Room-temperature watt-level and tunable ∼3 µm lasers in Ho3+/Pr3+ co-doped AlF3-based glass fiber

A room-temperature watt-level continuous-wave-output power mid-infrared fiber laser operating at λ ∼ 3 µ m is demonstrated using a H o 3 + / P r 3 + co-doped A l F 3 based glass fiber as a gain fiber. This fixed-wavelength laser had maximum output power of 1.13 W with a slope efficiency of 10.3% and a long-term operating stability of > 40 min without any additional packaging or active thermal management. A fiber laser with tunability from 2.842 to 2.938 µm showed a maximum output power of 110 mW.