聚合物微环辅助MZI型可调谐滤波器

Tunable Filter with Polymer Microring Resonator Assist MZI

为改善普通马赫-曾德尔干涉仪滤波器的滤波性能,将微环谐振器与马赫-曾德尔干涉仪相结合,设计出一种新型滤波器结构。利用信号流程图理论推导出滤波器传递函数,并对其输出端口透射谱进行仿真分析。仿真结果表明:当微环谐振器周长(L_1和L_2)与马赫-曾德尔干涉仪上下臂臂长差Δd满足如下关系:L_1=2L_2=Δd时,滤波器输出光谱顶部平坦,边沿陡峭,形状类似于"方形"。通过数值计算,取微环谐振器周长L_1=1 510μm时,滤波器的自由光谱范围为2nm、3dB带宽为1.15nm、精细度达到1.74、品质因子为1 347.82。文章提出的微环辅助马赫-曾德尔干涉仪型滤波器的滤波性能与普通马赫-曾德尔干涉仪滤波器相比有了明显改善。选择光电特性优良的聚合物材料设计微环谐振器和马赫-曾德尔干涉仪,当施加在滤波器上的电压发生变化时,滤波器输出光谱向右漂移,可以满足不同的滤波需求。

To improve the filtering performance of conventional Mach-Zehnder Interferometer（MZI） filter,a new structure offilter which combining ring resonator and MZI is proposed in this paper. The transfer function of this structure is first realizedby using the Signal Flow Graph （SFG） method. Then the output spectra are simulated and analyzed. The results show thatwhen the perimeter of ring resonator （L1 ,L2 ） and the length difference （Ad） of MZI arms meet the relationship of L1 ~ 2L2 =Ad, the improved filter can give rectangular waves approximating flat top and steep edge. Through numerical calculation whenchoosing the perimeter of ring resonator is L1 ~ 1 510 ~tm,the free spectral can range up to 2 nm, the full bandwidth at half-maximum is 1.15 nm, the sharpness factor is 1.74 and the quality factor is 1 347.82. Therefore, compared with the conven-tional filter of MZI＇s spectrum, the filtering performance is improved significantly. It is noted that by choosing the polymermaterials with excellent photoelectric properties to design the ring resonator and MZI, the spectra are moving to the right sidewhich can be adapted to the different filtering requirements when char^ging the voltage on the filter.