Performance of thermo-optic components based on dielectric-loaded surface plasmon polariton waveguides

Theoretical analysis of thermo-optic (TO) modulation with dielectric-loaded surface plasmon polariton waveguide (DLSPPW) components at telecom wavelength of 1.55 μm is presented with simulations performed using the finite-element method (FEM). The investigated DLSPPW configuration consists of a 1 μm-thick and 1 μm-wide polymer ridge placed on a 50 nm-thin gold stripe and supported by a buffer layer material covering a Si wafer. Our analysis covers a broad range of parameters, including the buffer layer thickness, its thermal conductivity, and the metal stripe width, and takes into account the effect of isolation trenches structured along the heated part of waveguide. The results of our simulations agree well with the reported experimental data and provide valuable information for further development of TO plasmonic components with low switching powers, fast responses and small footprints.