Analysis of an ultra-compact wavelength filter based on hybrid plasmonic waveguide structure

In this letter, we propose and analyze an ultra-compact wavelength filter on silicon-based hybrid plasmonic waveguides, which confines light in a nanometeric silica dioxide layer between the silicon substrate and metal cap. The filter consists of a stub structure coupled to a straight waveguide. The three-dimensional finite-difference time-domain (FDTD) method is applied to calculate the spectral responses of such devices. Similar resonant behaviors are obtained since those devices are based on two-dimensional Metal-Insulator-Metal waveguide structure. Results also show that by adding stubs and tuning the distance between stubs can further improve the device's performance and shape the spectral response to some extent.