为了消除光子晶体环形腔滤波器的多模特性,通过在环形腔的输出负载通道中引入点缺陷,提出了一种复合缺陷光子晶体滤波器结构。将线缺陷作为主波导,将环形腔和点缺陷相结合作为负载波导来实现对特定波长的滤波。分析了光子晶体整体介质柱折射率、点缺陷的折射率以及点缺陷的尺寸对滤波器滤波特性的影响。令m=r-point/r,由数值模拟分析得出,当m取0~0.6时,B端口输出的滤波波长值没有发生改变,而在m∈[0.6,1.8]的合理区间范围内,若改变点缺陷介质柱半径,则可实现滤波器的单纵模滤波和滤波特性的可调谐,这将对多通道滤波器结构的设计提供有效的理论参考。 In order to eliminate the multimode characteristics of the photonic crystal circular cavity filter, a defect of photonic crystal with composite defects is proposed by introducing point defects into the output load channel of the circular cavity. The line defect as the main waveguide, the annular cavity and point defects combined as a load waveguide to achieve a specific wavelength filtering. The influence of the refractive index, the refractive index of the point defect and the size of the point defect on the filter characteristics of the photonic crystal bulk dielectric column were analyzed. Let m = r-point / r. From the numerical simulation results, it can be seen that when m is 0 ~ 0.6, the output wavelength of the B port does not change. In the reasonable range of m ∈ [0.6,1.8] If the diameter of the point defect dielectric column is changed, the single-longitudinal mode filter and the tunable filter characteristic of the filter can be achieved, which will provide an effective theoretical reference for the design of the multi-channel filter structure.