熔石英紫外光学元件加工表面特性及其强光辐照损伤抑制方法

In the large laser system, the high power laser irradiates the fused silica ultraviolet optical elements, and the laser induced damage becomes the key of the highlight optical system power improvement, as well as restricts the development of high laser techniques such as inertial confinement fusion. This project focuses on the generation, measurement and characterization of the fused silica ultraviolet optical elements' defects in the machining process, and explores the new technology of restraining the machining defects in order to improve the laser damage threshold of the fused silica ultraviolet optical elements. Based on the confocal time-resolved photoluminescence techniques, full and accurate characterization of the machining defects is established by the machining damage metrology correlated with the laser induced damage performance. Based on theory of laser optical field modulation, the laser induced damage mechanism caused by the machining defects in specific processing condition is analyzed to reveal the impacting rule of processing technic in the laser induced damage of fused silica. Furthermore, the fused silica material's generating mechanism of the near surface defect with a low stress polishing method and the surface impurity caused by the post etching processing are studied to establish the restraining method and technology of the machining defects. This project aims at achieving processing defect free of the fused silica ultraviolet optical elements and improving the laser induced damage threshold to the level of shallow blue line, as well as providing technical support for breaking through the bottleneck of laser damage threshold in national high power optical projects.

在强光光学系统中，熔石英紫外光学元件要经受强光辐照，加工缺陷引起的辐照损伤是制约强光光学系统能量提升的瓶颈，制约激光核聚变等强激光技术的发展。项目围绕熔石英紫外光学元件加工缺陷产生、检测和表征，探索其加工缺陷抑制新工艺，以提升熔石英紫外光学元件激光损伤阈值。基于光致发光原理，研究激光损伤性能直接关联的加工损伤检测方法，以获得更全面、准确的加工缺陷表征；基于激光光场调制理论，分析特定工艺条件产生的加工缺陷导致激光损伤机理，以揭示加工工艺对熔石英材料激光损伤影响规律；研究熔石英材料在低应力抛光工艺条件下的近表面机械裂纹和腐蚀后处理工艺中表面杂质等加工缺陷的形成机制，并研究该加工缺陷抑制工艺方法，形成加工缺陷抑制新工艺。实现熔石英紫外光学元件近零缺陷加工，提升熔石英光学材料激光损伤阈值至浅蓝线水平，为我国重大强光光学工程实施提供制造理论与技术支撑。

在强光光学系统中，熔石英紫外光学元件要经受强光辐照，加工缺陷引起的辐照损伤是制约强光光学系统能量提升的瓶颈，制约激光核聚变等强激光技术的发展。项目围绕熔石英紫外光学元件加工缺陷产生、检测和表征，探索其加工缺陷抑制新工艺，以提升熔石英紫外光学元件激光损伤阈值。基于光致发光原理，研究激光损伤性能直接关联的加工损伤检测方法，以获得更全面、准确的加工缺陷表征；基于激光光场调制理论，分析特定工艺条件产生的加工缺陷导致激光损伤机理，以揭示加工工艺对熔石英材料激光损伤影响规律；研究熔石英材料在低应力抛光工艺条件下的近表面机械裂纹和腐蚀后处理工艺中表面杂质等加工缺陷的形成机制，并研究该加工缺陷抑制工艺方法，形成加工缺陷抑制新工艺。实现熔石英紫外光学元件近零缺陷加工，提升熔石英光学材料激光损伤阈值至浅蓝线水平，为我国重大强光光学工程实施提供制造理论与技术支撑。