A Distributed Raman Amplifier Based on the Backward-Pumped Random Fiber Laser

For the first time, a backward-pumped random distributed feedback fiber laser is applied to the conventional distributed Raman amplification (DRA). A new asymmetric DRA scheme for improving the signal power variation (SPV) performance was achieved. The scheme was studied numerically and was shown to effectively reduce the SPV of all signals to less than 1.2 dB, whilst maintaining a flat ON-OFF gain over 40 nm bandwidth for a 61.5 km fiber span. Moreover, the nonlinear Fourier transform technique, which is utilized to deal with the nonlinear noise, could be realized on the proposed scheme with such a low SPV.