Zhou Xue, Li Jiatong, Huang Shengjun, Sun Qijia, Nie Hongkun, Li Tao, Zhang Baitao, He Jingliang, Yang Kejian
Opt Express. 2024 Sep 9;32(19):33262-33270. doi: 10.1364/OE.537715.
A high-efficiency Tm:YLF laser at 2.3 µm is demonstrated based on a dual-wavelength pumping scheme with 790 nm LD and a tunable Yb:CALGO laser at around 1.05 µm. When employing single-wavelength pumping at 790 nm, a maximum output power of 3.1 W is obtained, while the maximum output powers of 0.35 W and 0.25 W are achieved for single-wavelength up-conversion pumping at 1055 nm and 1041 nm, respectively. By using 790 nm and 1055 nm dual-wavelength pumping regime, the maximum output power is enhanced to be 3.52 W, which is the highest output power ever achieved from the 2.3 µm Tm:YLF lasers, to the best of our knowledge. The output power of 3.52 W achieved by dual-wavelength pumping exceeds the sum of output powers obtained with the separate single-wavelength pumping at 790 nm and 1055 nm, which well shows that the ground state absorption process H→H under intense 790 nm pumping would induce a significant accumulation of Tm ions on metastable level F via cross-relaxation process, greatly promoting the excited-state absorption process F→F and enhancing the 2.3 µm radiation.
基于790nm激光二极管（LD）和波长约为1.05μm的可调谐Yb:CALGO激光器的双波长泵浦方案，展示了一台2.3μm的高效Tm:YLF激光器。当采用790nm单波长泵浦时，获得的最大输出功率为3.1W，而在1055nm和1041nm进行单波长上转换泵浦时，最大输出功率分别为0.35W和0.25W。通过使用790nm和1055nm双波长泵浦方式，最大输出功率提高到3.52W，据我们所知，这是2.3μm Tm:YLF激光器有史以来获得的最高输出功率。双波长泵浦实现的3.52W输出功率超过了在790nm和1055nm分别进行单波长泵浦所获得的输出功率之和，这充分表明在强790nm泵浦下基态吸收过程H→H会通过交叉弛豫过程使Tm离子在亚稳能级F上显著积累，极大地促进激发态吸收过程F→F并增强2.3μm辐射。
