Electric-field-resolved detection of localized surface plasmons at petahertz-scale frequencies

TL;DR

This paper introduces a new electric-field-resolved method to directly observe ultrafast localized surface plasmon dynamics in metallic nanoparticles at petahertz frequencies, providing detailed time-domain and spectral information.

Contribution

The authors develop a novel approach that captures the complex spectral response of localized surface plasmons using broadband few-cycle pulses, enabling direct time-domain analysis of plasmonic dynamics.

Findings

Successfully measured ultrafast plasmonic responses.

Correlated experimental data with classical Mie theory.

Demonstrated broadband, phase-resolved detection of surface plasmons.

Abstract

We present a novel electric-field-resolved approach for probing ultrafast dynamics of localized surface plasmons in metallic nanoparticles. The electric field of the broadband carrier-envelope-phase stable few-cycle light pulse employed in the experiment provides access to time-domain signatures of plasmonic dynamics that are imprinted on the pulse waveform. The simultaneous access to absolute spectral amplitudes and phases of the interacting light allows us obtaining a complex spectral response associated with localized surface plasmons. We benchmark our findings against the absorbance spectrum obtained with a spectrometer as well as the extinction cross-section modeled by a classical Mie scattering theory.