基于微环谐振器阵列与马赫-曾德尔干涉仪的反射型滤波器性能分析

理论分析了一种将微环谐振器阵列与马赫-曾德尔干涉仪(MZI)相结合实现的反射型滤波器结构。将此结构类比为两类四端口网络级联模型,利用传输矩阵法推导出其通用函数形式,并给出单环及三环结构下的能量反射系数具体公式。通过传输函数矩阵模拟计算了取不同耦合系数值情况下的反射谱形变化,给出了原因分析及讨论。并模拟了引入传输损耗对三环结构谐振峰反射率的影响。数值结果表明:适当选取直波导与微型环以及微型环间耦合系数幅值时,此结构能够作为反射型滤波器件应用于密集波分复用(DWDM)系统,也可实现激光器反射镜面的功能;由于传输损耗增加而引起的谐振峰反射率下降程度依赖于所选取的耦合系数值。

Properties Analysis for Reflection-Type Filter Composed of Microring Resonator Array and Mach-Zehnder Interferometer

The theoretical analysis is presented for the wavelength-selective reflection-type filter realized by combination of microring resonator array and Mach-Zehnder interferometer.By introducing the seriescascaded two kinds of four-port network,the general formulas are derived with the transfer matrix method,and explicit expressions for the power reflection coefficients of single-ring and three-ring structures are given.The changes of the reflection spectrum shapes are computed for different values of coupling coefficients by the transmission function matrices,and detailed analysis and discussions are given for the reason.For the three-ring structure,the influences of transmission loss on the power reflectivity of resonant peaks are simulated.The simulation results show that: when the ring-bus and ring-ring coupling ratios are selected properly,this device can be used as a reflection-type filter in dense wavelength division multiplexing(DWDM) system and an end mirror for lasers;the degradation of the peak reflectivity value with the transmission loss increase depends on the values of selected coupling ratios.