Soliton WDM system using channel-isolating notch filters

We propose a WDM system of sech or Gaussian type of optical pulses using a set of fixed- or sliding-frequency notch filters for channel-channel isolation. We have first demonstrate that a soliton trapped in a channel between two notches is very robust. We have also predicted optimum ratios between the channel separation and the soliton's spectral width for both the sech and Gaussian pulses. We find that the Gaussian pulses admit approximately 70% more channels than sech pulses for the same bandwidth. We investigated suppression of effects of interchannel collisions. We demonstrate that the effects can be largely eliminated by notch filters, while requiring an additional gain approximately 100% and only approximately 5%, respectively for the sech and Gaussian pulses, of the basic gain for compensating the fiber loss.