缺陷对光子晶体透射能带谱的简并效应研究

为了设计高品质、高性能的光学滤波器和光开关，利用传输矩阵法通过数值计算模拟的方式绘制1维光子晶体的透射能带谱，研究和分析了两缺陷之间距离和缺陷的厚度对光子晶体透射能带谱的简并效应。结果表明，当两缺陷之间距离越大，透射能带谱简并效应越明显，当间距增大到一定数值时，出现分立透射峰完全简并现象；当缺陷厚度整数倍增大时，光子晶体透射能带谱出现简并的趋势，但缺陷厚度奇数倍增大与偶数倍增大时，透射能带谱简并速度不一样，前者的简并速度小于后者的简并速度；缺陷厚度无论是奇数倍增大还是偶数倍增大，光子晶体透射能带谱简并的速度均逐渐减小。缺陷对光子晶体透射能带谱简并效应的调制规律，为光子晶体设计新型光学滤波器件、光学开关及其调制机制等提供了指导。

Degeneracy effect of defects on transmission spectrum band of photonic crystal

To design optical filter and optical switch with high quality and performance,by using the transfer matrix method theory and computational simulation method to draw the transmission spectrum band of 1-D photonic crystal, the degeneracy effect of the distance between two defects and the thickness of the defect on the transmission band spectrum of photonic crystal were studied and analyzed. The results show that the transmission band degeneracy of the photonic crystal is sensitive to the distance between two defects, the transmission band degeneracy is more obvious with the greater distance between two defects. When the distance between two defects is larger, the degenerate effect of transmission band spectrum is more obvious. When the distance increases to a certain value, complete degenerate of discrete transmission peak appears. When the defect thickness increases with integer times, the tendency of degenerate of transmission band spectrum of photonic crystal appears. When defect thickness increases with odd and even number of times, the degenerate speed of transmission spectrum is not the same. The former is shorter than the latter. No matter defect thickness increases with odd or even number times, the degeneracy of transmission band spectrum of photonic crystal reduces gradually. Degeneracy effect can provide the guidance for photonic crystal design of the new optical filter, optical switch and modulation mechanism.