Extinction by plasmonic nanoparticles in dispersive and dissipative media

TL;DR

This paper investigates how host medium dissipation affects the extinction efficiency of plasmonic nanospheres, revealing damping effects, resonance shifts, and potential for broadband extinction enhancement beyond classical predictions.

Contribution

It introduces a generalized Mie theory to isolate and analyze the specific influence of host dissipation on plasmonic extinction, highlighting effects not predicted by classical models.

Findings

Host dissipation causes resonance broadening and amplitude reduction.

Resonance positions are shifted by host dissipation, beyond classical predictions.

Wide-band extinction enhancement can occur away from LSPR positions.

Abstract

Extinction of small metallic spheres has been well understood through the classical Mie theory when the host medium is dispersive and transparent. However, the role of host dissipation on the particulate extinction remains a competition between the enhancing and reducing effects on the localized surface plasmonic resonance (LSPR). Here, using a generalized Mie theory, we elaborate on the specific influence mechanisms of host dissipation on the extinction efficiency factors of a plasmonic nanosphere. To this end, we isolate the dissipative effects by comparing the dispersive and dissipative host with its transparent counterpart. As a result, we identify the damping effects of host dissipation on the LSPR including the resonance widening and amplitude reducing. The resonance positions are shifted by host dissipation, which cannot be predicted by the classical Fr\"ohlich condition. Finally, we demonstrate that a wide-band extinction enhancement due to host dissipation can be realized away from the positions of LSPR.