Anisotropic Diffraction in Photorefractive Volume Hologram

Recently, there are extensive studies on applying the photorefractive effect for optical data storage and processing[1][2]. One of the most important applications is for the volume holographic storage. In this paper we report theoretical derivations and experimental results on the important properties of the anisotropic diffraction in a photorefractive volume hologram in a BaTiO3. As we shall see, the diffraction efficiency, the angular sensitivity, and the optimal reconstructing angle for obtaining the maximum diffraction efficiency depend very much on the grating vector and crystal orientations. The crystal orientation and the light beam directions are shown in Fig.1. In order to avoid the beam coupling phenomena[3], we use S-polarized light for writing holograms and P-polarized light for reconstruction.