基于种子注入方式的窄线宽可调谐长波红外ZGP-OPO研究

The all-solid-state long-wave IR tunable lasers with narrow linewidth have various applications in lidar, environmental monitoring and spectroscopy. The existing long-wave IR lasers were difficult to meet the requirements of the practical application due to they can not be taking into account wide tuning and narrow linewidth simultaneously. We proposed a long-wave IR ZGP-OPO laser using the seed injection technique to achieve narrow linewidth for the first time. This long-wave IR laser can produce wide tuning and narrow linewidth laser output. The continuous wave seed laser is intended to acquire from MgO:PPLN-OPO, with the wide tuning is achieved by combination of different polarization periods and crystal temperatures, and the narrow linewidth is achieved by single longitudinal pump source combined with several F-P etalons inserted in the cavity. Based on the theoretical analysis and experimental data of the thermal effects of ZGP crystal, we design and optimize the performance of the long-wave infrared ZGP-OPO. We solve the mode matching problem between the seed and the parametric laser. The wide tuning and narrow linewidth long-wave IR solid laser can be achieved from tuning the seed and the signal of the ZGP-OPO. These research results can be employed in the fields of spectroscopy, chemical remote sensing, environmental monitoring, and toxic gas detection.

宽调谐、窄线宽的全固态长波红外激光光源在激光雷达、环境监测以及光谱学等研究领域具有非常广阔的应用前景。现有的长波红外激光器不能同时兼顾宽调谐和窄线宽这两个特性，难以满足实际应用的要求。本课题首次提出以种子注入方式压窄长波红外ZGP-OPO的输出线宽，将窄线宽与可调谐这两个特性结合在一起，从而实现长波红外波段的宽调谐、窄线宽激光输出。本课题拟采用单纵模泵浦源与腔内F-P标准具相结合的方法，组合极化周期和晶体工作温度的调谐方式，在MgO:PPLN-OPO上实现宽调谐、窄线宽的连续波种子光输出；以ZGP晶体热效应的理论和实验研究结果为依据，设计和优化长波红外ZGP-OPO的性能；解决种子光与参量光之间的模式匹配问题，采用ZGP-OPO信号光与种子光联动调谐的方式，实现宽调谐、窄线宽的长波红外固体激光输出。本课题的研究成果可应用于光谱学、化学遥感、环境监测以及毒气侦测等领域。

宽调谐、窄线宽的全固态长波红外激光光源在激光雷达、环境监测以及光谱学等研究领域具有非常广阔的应用前景。现有的长波红外激光器不能同时兼顾宽调谐和窄线宽这两个特性，难以满足实际应用的要求。本课题首次提出以种子注入方式压窄长波红外ZGP-OPO的输出线宽，将窄线宽与可调谐这两个特性结合在一起，实现了长波红外波段的宽调谐、窄线宽激光输出。本课题采用单纵模泵浦源与腔内F-P标准具相结合的方法，组合极化周期和晶体工作温度的调谐方式，在MgO:PPLN-OPO上实现了2802.5nm到2703.3nm的窄线宽连续波种子光输出；测量了ZGP晶体的热焦距，设计出了高热稳定性OPO谐振腔；从长波红外ZGP-OPO的光束质量改善和调谐方式上解决种子光与参量光之间的模式匹配问题；最终，利用环形结构谐振腔，实现长波红外ZGP-OPO的种子光注入，获得了从8044nm 到9021nm 的窄线宽可调谐的长波红外固体激光输出。闲频光线宽保持在3.2nm，输出波长为8044nm 和9021nm 时的功率分别为2.73W 和0.33W。本课题的研究成果可应用于光谱学、化学遥感、环境监测以及毒气侦测等领域。