基于晶体拉曼技术的钠导星激光实现研究

In this project, we bring forward the idea of sodium lasers based on crystalline Raman laser technique. The main idea is that by using crystalline Raman lasers and Raman amplifiers we try to obtain 1178.318 nm near-infrared lasers with high beam quality, narrow line-width and high power, then through frequency-doubling we can obtain 589.159 nm sodium lasers. The key techniques are realization of single-longitudinal-mode crystalline Raman lasers, frequency stabilization of single-longitudinal-mode crystalline Raman lasers, and power improvement of 589.159 nm lasers. The main research contents are: pulsed single-longitudinal-mode crystalline Raman lasers, continuous-wave single-longitudinal-mode crystalline Raman lasers, single-longitudinal-mode crystalline Raman amplifiers, frequency stabilizing technique of single-longitudinal-mode crystalline Raman lasers, and frequency doubling technique of single-longitudinal-mode crystalline Raman lasers. And we have made detailed and feasible technical plans. This is a fancy idea that is valuable in applications. The research contents are abundant and necessary, the research plans are detailed and feasible, and our group has good experience in this field and has good experimental environments. So we believe that this project can be accomplished smoothly with impressive results. Through this project, we hope to offer a novel choice for sodium lasers, and obtain some important and novel results in the research field of Raman lasers.

本项目提出基于晶体拉曼技术的钠导星激光实现方案，核心思想是利用晶体拉曼激光器和放大器获得高光束质量、窄线宽、高功率的1178.318nm近红外光，再经过倍频获得589.159nm钠黄光。对晶体拉曼激光器的单纵模运转、单纵模晶体拉曼激光的稳频技术、单纵模589.159nm激光的功率提升等关键技术进行研究。明确了主要研究内容：脉冲式晶体拉曼激光器的单纵模稳定运转方案研究、连续式晶体拉曼激光器的单纵模稳定运转方案、单纵模晶体拉曼放大技术研究、单纵模晶体拉曼激光的稳频技术研究、单纵模晶体拉曼激光的倍频技术研究。并制定了切实可行的技术路线和研究方案。本思路的提出是创新性的，具有重要的实用价值，且研究内容丰富充实，研究方案和技术路线切实可行，课题组也积累了不错的研究基础和工作条件，能够很好地完成本项目。希望通过本项目的研究，为钠导星激光提供一种新的可行选择，并在晶体拉曼激光研究方面开辟一片新的领域。

“钠导星激光”是指波长589.159 nm、线宽<3 GHz、具有一定功率且光束质量好的激光。该激光能够激发90 km 高的大气层中的钠元素，对大气湍流引起的光学畸变进行实时修正。因此，在改善大型望远镜的分辨率，提升激光武器效率等方面具有重要应用。. 本项目提出基于晶体拉曼技术的钠导星激光实现方案，核心思想是利用晶体拉曼激光器和放大器获得高光束质量、窄线宽、高功率的1178.318 nm 近红外光，再经过倍频获得589.159 nm 钠黄光。本研究周期内，我们通过对晶体拉曼放大技术的泵浦源研究，晶体拉曼激光器及倍频晶体拉曼激光器技术研究，基于CaWO4晶体的单纵模1178 nm拉曼放大器性能研究、基于LiF:F2-色心晶体的单纵模1178 nm激光器性能研究，及新型激光光源性能研究多个方面研究，成功掌握了晶体拉曼激光的单纵模运转技术，单纵模晶体拉曼激光的稳频技术，以及单纵模晶体拉曼激光的高效倍频技术，最终获得了589 nm黄光的单脉冲能量为8.2 mJ，线宽为1.3 GHz，光束质量小于1.5。项目负责人刘兆军先后应邀担任国际会议分会主席1次，在国际、国内会议做邀请报告6次，口头报告4次。在Optics Letters，Optics Express等期刊发表SCI学术论文19篇，EI论文1篇。已授权发明专利2项。完成所有预期研究目标。