Starting from the three-dimensional version of a standard photorefractive model (STPM), we obtain a reduced compact Set of equations for an electric field based on the assumption of a quasi-steady-state fast recombination. The equations are suitable for evaluation of a current induced by running gratings at small-contrast approximation and also are applicable for the description of space-charge wave domains. We discuss spatial domain and subharmonic beam formation in bismuth silicon oxide (BSO) crystals in the framework of the small-contrast approximation of STPM. The experimental results confirming holographic current existence in BSO crystal are reported. (C) 2005 Optical Society of America.
Journal of the Optical Society of America B, 2005, Vol 22, Issue 9, p. 1917-1922