融石英表面高质量亚波长光栅结构的飞秒激光加工  

High-quality Subwavelength Grating Structures Fabrication on FusedSilica Surfaces by Femtosecond Laser

作　　者：刘洋[1,2,3] 朱香平 靳川[1,2,3] 张笑墨 赵卫 LIU Yang;ZHU Xiangping;JIN Chuan;ZHANG Xiaomo;ZHAO Wei(Xi'an Institute of Optics and Precision Machinics,Chinese Academy of Sciences,Xi'an 710119,China;State Key Laboratory of Transient Optics and Photonics Technology,Xi'an 710119,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院西安光学精密机械研究所,西安710119 [2]瞬态光学与光子技术国家重点实验室,西安710119 [3]中国科学院大学,北京100049

出　　处：《光子学报》2023年第7期57-66,共10页Acta Photonica Sinica

基　　金：国家自然科学基金国家重大科研仪器研制项目(No.52127817);中国科学院重大科研仪器设备研制项目(No.ZDKYYQ20220007)。

摘　　要：采用钛蓝宝石飞秒激光加工系统在融石英表面诱导表面周期性微纳结构,研究了激光诱导表面周期结构的形成过程以及激光能量密度、脉冲数、光斑大小和脉冲的空间间隔对融石英表面激光诱导表面周期结构的形貌的影响。实验结果表明,飞秒激光在融石英表面可以诱导出周期性的亚波长结构,主要以垂直于激光偏振方向的光栅状结构为主,其周期在百纳米量级且具有更好的可复现性。在激光光斑控制在1μm附近时,所得到的形貌具有较高的规则性。根据实验结果设计了聚焦高斯光斑低通量的加工方式。所制备的光栅结构具有200~300 nm的周期,平均深度约为300 nm。The“moth eye”micro-nano structure has recently attracted much attentions due to its high potential value in scientific,biomedical,and industrial applications.For example,by manufacturing specific micro-nanostructures on the surface of an optical device,the incident light would be reflected multiple times on its surface,which lets the surface achieve the co-called“light trap effect”,reducing the transmission loss caused by Fresnel reflection at the interface.Laser Induced Periodic Surface Structures(LIPSS)provide a robust,flexible,non-contact,simple,and low-cost potential method for the fabrication of large-scale surface micro-nanostructures.As the most frequently used material on optical devices,it is of great significance to study the fabrication of optical micro-nanostructures on fused silica surfaces.In this paper,by using Ti:sapphire femtosecond laser processing system,the general laws of femtosecond laser induced LIPSS morphology on fused silica samples have been studied.Through designed experiments,the effects of different laser fluence and repetition frequency,pulse number,spot size,and pulse spatial interval on the morphology of LIPSS on fused silica surface were studied.We also focus on how to obtain the high-quality LIPSS,which can have a great impact on the final performance of the device.Different fluences were first set in the experiments.It was found that at a laser fluence of 5 J/cm2,irregularly arranged nanospikes were densely distributed in the crater,and at 7 J/cm2,ripple-like structures appeared in the center of the crater.After that,as the laser fluence increased,the periodicity increased,accompanied by an increase in proportion.A laser surface plasma interference model is used to explain the relationship between periodicity and laser fluence,which is in good agreement with the observed phenomena.In order to investigate the effect of laser spot size(or the influence aera size of laser spot)on the morphology of LIPSS,diminished laser spot sizes were set to observe the changes.To further

关 键 词：飞秒激光加工 表面形貌 亚波长结构 融石英 周期性结构 

分 类 号：TN249[电子电信—物理电子学]