High power Tm:silica fiber lasers: Current status, prospects and challenges

Reported near-diffraction-limited, cw power levels from Tm-doped silica fiber lasers in the 2000-nm wavelength region have now passed the 1 kW level, due to advances in fiber technology, pump lasers and associated pump-coupling fiber optics. Compared to the more common high-power Yb-doped fibers, Tm:silica fibers have several advantages, particularly with respect to limits set by fiber nonlinear effects such as stimulated Brillouin scattering. These have been exploited to allow generation of 600 W of single-frequency, narrow-linewidth power, the most, to our knowledge, of any fiber-based laser. In addition, there have been significant advances in generation of high-peak-power pulses from Tm:fiber-based sources.