Flatness Improvement of FRA with Multi-Wavelength Pump

A fiber Raman amplifier (FRA) based on the properties of silica fiber can not only get a wideband gain spectrum by using multiple pumps, but also has the nature of low noise and cost. In the study of FRA, gain-flatness is one of the most key and hot issues. In this paper, we focus on the gain flatness of fiber Raman amplifier by multi-pump, and various parameters in term if power and number of pump source are analyzed comprehensively. According to the numerical results obtained, the optimized within power and number of the pump source are determined. And we controlled the gain-flatness of FRA within ±1 dB from 1512nm to 1566nm in a dense wavelength division multiplexing system with 67 channels.