Self-interaction of a noncoherent light beam

The problem of self-interaction of a Gaussian light beam with Gaussian statistics in a cubic medium is tackled by numerical analysis of a closed nonlinear parabolic equation for a second-order correlation function. Changes in the cross-correlation functions as a result of self-focusing are investigated for the first time and the nature of changes in the effective length and correlation radius of a spatially noncoherent light beam are analyzed along its propagation path. It is shown that the process of propagation disturbs the statistical homogeneity of the beam and this is due to the occurrence of "noise" aberrations.