Modal analysis of thin long-range plasmonic waveguides

In this work, we present a comprehensive modal analysis, by means of numerical simulations, of a long-range surface plasmon polariton waveguide consisting of a metal stripe sandwiched between two dielectric claddings. Our results complement those from previous reports where similar structures have been studied and optimized for attenuation-based measurements. Specifically, we found conditions where a significant phase change can be induced while the losses of the structure vary minimally. Around these regions, an attenuation-based measurement would be insensitive for sensing, however, a high-sensitivity interferometric measurement could be performed without a significant penalty on the contrast of the interference signal. Our structure is designed specifically for biologically relevant situations and it can be fabricated with commercial grade materials that are commonly available in clean room facilities.

Automated summary

In this study, a comprehensive modal analysis of a long-range surface plasmon polariton waveguide was conducted using numerical simulations. The research found conditions where a significant phase change can be induced with minimal losses in the structure. The designed waveguide is suitable for biologically relevant situations and can be fabricated with commercial grade materials commonly available in clean room facilities.