High power widely tunable Tm:fiber laser with spectral linewidth of 10 pm

We report on high-power, efficient operation of a widely tunable, cladding pumped Tm:fiber laser using a volume Bragg grating (VBG) for wavelength selection and spectral narrowing. The operating wavelength was tunable from 1943 to 1998 nm, with > 53 W output power over a tuning range of 50 nm from 1948 nm to 1998 nm and a spectral linewidth of 10 pm. Over 58.1 W of diffraction limited (M-2 similar to 1.5) CW output power was generated for 143.6 W of launched pump power at 792 nm, corresponding to a slope efficiency with respect to launched pump power of 45%.