红外宽带圆偏振探测全介质手性超构表面设计  

Design of Infrared Broadband All-Dielectric Chiral Metasurface for Circular Polarization Detection

作　　者：常卫杰 林晓晖 李晋平 黄峰 徐圣瑶 Chang Weijie;Lin Xiaohui;Li Jinping;Huang Feng;Xu Shengyao(School of Mechanical Engineering and Automation,Fuzhou University,Fuzhou 350116,Fujian,China;Key Laboratory of Luminescence Science and Technology,Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,Jilin,China)

机构地区：[1]福州大学机械工程及自动化学院,福建福州350116 [2]中国科学院长春光学精密机械与物理研究所特种发光科学与技术重点实验室,吉林长春130033

出　　处：《光学学报》2024年第23期245-251,共7页Acta Optica Sinica

基　　金：国家自然科学基金(62205064,62304225);福建省自然科学基金(2023J05095,2022J01230024)。

摘　　要：针对偏振探测手性超构表面难以实现大带宽、高圆二色性和高消光比的设计挑战,利用粒子群算法设计出一种硅基全介质二维手性超构表面。仿真结果表明,该器件在1416~1742 nm的工作波段内可作为左旋圆偏振光的二分之一波片并阻挡右旋圆偏振光的透射,平均圆二色性值为0.72且最大值达0.94,消光比达42 dB,透射率达95%,同时实现了高透过率、高圆二色性以及大带宽,且具有易制造、易集成等优点。Objective Chiral-effect-based metasurfaces provide a new solution for the design of circular polarized light(CPL)detectors due to their high design flexibility and compact structure.However,the design of polarization-sensitive chiral metasurfaces still faces challenges in high bandwidth,high circular dichroism(CD),and high extinction ratios.To further enhance the extinction ratio performance of infrared circular polarization detectors and achieve higher CD and extinctionratios over a wide bandwidth, we propose a silicon-based two-dimensional chiral metasurface for circular polarizationdetection, thereby promoting the practical application of circular polarization detection.Methods We design and propose a high-performance, broadband all-dielectric two-dimensional chiral metasurface forcircular polarization detection, thus achieving high bandwidth, high CD, and high transmittance. Firstly, a chiral metaatomwith a high degree of freedom is introduced, composed of a lateral rectangle and two pairs of center-symmetrictrapezoids, one large and one small (trapezoid ① and trapezoid ②). Subsequently, based on the finite-difference timedomainmethod, an optimization objective function targeting high CD is established. Meanwhile, a chaotic particle swarmoptimization algorithm is employed to conduct a global search in high-dimensional space, ultimately leading to a highperformancechiral metasurface for circular polarization detection.Results and Discussions The designed infrared broadband chiral metasurface enables efficient transmission of left-handedcircularly polarized (LCP) incident light, achieving maximum transmittance of 95%. After passing through the chiralmetasurface, the polarization state of LCP light is converted to right-handed circularly polarized (RCP) light, withextinction effects on RCP incident light shown (Figs. 2 and 3). When LCP light is incident, the device demonstrates hightransmittance characteristics due to strong coupling effects and localized field enhancement between the LCP light and themetasu

关 键 词：超构表面 偏振探测 圆二色性 消光比 圆偏振 

分 类 号：O436[机械工程—光学工程]