Plasmonic tunable filter based on trapezoid resonator waveguide

摘要

The metal-insulator-metal waveguide structures coupled with a trapezoid cavity are proposed in theory. A variety of transmission features have been found from the simulation results, which is caused by the interference of the plasmonic modes in the trapezoid resonator. The transmission spectra can be effectively modulated by optimizing the geometrical parameters of our configurations such as the height, the upper and bottom edge lengths. Also, the coupling distance possesses great importance on the transmission characteristic. It is found that when the coupling distance is chosen to be around 20 nm, the filter works efficiently. When the trapezoid resonator is attached to the waveguide bus, the bandwidth becomes large. Besides, an effective band-stop filter can be achieved when the bottom edge length is large enough. The finite element method is carried out to verify our designs. We hope our work may open some new avenues for a high-performance plasmonic filter.