Laser action along and near the optic axis of a holmium-doped KY(WO₄)₂ crystal

Opt Lett. 2014 Nov 15;39(22):6407-10. doi: 10.1364/OL.39.006407.

Abstract

We demonstrate the first (to our knowledge) quasi-three-level conical refraction laser operating at 2 μm, with 1.6 W of output power at 2074 nm, using a holmium-doped KY(WO4)2 crystal. A maximum slope efficiency of 52% has been achieved, along the optic axis with respect to the absorbed pump power. Furthermore, lasing operation around the optic axis has been performed. In this case, a maximum output power of 3 W has been reached, with a slope efficiency better than 70%, which are the best performances ever reported on this material.