熔石英材料因加工产生的表面缺陷是造成其在实际应用过程中抗激光损伤能力下降的主要原因。利用CO2激光对石英表面特征缺陷进行定点局部高温熔融修复的技术研究, 结果发现这种熔融修复可明显减小熔石英表面缺陷尺度并改善缺陷内结构质量。通过对修复后的表面缺陷进行损伤阈值考核发现, 熔石英表面200 nm深度左右的划痕在修复后损伤阈值提升1倍左右, 横向尺度10～100 μm内的表面初始坑状损伤点的损伤扩展阈值和相同辐照通量下的抗辐照次数也获得明显提高, 从而证实了利用CO2激光局部定点修复以提高熔石英负载能力、延长使用寿命的可行性。

Surface defect induced by machining in fused silica is the main causation weakening anti-laser-damage ability in actual application. The technology using local high temperature CO2 laser treatment repairing surface characteristic defect in fused silica is developed. It is presented that scale of surface defect is decreased and microcosmic interior structure quality of defect is improved after CO2 laser repairing. Through measuring the damage-threshold of repaired defect, is discovered that damage threshold of scrape-line with depth 200 nm is increases about 100 percent, and the damage growth threshold and anti laser radiation times of initial damage pit with diameter 10-100 μm is increased obviously too. It proves that the method using CO2 laser treatment repairing surface defect in fused silica can improve anti-damage ability and the life extending is doable.