Kinetics of photorefractive recording for circular light beams

We show, theoretically and experimentally, that the buildup of the space-charge field in photorefractive crystals is far from monoexponential for circular light beams. This is a general property of the two-dimensional (2D) case, in contrast to the one-dimensional case. The results form a basis for determination of the photoelectric parameters of photorefractive crystals within a wide intensity range, which is important, e.g., for solving of the optical-damage problem in LiNbO3 and LiTaO3 crystals.