超宽带隙一维光子晶体的设计与优化

Design and optimization of one-dimensional photonic crystal containing super-broad bandgap with defect structure

一维光子晶体结构简单,不难制备,成本低廉,有一定的研发应用潜力。为了获得在可见光频段内具有超宽带隙的一维光子晶体,以Al2O3和TiO2为组分材料,将缺陷结构光子晶体与周期结构光子晶体进行组合,研究含有缺陷结构一维光子晶体(多层膜)的带隙性能。结果表明:在周期性一维光子晶体结构中插入缺陷层,带隙中出现缺陷模态的同时,原来的光子能带的区域宽度也随着增宽,利用这一性质,可将周期结构与含缺陷的结构组合成"异质结构",利用周期结构的带隙来补偿缺陷层引起的缺陷模,从而实现带隙的增宽。此外,对"异质结构"进行了优化,结果表明,优化可以大大减少总层数、简化结构,但基本不影响展宽的光子带隙性能。

Aiming at prepare one-diamensional photonic crystal containing super-broad bandgap with defect structure, the one-dimensional photonic crystals, consisting of two kinds of oxide films, A1203 and TiO2, have been investigated. It is found that the photonic bandgaps can be greatly broadened using hetero-structure that containing defect layers. The defect-mode range within the bandgap caused by the defect layers can be compensated for by the photonie bandgap of a superposed photonic crystal that has a perfectly periodic structure. Thus, a broad bandgap is obtained. Broadened omni-directional bandgaps can also be realized by this method. In order to reduce the total number of layers of the betero-structures, optimization of the structures has been carried out.