slant angle and on the applied field strength is examined.