熔石英光学元件的CO2激光加工技术研究新进展

New Progress of CO2 Laser Processing Techniques for Fused Silica Optics

熔石英元件是一种典型的硬脆性且难加工的材料,在传统机械加工中的加工效率极低,并且加工过程中引入的机械弱化层,严重影响了熔石英元件在强冲击、高载荷、高能量环境下的使用寿命。和传统机械加工方法相比,CO2激光加工技术的优点在于可实现非接触式加工,并且去除精度高和去除效率高。尤其重要的是,CO2激光加工后的熔石英光学元件无表面/亚表面裂纹、划痕等缺陷,使得CO2激光加工技术在熔石英元件的加工中得到了重要且广泛的应用。因此,从熔石英元件的CO2激光加工理论、大口径器件CO2激光加工工艺、局部区域CO2激光损伤修复,以及表面微结构加工4个方面出发,对熔石英光学元件的CO2激光加工技术研究现状进行综述,重点分析了CO2激光加工技术在熔石英元件大口径器件/局部区域加工的工艺水平现状以及微结构加工的应用现状,并探讨了CO2激光加工过程中引入的负面效应以及仍需解决的问题,希望为推动CO2激光加工技术在熔石英元件加工的进一步应用提供参考。

Fused silica optics is a typical hard and brittle material, which is inefficient in traditional mechanical processing for the difficult-to-process materials. And the mechanical weakening layer produced on processed surface seriously affects the service life of fused silica optics in the conditions of strong impact, high load, and high energy. Compared with traditional mechanical processing, the advantages of CO2 laser processing technique are non-contact processing, high removal accuracy and high removal efficiency. Especially, the surface/subsurface cracks and scratches of fused silica optics processed by CO2 laser do not exist. CO2 laser processing technique has been widely used in processing of fused silica optics for these advantages. Therefore, this work reviews the development of CO2 laser processing technique for fused silica optics from four aspects, i.e., the CO2 laser processing theory of fused silica optics, the CO2 laser processing technology for large-aperture optical elements, the CO2 laser mitigating damages in local regions, and the CO2 laser processing of surface microstructures. The respective capabilities and application status of CO2 laser processing techniques for large-aperture or local region fused silica optics and surface microstructures have been analyzed. And the negative effects induced in CO2 laser processing and the problems needing to be solved discussed in detail. This work is expected to provide reference for further application of CO2 laser processing techniques for fused silica optics.