Narrow-pulse-width gain-switched thulium fiber laser

A hybrid-pumped gain-switched Tm 3+ fiber laser with an all-fiber configuration is demonstrated to achieve over 10 W 2 μm pulsed laser beams. This laser system is complementarily pumped by a 790 nm continuous-wave diode laser and a 1 μm pulsed Yb 3+ fiber laser. Based on the triggering effect of a 1 μm pulse pump and the Rayleigh scattering induced Brillouin scattering effect, the 2 μm laser pulse can be narrowed to less than 20 ns, which is the narrowest pulse width ever achieved in high-power gain-switched thulium fiber lasers. The maximum pulse energy is 2 mJ and the maximum peak power is over 100 kW. Supercontinuum generation spanning over 200 nm can be observed with an average-power spectral density of >30 mW nm −1 .