Numerical Simulation and Optimization of Backward and Bi-Directionally Pumped Raman Amplifiers

In this paper, the optimization method of pump configuration is summarized for backward and bi-directionally pumped Raman amplifiers. Moreover, the power distribution of pumps, 100-channel optical signals, ASE and DRBS is simulated and demonstrated in detail, and DRBS noise power is far less than ASE noise power. For the bidirectional pumping scheme, less than 0.5 dB flatness of both gain and OSNR is realized within 80nm gain bandwidth by optimizing pump wavelengths and pump powers. On the contrary, if a backward pumping RA is optimally designed for having a flattened broadband gain spectrum, then its´ OSNR profile must be tilted, and shorter wavelength signals have experienced greater change magnitude than longer wavelength signals.