【摘要】 研究了双面抛光氧化镁单晶(111)表面800nm飞秒激光单脉冲烧蚀阈值和激光脉宽的依赖关系.利用泵浦-探针技术,测量不同能量和脉宽作用下飞秒激光烧蚀的时间分辨反射率的演化.通过扫描电镜观察其烧蚀形貌,发现大量的沿氧化镁[100]晶向开裂的裂纹.讨论了表面裂纹的形成机理,并解释了飞秒激光烧蚀氧化镁的超快动力学过程.更多还原

【Abstract】 Single-shot laser damage of polished MgO (111) surfaces induced by 800 nm pulses at different laser pulse duration was studied by scanning electron microscopy (SEM) and time-resolved measurements of reflectivity.SEM observations after laser irradiation indicated that substantial surface fracture dominated over rapid vaporization.The linear relationship between the ablation area and the logarithm of the pulse energy provided the single-shot ablation threshold.The pump-probe technique was used to investigate the change of the reflectivity during and after laser irradiation.The results showed that the charged particle emission time was about 15 ps.The ablation mechanism was also discussed.更多还原