熔石英紫外激光初始损伤形态分析

 采取355 nm激光脉冲辐照熔石英样品，利用Nomarski微分干涉差显微镜、原子力显微镜和扫描电子显微镜观测手段对前后表面产生的损伤点进行了观察分析。对前后表面损伤形态做出详细的描述和分类，从理论上对每种损伤类型产生的条件与机理做出推测。实验结果表明：熔石英前表面存在小麻点群损伤和星状裂纹损伤两种损伤形态，横向尺寸分别为0.8～2.5和1.0～5.5 μm；后表面存在小麻点群损伤、壳状剥离损伤和火山口3种损伤形态，损伤横向尺寸分别为0.48～1.33，4～20和12～30 μm。实验证明了1 μm尺度损伤点的产生与再沉积层密切相关。

Morphology of UV laser initiated damage in fused silica

In order to systemically investigate the morphology and microstructure induced in fused silica by UV (355 nm) laser pulses at high fluence,a suite of microscopic tools have been used,such as Nomarski optics microscope,AFM and SEM.Two types of damage are observed on the input surface of fused silica,that is,micro-pits and star-like cracks with diameters of 0.8～2.5 μm and 1.0～5.5 μm,respectively.Correspondingly,there are three types of damage on the output surface,namely micro-pits,shell-like damage and craters with diameters of 0.48～1.33 μm,4～20 μm and 12～30 μm,respectively.By comparing morphology of fused silica and laser fluence,several assumptions have been given to understand the damage initiation mechanism,especially for 1 μm scale laser initialed damage.