通过结合HF酸洗和微分干涉差显微成像对两组抛光元件的亚表面损伤进行直接观测和分析。结果显示微分干涉差显微成像相比于传统的明场成像具有更好的分辨率, 可以更有效检测HF酸洗后暴露的各种浅塑性亚表面损伤。对两组抛光元件的亚表面损伤的对比分析发现熔石英元件在抛光中会产生大量的亚表面损伤, 这些亚表面损伤绝大多数是浅塑性的划痕和坑, 仅有少量的脆性断裂损伤, 较大的抛光颗粒会产生更多更严重的亚表面损伤, 并且这些亚表面损伤被表面沉积层所掩盖, 表面粗糙度不能反映亚表面损伤的严重程度。

Combining HF etching and differential interference contrast microscopy, this paper directly observes and analyzes the subsurface damages in fused silica optics. It is proved that the differential interference contrast microscopy has higher resolution than bright field microscopy and could detect the shallow scratches and dots. It is also revealed that polishing process would introduce lots of subsurface damages which are always covered by the redeposition layer. Most of the subsurface damages are plastic deformation induced shallow scratches and dots. A few fracture induced deep scratches and pits also exist. It is deduced that larger polishing particles incline to create severer and more subsurface damages.