计算了由正负折射率材料交替生长形成的半无限一维光子晶体的反射率,发现在带隙中,反射率等于1,在通带内,半无限结构的反射率是有限层结构迅速振荡的反射率平均的结果.当该结构中正负折射率材料的光学厚度相互抵消时,会出现零平均折射率能隙.解析地证明了该结构零平均折射率附近的能隙几乎不随入射角度和偏振情况变化,而且跟晶格常数的标度无关.
The reflection on the semi-infinite periodic one-dimensional photonic crystal composed of alternate layers of ordinary material and negative refraction material is investigated.We find that the reflectivity is exactly equal to 1 in the forbidden frequency gap,and in the pass band,it averages out the rapid fluctuation of reflection of the finite structure.When the optical thickness of both ordinary material and negative refraction material are in opposite sign,there will be a zero-[AKn-D] band gap.We analytically prove that the zero-[AKn-D] band gap is insensitive to incident angle and polarization.It is also anticipated that the zero-[AKn-D] band gap is invariant with the scaling of lattice constant.