近日，华中科技大学的王健及其研究团队取得一项新进展。他们对三维倏逝场耦合产生的光自旋和手性进行了研究。相关研究成果已于2024年12月11日在国际知名学术期刊《物理评论A》上发表。

据悉，光自旋和手性在光子发射和光与物质相互作用的设计中起着关键作用。

本研究表明，通过强限制波导实现的三维倏逝波导模式耦合，可以外在地产生光自旋和手性。这些新兴的光学特性本质上源于两个耦合模式之间固有的π/2相位延迟。对于一个具有2×2输入端口的方向耦合器来说，所产生的光自旋和手性分别具有侧锁定和路径锁定的固有特征。

研究人员通过数值模拟证明，这些光自旋和手性可以普遍通过高阶模式耦合和其他结构波导产生。光波导中的这些新特性，可能为开发近场光子自旋和片上手性光与物质相互作用开辟新途径。

附：英文原文

Title: Emerging optical spin and chirality by three-dimensional evanescent field coupling

Author: Liang Fang, Jian Wang

Issue&Volume: 2024/12/11

Abstract: Optical spin and chirality play key roles in engineering photonic emission and light-matter interactions. Here we show that three-dimensional evanescent coupling of guided modes by strongly confined waveguides can extrinsically produce optical spin and chirality. These emerging optical quantities are essentially derived from an intrinsic phase retardation of π/2 between two coupled modes. For a directional coupler with 2 × 2 input ports, the produced optical spin and chirality are inherently characterized by the side-locked and path-locked phenomena, respectively. We numerically demonstrate that these optical spins and chiralities can be ubiquitously produced by higher-order mode coupling and other structural waveguides. These new quantities in optical waveguides may pave the way to exploit near-field photonic spin and on-chip chiral light-matter interactions.

DOI: 10.1103/PhysRevA.110.063514

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.110.063514