Nanoscale surface plasmon based resonator using rectangular geometry

The authors present an optical range resonator based on single mode metal-insulator-metal plasmonic gap waveguides. Complete transmission at 90° bends would enable the design of rectangular structures with cross-section area less than 500nm2, which consequently leads to easing the fabrication process. The resonator exhibits a free spectral range of 270nm. We show that a small bridge between the resonator and the input waveguide can be used to tune the resonance frequency. In addition, ultracompact add/drop directional couplers are realizable using the presented ring resonator structure.