Suppression of CC-FWM inter-channel crosstalk using unequal channel spacing in an 8-channel WDM transmission system with parametric amplification

In this research the authors investigate the opportunities of suppression of CC-FWM produced inter channel crosstalk by introducing unequal channel spacing in an 8-channel DWM transmission system with a single-pump FOPA used for signal amplification. The frequency spacing between the neighbor channels was consistently increased from 50 GHz to 125 GHz with steps of 12.5 GHz, thus the overall frequency band used from transmission was just 0.6125 THz. In order to estimate the performance of the provided solution, the dependence of bit-error ratio (BER) values on the power of the detected signal was obtained in the channel with the highest BER. These results were compared with the corresponding results obtained the same WDM transmission system but with 100 GHz channel spacing.