High-efficiency CW and passively Q-switched operation of a 2050 nm L-shaped Tm3+:Y2O3 ceramic laser in-band fiber-laser pumped at 1670 nm

A Tm3+:Y2O3 ceramic laser with the L-shaped cavity in-band pumped by a fiber laser at 1670 nm was studied in the CW and passively Q-switched regimes. The CW laser was tunable in the range between 2046 and 2054 nm. The output power reached up to 4.9 W and the average slope efficiency was 75% in the high-quality single-transverse-mode beam The highest CW output power in the multi-transverse-mode beam was 12 W. A Cr2+:ZnSe saturable absorber was used to achieve the Q-switched operation at 2051 nm with the average power of up to 1.3 W in the single transverse mode, at the pulse repetition rate of 2–10 kHz and the pulse width of 80–150 ns.