矩形缺陷光子晶体太赫兹波波导的慢波特性

Slow-wave characteristics of photonic crystal defect waveguide with rectangular holes in THz wave domain

设计了一种工作于太赫兹波段的矩形孔缺陷光子晶体慢波波导。首先分析三角空气孔型光子晶体的带隙特性,引入线缺陷形成波导,并将邻近缺陷空气孔设为矩形,通过分析矩形孔尺寸对波导的带隙结构、群速度的影响,确定孔尺寸;研究缺陷宽度对缺陷模式的影响,并通过优化将缺陷模式频率移到目标频率338 GHz处,最终在布里渊边界处实现了c0/1543(c0=3×108m/s)的低群速度,证明了矩形缺陷光子晶体太赫兹波导良好的慢波特性。

A kind of photonic crystal defect waveguide with rectangular holes which works in the terahertz domain is designed. Firstly, the band-gap property of the triangular air hole photonic crystal is analyzed. A line defect is intro- duced into the photonic crystal to form the waveguide. The air holes adjacent the defect are set as rectangle. The effect of the rectangular holes size on the band gap and the group velocity of the waveguide is analyzed and the holes size is obtained. The effect of the width of band gap on the defect mode is also studied. Then the defect mode frequency is moved to the target frequency 338 GHz by optimizing. A low group velocity of c0/1543 （Co =3 × l0^8 m/s） at the Bril- louin boundary is realized by using the photonic crystal defect THz waveguide with rectangular holes. Then its good slow-wave characteristic is 13roved.