Spatial rectification of electric field of space charge waves in sillenites

Summary form only given. During holographic recording in photorefractive crystals an electric grating arises. It is commonly believed that no homogeneous electric field can emerge due to space charge redistribution under recording conditions. This is obvious for the diffusion recording mechanism under stationary conditions (there is a full symmetry in the charge distribution) or for the drift mechanism if a crystal is connected to an ideal voltage source (a homogeneous electric field is fixed and completely determined by the voltage source). In this report we show that quite a strong homogeneous space charge field can exist in photorefractive materials. We succeeded in detecting it in the crystals of the sillenite family (BSO, BTO, BGO). We have also developed the theory that adequately describes the nature and properties of this field. The model including the process of space charge wave excitation was used.