Multi-watt laser operation and laser parameters of Ho-doped Lu_2O_3 at 212 μm

Abstract

We present spectroscopic investigations and the first laser operation of Ho:Lu2O3. Laser operation was obtained with two different setups at room temperature: In a 1.9 Œºm diode pumped setup a maximum output power of 15 W was achieved. With a Tm-fiber laser pumped setup the maximum output power was 5.2 W and the slope efficiency was 54% with respect to the absorbed pump power. Absorption measurements revealed absorption cross sections of up to 11.7 x 10^-21 cm2 at 1928 nm. In the 2.1 µm range a maximum emission cross section of 4.5 x 10^-21 cm2 at 2124 nm was determined, which remains the highest gain peak even for high inversions. The fluorescence lifetime of the 5I7-manifold was found to be 10 ms.