CO2激光扫描辐照修复熔石英表面损伤

Mitigating laser induced damage in fused silica with CO_2 laser

采用振镜系统结合10.6μm的CO2激光,对熔石英表面损伤点进行辐照,成功地修复了直径500μm的大尺寸损伤点,损伤修复后表面无烧蚀残留,损伤内部完全愈合,无气泡和残余裂纹。和定点修复方式相比,这种修复具有修复尺度大、面形影响区域小、应力分布范围小的优势。80%扫描辐照修复的损伤点的初始损伤阈值恢复甚至超过了基底的初始损伤阈值。

Laser induced damage sites in fused silica were irradiated by a galvanometer scanned CO2 laser.Most damage sites are completely repaired（no ablation deposits,air bubbles and cracks） and the largest is 500 μm in diameter.Compared with localized mitigation,scanning mitigation can repair larger-sized damage,and bring about smaller surface deformation and lower thermal stress.The damage testing at 355 nm shows that,80% of the mitigated damage sites can withstand the laser power density up to the initial damage threshold of the substrate.