论文标题
通过非热掺杂来控制跨境的不对称吸收
Controlling asymmetric absorption of metasurfaces via non-Hermitian doping
论文作者
论文摘要
基于亚波长的谐振器的元曲面可实现在光学接口处操纵光流的新方法。为了追求多功能或可重构的MetadeVices，对宏观性能的有效调整几乎没有结构/材料变化仍然是一个挑战。在这里，我们提出了在元信息中掺杂的非富集掺杂的概念，这表明可以通过在局部区域引入吸收缺陷来切换普通的逆转录器。不对称的吸收性能始于冬宫状态下的零，在非铁毒液掺杂下逐渐增加，并在特殊点达到最大统一性。通过观察不对称的近场分布和远场散射特性以及从平面跨表面，在微波频率上进行了实验证明这种效果。此外，在常规逆流器中导入局部增益成分，但可以调整为极不对称的一侧放大器，并将单向扩增从一维波指导扩展到二维散射系统。所提出的方法为工程电磁MetadeVices和具有少量扰动的系统提供了替代途径。介绍
Metasurfaces based on subwavelength resonators enable novel ways to manipulate the flow of light at optical interfaces. In pursuit of multifunctional or reconfigurable metadevices, efficient tuning of macroscopic performance with little structural/material variation remains a challenge. Here, we put forward the concept of non-Hermitian doping in metasurfaces, showing that an ordinary retroreflector can be switched to asymmetric one by introducing absorptive defects in local regions. The asymmetric absorption performance begins with zero at the Hermitian state, gradually increases under non-Hermitian doping, and reaches the maximum of unity at the exceptional point. This effect is experimentally demonstrated at microwave frequencies via the observation of asymmetric near-field distribution and far-field scattering properties and from a planar metasurface. Furthermore, while importing local gain constituents in conventional retroreflector, it can be tuned to an extremely asymmetric one-side amplifier, extending unidirectional amplification from one-dimensional waveguide to two-dimensional scattering systems. The proposed methodology provides an alternative pathway for engineering electromagnetic metadevices and systems with small perturbations. Introduction
