A novel long-range hybrid insulator-metal-insulator plasmonic waveguide with tight light confinement

The paper presents a novel long-range hybrid insulator-metal-insulator (IMI) plasmonic waveguide, which is composed of two silicon wedge nanowires and a cylinder metal nanowire. Compared with other hybrid plasmonic waveguide, the proposed waveguide shows better properties. With strong coupling between the silicon nanowire mode and long-range surface plasmon polariton (SPP) mode, both deep subwavelength mode confinement and low propagation loss have been achieved. The properties of the hybrid IMI plasmonic waveguide including propagation length (L), normalized mode area (A(eff) /A(0)) and figure of merit (FoM) are evaluated. Compared with the hybrid plasmonic waveguides, the designed waveguide enables an ultra-small deep-subwavelength mode in smaller area. The propagation length is nearly 1mm and FoM is similar to 10(4), which is larger than that of wedge or rectangle hybrid plasmonic waveguides. We also evaluate the impacts of practical fabrication imperfections on the mode properties. The results show that the proposed waveguide is fairly tolerant to the practical fabrication errors in geometry parameters. The proposed waveguide has many potential applications for nano-photonic components of high performance.