Propagation of partially coherent light with the Maxwell-Debye equation

We deal with the propagation of broadband Schell-model sources in nonlinear media with finite relaxation time. The approach is based on a study of the Wigner distribution function and on a separation of scales technique between the microscopic random fluctuations of the field and the macroscopic intensity profile. The regime in which the nonlinearity is strong and slow is considered. Precise results are obtained for the small-and large-scale characteristics of the pulse: optical intensity profile, speckle radius, and typical intensity profile of the speckle spots. (C) 2003 Optical Society of America.