We present a high-power single-frequency continuous-wave (CW) 671 nm laser by the second-harmonic generation (SHG) of a 1342 nm laser based on an external bow-tie enhancement cavity. Different from previous works, and using periodically poled nonlinear crystals for the SHG, we adopt the high damage-threshold nonlinear crystal lithium triborate (LBO) in the external SHG cavity to achieve a high-power CW SHG. In our experiment, with a type-II noncritically phase-matched LBO, an up to 12.6 W CW 671 nm laser is obtained with a 24 W incident 1342 nm laser, corresponding to an SHG conversion efficiency of 52.5 %. To our knowledge, this is a new record of power for the single-frequency CW 671 nm laser.

中文翻译：

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具有外部二次谐波产生腔的12.6 W单频连续波671 nm激光器

我们提出了一种基于外部领结增强型腔的1342 nm激光器的二次谐波产生（SHG）的高功率单频连续波（CW）671 nm激光器。与以前的工作不同，在SHG中使用周期性极化的非线性晶体，我们在外部SHG腔中采用高损伤阈值非线性晶体三硼酸锂（LBO）来实现大功率CW SHG。在我们的实验中，使用II型非关键相位匹配LBO，使用24 W入射的1342 nm激光器可获得高达12.6 W的CW 671 nm激光器，相当于SHG转换效率为52.5％。据我们所知，这是单频CW 671 nm激光器功率的新记录。