Propagation of mutual coherence functions of partially coherent Gaussi
an Schell-model beams in a medium with third-order nonlinearities is c
onsidered. It is shown that incoherence suppresses self-focusing. The
spatial coherence of the axial part of the beam improves in the self-f
ocusing regime, whereas the transverse correlation length of the beam
decreases in the same region. At high powers, waveguide formation is a
lso studied in media with saturating nonlinearity. (C) 1997 Optical So
ciety of America.