Efficient Tm-laser operation based on 5at.%Tm:KLu(WO4)2 with Nm and AT orientations

We report on highly-efficient room-temperature lasing in 5at.%Tm:KLu(WO4)2 mini slabs with Nm and AT orientations side-pumped by a 50W diode bars. CW maximum output power of 16.7 W at 1910 nm has been demonstrated with optical and slope efficiencies being of 35% and 45%, respectively.