二维正方晶格各向异性光子晶体缺陷模  

Study of Defect Modes in Two-dimensional Square Photonic Crystal Consisting of Anisotropic Cylinders

作　　者：余建立[1,2] 沈虹君[2] 

机构地区：[1]安徽省巢湖学院物理系,安徽巢湖238000 [2]宁夏大学物理系,宁夏银川750021

出　　处：《发光学报》2009年第1期25-30,共6页Chinese Journal of Luminescence

基　　金：安徽省巢湖学院科学研究基金资助项目(XLY200814)

摘　　要：为了得到对TM和TE模具有相同缺陷模的共振微腔,通过在完整各向异性碲介质柱二维正方光子晶体中,引入各向同性的介质圆柱作为点缺陷,利用超胞平面波展开法计算该光子晶体的缺陷模,系统计算了在同时改变点缺陷介质柱介电常数和半径两种情况下的两种偏振缺陷模的变化规律。结果表明,在完全禁带中,缺陷介质柱介电常数从5.44变化到38.44、半径与晶格常数的比从0.05变化到0.50的整个区域,均会出现对TM和TE模具有相同缺陷模,且随着介电常数的减小,缺陷模随着缺陷半径的变化趋于缓慢,归一化共振频率在0.2418～0.2432之间可调,在引入εe<εo的各向异性介质柱缺陷时,亦可得到对TM和TE模具有相同缺陷模,且共振频率的可调范围增大,该研究为光子晶体器件的设计提供了理论依据。Photonic crystals are new manual microstructure materials with periodic refractive indices distribution. They have photonic band-gaps analogous to the electronic band-gaps in semiconductors. If the frequencies of electromagnetic waves are within the photonic band-gaps, they cannot propagate in the photonic crystals. In recent years, a lot of theories and experiments on the application of photonic crystals have been studied. The electromagnetic wave in two dimensions can be separated into two polarized modes, namely TM and TE. In this paper, a resonant micro-cavity is designed by introducing isotropic cylinder in a two-dimensional square photonic crystal consisting of anisotropic tellurium cylinder. The micro-cavity can drop TM and TE two polarized modes synchronously. The defect mode is calculated using supercell plane-wave expansion method. The characteristics of defect modes have been calculated systematically when the defect cylinder varies with the defect dielectric constant and radius. The result shows that the same defect modes of TM and TE appear in the absolute band-gap with the variation of defect dielectric constant from 5.44 to 38.44 and the rate of radius and lattices constant from 0.05 to 0.5. When the dielectric constant decreases, the defect modes change slowly with the variation of the radius. The normalized resonating frequency of defect modes can be adjusted between 0. 241 8 and 0. 243 2. The same defect modes of TM and TE also appear in the absolute band-gap when the anisotropic cylinder with the dielectric constant εe greater than εo （εe 〈 εo ） is introduced. The resonating frequency can be adjusted on a larger scale. This research provides theoretical support for the design of photonic crystal components.

关 键 词：光子晶体 各向异性 缺陷模 平面波展开法 

分 类 号：O431[机械工程—光学工程]