A Silicon-Based Hybrid Plasmonic Waveguide for Nano-Scale Optical Confinement and Long Range Propagation

A silicon-based hybrid plasmonic waveguide for nano-scale optical confinement and long range propagation at λ = 1.55 μm has been proposed in this paper. This structure is based on a silicon-on-insulator rib and its top is with a metal cap. Through introducing a ridge on the top of the silicon layer, it can improve the performance of the confinement and the loss significantly. Further parameter studies are carried out by using finite element method (FEM) and the numerical results show that this design has lower loss (propagation length over 200 μm) and better confinement (effective mode area below 0.05) as compared with the traditional hybrid ones. Additionally, further extension and discussion of the width restriction and fabrication error are also taken into account for real application in the last part of this paper. Our design may serve as a potential choice for various nano-photonic components, especially for plasmonic waveguide design.