飞秒激光烧蚀Ag膜的研究

The ablation study on Ag film by femtosecond laser

研究飞秒激光烧蚀Ag膜表面,采用扫描电镜(SEM)观测其表面烧蚀形貌,发现烧蚀点大致分为3个区域,烧蚀面积随着脉冲能量的增大而增大,脉冲数的增加而增大,但当脉冲数达到一定值后烧蚀面积变化不大。改变脉冲数在烧蚀点得到了周期为650和150nm的长短周期条纹结构。根据烧蚀区域面积与脉冲能量的关系算出单脉冲与多脉冲的烧蚀阈值,Ag膜的单脉冲烧蚀阈值为0.189J/cm2。通过烧蚀点的累计能量和激光脉冲个数计算出Ag膜的多脉冲累计因子s=0.785。

The laser damage studies performed by femtosecond laser on Ag film were presented. Scanning elec- tron microscope was applied to observe the ablation morphology of surface. It shows that ablation dot can be roughly divided into three regions, ablation area increases with the increase of pulse energy, pulse number,but the ablation area has little change after the pulse number reaches a certain value. Periodic striped structures with period of 650 nm and 150 nm are produced at the ablation dots with the change of pulse number. The thresholds for single pulse and multi-pulse can be obtained from the relationship between the ablated area and the pulse energy. The thresholds of Ag film for single pulse is 0. 189J,/cm^2. From the plot of accumulated laser fluence and the number of laser pulses, multi pulse incubation coefficient of Ag film was obtained,s=0. 785.