基于周期性极化铌酸锂(PPLN)晶体和准相位匹配的连续波光学参变振荡器可以在3μm～5μm中红外波段产生连续可调谐相干辐射, 在大气环境污染监测、遥感、激光雷达、光谱分析以及**红外对抗等领域具有很高的应用价值。介绍了基于PPLN晶体的中红外连续波光参变振荡器近年来在高功率、低抽运阈值、宽调谐、窄线宽等方面的研究进展, 并对基于PPLN晶体的连续波光学参变振荡器的优势特点及其涉及的一些技术方法展开讨论。目前基于PPLN的中红外连续光学参变振荡器的研究主要集中在上述4个领域, 随着抽运光源性能及非线性晶体制备水平不断提高, 将向着更高功率、更低阈值、更宽调谐范围、更窄线宽的方向迈进。

Optical parameter oscillator (OPO) based on periodically poled lithium niobate(PPLN) crystal and quasi phase matching (QPM) are suitable for generating continuous wave (CW) and tunable coherent radiation in mid-infrared wavelength range 3μm~ 5μm, which has important applications in atmosphere pollution monitoring, remote sensing, laser radar, spectroscopy analysis, and military infrared countermine. The recent development and advantages of CW mid-infrared optical parameter oscillator base on PPLN crystal was introduced. Specifically, the progress of techniques to increase the output power, lower the pump threshold, widen the tunable range and narrow the linewidth was addressed. Currently, the researches of optical parameter oscillator based on PPLN crystal are focus on the four areas mentioned above. Along with the development of the pump laser and nonlinear crystal, it will make further progresses toward the direction of higher power, lower threshold, wider tuning range, and the narrower line width as well.