High-performance Ho:YAG single-crystal fiber laser in-band pumped by a Tm-doped all-fiber laser

We report on, to the best of our knowledge, the first Q-switched single-crystal fiber (Ho:YAG SCF) laser in the 2 μm spectral range, in-band pumped by a Tm-doped all-fiber laser. A continuous-wave laser with 12.5 W output power and Q-switched laser with 1.44 mJ pulse energy and 7.5 ns pulse duration at a repetition rate of 1 kHz were demonstrated. The high laser performance is attributed to the high gain, suppressed nonlinear effects, and easy thermal management which benefited from the unique geometric construction of the SCF.