“π”型双频负折射率超材料  

A “π-shaped”metamaterial with dual-band negative refraction index

作　　者：陈怀军 赵文霞 宋坤[2] CHEN Huai-jun;ZHAO Wen-xia;SONG Kun(College of Physics and Electronic Information Engineering,Engineering Research Center of Nanostructure and Functional Materials,Ningxia Normal University,Guyuan 756000,Ningxia,China;School of Natural and Applied Sciences,Northwestern Polytechnical University,Xi'an 710072,Shaanxi,China)

机构地区：[1]宁夏师范学院物理与电子信息工程学院,纳米结构及功能材料工程技术研究中心,宁夏固原756000 [2]西北工业大学理学院,陕西西安710072

出　　处：《西北师范大学学报（自然科学版）》2018年第2期49-53,共5页Journal of Northwest Normal University(Natural Science)

基　　金：国家自然科学基金资助项目(11764033,21561027,61601375);宁夏自治区自然科学基金资助项目(NZ17253);宁夏高等学校科学研究项目(NGY2016173);宁夏师范学院2017年本科教学工程资助项目

摘　　要：基于有效媒质理论,设计了一种"π"型光频段电磁超材料.仿真结果表明,这种超材料能够在550.4THz和577.8THz 2个频率附近产生谐振,并且在谐振频率附近样品的介电常数和磁导率同时为负值;通过将"π"型单元排列成楔形结构,验证了电磁超材料的负折射性能;进一步的研究证实,这种超材料的电磁响应与前后"π"型结构之间的旋转角度密切相关.另外,这种"π"型电磁超材料具有较低的能量损耗,弥补了其他渔网结构损耗高的缺陷,同时也为设计可见光频段的多频电磁超材料提供了一种新模型.In this paper,a kind ofπ-shaped visible electromagnetic metamaterial on the basis of effective medium theory is designed.The simulated results demonstrate that the proposed metamaterial can generate resonances around 550.4 THz and 577.8 THz,with the permittivity and permeability being negative simultaneously.The negative refraction performance of the metamaterial is confirmed by using a wedge-shaped array composed ofπ-shaped unit cells.Further simulations reveal that the electromagnetic responses of the proposed metamaterial are closely related with the twist angle between the front and backπ-shaped patterns.This kind ofπ-shaped metamaterial exhibits low loss feature,which overcomes the drawback of high losses existing in some other fishnet metamaterials and also provides a new model for designing multiband visible electromagnetic metamaterials.

关 键 词：负介电常数 负磁导率 负折射 多频带 电磁超材料 

分 类 号：O0429[理学]