Analysis of Hybrid Dielectric Plasmonic Waveguides

Future ultracompact photonic integrated circuits (PICs) will rely on high-index-contrast dielectric materials, which permit a strong confinement of the optical field in the diffraction limit as well as low propagation losses. This is the case of PICs implemented on a silicon-on-insulator (SOI) platform. To achieve confinement beyond the diffraction limit, plasmonic waveguides (based on metal-dielectric interfaces) have been recently proposed. This new kind of waveguide provides a strong enhancement of the field in the metal-dielectric interface, which is of paramount importance for nonlinear functionalities or sensing. Plasmonic waveguides can also be built on SOI wafers. Thus, it can be reasonably thought that high index contrast as well as plasmonic waveguides can coexist in future ultradense PICs. In this paper, a theoretical and numerical study on the performance of several dielectric and plasmonic waveguides is presented. Thanks to their plasmon-coupled supported modes, ultracompact devices as hybrid ring resonators can be devised and integrated with silicon photonic circuits.