Suppression of the Soliton Frequency Shifts in a Two Channel WDM System

Abstract

Wavelength Division Multiplexing (WDM) can be resorted to when the information carrying capacity of a fiber is to be increased. When subpicosecond pulses are used in different channels, higher order nonlinear effects, most importantly Raman scattering becomes significant. Intra pulse stimulated Raman scattering (SRS) gives rise to self frequency shift (SFS) of the pulses¹. The presence of the other channels result in inter pulse Raman scattering and hence cross frequency shifts. Both self and cross frequency shifts should be suppressed if WDM is to be used. Suppression of SFS has been studied before ^2–4. For the case of WDM, with the channels propagating under the influence of Raman scattering, only gain compensation schemes have been looked into. No attempt was made to study schemes for compensating the frequency shifts suffered by the individual channels in a WDM system. In this paper, we look into a 2 channel system usine picosecond pulses and undergoing Raman scattering.