Plasmonic Band-pass/stop Filters Based on Metal-Insulator-Metal Slit Waveguides

A novel plasmonic band-pass/stop filter based on metal-insulator-metal (MIM) plasmonic waveguides in telecommunication systems is proposed and investigated. In order to study the propagation of these surface waves and formation of plasmonic modes in the gap distance between metals, we use the finite element method (FEM) as numerical methods and microwave Transmission Line Method (TLM) for analytical one. The results of these calculations shows a significant transmission/reflection around λ ~ 1.57 μm where these spectral responses are acceptable for realizing band-pass/stop filtering in telecommunication window. Changing the gap distance between metallic sides in MIM slit, leads to a red or blue shift in the filtering spectra. These results would be helpful in designing the band-stop filters and band-pass filters, and have guiding significance for plasmonic integration circuits applications.