Er:KY₃F₁₀ laser at 2.80  µm

We report on the mid-infrared laser operation of a cubic 15 at.% Er³⁺:KY₃F₁₀ crystal. In the quasi-continuous-wave regime, the peak power reaches 255 mW at 2.80 µm (the ⁴I_11/2→⁴I_13/2 transition) with a slope efficiency of 10.9% and a laser threshold of 58 mW. Two pumping schemes (to the ⁴I_11/2 and ⁴I_9/2 states) are compared. The emission properties of the Er³⁺ ions in KY₃F₁₀ are studied, indicating high stimulated-emission cross-section of 0.57×10^-20cm² at 2.80 µm, a large gain bandwidth of 40 nm, and a long ⁴I_11/2 state lifetime of 4.64 ms.