Fig. 1. The experimental schematic of the linearly polarized Raman fiber laser. LP: linearly polarized; AMP: amplifier; GDF: germanium-doped fiber; CMS: cladding mode stripper.

Fig. 2. (a) The spectrum and (b) the output power of the tunable pump source.

Fig. 3. (a) The output power of the first-order Stokes wave versus pump wavelength; (b) the output spectrum as a function of pump wavelength.

Fig. 4. The output power of first-order Stokes wave and corresponding conversion efficiency.

Fig. 5. (a) The output power as a function of pump power; (b) the spectrum at maximum power in the linear coordinate.

Fig. 6. (a) The experimental setup of the comparative experiment; (b) the spectrum of comparative Raman fiber laser at 1062.5 and 1070 nm.

Fig. 7. The measurement setup of PER.

Fig. 8. The PER of the residual pump and first-order Stokes wave at the pump wavelength of 1070 nm.

Fig. 9. The stability of the output power at the time scale of 300 s.

Fig. 10. The experimental setup of 1178 nm Random laser.

Fig. 11. (a) The output power and (b) spectra versus pump power of 1178 nm random laser.