{'fraction_non_alphanumeric': 0.012039660056657223, 'fraction_numerical': 0.000708215297450425, 'mean_word_length': 5.224669603524229, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Study on subsurface damage of fused quartz in grinding stage

With the increasing energy of high power laser devices, the laser-induced damage of optical components, especially fused quartz components, has become one of the core problems in the development of high power laser devices. Studies show that pure fused quartz glass has a high intrinsic damage threshold, but fused quartz glass will inevitably introduce a large number of subsurface damage during the process of grinding and polishing, and these subsurface damage is one of the important factors leading to the decline of laser damage resistance of optical components. It is of great significance to study the subsurface damage of solid abrasive for improving the damage resistance threshold of optical components. In this experiment, 3M's abrasive pad is used as a solid abrasive. The subsurface damage of fine grinding elements are directly observed and analyzed by combining HF pickling and optical microscopy. The results show that various subsurface damage can be detected by optical microscopy after HF pickling. Profilometer is used to measure the surface roughness of the sample, the comparative analysis of the subsurface damage of the fine grinding elements shows that the elements with solid abrasive lapping have smaller roughness when the abrasive size is the same, which has a shallower depth of subsurface damage layer correspondingly.