Highly efficient 2  μm CW and Q-switched Tm^3+:Lu_2O_3 ceramics lasers in-band pumped by a Raman-shifted erbium fiber laser at 1670  nm

Highly efficient laser oscillations at 2 μm were investigated in Tm:Lu2O3 ceramics in-band pumped at 1670 nm by a Raman-shifted erbium fiber laser. Both 23 W CW and 15 W active Q-switched oscillations with 40 ns pulse duration and 15–30 kHz repetition rate were achieved in a high-quality beam. The evolution of two generated waves at 1966 and 2064 nm in dependence on pump power was studied.