Influence of Insulator Layer Width on Propagation Properties of Symmetric Surface Plasmon Polariton Mode in Metal-Insulator-Metal Waveguide

Influence of insulator layer width on propagation properties of symmetric surface plasmon polariton (SPP) mode, which is excited through a dipole embedded in SiO2 layer of Au/SiO2/Au structure in metal-insulator-metal (MIM) waveguide, has been investigated. The symmetric SPP mode has a propagation length along SiO2/Au interface that depends on SiO2 layer width. Its maximal value is 0.61 μm with SiO2 layer width of 100 nm. These values provide a theoretical reference for designing a high-performance SPP source using Au/SiO2/Au structure.