高精细度光纤谐振环辅助MZI滤波器的数值分析

Numerical Analysis of High Finesse Filter Based on Optical Fiber Ring Resonator Assisted Mach-Zehnder Interferometer

将4个光纤谐振环采用耦合器相互级联,再与普通马赫-曾德尔干涉仪滤波器上下臂相耦合,设计了一种新型的光纤谐振环辅助马赫-曾德尔干涉仪滤波器。根据光纤环谐振理论与信号流程图理论,推导出滤波器输出端的光学传递函数,并对其传输特性进行模拟分析。仿真结果表明:滤波器输出光谱具有顶部平坦、边沿滚降明显、窄带宽、高精细度的优良性能。数值计算得出,滤波器的精细度达到69.4,能够对密集波分复用系统中的光信号做到精确提取与选择。

A novel optical filter combining ring resonator with Mach-Zehnder interferometer was de-signed. In this structure, four fiber ring resonators were cascaded and combined with Mach-Zehnder in-terferometer using coupler. Formulas of the transfer functions were deduced by fiber ring resonance theo-ry and signal flow graph method and the simulation analysis was given as well. The results showed thatoutput spectrum of this filter had excellent performance such as flatness filtering response, strengtheningof rolloff in transition band, narrow bandwidth and high finesse. The numeral calculations showed thatthe fineness of this structure reached 69. 4, it is able to select and extract optical signal precisely indense wavelength division multiplexing system.