飞秒激光烧蚀石英玻璃表面质量分析

Analysis of Surface Quality for Femtosecond Laser Ablation Silica Glass

基于不同激光功率线烧蚀试验,研究激光偏振模式对烧蚀线宽度及表面形貌特征的影响。结合线烧蚀优化参数,开展不同线重叠率δ的面烧蚀试验,利用表面轮廓仪进行烧蚀表面粗糙度分析;建立扫描速度和线重叠率对残留高度影响的关系表达式,并进行计算分析。研究表明,当线偏振方向平行于扫描方向时,线偏振光烧蚀线质量优于圆偏振光,且其烧蚀线宽比圆偏振光大。当δ由65%增大到90%时,线偏振光烧蚀面垂直于扫描方向的轮廓算数平均偏差Ra先减小后增大,并在δ=80%时达到最小值1.05μm;圆偏振光Ra随δ增大而减小,在δ=90%时达到最小值1.63μm。此外,烧蚀面微观不平度十点高度Rz计算结果与试验结果基本吻合,且Rz与δ呈线性关系,并随δ增大而减小。

The influences of polarization state on ablation line width and morphology are investigated based on line experiments of different laser power. The surface ablation experiments of different line overlap rateδ are carried out in the combination of linear ablation optimized parameters. Also, the surface roughness is analyzed by using surface profiler. In addition, the relational expressions of scanning velocity and line overlap rate on the influence of scallop height are established, and then the expressions are calculated. The results show that the ablation line quality of linearly polarized laser is better than the circularly polarized laser, and its line width is greater than that of circularly polarized laser. Whenδ increases from 65% to 90%, the arithmetical mean deviationRa of ablation surface for linearly polarized laser decreases firstly and then increases, and it reaches to a minimum of 1.05μm atδ=80%. But, theRaof circularly polarized laser decreases with the increasing ofδ, and it reaches to a minimum of 1.63μm atδ=90%. The calculated results of roughnessRz are consistent with the experimental results, and it is a kind of linear relation betweenRz andδ. Also, theRzdecreases with the increasing of δ.