63-W average power from femtosecond Yb:Lu2O3 thin disk laser

In this work, we demonstrate the successful power scaling of Yb:Lu
₂
O
₃
in pulsed and cw-operation. We used an Yb:Lu
₂
O
₃
disk with a thickness of 250 Im and a Yb-doping concentration of 2%. The disk was pumped at 976 nm with a 0.5 nm broad fiber coupled diode. The pump spot diameter was 1.9 mm. In a simple multimode resonator with a curved outcoupling mirror (R = 100 mm, T = 2.7%) we obtained 149 W continuous wave (cw) output power at 1034 nm. The incident pump power was 204 W, which corresponds to an optical-to- optical efficiency (77opt) of 73%. This is the highest output power reported from an Yb:Lu
₂
O
₃
laser so far.