平板光子晶体微腔缺陷模的计算

Computation of Defect Modes in a Photonic Crystal Slab Cavity

采用时域有限差分方法结合群论知识,得到平板光子晶体微腔的缺陷模分布.采用对称化边界条件,首先通过宽频脉冲求解微腔所具有的缺陷频率,其次,对于确定缺陷频率,采用窄频脉冲保证只能激发所要求解的一个模式,将空间的电磁场值进行离散傅立叶变换求解其模场分布.计算结果表明,该方法能求解出微腔所有的缺陷模式.

Defect modes in a photonic crystal slab cavity are calculated with finite difference time domain method and group theory. Using symmetry boundary condition, all frequencies of defect modes are obtained through dipole driving-sources with a broadband pulse. For one given frequency of defect mode, we use one narrowband pulse to excite one single defect mode. Numerical results show that all defect modes with different symmetries can be obtained with this method.