Fig. 1. Experimental setup of OPI-MWRBFL with single BFS interval

Fig. 2. Measured results of output spectra of OPI-MWRBFL experimental system with single BFS interval. (a) Output spectra of odd (solid) /even (dotted) order Stokes lasers at pump power of 80 mW; (b) total output spectrum at pump power of 80 mW; (c) output spectra of odd (solid)/even (dotted) order Stokes lasers at pump power of 100 mW; (d) total output spectrum at pump power of 100 mW

Fig. 3. Output spectra of OPI-MWRBFL with single BFS interval at different pumping optical powers

Fig. 4. Stability measurement results of each order of output laser when EDFA output power is set to 100 mW. (a) Power stability; (b) wavelength stability

Fig. 5. Experimental setup of OPI-MWRBFL with double BFS interval

Fig. 6. Measured results of output spectra of OPI-MWRBFL experimental system with double BFS interval. When output powers of both EDFA1 and EDFA2 are 60 mW, (a) output spectra of laser in fast and slow axis polarization directions and (b) total laser output spectrum; when output powers of both EDFA1 and EDFA2 are 130 mW, (c) output spectra of laser in fast and slow axis polarization directions and (d) total laser output spectrum

Fig. 7. Stability measurement results of each order of output laser when powers of both EDFA1 and EDFA2 are set to 130 mW. (a) Power stability; (b) wavelength stability

Fig. 8. Measured result of linewidth of output laser from OPI-MWRBFL with double BFS interval