FWM resonances in dispersion slope-matched and nonzero-dispersion fiber maps

We show that four-wave mixing (FWM) resonances can affect performance of selected channels within the dense wavelength-division-multiplexing band. The FWM resonances may cause a Q-factor penalty in excess of 1 dB. We develop an analytical model to predict the spectral location and the intensity of the resonances. Dispersion slope-matched maps and manufacturing variations help to suppress the resonances.