103 W in-band dual-end-pumped Ho:YAG laser

An efficient 2 μm in-band pumped Ho:YAG laser was demonstrated. The resonator involves two Ho:YAG crystals, each of which was dual-end-pumped by two orthogonally polarized diode-pumped Tm:YLF lasers. The maximum continuous wave output power of 103 W was achieved, corresponding to a slope efficiency of 67.8% with respect to the incident pump power and an optical-to-optical conversion efficiency of 63.5%. Under Q-switched mode, we obtained 101 W laser output at 30 kHz, corresponding to a slope efficiency of 66.2%. The beam quality or M2 factor was found to be less than 2.