Fig. 1. Optical power distribution of pump1 using shooting method

Fig. 2. Optimized Raman gain spectrum

Fig. 3. Optical power distribution of backward RFA in G.652 fiber

Fig. 4. The scheme of RFA

Fig. 5. The experimental setup of RFA

Fig. 6. Gain spectrum of ultra wideband RFA in G.652 fiber

Fig. 7. Gain spectrum of ultra wideband RFA in G.654 fiber

Fig. 8. Gain spectrum of ultra wideband RFA in LEAF