Plasmonic enhancement of spatial dispersion effects in prism coupler experiments

TL;DR

This paper demonstrates that plasmonic structures significantly enhance the sensitivity of prism coupler experiments to spatial dispersion effects, enabling more precise optical measurements of multilayered plasmonic waveguides.

Contribution

It shows that plasmonic enhancement can increase the sensitivity of prism coupler experiments to spatial dispersion by two orders of magnitude, providing a better platform for studying these effects.

Findings

Plasmonic structures amplify spatial dispersion effects in prism experiments.

Enhanced sensitivity allows for more accurate characterization of multilayered plasmonic waveguides.

Prism couplers can be used as a precise tool to study spatial dispersion phenomena.

Abstract

Recent experiments with film-coupled nanoparticles suggest that the impact of spatial dispersion is enhanced in plasmonic structures where high wavevector guided modes are excited. More advanced descriptions of the optical response of metals than Drude's are thus probably necessary in plasmonics. We show that even in classical prism coupler experiments, the plasmonic enhancement of spatial dispersion can be leveraged to make such experiments two orders of magnitude more sensitive. The realistic multilayered structures involved rely on layers that are thick enough to rule our any other phenomenon as the spill-out. Optical evanescent excitation of plasmonic waveguides using prism couplers thus constitutes an ideal platform to study spatial dispersion.