Dispersion-induced $Q$-factor enhancement in waveguide-coupled surface lattice resonances

TL;DR

This paper demonstrates that embedding plasmonic nanoparticle arrays in strongly dispersive media within waveguides can significantly reduce array sizes while maintaining ultra-high Q-factors exceeding 10,000, advancing nanophotonic device miniaturization.

Contribution

The study introduces a method to dramatically decrease the size of high-Q metasurfaces by leveraging dispersion effects in waveguide-coupled nanoparticle arrays, a novel approach in nanophotonics.

Findings

Array size reduced by up to two orders of magnitude.

Achieved Q-factors exceeding 10^4.

Validated through theoretical and numerical analysis.

Abstract

Diffractively coupled nanoparticle arrays are promising candidates for helping to flatten many photonic devices such as lasers, lenses, and metrology instruments. Their performance, however, is directly linked with the size of the metasurfaces, limiting their applicability in nanophotonic applications. Here, we dramatically reduce array sizes of high-$Q$-factor metasurfaces by utilizing strongly dispersive media. The effect is demonstrated by theoretically and numerically studying periodic arrays of plasmonic nanoparticles embedded inside Bragg-reflector waveguides. We demonstrate array dimensions reduction up to two orders of magnitude while still achieving ultra-high $Q$-factors in excess of 10$^4$.