基于光子晶体单向传输波导,设计了一种三端口和两种四端口结构的通道下路滤波器.为取得100%的通道下路效率,运用实时耦合模理论对这三种结构进行了分析.理论分析表明该通道下路滤波器比利用光子晶体普通介质波导设计的通道下路滤波器具有更简单的结构,降低了器件制作难度.用有限元方法对滤波器结构进行了数值仿真分析,仿真计算结果表明所设计的三种结构具有超过90%的通道下路效率,与理论分析结果相符合.

Based on photonic crystal oneway waveguide, one threeport system and two kinds of fourport systems were designed. According to coupled mode theory in time, it was confirmed that the channel drop filters on the basis of oneway waveguide have more simple structure than that with only general dielectric photonic crytal waveguides in order to achieve 100% channel drop efficiency, which is benefit to the solution to the fabrication difficulty of the devices. The simulation results calculated by the finite element method shows that the channel drop efficiencies are all over 90%, which does agree well with the theoretical analysis.