构造和研究了光子晶体插入式二元缺陷和替代式二元缺陷微腔的光学传输特性,结果表明:随着二元缺陷自身周期数增大,微腔透射谱中分立缺陷模的数目增加,且替代式二元缺陷微腔分立缺陷模多于插入式二元缺陷微腔;随着缺陷高折射率介质厚度的增大,二元缺陷微腔的缺陷模向中间靠拢呈现简并趋势,同时禁带两侧出现多组双缺陷模,且高频一侧出现双缺陷模多于低频一侧,但替代式二元缺陷微腔出现的双缺陷模数目多于插入式二元缺陷微腔;随着缺陷低折射率介质厚度增大,插入式二元缺陷微腔的缺陷模向低频方向移动同时呈现耦合分开趋势,且透射率逐渐降低,而替代式二元缺陷微腔的缺陷模则向中间靠拢呈现简并趋势,同时缺陷模整体向高频方向缓慢移动,而透射率保持100%不变。光子晶体二元缺陷微腔的光传输特性为光学滤波器、光学开关和激光器等的设计提供了参考。
Light propagation characteristic of dual defect microcavity inserted or replaced by photonic crystal were studied by numerical calculation and simulation. The result shows that when the periodicity of dual defect becomes larger, there will be more defect modes in microcavity transmission spectrum, the modes in replaced dual defect microcavity are more than that in inserted dual defect microcavity. As the high-refractive medium of defect thickens, the defect modes in dual microcavity draw close to the center and tend to degenerate; at the same time, pairs of double defect modes appear on both sides of band gap, with more on the high frequency side and less on the low frequency side; however, the defect mode quantity in replaced dual defect microcavity is larger than that in inserted dual defect microcavity. While the low-refractive medium of defect thickens, defect modes of inserted dual defect microcavity move tolow frequency and tend to separate for function coupling, with the transmission index decreasing; but the defect modes of replaced dual defect microcavity draw close to the center and tend to degenerate, and meanwhile the whole defect modes slowly shift to high frequency and the transmissivity remains 100%. Theses light propagation characteristic provide design reference for optical filter, switch and laser devices.