Fig. 1. Structure diagram of frequency interval switchable multi-wavelength Brillouin random fiber laser

Fig. 2. Structure diagrams of BP experiment and Stokes lines.(a) Structure diagram of single FW-BP experiment and (b) even-order Stokes lines measured from OSA2 on the right; (c) structure diagram of single BW-BP and (d) odd-order Stokes lines measured from OSA2 on the right

Fig. 3. Combined spectra of Stokes lines outputed by single FW-BP and BW-BP

Fig. 4. Measured spectra and their detailed enlarged graphs when splitting ratio is 10∶90. (a) Spectrum measured from OSA2 and (b) its detailed enlarged graph; (c) spectrum measured from OSA1 and (d) its detailed enlarged graph

Fig. 5. Measured spectra and their detailed enlarged graphs when splitting ratio is 90∶10. (a) Spectrum measured from OSA1 and (b) its detailed enlarged graph; (c) spectrum measured from OSA2 and (d) its detailed enlarged graph

Fig. 6. Measured spectra and their detailed enlarged graphs when splitting ratio is 30∶70. (a) Spectrum measured from OSA1 and (b) its detailed enlarged graph; (c) spectrum measured from OSA2 and (d) its detailed enlarged graph

Fig. 7. Measured spectra and their detailed enlarged graphs when splitting ratio is 70∶30. (a) Spectrum measured from OSA1 and (b) its detailed enlarged graph; (c) spectrum measured from OSA2 and (d) its detailed enlarged graph

Fig. 8. Measured spectra and their detailed enlarged graphs when splitting ratio is 50∶50. (a) Spectrum measured from OSA1 and (b) its detailed enlarged graph; (c) spectrum measured from OSA2 and (d) its detailed enlarged graph