Abstract
In wavelength-division multiplexing optical systems, cross-phase modulation induced by the Kerr effect gives rise to a nonlinear phase modulation of each channel, which depends on the overall power in all the other channels. The analysis proposed leads to model the effect due to cross phase modulation on the above systems as a "space-time filtering" effect on the interfering signals. In particular, the dependence of the effect on the channel number is explained quantitatively. The proposed model provides results that are in agreement both with the ones obtained by simulative approaches and with experiments, and it provides a tool to analyze quantitatively effects due to Kerr nonlinearity.