Theoretically Analyze the Tunable Wide Band-Stop Filtering in Plasmonic Waveguide Coupled With Fixed Height to Length Stubs

A metal-dielectric-metal (MDM) waveguide coupled with fixed height to length (bi/ai = 0.8) stubs is proposed in our work. Then, an obvious band-stop filtering phenomenon can be observed in MDM waveguide coupled with single fixed height to length stub. Interestingly, the MDM waveguide coupled with two fixed height to length stubs exhibits better band-stop filtering performance than that in a single fixed height to length stub coupled waveguide structures. The phase difference analysis and transmission line theory are established to discuss the transmission spectrum and the wide band-stop filtering phenomenon of our proposed structure. Inconceivably, the bandwidth of band-stop filtering can reach to 1750 nm through tuning structure parameters and the number of the fixed height to length stub. These results may provide great potential applications for plasmonic filtering devices.