线性交叉超构材料及其应用(特邀)  

Linear-crossing Metamaterials and Their Applications(Invited)

作　　者：郭志伟[1] 江海涛[1] 陈鸿[1] GUO Zhiwei;JIANG Haitao;CHEN Hong(Key Laboratory of Advanced Microstructure Materials Ministry of Education,School of Physics Science and Engineering,Tongji University,Shanghai 200092,China)

机构地区：[1]同济大学物理科学与工程学院,先进微结构材料教育部重点实验室,上海200092

出　　处：《光子学报》2022年第1期186-206,共21页Acta Photonica Sinica

基　　金：国家重点研发计划(No.2016YFA0301101);国家自然科学基金(Nos.12004284,11774261,61621001);上海市自然科学基金(No.18ZR1442900);中国博士后基金(Nos.2019TQ0232,2019M661605)。

摘　　要：操控材料的等频率线可以有效的调控光与物质的相互作用。近年来,基于双曲超构材料的研究表明,等频率线从封闭圆形到开放双曲线的拓扑相变对光的传输和辐射特性有着显著的影响。本文主要综述了一类存在于双曲拓扑转变中的新型各向异性超构材料,其等频率线对应为两条相交的直线,因而被称为线性交叉超构材料。一方面,由于具有开放的等频率面,线性交叉超构材料类似于双曲超构材料,可以支持大波矢模式。另一方面,线性交叉超构材料类似于零折射率超构材料,线性的色散关系使得线性交叉超构材料中传播的电磁波的群速度方向与相速度方向垂直,这将导致电磁波沿着传播路径的零相位累积。本文系统性介绍了线性交叉超构材料的实现、物理特性以及相关重要应用,并在最后对线性交叉超构材料的发展进行了展望。Manipulating the isofrequency curves of materials can effectively improve the interaction between light and matter. In recent years,based on the hyperbolic metamaterials,it has been widely proved that the topological phase transition from closed circle to open hyperbola will strongly affect the light transmission and radiation. In this review,a new type of anisotropic metamaterials,Linear-Crossing Metamaterials(LCMMs),which exist in hyperbolic topological transition is introduced. Because the signs of the in-plane permeabilities are opposite and the permittivity tends to zero,an LCMM may simultaneously possess the characteristics of an hyperbolic medium and a zero-index medium. On one hand,LCMMs support high-k modes just like hyperbolic medium because of the open iso-frequency contours. On the other hand,the linear dispersion relationship of the LCMMs ensures that the group velocity is perpendicular to the phase velocity,which leads to the zero phase accumulation along the propagation path just as in a zero-index medium. In addtion,LCMMs can have many unique properties. For example,considering that the signs of the in-plane permeability can also be tuned,two kinds of LCMMs with positive and negative refractions will be realized. Moreover,the refraction angle of incident light will be locked in two fixed directions that are independent of the incident angles. For a vertical incident beam incident on the LCMM,it will split into two beams just as does the valley-dependent propagation in photonic crystals. Due to the fact that the refracted light is locked in the two fixed directions,the propagation of light will not be affected when we put a defect inside the structure so long as it is not placed in the path of refraction. This property can be utilized for a partial cloaking effect that is robust to the presence of defects. LCMMs can also be used to realize the non-diffraction Bessel beam possessing unique self-healing properties. By mean of directional propagation and negative refraction,a point source instead of t

关 键 词：超构材料 各向异性材料 拓扑转变 高波矢模式 等效介质理论 超分辨成像 

分 类 号：O436[机械工程—光学工程]