基于柱矢量光调控的纵向超分辨率准球形多焦点阵列  

Longitudinal super-resolution spherical multi-focus array based on column vector light modulation

作　　者：夏小兰 曾宪智 宋世超 刘小威 曹耀宇 Xia Xiaolan;Zeng Xianzhi;Song Shichao;Liu Xiaowei;Cao Yaoyu(Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications,Institute of Photonics Technology,Jinan University,Guangzhou,Guangdong 511443,China;Research Center for Humanoid Sensing,Zhejiang Lab,Hangzhou,Zhejiang 311121,China)

机构地区：[1]暨南大学光子技术研究院,广东省光纤传感与通信技术重点实验室,广东广州511443 [2]类人感知研究中心,之江实验室,浙江杭州311121

出　　处：《光电工程》2022年第11期44-53,共10页Opto-Electronic Engineering

基　　金：国家自然科学基金资助项目(61875073,61605061,61905097);广东省创新创业项目(2016ZT06D081);浙江省之江实验室(2020MC0AE01)。

摘　　要：激光多焦点阵列以兼具更高的光场操控自由度和焦斑单元高空间分辨率的特点,被广泛应用在光学诱捕以及飞秒激光微纳制造等领域。然而由于阵列中焦斑的纵向分辨率弱于横向分辨率,在激光加工应用中限制了其对各向同性结构的加工能力。因此,本文提出一种基于柱矢量光调控生成纵向超分辨准球形多焦点阵列的方法。利用对柱矢量光的两组基径向偏振光和角向偏振光分别进行聚焦调控,结合环形衰减调制可形成纵向超分辨焦斑,再将两种偏振光场以适当的振幅比例在焦区叠加,从而合成准球形多焦点阵列。实验结果表明,10×10的多焦点阵列中各焦斑尺寸均一,具有近球形光强分布。其中,阵列中所有焦点的纵向半高全宽的平均值为0.76λ、标准差为0.005λ,横向半高全宽的平均值为0.76λ、标准差为0.019λ。该具有高尺寸均一性的准球形多焦点阵列可为激光微纳加工精准制备微纳器件提供新的途径。Featured by the capability of multi degree-of-freedom light-field manipulations while reserving high spatial resolution,multifocal laser arrays have been widely applied in femtosecond laser micro/nanofabrication,optical trapping,and so forth.Yet,due to the relatively lower axial resolution of single focuses within the array in comparison with the lateral resolution of their own,multifocal laser array has been refrained from isotropic 3D nanofabrication.Herein,we propose a feasible method for generation of axially super-resolved multifocal array with quasi-spherical focal spots.In particular,quasi-spherical multifocal array is optically synthesized via precise modulation on the coherent superposition of the orthogonal radially polarized beam(RPB)and azimuthally polarized beam(APB)states in the focal region based on annular amplitude modulation.We show theoretically the generation of quasi-spherical multifocal array with a high uniformity up to 99%.The average axial and lateral fullwidth-half maximum(FWHM)of the focal array are measured to be 0.76λwith the standard deviations in the axial and lateral directions being 0.005λand 0.019λ,respectively.The presented strategy for synthesis of quasi-spherical multifocal array with high uniformity paves the way for high-precision laser fabrication of 3D micro/nano devices.

关 键 词：柱矢量光 球形多焦点 纵向超分辨率 光场调控 

分 类 号：O436.3[机械工程—光学工程]