A systematic approach to diffusion recording in photorefractive sillenite crystals

Abstract We present a new method to solve the coupled equations for two-wave mixing (TWM) in sillenites. The first-order solutions, based on the approximation of a weak grating and strong optical activity, can describe BSO crystals well. The result is generally valid and the maximum gain for arbitrary cut is shown. The fundamental properties of TWM are systematized for the practically relevant cut (1 1 1). For the optimization of BTO crystals, characterized by not very large optical activity, dynamic gratings are taken into account. We find an approximation scheme, related to the parallel subsystem, which works for quite large coupling coefficients and for a wide range of crystal thicknesses.