Soliton-type and oscillatory behavior of spatially incoherent beam captured by nonlinear medium

Summary form only given. Recent observation of self-trapping white light by photorefractive crystals stimulated theoretical discussion of self-focusing effect in application to spatially incoherent beams. Several models of incoherent self-trapping by slow responding optical nonlinearity have been proposed. We propose a simple model, which generalizes previous results and allows for explicit analysis of longitudinal dynamics. The model is based on a radiation transfer approach, which is modified to take into account slow spatial variations of dielectric constant in a medium.