All-fiberized continuous-wave thulium-doped fiber laser with >1 kW output power at 1940 nm

초록

We report a continuous-wave thulium (Tm)-doped fiber laser oscillator with >1 kW output power operating at 1940 nm under the optimized cooling condition. Using a water calorimetry method, the temperature increases and its impact on output power were experimentally investigated, confirming good agreement with theoretical predictions. To mitigate thermal effects on laser performance, a bi-directional pumping configuration was implemented, theoretically reducing the maximum Tm fiber temperature by ∼40% compared to forward pumping. Under the optimized cooling condition, the Tm fiber laser yielded a maximum output power of 1032 W for an incident pump power of 1785 W, corresponding to a slope efficiency of 58.5%. A near-diffraction-limited beam quality was maintained at all power levels, along with excellent output stability. © 2026 Elsevier B.V.

키워드