二维芯壳异质结构光子晶体禁带特性分析

Two-dimensional photonic band-gap of photonic crystals with core-shell type heterostructures

研究了一种新的二维芯壳型异质结构光子晶体,即介质纳米柱外被覆盖一薄层材料.针对正方排列及三角排列两种方式,利用平面波方法,比较了在折射率为2的介质纳米柱外表面涂覆折射率为3.5的薄层后,其能带曲线的变化,发现光子晶体的禁带明显变宽,且三角排列比正方排列更易形成较宽的光子禁带.

A new type of two-dimensional photonic crystal called core-shell type photonic crystals such that a dielectric nanorod is covered by a thin interfacial layer are studied.Using the plane-wave numerical expansion method,the paper studies the modification of the band gap spectrum when the nanorods with refractive index 2 are covered by a thin interfacial layer with refractive index 3.5,and reveals that the photonic band gap is considerably enhanced in size for both square and triangular lattices.Also,band gaps are more favored in a triangular lattice than in a square lattice.