We present an analytical model and measurements of the pump to signal relative intensity noise (RIN) transfer characteristics of copumped and counterpumped Raman amplifiers. We give a quantitative analysis of noise averaging from chromatic dispersion in copumped systems and from different propagation directions in counterpumped systems. It is shown that nondispersion-shifted fibers and other fibers with high dispersion between the signal and pump wavelengths give a greater potential for use in copumped Raman amplified systems.
C. R. S. Fludger, V. Handerek, and R. J. Mears, "Pump to Signal RIN Transfer in Raman Fiber Amplifiers," J. Lightwave Technol. 19, 1140- (2001)