Spectroscopic and laser properties of Er3+, Pr3+ co-doped LiYF4 crystal

In this paper, the absorption and fluorescence spectra of Er3+, Pr3+ co-doped LiYF4 (Er,Pr:YLF) crystal were measured and analyzed. The Pr3+ co-doping was proved to effectively enhance the Er3+: I-4(11/2) -> I-4(13/2) mid-infrared transition at the 2.7 mu m with 74.1% energy transfer efficiency from Er3+:I-4(13/2) to Pr3+: F-3(4). By using the Judd-Ofelt theory, the stimulated emission cross section was calculated to be 1.834 x 10(-20) cm(2) at 2685 nm and 1.359 x 10(-20) cm(2) at 2804.6 nm. Moreover, a diode-end-pumped Er,Pr:YLF laser operating at 2659 nm was realized for the first time, to the best of our knowledge. The maximum output power was determined to be 258 mW with a slope efficiency of 7.4%, and the corresponding beam quality factorsM(x)(2) = 1.29 and M-Y(2) = 1.25. Our results suggest that Er,Pr:YLF should be a promising material for 2.7 mu m laser generation.

Automated summary

This study investigated the absorption and fluorescence spectra of Er3+ and Pr3+ co-doped LiYF4 crystals, showing that Pr3+ co-doping effectively enhances the mid-infrared transition of Er3+. Using Judd-Ofelt theory, the stimulated emission cross section was calculated and a diode-end-pumped Er,Pr:YLF laser operating at 2659 nm was successfully realized for the first time. This laser showed promising potential for 2.7 μm laser generation.