AVOIDING HOLOGRAM BENDING IN PHOTOREFRACTIVE CRYSTALS

coupled-wave theory predicts the bending of recorded hologram phase pl anes in most photorefractive crystals. Bent holograms occur in LiNbO3 and other photovoltaic crystals that are particularly interesting as h olographic storage media and result in a reduced overall diffraction e fficiency. We show that hologram bending in LiNbO3 can be avoided or a t least sensibly reduced by use of an actively stabilized recording te chnique. (C) 1996 Optical Society of America