1.6μm波段Er:GSAG晶体性能调控与抗辐照机理研究

Lasers at 1.6μm is the ideal source of satellite-based laser because it located in the infrared window of the atmosphere, which is widely used in ground detection, information transmission, remote sensing and atmospheric wind field measurement etc. Laser crystal is the most vulnerable part of all solid-state lasers, and it is very susceptible to the space irradiation, leading to the laser devices unworkable properly or scrapped prematurely. Thus, it is worthful to explore the laser crystal at 1.6μm with high effective radiation resistance, which is valuable to promote the space scientist development. . In this project, Er:GSAG laser crystal at 1.6μm with high efficient radiation resistance is proposed for application in space environment. Er:GSAG crystal is grown by Cz method. The structural relationship between the crystal components and the radiation resistance is established by optimizing with the content of Sc ion. The mechanism and rules of crystal growth are mastered to obtain Er:GSAG crystal with high effective anti-irradiation resistance. The irradiation experiment for GSAG crystals are carried out with gamma ray irradiation at different doses to reveal the radiation resistant micro-mechanism. The structure of laser cavity is designed and optimized to achieve 1.6μm laser with low threshold and high efficiency, realizing the applications in space radiation environment.

1.6μm波段的激光器处于大气红外窗口，是星载激光应用发展的理想光源，在对于地面的探测、信息传输，远程遥感及大气风场的测量等方面具有巨大的潜力和广泛的应用。激光晶体，作为全固态星载激光器件最脆弱的部件，易受到太空辐照的影响，从而使得服役于空间科学的激光器件无法正常工作或提早报废。因此，探索1.6μm波段高效抗辐照激光晶体对于促进空间科学的发展十分重要。.本项目提出一种适合空间环境应用的1.6μm波段高效抗辐照激光晶体Er:GSAG。拟采用提拉法进行Er:GSAG晶体生长，通过对Sc离子含量的组分优化调控，建立晶体组分与抗辐照特性的结构关系；优化生长工艺，掌握生长机理和规律，获得高效抗辐照Er:GSAG晶体；开展通过不同强度、剂量γ射线辐照研究，揭示晶体抗辐照损伤的微观机理；设计优化激光谐振腔，实现低阈值、高效率的1.6μm波段激光，满足空间等强辐射环境的应用需要。

1.6 μm波段的激光器处于大气红外窗口，是星载激光应用发展的理想光源，在对于地面的探测、信息传输，远程遥感及大气风场的测量等方面具有巨大的潜力和广泛的应用。激光晶体，作为全固态星载激光器件最脆弱的部件，易受到太空辐照的影响，从而使得服役于空间科学的激光器件无法正常工作或提早报废。因此，探索1.6μm波段高效抗辐照激光晶体对于促进空间科学的发展十分重要。本项目旨在探索和发展直接可应用于空间辐射环境的新型1.6 μm高效抗辐照激光晶体，研究了Sc离子含量对GSAG相结构的影响趋势，通过对不同浓度Er3+在GSAG中的发光机理研究，建立了Er3+在GSAG晶体场中的能量传递机理; 此外，我们建立有效的全局数值模拟模型，研究GSAG晶体生长系统内流场和温场的整体特性，为晶体生长炉结构设计以及晶体生长工艺优化提供参考，进而优化GSAG单晶提拉法生长工艺，进一步通过温场、生长工艺参数的优化，生长出高光学质量尺寸为Ø 30 ×70mm3的Er:GSAG抗辐照激光晶体，对晶体的结构、热学和物理化学性能进行了表征和探讨；通过中子射线对GSAG激光晶体的性能影响及机理探索，揭示晶体抗辐照损伤的微观机理，为含钪石榴石抗辐照晶体的结构的研究提供参考和依据；最后，我们开展了掺Er光纤激光器泵浦Er:GSAG人眼安全激光实验，获得了中心波长位于1.605 μm波段的激光输出实验，首次实现了该类晶体在1.6 μm波段的激光输出，填补了空间抗辐照固体激光材料在该波段的空白。