针对1 080 nm连续激光光学系统中反射镜的需求, 设计了低损耗高反膜膜系, 优化了膜系中的电场分布, 对高反膜元件工艺体系进行了控制。采用离子束溅射工艺, 成功地在超光滑石英玻璃基底上研制出了Ta2O5/SiO2体系高反膜, 对所获得的高反膜元件表面粗糙度、光学性能及抗激光损伤能力进行了讨论与分析。结果表明: 研制的低损耗1 080 nm高功率激光高反膜元件表面粗糙度达到0.115 nm, 在1 064 nm处吸收和散射损耗之和约17 ppm, 可承受500 kW/cm2的激光辐照而不损伤, 工艺技术应用前景良好。

In this paper, low loss mirrors are designed for 1 080 nm CW laser optical system. Electrical field and the process of HR coating elements are optimized and controlled carefully. HR coating designed by Ta2O5 and SiO2, is successfully prepared on super-polished silica glass by ion beam sputtering technology. Roughness, optical properties and ability anti-laser radiation of HR coating elements, are analyzed and discussed. The results show that the HR coating's roughness is 0.115 nm, and the sum loss of absorption and scattering at 1 064 nm is just 17 ppm, the coating HR elements are without any damage after 1 080 nm CW laser radiation with the power density is 500 kW/cm2. The technology of HR coating elements show good application prospects.