报道了采用1064 nm激光抽运掺MgO周期极化LiNbO3(PPMgLN)晶体准相位匹配(QPM)技术实现高效率红外激光输出的实验结果,理论计算了PPMgLN晶体准相位匹配温度调谐曲线。抽运源为激光二极管连续(CW)抽运Nd∶YAG晶体声光调Q 1 μm激光器,PPMgLN晶体(MgO摩尔分数为5%)单谐振光参量振荡技术采用e→e+e相位匹配,消除了光束之间的走离效应和利用了PPMgLN晶体的最大非线性系数d33(27.4 pm/V)。在1064 nm激光抽运功率104 W,声光Q开关工作频率7 kHz和PPMgLN晶体工作温度110 ℃条件下,获得了平均功率62.7 W红外激光输出,斜率效率71.7%,其中中红外波长3.84 μm激光输出功率16.7 W,近红外波长1.47 μm激光输出功率46 W。

The experimental results of a high-efficiency infrared-laser are demonstrated on a quasi-phase-matched (QPM) single-resonated optical parametric oscillator (OPO) in PPMgLN (5% MgO-doping) pumped by a 1064 nm laser of an elliptical beam. Theoretical analyses of the PPMgLN temperature tuning are presented. The pump source was an acousto-optically Q-switched continuous wave (CW)-diode-side-pumped Nd∶YAG laser,the pump beam polarization matches the e→e+e interaction in PPMgLN,thus maximal nonlinear coefficient d33 (27.4 pm/V) is effective and walk-off of beams can be avoided. When the pump power was 104 W with a repetition rate of 7 kHz and PPMgLN crystal temperature of 110 ℃,an average output power of 62.7 W was obtained with a slope efficiency of 71.7%,with 16.7 W at the mid-infrared wavelength of 3.84 μm and 46 W at the near-infrared wavelength of 1.47 μm.