Detailed research of the performance of bidirectionally pumped Raman fiber amplifier

The noise characteristics and gain saturation of bidirectionally pumped Raman fiber amplifier (RFA) are investigated in detail. The results show that the noise characteristics of bidirectionally pumped RFA are intermediate between that of the co- and counter-pumped RFA, and can be improved by the reasonable increment of co-gain. The saturation power is decreased and the gain saturation phenomenon is deepened with the increment of the ratio of the co-gain to the counter gain.