Coupled wave analysis of anisotropic self-diffraction in photorefractive materials with an external electric field

Anisotropic self-diffraction in doped KNSBN crystals has been observed for the experimental configuration where the c-axis is parallel to the incident plane when an external electric field is applied. The space distribution o f grating vector may be the main reason for the generation of anisotropic s elf-diffraction in our experimental configuration. The coupled wave equatio ns and the numerical solutions including the space distribution of grating vector and the first two order space-charge field are presented. Both theor etical analysis and experimental results show that anisotropic self-diffrac ted light arises from the contribution of both incident beams. (C) 2000 Els evier Science B.V. All rights reserved.