Effect of stimulated Brillouin scattering on the gain saturation of distributed fiber Raman amplifier and its suppression by phase modulation

Zhang Yi-Chi^a),^b), Chen Wei^a),^b), Sun Shi-Lin^a),^b), Meng Zhou†^a),^b)

Results of frequency-fixed phase modulation experiments on the forward-pumped DFRA, showing (a) curves of on–off gain versus input signal power with various modulation indexes and a fixed frequency of 25 MHz, (b) enhancements of gain saturation power versus phase modulation index with a fixed modulation frequency of 25 MHz, and (c) backscattering optical spectra with various modulation indexes and a fixed frequency (the input signal power is 3 dBm).