Transmission characteristics analysis of a hybrid SNIMS plasmonic waveguide

We propose a new kind of hybrid plasmonic waveguide structure, namely the semiconductor nanowire -insulator-metal strip waveguide, or SNIMS. It has been demonstrated using Finite Element Methods (FEM) that this structure support hybrid plasmonic modes traveling over large distances(100~330um) with strong mode confinement (ranging from λ2/300 to λ2/30) at telecom wavelengths. The result is better than that of a traditional semiconductor waveguide. In addition，we stimulated a coupler based on the SNIMS structure. The coupling length Lc can be as short as 2.2um when the separation D=400nm . In other words, this device can be used as a highly compact directional coupler.