Unequally Spaced Channels for Upgrading WDM System from 3-Channel to 10-Channel Preserving No FWM Crosstalk

Abstract Crosstalk due to four-wave mixing (FWM) increases sharply when lightwave channels are upgraded in wavelength division multiplexing (WDM) fiber-optical communication systems. A technique is proposed for reducing crosstalk due to FWM when multichannel communication is extended from 3 channels to 10 channels in WDM system. The results of this simulation are presented. It is shown that suitable unequal channel separations can be found for which no FWM product term is superimposed on any of the transmitted channels, and the bandwidth expansion factor is not more than 2.7. Our method is better than previous ones.