含有多缺陷的光子晶体中的局域缺陷模

Local defect modes in photonic crystals with a number of structural defects

采用紧束缚法,研究含有缺陷的光子晶体中的缺陷模,导出了缺陷模频率方程。作为特例,采用转移矩阵法,数值计算了含有三个缺陷的一维光子晶体的透射谱和与光子带隙中缺陷模频率对应的光场强度分布,讨论了缺陷间的相互作用对缺陷模的影响。结果表明:当光通过含有多个半波缺陷的光子晶体时,在透射谱的禁带中出现缺陷模,缺陷模的数目与半波缺陷数目相同,而缺陷模频率的间隔随着半波缺陷间隔层数的增加而减小,最后形成一个缺陷模通带;与缺陷模频率对应的光场分布为局域状态,并发现局域光场峰值出现在缺陷邻近层。

Local defect modes in photonic crystals with structural defects is investigated. Using the tight - binding method, we obtain an equation for the local modes in photonic crystals with many structural defects. Using the transfer - matrix - method simulation, we observe the degeneracy and split of defect mode frequency in certain conditions and light field intensity distribution of the defect modes frequency. The result shows that there exist defect modes in the transmissivity spectrum, the number of which is number of defect and the interval between , equal to the layers frequency two neighboring defect modes decreases with the increasing of the layer s numbers between neighboring defect layers, finally a defect - mode - band is formed .There are local states for the light field intensity distribution of the defect modes, and we find a novel phenomenon that the amplitude of the local states occurs in the neighboring layers of defect layers.