A Silicon-Based 3-D Hybrid Long-Range Plasmonic Waveguide for Nanophotonic Integration

Decreasing the widths and thicknesses of thin metal stripes can effectively increase the propagation distance of long-range surface plasmon polaritons, but at the cost of significant reduction on the overall mode confinement, which fundamentally limits the packing density in nanophotonic integration. By utilizing the coupling between the dielectric waveguide and plasmonic modes, we propose a silicon-based 3-D hybrid long-range plasmonic waveguide that not only supports long-range propagation, but also has compact modal size. Our simulation result shows that a propagation distance of 696 $\mu$m with an ultrasmall modal area of 0.0013 $\mu$m2 can be simultaneously achieved at 1.55 $\mu$m.