Structure, spectroscopy and LD end-pumped laser performance of an Er,Pr:LuYSGG crystal operated at ∼2.8 μm

Abstract

We demonstrate the structure, spectroscopy, and laser performance of an Er³⁺ and Pr³⁺ co-doped LuYSGG crystal grown by the Cz method. The XRD result shows that it belongs to the cubic system with the space group I_ad. A refractive index curve in the range of 320–3000 nm is obtained by fitting the Sellmeier equation. The lifetimes of the ⁴I_13/2 and ⁴I_11/2 levels are 0.871 and 0.728 ms, and the ratio is reduced obviously from 3.4 to 1.2 due to the doping of deactivator Pr³⁺. In CW mode, a maximum output power of 1059 mW is achieved with a slope efficiency of 17.58% and laser center wavelength of ∼2.8 μm. Beam quality factors of 1.40/1.34 are achieved. The results suggest that the Er,Pr:LuYSGG crystal is a potential candidate for generating a high-power mid-infrared laser and can be applied in irradiation environments.