The inhomogeneity of two-wave coupling in photorefractive crystals in 90° geometry

We derived the coupling equations of two-wave coupling in photorefractive crystals in 90° geometry where pump and signal beams enter two mutually orthogonal crystal faces vertically. We solved the equations numerically in the case of non-local response and illustrated the influence of the coupling coefficientΓ, the absorption coefficient α and the ratio of intensities of the two incident beams,R, on the inhomogeneity of transmitted pump and signal beams.