Numerical modeling of a teeth-shaped nanoplasmonic waveguide filter

Tooth-shaped and multiple-teeth-shaped plasmonic filters in the metal-insulator-metal (MIM) waveguides are demonstrated numerically. By introducing a three-port waveguide splitter, a modified model based on multiple-beam interference and the scattering matrix method is given. The transmittance spectra as a function of teeth width, depth, period, and period number are addressed, respectively. The results show that the new structure not only performs the filtering function as well as MIM gratinglike structures, but that it is also of submicrometer size for ultrahigh integration and relatively easy fabrication.