紧凑型MgO:PPLN宽波段可调谐连续光参量振荡器

报道了基于掺MgO周期极化铌酸锂（MgO:PPLN）晶体的可调谐连续光参量振荡器。该光参量振荡激光器采用了多周期可调谐的MgO:PPLN作为非线性光学晶体，Nd:YVO4为激光晶体的紧凑型半导体激光端面抽运直线腔系统。实验中采用的MgO:PPLN晶体包含28.5~31.5 m之间的7个极化周期，相邻极化周期的间隔为0.5 m。通过调节7个极化周期实现信号光波长1.43~1.67 m和闲频光波长2.93~4.16 m的激光调谐输出。对同一温度下不同极化周期对应的输出波长进行理论计算，与实验结果符合较好。对比分析了输出功率随着不同极化周期和抽运功率的变化关系。当半导体激光入射抽运功率为15.4 W，在31 m极化周期和35℃的控制温度下，最高获得了2.94 W的1 595 nm信号光和1.45 W的3 190 nm闲频光，对应的光光转换效率达28.5%。

Compact widely tunable continuous-wave MgO:PPLN optical parametric oscillator

A compact, intra-cavity widely tunable continuous-wave singly resonant optical parametric oscillator (SR-OPO) was reported based on a MgO-doped periodically poled lithium niobate (MgO:PPLN). A diode-pumped Nd:YVO4 laser at 1 064 nm was employed as the pump source of this SR-OPO with a compact linear cavity. The MgO:PPLN crystal used contained seven different periodically poled gratings from 28.5 to 31.5 m with a step of 0.5 m between the neighbor periods. The output wavelengthes at the different grating periods of MgO:PPLN crystal was measured, which was well matched with the theoretical value. The widely tunable SR-OPO output signal wavelength range from 1.43 to 1.67 m and idler wavelength range from 2.93 to 4.16 m were achieved. The output power as the function of grating periods and pump power was investigated. Under an incident pump power of 14.5 W, a maximum signal output power of 2.94 W at 1 595 mm and an idler output power of 1.45 W at 3 190 nm were obtained with the temperature controlled at 35℃ and the period set at 31 m. The diode to OPO total output conversion efficiency reached 28.5%.