7-W single-mode thulium-doped fibre laser pumped at 1230 nm

An efficient thulium-doped fibre laser emitting at ~2 μm upon pumping into the long-wavelength ³H₆ → ³H₅ absorption band of Tm³⁺ ions is developed. The maximum output power of the single-mode thulium laser pumped at 1230 nm was 7 W at 1956 nm for a pump conversion efficiency of 35%.