Nonlinear Interference Noise in Raman-amplified WDM Systems

Raman amplification is a solution for broadband wavelength-division multiplexed (WDM) systems that require fine and reconfigurable gain tuning. However, as the fiber nonlinearity ultimately limits performance of fiber-optic communication systems, accurate models nonlinear interference affecting signal propagation in presence multiple pumps are critical system design. In this study, we propose an extension time-domain noise (NLIN) model analyzing Raman-amplified polarization WDM links. Our proposed enables evaluation NLIN power inter-channel transfer induced by stimulated scattering (SRS) with Raman-gain equalization. It also accounts evolution average along link, which varies from channel to channel. To compute contributions efficiently, employ method us apply three relevant pumping scenarios: co-propagating, counter-propagating, bidirectional pumping. Using model, evaluate differences over all channels. Additionally, can estimate amplified emission power, be used optimize optical signal-to-noise ratio respect input pump powers.