A good beam quality Ho:GdVO₄ laser pumped by thulium-doped fiber laser at 1940 nm

We demonstrate a Ho:GdVO₄ solid-state laser pumped by a thulium (Tm)-doped fiber laser at 1940nm. In continuous wave mode, a maximum output power of 6.1 W was obtained under the absorbed pump power of 31.9 W with the slope efficiency of 24.3% at the temperature of 18°C. The wavelength of output laser was 2048.53 nm with full width at half maximum of 0.2 nm. In Q-switched mode, a maximum single pulse energy of 0.94 mJ was obtained with a minimum pulse duration of 7.3 ns at the pulse repetition frequency of 5 kHz, corresponding to a peak power of 129 kW and an average output power of 4.7 W. The beam quality factor of M² was 1.01 under the maximum absorbed pump power. To the best of our knowledge, 0.94 mJ is the highest single pulse energy in single holmium (Ho) doped GdVO₄ laser pumped by Tm-doped fiber laser at 1940 nm, and 1.01 is the best beam quality factor of M² in Ho:GdVO₄ laser pumped by a Tm-doped fiber laser.