Multiwavelength Brillouin-Thulium Fiber Laser

We demonstrate the first multiwavelength Brillouin-thulium fiber laser (BTFL) with wavelengths near 1.97 μm. The multiwavelength fiber laser was realized based on stimulated Brillouin scattering and nonlinear polarization rotation effects. The laser can generate five Brillouin wavelengths with spacing of about 0.105 nm, which is identical with the wavelength spacing of adjacent Brillouin Stokes lines. The peak power fluctuations of the multiwavelength BTFL were less than 0.5 dB, and the wavelength shifts were less than 0.01 nm in 20 min.