Active Q-switching operation of slab Ho:SYSO laser wing-pumped by fiber coupled laser diodes.

ABSTRACT

In this paper, we demonstrate the continuous-wave and acousto-optical Q-switched performance of diode-pumped slab Ho(Sc0.5Y0.5)2SiO5 (HoSYSO) laser at 2.1 µm for the first time. Two 1.91-µm laser diodes were used to pump the HoSYSO crystal. With a wing-pumping structure, at absorbed pump power of 44.7 W, the continuous wave slab HoSYSO laser produced 20.7 W maximum output power at 2097.9 nm, resulting in a slope efficiency of 53.1% with respect to the absorbed pump power. In the Q-switched regime, the slab HoSYSO laser produced up to 3.4 mJ pulse energy with 20 ns minimum pulse width at pulse repetition frequency of 5 kHz, corresponding to a peak power of 170 kW.