A rectangular metal-insulator-metal based nanoscale plasmonic resonator

We present an optical range resonator based on single mode metal-insulator-metal plasmonic gap waveguides. Near lossless transmission at 90deg bends enables us to design rectangular structures with cross-section area less than 500 nm
²
, which also leads to easing the fabrication process. The resonator exhibits a free spectral range of 270 nm. We show that a small bridge between the resonator and the input waveguide can be used to tune the resonance frequency. In addition, nanoscale add/drop directional couplers are realizable using the presented ring resonator structure.