标题：High-efficiency watt-level continuous-wave 2.9 mu m Ho, Pr:YLF laser
作者：Nie, Hongkun; Xia, Haiping; Shi, Bingnan; Hu, Jianxu; Zhang, Baitao; Yang, Kejian; He, Jingliang
作者机构：[Nie, Hongkun; Shi, Bingnan; Zhang, Baitao; Yang, Kejian; He, Jingliang] Shandong Univ, State Key Lab Crystal Mat, Jinan 250100, Shandong, Peoples R C 更多
通讯作者：Zhang, BT;Zhang, Baitao
通讯作者地址：[Zhang, BT]Shandong Univ, State Key Lab Crystal Mat, Jinan 250100, Shandong, Peoples R China.
摘要：The bottleneck in Ho3+:I-5(6) -> (5)I(7)2.9 mu m laser emission, where the upper-level lifetime (I-5(6)) is significantly shorter than that of the lower-level (I-5(7)) lifetime, is overcome by co-doping Ho3+ and Pr3+ ions. A novel kind of Ho3+, Pr3+:YLIF4 (Ho, Pr:YLF) crystal is fabricated by optimizing the doping concentration ratios. By using as-grown Ho, Pr:YLF crystals with doping concentrations of 0.498 at. % Ho3+, 0.115 at. % Pr3+ and 0.489 at. % Ho3+, 0.097 at. % Pr3+ as gain media, both high-efficiency and continuous-wave 2.9 mu m laser operations are realized under 1150 nm fiber laser pumping, respectively. With the 0.498 at. % Ho3+, 0.115 at. % Pr3+:YLF crystal, a maximum output power of 1.27 W with a corresponding slope efficiency of 28.3% is yielded under a 4.48 W absorbed pump power, which is the highest output power among the Ho3+-doped 2.9 mu m lasers ever reported, to the best of our knowledge. The results well reveal the great potential of Ho, Pr:YLF crystals in developing high-power, high-efficiency 2.9 mu m mid-infrared lasers. (c) 2018 Optical Society of America