Optical performance of single-mode hybrid dielectric-loaded plasmonic waveguide-based components

The single mode hybrid dielectric-loaded plasmonic waveguide is presented at the wavelength of 1.55 μm. We show that this waveguiding structure, consisting of a low-index SiO2-stripe sandwiched between a high-index Si-nanowire and a silver film, achieves both long propagation length and strong field confinement with high power intensity. Components such as 90°-circular and S-shaped bends, based on the proposed waveguide with an intensity confinement area of 50×200 nm2, can obtain a total transmission efficiency exceeding 85% for various bend radii. Finally, we demonstrate that the efficient directional couplers can be developed using two coupled waveguides. In particular, we determine the typical coupling lengths and maximum transfer power for different structural parameters of the coupler. These investigations provide the foundations for the design of chip-scale integrated plasmonic circuitry.