采用传输矩阵法理论,研究缺陷参数奇偶性对含缺陷光子晶体(AB)m (ACx B)n (AB)m光传输特性的影响,研究结果表明:缺陷数目 n 的奇偶性仅影响缺陷模(透射峰)数目的奇偶性,即缺陷模数目的奇偶性与 n 对应;随着缺陷周期数 x 奇数倍增大,透射谱中的缺陷模向禁带中心靠拢,但缺陷模数目不变且等间距排列,随着 x 偶数倍增大,禁带两侧的两组缺陷模向禁带中心靠拢,且各组缺陷模数目与缺陷周期数 x 相关;缺陷光学厚度 DC 奇偶性对光子晶体透射谱的影响也很明显,随着 DC 增大且 DC <DA 时,分布在禁带右侧的缺陷模数目增加且向低频方向移动,随着 DC 增大且 DC >DA 时,分布于禁带左侧的缺陷模数目则减少但亦向低频方向移动。缺陷参数奇偶性对光子晶体透射谱的影响规律,为光子晶体设计可调性多通道光学滤波器件、光开关等提供理论借鉴,并为光子晶体的理论研究提供参考。
The effect of defect parity on the transmission properties of photonic crystal(AB)m (ACx B)n (AB)m is studied by transmission matrix method theory.The results show that the parity of defect number(n )only has effect on parity of defect modes(transmission peaks),namely,the parity of defect modes number is corresponding to n.The defect modes are closing to the band gap center with odd-multiple increase of periodicity(x ),but the number of defect modes are un-changed and arranged equidistant from each other.On both sides of band gap,the two groups of modes are closing to the band gap center with even-multiple increase of periodicity(x),and the number of modes in each group depends on the periodicity(x ).The effect of parity of the defect layer optical thickness(DC )on transmittance spectrum is also obvi-ous.In the right band gap,the number of defect mode is increasing and the mode is moving towards low frequency direc-tion with the increase of DC(DC 〈DA ).On the contrary,while DC 〉DA ,the number of defect mode in the left band gap is reducing with the increase ofDC ,and the defect mode is also moving towards low frequency.The law of defect pa-rameters parity effect on transmission spectrum can provide theoretical reference for designing adjustable multichannel optical filter and optical switch,and also provide definite reference for theoretical study of photonic crystal.