基于纳米颗粒的近场光场多分量表征技术  

Mapping the multi-component of near fields using nanoparticles

作　　者：马志远 孟繁斐 杨爱萍 陈志峰[1] MA Zhiyuan;MENG Fanfei;YANG Aiping;CHEN Zhifeng(School of Physics and Materials Science,Guangzhou University,Guangzhou 510006,China;School of Physical Sciences,Great Bay University,Dongguan 523000,China;School of Materials Science and Engineering,Dongguan University of Technology,Dongguan 523808,China)

机构地区：[1]广州大学物理与材料科学学院,广东广州510006 [2]大湾区大学(筹)物质科学学院,广东东莞523000 [3]东莞理工学院材料科学与工程学院,广东东莞523808

出　　处：《光学仪器》2024年第6期9-24,共16页Optical Instruments

基　　金：国家自然科学基金青年项目(62205217);深圳市基础研究项目面上项目(JCYJ20220531103403008);广东省自然科学基金面上项目(2023A1515012670,2020A1515010411);广州市科技计划基础研究计划项目(2023A03J0125)。

摘　　要：近场光学主要探索光波长以内的近场区域的光学现象,是一门研究光与物质在纳米尺度相互作用的学科。近场光场区域内会产生如自旋轨道耦合等诸多独特的物理现象,是光学领域的研究热点,对其进行精确的表征有助于相关物理现象的探究。然而,近场光场较强的束缚性和复杂的矢量性使近场光学表征技术成为该领域研究的难点和热点。典型的近场扫描光学显微技术采用近场探针探入到近场区域从而收集近场光信息,可以在一定程度上解决束缚性的问题。但是其复杂的矢量性需要设计独特的近场探针来实现不同光场分量的探测,相应的探针也需要纳米尺度的结构设计和昂贵复杂的半导体微纳加工工艺作为保证。本文着重介绍关于利用纳米颗粒作为近场探针的新型近场光场多分量表征技术的一系列工作。纳米颗粒是圆对称结构,理论上可以响应所有近场分量。依据米散射理论可以通过对颗粒材质、尺寸的设计,表征所需近场分量,包括面内、面外的光频电场、磁场等分量,并且通过对这些分量的精确测量,还可以对近场区域内自旋分量、轨道自旋耦合、光学拓扑结构等进行精确地表征。该类方法使用的近场探针易于制造,具有低成本、无需复杂控制系统等优势,为近场光学的研究提供了一种高效的表征手段。Near-field optics primarily investigates optical phenomena that occur in the near-field region,defined as being within the wavelength of light.This discipline explores the interaction between light and matter at the nanoscale.Unique physical phenomena,such as spin-orbit coupling,emerge in this region,making it a significant area of research in optics.Accurate characterization of these phenomena is crucial for further exploration.However,challenges arise due to the strong confinement and the complex vector nature of near fields.Traditional near-field scanning optical microscopy employs a near-field probe to access this region and collect information about nearfield light.While this approach partially addresses the confinement issue,the intricate vector nature of the near fields necessitates specially designed probes to detect various components of near fields.These probes require nanoscale structural designs and complex,expensive semiconductor fabrication processes.This paper focuses on a series of studies utilizing nanoparticles as near-field probes for multi-component characterization of optical near fields.Being spherically symmetric structures,nanoparticles can theoretically respond to all near-field components.Mie scattering theory enables us to characterize the desired near-field components,including in-plane and out-ofplane electric and magnetic fields,by choosing appropriate materials and sizes for the particles.Furthermore,precise measurements of these components allow for accurate characterization of spin components,orbital-spin coupling,and optical topological structures in the near-field region.The probes developed in this approach are easy to fabricate,cost-effective,and do not require complex control systems,providing an efficient method for research in near-field optics.

关 键 词：近场光学 米散射 纳米颗粒 紧聚焦 表面等离激元 近场光学显微镜 

分 类 号：O436.2[机械工程—光学工程] TH742[理学—光学]