High power, 100 W-class, thulium-doped all-fiber lasers

In this work, sub-kilowatt, compact thulium-doped fiber laser systems, operating at a wavelength of 1940 nm, have been presented. The continuous-wave laser power generated out of a single oscillator was 90 W with a slope efficiency of 56.7%. Applying a master oscillator - power amplifier configuration, an output power of 120.5 W with a slope efficiency of 58.2% was demonstrated. These are the first results of the works aimed at developing kW-class eye-safe laser systems in Poland.