Low-loss Plasmonic Dielectric Nanoresonators

TL;DR

This paper introduces hybrid dielectric-metal nanoresonators that significantly reduce material losses in plasmonics, achieving high efficiency, tunable quality factors, and robust, directional emission at visible and infrared wavelengths.

Contribution

It proposes and demonstrates a new class of hybrid dielectric-metal resonators that mitigate metal losses and enhance plasmonic performance with high efficiency and tunability.

Findings

Achieve high Purcell factors (>5000) and quantum efficiency (>90%)

Enable strong, directional scattering beyond all-metal and all-dielectric limits

Offer quality factors tunable from ~10 to ~1000

Abstract

Material losses in metals are a central bottleneck in plasmonics for many applications. Here we propose and theoretically demonstrate that metal losses can be successfully mitigated with dielectric particles on metallic films, giving rise to hybrid dielectric--metal resonances. In the far field, they yield strong and efficient scattering, beyond even the theoretical limits of all-metal and all-dielectric structures. In the near field, they offer high-Purcell-factor (${>}5000$), high-quantum-efficiency (${>}90\%$), and highly directional emission at visible and infrared wavelengths. Their quality factors can be readily tailored from plasmonic-like (${\sim}10$) to dielectric-like (${\sim}10^3$), with wide control over the individual resonant coupling to photon, plasmon, and dissipative channels. Compared with conventional plasmonic nanostructures, such resonances show robustness against detrimental nonlocal effects and provide higher field enhancement at extreme nanoscopic sizes and spacings. These hybrid resonances equip plasmonics with high efficiency, which has been the predominant goal since the field's inception.