Probing the Photonic Spin-Orbit Interactions in the Near Field of Nanostructures
Probing the Photonic Spin-Orbit Interactions in the Near Field of Nanostructures
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探测纳米结构近场中的光子自旋轨道相互作用
DOI：
10.1002/adfm.201902286
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发表时间：
2019
影响因子：
19
通讯作者：
Huang Lingling
中科院分区：
文献类型：
--
作者：
Sun Lin;Bai Benfeng;Wang Jia;Zhang Mingqian;Zhang Xiaomeng;Song Xu;Huang Lingling
光子自旋-轨道相互作用(SOI)为功能纳米材料和纳米结构提供了一种新的设计范式，特别是加速了自旋-轨道光子学的发展。作为SOI的一个显著特性，浆果相或几何相在这一过程中起着至关重要的作用。因此，对于光学自旋霍尔效应、自旋-涡旋转换和拉什巴效应等研究来说，光子SOI过程和Berry相的表征是非常必要的。本文提出并实验证明了一种自旋选择性和相分辨的近场微观方法，用于在介观尺度上实时探测和直接显示光子SOI，并实现了光学位相空间演化的三维层析成像技术。通过分析金属亚表面作为自旋到涡旋的转换平台，直接测量并直观地显示了突变的几何相和空间演化的动态相。这项工作为研究近场光学中的自旋-轨道现象提供了有力的工具，并有望直接探索等离子体和光子拓扑绝缘体中与自旋相关的表面态。
Photonic spin–orbit interactions (SOI) provide a new design paradigm of functional nanomaterials and nanostructures, and have especially accelerated advances in spin–orbit photonics. The berry phase or the geometric phase, a salient property of SOI, plays a vital role in this process. Thus, the characterization of photonic SOI processes together with the Berry phase is highly demanded for studies such as the optical spin‐Hall effect, spin‐to‐vortex conversion, and Rashba effect. Here, a spin‐selective and phase‐resolved near‐field microscopic method is proposed and experimentally demonstrated for real‐time probing and direct visualization of photonic SOI at mesoscale, and a 3D tomographic technique for imaging the spatial evolutions of the optical phases is also properly realized. By analyzing a metallic metasurface as a spin‐to‐vortex conversion platform, the abrupt geometric phase and the spatially evolutional dynamic phases are directly measured and intuitively illustrated. This work provides a powerful tool for the study of spin–orbit phenomena in near‐field optics, and can hold the promise for directly exploring the spin‐dependent surface states in plasmonics and photonic topological insulators.