High-Efficiency CW and Passively-Q-Switched Operation of a 2050 nm Tm3+:Y2O3 Ceramic Laser In-Band Fiber-Laser Pumped at 1670 nm

2-μm solid-state lasers have a variety of applications in surgery, materials processing, environmental monitoring, gas detection and pumping of mid-IR optical parametric oscillators [1] , [2] . In-band pumping of the 3 H 6- 3 F 4 Tm 3+ -ion transition enables high-efficiency and high-power operation of the Tm 3+ -doped lasers at 1900-2100 nm with a low quantum defect [3] - [5] . In this paper we report an efficient L-shaped Tm 3+ :Y 2 O 3 ceramic laser in-band pumped by a fiber laser at 1670 nm.