用紧束缚方法描述光子晶体缺陷耦合的共振频率移动  

Resonant frequency shift in coupled photonic crystal defects described by the tight-binding method

作　　者：蔡旭红[1] 林旭升[1] 石全[1] 赵年顺[1] 

机构地区：[1]汕头大学物理系,汕头515063

出　　处：《物理学报》2007年第5期2742-2746,共5页Acta Physica Sinica

摘　　要：通常采用含两个耦合参数的紧束缚近似,就能很好地描述光子晶体缺陷因耦合而导致的共振频率分裂.然而,缺陷耦合造成的共振频率移动,即包含奇数个缺陷的耦合系统的中央共振频率位置与原来单缺陷时的共振频率位置存在差异,则只有采用含三个耦合参数的严格紧束缚方法才能正确描述.根据耦合参数与共振频率的关系,利用三缺陷耦合系统的模拟计算结果确定了三个耦合参数的具体值,从而在理论上能够预言由任意个缺陷构成的耦合系统的共振频率的移动和分裂.理论预言与基于有限时域差分法的数值计算完全相符.The resonant frequency splitting caused by photonic crystal （PC） defect coupling can be well described by the tight-binding （TB） approximation in which only two coupling parameters are used. However, the description of the resonant frequency shift that represents the difference between the center resonant frequency of the coupled structure containing odd number of defects and the resonant frequency of a single defect, requires the employment of the rigorous TB that involves three coupling parameters. By using the relation between the coupling parameters and the resonant frequencies, we extract the values of the three coupling parameters from the simulation of a three-coupled-defect structure and use them to predict the resonant frequency shift and splitting of the coupled structures consisting of arbitrary number of PC defects. They are in good agreement with the simulation results based on the finite-difference time-domain method.

关 键 词：光子晶体缺陷耦合 紧束缚方法 共振频率分裂 共振频率移动 

分 类 号：O77[理学—晶体学]