基于飞秒激光自调制的高数值孔径微透镜阵列制备  

Fabrication of Microlens Arrays with High Numerical Aperture Based on Femtosecond Laser Self-Modulating Processing Method

作　　者：苑欣然 邓景扬 徐地华 孙相超 于颜豪 陈岐岱[2] Yuan Xinran;Deng Jingyang;Xu Dihua;Sun Xiangchao;Yu Yanhao;Chen Qidai(Guangdong Zhengye Technology Co.,Ltd.,Dongguan 523000,Guangdong,China;College of Electronic Science&Engineering,Jilin University,Changchun 130012,Jilin,China)

机构地区：[1]广东正业科技股份有限公司,广东东莞523000 [2]吉林大学电子科学与工程学院,吉林长春130012

出　　处：《光学学报》2023年第16期302-311,共10页Acta Optica Sinica

基　　金：广东省基础与应用基础研究基金(2019B1515120081)。

摘　　要：针对硬质材料高数值孔径(NA)微透镜阵列制备难的问题,提出一种基于像差的自调制激光加工方法。该方法将飞秒激光聚焦于石英衬底的下表面,能够实现对激光焦点的纵向拉伸,结合氢氟酸溶液湿法刻蚀实现了具有高数值孔径微透镜的制备。结果表明,利用该技术通过改变单脉冲能量能够对微透镜形貌进行调控,在此基础上进一步优化离焦位置,有效地增大了微透镜的数值孔径,制备出达到理论极限(NAmax=0.46)的高数值孔径石英微透镜。相对于传统的正面加工方法,所提方法方式不仅提升了微透镜的数值孔径,而且无需复杂的光调制系统,对于高性能硬质材料微透镜阵列的制备与实际应用具有重要的意义。Objective Microlenses and microlens arrays have applications in various fields,which is primarily due to their miniaturization and easy integration.The numerical aperture(NA)is an essential parameter that significantly affects imaging quality.In the field of micro-imaging,one approach to achieve higher imaging quality is manufacturing multiple lenses with different focal lengths within a single plane.Therefore,the efficient fabrication of microlenses and microlens arrays with controllable heights is crucial for enhancing the imaging effect.In 2010,Chen et al.put forward a maskless method for rapidly fabricating microlens arrays on quartz surfaces using femtosecond laser single-spot exposure combined with wet etching.This technique allows for flexible control of size and arrangement by adjusting parameters such as laser pulse energy,etching time,and displacement platform.However,one limitation of this method is that it cannot achieve deep structure due to laser energy loss caused by surface damage.As a result,the aspect ratio of the laser-modified area is small,making it challenging to fabricate microlenses with high NA.To solve this problem,the regular front-side processing method has been improved through multiple exposures in the Z-axis direction,which increases the numerical apertures,but it cannot reach its theoretical maximum.Furthermore,researchers have conducted extensive studies on optical field modulation which have successfully produced quartz microlenses with high numerical apertures that approach the theoretical limit of 0.46.However,it should be noted that these methods rely on precise optical devices and involve complex processes.Methods Microlenses and their arrays are prepared by hydrofluoric acid wet-etching assisted femtosecond laser processing method,and the preparation process is divided into two steps,first using femtosecond laser to modify the material on the bottom surface,and then using 20%hydrofluoric acid for wet etching under 25℃.In the preparation of high aspect ratio modified region

关 键 词：激光技术 飞秒激光加工 高数值孔径 微透镜阵列 熔融石英 

分 类 号：TN249[电子电信—物理电子学]