单负色散材料光子晶体的带隙特性研究

Bandgap Characteristics of One-dimensional Photonic Crystals with Single-negative Dispersive Material

针对单负色散材料构成的光子晶体的带隙特性进行了详细地研究。首先采用传输矩阵法分析计算了该结构的带隙产生与材料介电常数、磁导率色散特性间的关系,然后计算了带隙宽度和中心频率受入射场极化方式、入射方向、介质材料厚度比例缩放和厚度无序的影响程度,最后分析并对比了单负色散材料和普通材料构成的渐变周期光子晶体的传输特性。结果证明单负色散材料可以在光子晶体中引入一种受结构参数影响很小的带隙,同时和普通材料相比,在渐变周期结构中可以有效地拓宽Bragg带隙宽度,改善传输特性。

Bandgap characteristics of one-dimension photonic crystal composed with two types of singlenegative materials are investigated in detail. First, by means of Transfer Matrix Method （TMM）, the relationships between the bandgap and the dispersive properties of permittivity and permeability is studied. Then, we analyze how the central frequency and forbidden bandwidth are affected by polarization mode, incidence angle, thickness scaling and disorder. Finally, three types of gradual periodic structure, which are composed positive or negative refractive index materials, are compared. It is found that, if the permittivity or the permeability is zero, the photonic crystal composed with single-negative dispersive materials can possess a new type of bandgap which is not sensitive to variety of structural parameters. Futhurmore, using this material, we could get better translation characteristic than traditional material in gradual periodic structure.