A 35 : Impurity - doped Micro - lasers

Rare-earth-ion-doped monoclinic potassium double tungstates KY(WO4)2, KGd(WO4)2, and KLu(WO4)2 are excellent host materials for solid-state lasers [1]. High-quality KY(WO4)2 optical waveguides were grown and laser operation was demonstrated for the first time [2]. Co-doping a KY(WO4)2 layer with Gd 3+ and Lu 3+ ions allows for lattice-matched layers with increased refractive index contrast with respect to the KY(WO4)2 substrate [3]. Waveguide laser operation was observed at 1025 nm. 195 mW output power and 82.3% slope efficiency were obtained [4]. In KGd1-xLux(WO4)2:Yb 3+ channel waveguides microstructured by Ar + beam etching [5], we produced 418 mW of continuous-wave output power at 1023 nm with 71% slope efficiency at 981 nm and achieved a record-low quantum defect of 0.7% [6]. Laser experiments on planar [7] and ridge-type channel waveguides [8] in KY1-x-yGdxLuy(WO4)2:Tm 3+