Highly efficient lasing and thermal properties of Tm:Y2O3 and Tm:(Y,Sc)2O3 ceramics

We report on thermal, spectroscopic, and laser properties of transparent 5 at.% Tm3+-doped yttria and "mixed" yttria-scandia ceramics fabricated by vacuum sintering at 1750 & DEG;C using nanoparticles produced by laser ablation. The solid-solution (Tm0.05Y0.698Sc0.252)2O3 ceramic features a broadband emission extending up to 2.3 & mu;m (gain bandwidth, 167 nm) and high thermal conductivity of 4.48 W m-1 K-1. A Tm:Y2O3 ceramic laser generated 812 mW at 2.05 & mu;m with a slope efficiency & eta; of 70.2%. For the Tm:(Y,Sc)2O3 ceramic, the output power was 523 mW at 2.09 & mu;m with & eta; = 44.7%. These results represent record-high slope efficiencies for any parent or "mixed" Tm3+-doped sesquioxide ceramics. & COPY; 2023 Optica Publishing Group