High beam quality of a Q-switched 2-µm Tm,Ho:LuVO 4 laser

A diode-end-pumped 2.05-µm Q-switched Tm,Ho:LuVO 4 laser is reported in this paper. The cryogenic Tm 3+ (5.0 at.%),Ho 3+ (0.5 at.%):LuVO 4 crystal was pumped by an 800-nm laser diode. At a pulse repetition frequency of 10 kHz, the maximum average output power of 3.77 W was achieved at 77 K when an incident pump power of 14.7 W was used. The slope efficiency and optical–optical conversion efficiency were 28.3 and 25.6%, respectively. The maximum per pulse energy was 2.54 mJ for a pulse duration of 69.9 ns. The beam quality factor Mx 2 was approximately 1.17 and My 2 was approximately 1.01 for the Tm,Ho:LuVO 4 laser.