Crosstalk Characteristics of WDM Channels in Quasi-Homogeneous Multicore Fibers

The relative average inter-core crosstalk (IC-XT) among wavelength-division multiplexed (WDM) optical channels in a quasi-homogeneous two-core fiber system exhibiting slight differences on the propagation constant, inverse group-velocity, and the group-velocity dispersion (GVD) between cores is numerically investigated. This analysis is performed using a theoretical formalism that includes fiber nonlinearities in the presence of random perturbations. The results show oscillations on the average IC-XT of WDM channels that mainly depend on the walk-off between cores. These oscillations arise superimposed to the linear wavelength-dependence of the IC-XT caused by the core-coupling coefficient. As transmission power increases, the nonlinearities do not reduce the presence of these oscillations, but slightly modify their amplitudes and periods. These results provide valuable information to fully understand the wavelength dependence of the average IC-XT of real multi-channel MCF systems, especially those of very short reach.