利用基于自动复形技术的二维光子晶体模型设计宽角度宽波长偏振分束器

基于自动复形技术，在148—152μm的近红外波段设计了可以实现全角度偏振分束（TM模透过，TE模反射）的波状膜层二维光子晶体结构.从能带角度解释了全角度偏振分束的原理.波状膜层倾角θ和a-Si单层膜厚T分别可以在38°—49°和014—015μm的范围内变动，不影响全角度的偏振特性.对波状膜层进行了变形，针对波长128—1 31μm设计了宽角度偏振分束的箭羽型二维光子晶体结构.对比两种结构的能带，阐明了二 维光子晶体偏振分束器光线入射角范围的拓宽与能带结构变化的关系.能带计算全部采用平 面波展开算法. 关键词： 偏振分束 平面波展开 完全禁带

Design of wide-angle and broad-band two-dimensional photonic crystal polarization splitter by the automatic shaping mechanism

Based on the mechanism of automatic shaping, the corrugated multilayer films of two_dimensional (2D) phtonic crystal is designed.This structure realizes omnidirectional polarization splitting with TM mode passing window between λ＝148 and 152μm, which is the complete band gap of TE mode. The variable rang es of the slope angle of the layers and the width of a-Si single layer are 38° —49° and 014—015μm, respectively. Band structure has been used to expl ain the omnidirectional polarization effect. An arrow-end_like 2D photonic cryst al which is the deformation of the corrugated multilayer films is introduced for comparison. It can only work as a wide-angle polarization splitter not as an o mnidirectional one for wavelength from 128 to 131μm. The comparison of th e band structures of these two different 2D photonic crystals leads to the metho d of extending the incident angle of polarization splitter.