一维光子晶体的对称缺陷模特性

Symmetrical Defect Mode Characteristics of 1-D Photonic Crystal

基于介质薄膜理论,设计了含对称缺陷的一维光子晶体结构,用传输矩阵法研究了该对称缺陷晶体的带结构及缺陷模的变化特点。结果显示,随缺陷层个数增大,缺陷模的峰值会增大,宽度会变窄;随缺陷层厚度增大,缺陷模会向长波方向移动,在一定厚度下会出现多缺陷模特点。随周期单元个数变大,缺陷模个数会减少,最终获得一窄带缺陷模。随周期单元厚度增大,禁带宽度明显变宽,缺陷模会变宽并出现右移特性。这些结果对设计新型光子晶体器件有着重要意义,如实现光波滤波器的可控选频、频带缩放功能等。

Based on the theory of dielectric film, the structure of 1-D photonic crystal with symmetrical defect layer is designed. The method of transfer matrix was used to analyze the band structure. The result shows that the peak of the defect mode will increase, but its width will narrow as the number of defect layers increases; and the defect mode will shift to the longwave direction as the thickness of the defect layer increases, and multi-defect mode will appear under a certain thickness. The bandgap becomes significantly wider as the periodic unit thickness increases. The defect mode number will reduce as the periodic unit number increases, and a narrow-band defect mode will be formed eventually. These results will play an important role in designing novel photonic crystal devices, such as realizing selectable frequency and scaleable frequency band.