Waveguide interrogation of a compound plasmonic nanoantenna

Abstract

While long-range propagating plasmons have been extensively investigated for implementing on-chip optical sensing platforms, waveguide-excited localized surface plasmon resonance-based sensing systems have not yet received much attention. Waveguide excitation and readout, an alternative to free-space single-particle spectroscopy, are particularly attractive. A numerical investigation of the optical response of a waveguide-excited plasmonic dolmen-shaped compound nanoantenna is presented. The dolmen shape is found to offer improved refractive index sensing performance in comparison to simpler shapes for both spectral-shift and intensity-shift measuring modalities. The compound plasmonic nanoantenna configuration presented is of interest in hybrid photonic-plasmonic sensing approaches with high-throughput capabilities.