香港城市大学王书波团队近日揭示了基于旋转圆柱的非互易光学超表面。2025年7月17日出版的《物理评论A》杂志发表了这项成果。

打破洛伦兹互易的光学系统由于其有趣的物理性质和应用而引起了广泛的关注。非互易超表面可以实现光的单向传输和反射，在光通信中具有重要的应用。传统的非互易超表面依赖于主题磁光或非线性材料来诱导非互易光学性质。

研究组提出并展示了一种基于运动介质的相对论效应实现非互易超表面的替代机制。超表面由位于介电衬底之上的周期性旋转的介电圆柱体组成。自旋运动打破了时间反演对称性，引起了元原子的双各向异性端列型响应。研究组证明了超表面可以实现入射平面波的非对称和非互反操纵。其潜在的机制归因于与耦合旋转圆柱的手性多极模式相关的Sagnac效应。

通过引入介电柱来调制相位轮廓，超表面可以实现非互易波前操作。该工作提供了一种在自由空间中实现非互反光操纵的机制。所提出的超表面可以作为探索非互易光学、非厄米光学和拓扑光子学等有趣物理的平台。

附：英文原文

Title: Nonreciprocal optical metasurface based on spinning cylinders

Author: Zheng Yang, Wanyue Xiao, Hengzhi Li, Hao Pan, Shubo Wang

Issue&Volume: 2025/07/17

Abstract: Optical systems breaking Lorentz reciprocity have attracted broad attention due to their intriguing physics and applications. Nonreciprocal metasurfaces can enable one-way light transmission and reflection with essential applications in optical communication. Conventional nonreciprocal metasurfaces rely on using magneto-optic or nonlinear materials to induce nonreciprocal optical properties. Here we propose and demonstrate an alternative mechanism for realizing nonreciprocal metasurfaces based on the relativistic effect of a moving medium. The metasurface is composed of periodic spinning dielectric cylinders located above a dielectric substrate. The spinning motion breaks the time-reversal symmetry and induces bi-anisotropic Tellegen-type response of the meta-atoms. We show that the metasurface can realize both asymmetric and nonreciprocal manipulations of the incident plane wave. The underlying mechanism is attributed to the Sagnac effect associated with the chiral multipole modes of the coupled spinning cylinders. By introducing dielectric pillars to modulate the phase profile, the metasurface can enable nonreciprocal wavefront manipulations. Our work offers a mechanism for realizing nonreciprocal light manipulation in free space. The proposed metasurface can serve as a platform to explore the interesting physics of nonreciprocal optics, non-Hermitian optics, and topological photonics.

DOI: 10.1103/w18x-xdyd

Source: https://journals.aps.org/pra/abstract/10.1103/w18x-xdyd