全介质超周期光栅太赫兹波段宽带完美反射器设计  

Design of an all-dielectric ultra-period grating terahertz broadband perfect reflector

作　　者：谢靖文 井绪峰 XIE Jing-wen;JING Xu-feng(Institute of Optoelectronic Technology,China Jiliang University,Hangzhou 310018,China)

机构地区：[1]光学与电子科技学院中国计量大学

出　　处：《光电子．激光》2019年第4期365-375,共11页Journal of Optoelectronics·Laser

基　　金：浙江省自然科学基金(LY17F050009);国家自然科学基金(61405182,61308090);留学人员择优资助人才项目资助的课题资助项目

摘　　要：提出一种超周期全介质光栅结构,该类结构在单个周期内具有多个不同宽度亚单元光栅条,基于优化超周期单元结构的占空比、高度以及光栅条宽度等几何参数,实现太赫兹波段(1.2-2.0THz)宽带完美反射特性。利用S-参数反演算法,有效提取亚波长超周期全介质光栅结构的等效参数,包括等效折射率、等效介电常数、等效磁导率以及等效阻抗。分析超周期光栅结构等效参数,结合完美反射条件,证实该类光栅结构的宽带完美反射特性。基于矢量全波计算方法,数值模拟超周期光栅结构的电磁场分布,揭示其宽带太赫兹波完美反射Mie氏谐振特性和电磁耦合特性。In this paper,we propose a ultra-period all-dielectric grating metamaterial structure. This structure has multiple sub-cell structure in a single big period. By optimizing the structure parameters of the super period grating structure, such as the duty cycle, height and the width of the grating strip, the broadband perfect reflection is achieved with the bandwidth of 1. 2 - 2.0 THz. Through the S-parameter inversion algorithm,the equivalent parameters of the sub-wavelength superperiodic all-dielectric grating structure are extracted? including equivalent refractive index, equivalent permittivity, equivalent magnetic permeability and equivalent impedance. By analyzing the equivalent parameters and combining the perfect reflection conditions, the perfect reflection characteristics of the super period grating structure proposed in this paper are confirmed. Based on the full-wave vector numerical simulation method,the electromagnetic field di stribution characteristics of the super period grating structure are calculated, and the Mie resonance characteristics and electromagnetic coupling characteristics of the broadband terahertz perfect reflection super-period grating structure are analyzed.

关 键 词：亚波长光栅 全介质 太赫兹波段 反射器 

分 类 号：O436[机械工程—光学工程]