报道了一种基于周期性极化晶体PPMgLN、连续波、线性外腔结构、宽带可调谐单谐振光学参量振荡器。泵浦源采用LDA 端面泵浦的Nd:YVO4 连续波1.064 μm 激光器，并通过优化泵浦光与信号光的模式匹配，获得了低阈值、高效率的中红外激光输出。光参量振荡阈值仅为1.09 W，是目前采用外腔结构所报道的最低值。在泵浦功率4.55 W 时，可以获得最大功率为346.8 mW、波长为3.202 μm激光输出，中红外光的光光转化效率达到了7.6%。并通过改变PPMgLN 晶体的极化周期，可以实现中红外2.98～4.19 μm 宽带可调谐激光输出。此中红外激光器结构简单紧凑，可以室温运行。

We report a linear extra-cavity, tunable mid-infrared, Continuous Wave (CW) singly resonant Optical Parametric Oscillator (OPO) based on periodically poled MgO-doped LiNbO3 (PPMgLN). A Nd:YVO4 laser pumped by 808 nm LDA is used as the pump source. The threshold of OPO system is only 1.09 W at 1 064 nm. A maximum idle laser output power of 346.8 mW at 3.202 μm has been achieved when the pump power is 4.55 W and it corresponds to an (only idler) optic-optic conversion efficiency of 7.6%. By shifting the PPMgLN crystal, the periods of the domain structure on the PPMgLN wafer can be changed, thus enabling a mid-infrared spectral widely tuning range of the laser output from 2.98～4.19 μm. This laser is very compact, simple and operated at room temperature.“中红外波段全固态光学参量振荡器产品研究与开发”。