宽波段连续调谐全固态CW PPMgLN光学参量振荡器

利用半导体激光泵浦输出1064 nm波长的全固态连续Nd:YVO4激光器作为泵浦源，采用周期调谐和温度调谐组合调谐技术，对基于掺氧化镁周期性极化铌酸锂晶体（MgO:LiNbO3， PPMgLN）准相位匹配（QPM）的全固态连续波（CW）光学参量振荡器（OPO）宽波段无分立连续调谐输出特性进行研究。实验采用连续工作模式和外腔结构，基于多周期PPMgLN晶体的30.2，30.4和30.6 m周期，在改变晶体的极化周期的基础上，同时在30～100 ℃范围内调节晶体工作温度。实验结果表明:CW PPMgLN OPO的泵浦阈值仅为0.22 W；不同极化周期需要的温度调谐范围不同；信号光在1 559.8～1 597.2 nm近红外波段和闲频光在3 187.3~3 347.3 nm中红外波段连续调谐输出。实现了外腔式全固态CW OPO在信号光和闲频光波段的无分立连续调谐输出。

Continuously board-waveband tunable all-solid-state CW optical parametric oscillator based on PPMgLN

The output characteristics of a multi-wavelength tunable optical parametric oscillator (OPO) pumped by an all-solid-state Nd:YVO₄ laser with the 1064 nm wavelength is investigated by quasi-phase-matching period tuning and temperature tuning technology. An experiment is carried out by using an external cavity structure and continuous wave (CW) operation mode, and changing the periods and temperature of a periodically poled MgO:LiNO₃ crystal (PPMgLN) from 30 to 100 ℃ with 30.2 μm, 30.4 μm and 30.6 μm grating period. The experimental results indicate that the threshold of the CW PPMgLN OPO is only 0.22 W and the different poling period needs different temperature-tuned range, and the continuously tunable near-infrared spectrum from 1 559.8 to 1 597.2 nm and mid-infrared spectrum from 3 187.3 to 3 347.3 nm are obtained. A continuously tunable PPMgLN-OPO at the signal and idler wavelength is realized.