手性介质-金属核壳结构及其壳层厚度对光力的影响  

Effect of Chiral Media-Metal Core-Shell Structure and Its Shell Thickness on Optical Forces

作　　者：周芳 张明富 程晓迪 郑雅君 王小云[1] 黄勇刚[1] hou Fang;Zhang Mingfu;Cheng Xiaodi;Zheng Yajun;Wang Xiaoyun;Huang Yonggang(College of Physics and Electromechanical Engineering,Jishou University,Jishou 416000,Hunan,China)

机构地区：[1]吉首大学物理与机电工程学院,湖南吉首416000

出　　处：《光学学报》2024年第13期206-212,共7页Acta Optica Sinica

基　　金：国家自然科学基金(11964010);湖南省自然科学基金(2020JJ4495);湖南省教育厅重点项目(22A0377,21A0333);吉首大学研究生科研创新项目(Jdy22047)。

摘　　要：基于手性介质与银的等离激元共振效应,利用手性介质-银核壳结构,采用线偏振光,应用麦克斯韦应力张量法模拟计算了该结构的光响应及光力特性,特别考虑了银壳层厚度及手性参数对其散射光谱和光力的影响。研究表明,与纯手性球相比,银包覆手性球能够增强手性球的光学响应,调节其共振峰的位置。随着银壳厚度的增加,散射光谱共振峰及其对应模式处光力蓝移,共振峰的半峰全宽变宽,光扭矩迅速减小,当壳层厚度增加到一定程度时,核壳结构的光学性质与纯银球一致。当手性参数不同时,银包覆层对手性球的光响应与光力调节效果不同,但银壳厚度较薄时银包覆手性球能有效增强光力,银壳厚度较厚时银包覆手性球表现出与纯银球一样的光学性质。Objective The optical response of natural chiral substances is usually very weak, necessitating the enhancement of the chiral optical response. Surface plasmon polaritons, collective oscillations of free electrons on metal surfaces interacting with incident light, possess the ability to surpass the diffraction limit and subwavelength constraints and are widely employed to miniaturize opto-electronic devices and to enhance light-matter interactions. In recent years, more and more studies have begun to focus on leveraging surface plasmon polaritons to enhance the optical response of chiral substances.While optical operation for chiral particles has garnered significant attention, the properties of optical operation for chiral media-metal core-shell structures remain unclear. On the one hand, the intricate relationship between the interaction of the core shell and the metal shell of chiral media and the shell thickness necessitates in-depth investigation. On the other hand,it is not clear how the shell thickness affects the optical response and optical force of the core-shell structure. This paper focuses on the modulation properties of the chiral medium/Ag core-shell structure and its shell thickness in terms of chiral sphere optical response and optical force.Methods Based on the plasma resonance effect of chiral media and silver, the optical response and optical force characteristics of the chiral media-Ag core-shell structure are simulated and calculated by applying Maxwell's stress tensor method using linearly polarised light. Special attention is devoted to investigating the influence of the silver shell thickness and chiral parameter on the scattering spectrum and optical force.Results and Discussions Coating silver shells outside the chiral spheres can effectively enhance the optical response(Fig. 2) and optical force(Fig. 3) of the chiral spheres. Moreover, the electric dipole resonance peak of the core-shell structure is blueshifted and the full width at half-maximum becomes wider as the thickness of the A

关 键 词：壳层厚度 手性介质 核壳结构 光力 

分 类 号：O439[机械工程—光学工程]