Property of the photorefractive volume grating written by orthogonally polarized beams in Ce:KNSBN crystal

Two-wave coupling between orthogonally polarized beams in a Cerium doped potassium sodium strontium barium niobate crystal is studied. The coupling gain coefficient, the response time and the saturation diffraction efficiency of the volume grating are measured with respect to the angle (phi) between the polarized direction of the pump beam and the c-axis of the crystal. It is found that they have the similar variation behavior. In our experimental condition, the maximum coupling gain coefficient is 3.2 cm-1, the maximum response time is about 55 seconds and the maximum saturation diffraction efficiency is about 18.5%. The maximum values are obtained at (phi) =20 degree(s) and (phi) =160 degree(s). Numerical calculated results from the couple-wave equations are given, which are coincident with the experimental data.