一维光子晶体中多缺陷耦合导致的杂质带

利用传输矩阵方法研究了包含多个周期性分布的缺陷的一维光子晶体的透射谱.以33个周期的1/4波堆存在5个缺陷的光子晶体为例作了数值计算.结果表明,在周期性光子晶体中加入多个缺陷时,将在截止带中产生多个缺陷模.这些缺陷模构成的杂质能带依赖于缺陷在晶体中的分布.当缺陷密集时,缺陷模耦合较强,杂质带中透射峰相距较远,它们对应禁带中许多分立定域的杂质能级;当缺陷稀疏时,缺陷模耦合较弱,透射峰相距较近,分立的杂质能级趋于简并,由此形成一个很窄的通带.

The Impurity Band Based-on Defects Coupled in One-dimensional Photonic Crystal

The transmission through one dimensional photonic crystal with a number of defects are studied by using transfer matrix method. Quarter wave stack photonic crystal of 33 periods with five half wave defects is taken as an example for numerical calculation. When some defects are put into the periodic photonic crystal of quarter wave, a number of defects modes appear in the stop band. These defect modes form an impurity band. It is found that the impurity band depends on the distribution of these defects in the photonic crystal. When the separation of the defects is small, the defect modes are coupled each other strongly, which results in wide separated transmission peaks. When the separation of the defects is large, the transmission peaks tend to close to each other and a narrow pass band is formed.