Interaction of node-induced crosstalk with fiber nonlinearities in regional and metropolitan WDM networks

Interest in the deployment of Wavelength Division Multiplexing in regional and metropolitan networks has increased recently. We consider an example of regional/metropolitan rings and investigate the interaction of node-induced crosstalk with fiber nonlinearities in it. The phenomenon is studied in two cases, namely the case of Non-Zero Dispersion Shifted Fiber operating in the anomalous dispersion regime and the case of Single Mode Fiber with uniformly distributed segments of Dispersion Compensating Fiber. The dependence of the effect of the crosstalk/nonlinear interaction on the frequency difference between signal and crosstalk carriers and on signal power is examined in detail. It is shown that the node-induced crosstalk can interact with fiber nonlinearities and introduce limitations on transmission performance. This interaction should therefore be taken into consideration in designing regional and metropolitan networks.