Schrodinger equation with a spatially and temporally random potential:   Effects of cross-phase modulation in optical communication
  We model the effects of cross-phase modulation in frequency (or wavelength) division multiplexed optical communications systems, using a Schr\"odinger equation with a spatially and temporally random potential. Green's functions for the propagation of light in this system are calculated using Feynman path-integral and diagrammatic techniques. This propagation leads to a non-Gaussian joint distribution of the input and output optical fields. We use these results to determine the amplitude and timing jitter of a signal pulse and to estimate the system capacity in analog communication. 
A. G. Green, P. B. Littlewood, P. P. Mitra and L. G. L. Wegener