Impairments due to the interplay between node crosstalk and nonlinear propagation in all optical transport networks

All optical transport networks should be designed to avoid the detrimental effect due to in-band crosstalk that may arise from nonideal components in optical nodes. In this letter, we numerically investigate the nonlinear propagation of signal with in-band crosstalk, finding much greater penalties than were previously established in the linear regime. This effect is observed in the anomalous dispersion regime, and the highest impact is obtained for a nonzero frequency detuning between the optical carriers of the signal and of the crosstalk. The phenomenon, which can be explained in terms of the modulation instability, can result in reduced tolerance to crosstalk.