Flat-gain DFRA design considering pump-to-pump FWM

Pumps of a Distributed Fiber Raman Amplifier (DFRA) built over Non-Zero Dispersion Shifted Fiber (NZ-DSF), can generate FWM waves which could degrade the flatness of the amplifier gain profile. In this paper a rigorous approach based on a Genetic Algorithm (GA) and a Message Passing Interface (MPI) strategy have been used, in order to design a flat-gain DFRA considering these FWM products. It was shown that a gain ripple lower than 0:22 dB can be obtained when high efficiency FWM products are generated in the system. Moreover, this paper shows the spatial evolution along the fiber of the amplifier pumps, FWM products and WDM channels, allowing a better understanding of the nonlinear interactions of the system.