Plasmonic resonances in hexagonal split-ring resonator

A nanoscale resonator is designed using a hexagonal split ring inside two metal-insulator-metal (MIM) waveguides. The split angle defined by the angular position of the split referring to the axis of the MIM waveguide is varied and thus the transmission properties as well as different plasmonic resonance modes have been investigated by numerical methods. The transmission efficiency of the odd modes was found to be higher than in the even modes. The split angle has been optimized for the highest transmission efficiency in even modes. The designed structure has potential application as tunable filters and the better transmission efficiency at wavelengths in biological window implies its usage in bio-sensing.