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题名	熔石英后处理技术研究
作者	许家锋
学位类别	硕士
答辩日期	2015
授予单位	中国科学院上海光学精密机械研究所
导师	徐学科
关键词	熔石英 HF蚀刻 亚表面缺陷 面形 表面质量
其他题名	The postprocess technique for fused silica optics
中文摘要	熔石英元件的抗激光损伤能力限制着高能量激光系统的最大输出通量。光学加工造成的研磨裂纹和划痕等亚表面机械损伤极易诱发激光损伤，因此表征这些亚表面损伤对优化加工工艺、制造出机械损伤尽量少的熔石英元件具有重要意义。我们用改进的磁流变斜面抛光法表征了不同粒径的Al2O3研磨的熔石英的亚表面损伤，拟合出了亚表面损伤深度与磨料粒径的线性关系，可据此关系估算一定粒径磨料造成的损伤深度，为后续加工工艺的去除深度提供指导。掺杂大颗粒磨料的混合磨料会比纯大颗粒磨料造成更深的损伤，并建立了模型解释该现象。 HF酸蚀刻是一项重要而有效的提高熔石英激光损伤阈值的后处理技术，论文详细研究了HF酸深蚀刻对熔石英表面质量(粗糙度和表面疵病)和面形的影响。残留的微米级研磨裂纹或亚微米级裂纹尖端经蚀刻演变成浅于1μm的坑点，这些坑点使样品的粗糙度大幅变差，同时降低了样品的明亮度，样品表面就像覆盖了一层灰尘，甚至变毛。研磨之后深蚀刻然后再抛光可完全去除这些坑点。蚀刻后的样品表面暴露出大量长1至60 mm的划痕，统计直径100 mm 的样品单面毫米级划痕总长度为200 mm。样品的边缘出现了集中分布的平行划痕。蚀刻前后短于1 mm 的划痕和研磨裂纹或裂纹簇则表现为样品表面的散射亮点。样品面形 PV 值的演变受初始面形特征的影响。“边缘尖端效应”使平放样品上表面的边缘比中心蚀刻快，侧面反应产物的不一致沉积破坏了下表面蚀刻去除量分布。“边缘尖端效应”、氟离子的不均匀分布和反应产物的不均匀分布共同造成了竖放时复杂的蚀刻去除量分布。
英文摘要	The output fluence of high power laser systems is limited by the laser damage resistivity of fused silica components. Subsurface damage, such as scratches and grinding cracks resulting from optical manufacturing, easily initiate damage on fused silica surfaces exposed to quite low laser fluence. Therefor, it makes good sense to characterize the subsurface damage to optimize the manufacturing process for subsurface damage free fused silica components. Using the magneto-rheological finishing wedge technique of better accuracy, we have characterized the subsurface damage on fused silica optical surfaces ground with loose Al2O3 abrasives of different sizes. Subsurface damage depth being proportional to abrasive size was fitted, which can be based on to predict subsurface damage depth according to the abrasive size. Addition of larger abrasives into abrasives of a given size produced deeper subsurface damage even than only the larger abrasives did. To explain this, a model was proposed. HF-based deep etching can greatly improve fused silica laser damage resistivity. How the surface quality(surface roughness and surface defect) and figure of fused silica subjected to etching evolve was researched in detail. Polishing insufficiently makes grinding cracks in micron size or submicron crack pits, which grow into digs through etching. These digs worsened the roughness, also lowered the brightness. Due to the digs' scattering, samples looked as if they were covered by dust, or more seriously, became frosted. Etching sufficiently immediately after grinding and just before polishing helps remove those digs. Etching uncovered lots of scratches from 1 to 60mm long, the total length was 200 mm statistically on single surfaces of 100 mm in diameter. Collections of parallel scratches were observed on the sample fringe areas. individual grinding cracks, clusters of cracks, or scratches with dimension less than 1 mm appear as sparkling points under the high power lamp. The figure features partly determine the PV change. In the case of samples placed horizontally, "fringe tip effect" cause faster etching removal on the edge than at central areas for the upper surface, while the nonuniform deposition of reaction product from the side render the lower surface assume a different etching removal distribution. As for the case to place samples vertically, combination of "fringe tip effect" and the nonuniform distribution of fluoride ion and reaction product made a more complex etching removal distribution.
语种	中文
内容类型	学位论文
源URL	[http://ir.siom.ac.cn/handle/181231/16941]
专题	上海光学精密机械研究所_学位论文
推荐引用方式 GB/T 7714	许家锋. 熔石英后处理技术研究[D]. 中国科学院上海光学精密机械研究所. 2015.

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