湿法刻蚀处理熔石英光学元件研究进展

Review on Wet Etching Technique of Fused Silica Optical Elements

熔石英光学元件经过精密加工后亚表面存在大量缺陷,这些缺陷在强激光辐照下易引发激光诱导损伤,威胁熔石英元件在紫外激光(351 nm/355 nm)辐照下的正常运行。在湿法刻蚀工艺中,刻蚀液与熔石英材料发生化学反应,钝化亚表面结构裂纹,去除污染杂质,从而降低缺陷对损伤的影响,提高元件抗激光损伤性能。分析了熔石英光学元件的损伤机理,介绍了强酸沥滤、氢氟酸基刻蚀技术及其他湿法刻蚀技术的进展情况,比较了湿法刻蚀中不同刻蚀参数对元件抗激光损伤阈值的影响,总结了该领域的研究现状并对今后的发展趋势进行了展望。

A large amount of defects are created on the subsurface of fused silica optical elements after precision finishing, which can easily cause laser-induced damage, threatening the normal work of optical elements under an ultra-violet(351 nm/355 nm) laser. In the process of wet etching, the etching solution reacts with fused silica to passivate structural cracks, remove contaminative impurities in the subsurface layer, thus alleviate defects to a great extent and improve the damage resistance performance of elements. The damage mechanism of fused silica optical elements is analyzed, the technical processes of mineral acid leaching, hydrofluoric acid-based etching and other wet etching are introduced. The influence of etching parameters on the laser-induced damage threshold of elements is investigated. The present research status of this field is summarized and the future development trend is prospected.