High Power and Efficient Operation of Tm:YAG Ceramic Laser Resonantly Pumped at 1620 nm

We report on high power and narrow linewidth laser operation of home-developed high optical quality Tm:YAG ceramic. The Tm
³⁺
ion is pumped directly to the upper energy level of the ∼ 2 μm laser transition (
³
F
₄
→
³
H
₆
) using a high power 1620 nm fiber Raman laser. The laser generated 15.1 W of output at 2013 nm in free running for 27.4 W of absorbed pump power, corresponding to a slope efficiency of 64.0% with respect to absorbed pump power. Employing a reflecting volume Bragg grating (VBG) as a resonator mirror and for spectrum control, the laser generated 11.8 W of 0.1 nm narrow linewidth output at 2015 nm for ∼24 W of absorbed pump power, corresponding to a slope efficiency of 61.5%.