Clocking plasmon nanofocusing by THz near-field streaking

TL;DR

This paper demonstrates the use of THz near-field streaking to measure plasmon polariton propagation on a nanotip, enabling precise control of localized photoelectron sources for advanced imaging techniques.

Contribution

It introduces a novel application of THz near-field streaking to directly measure plasmon group velocity on a nanostructure, combining experimental and simulation approaches.

Findings

Measured plasmon group velocity consistent with simulations

Enabled control over localized photoelectron sources

Demonstrated potential for time-resolved imaging and diffraction

Abstract

We apply terahertz (THz) near-field streaking in a nanofocusing geometry to investigate plasmon polariton propagation on the shaft of a conical nanotip. By evaluating the delay between a streaking spectrogram for plasmon-induced photoemission with a measurement for direct apex excitation, we obtain an average plasmon group velocity, which is in agreement with numerical simulations. Combining plasmon-induced photoemission with THz near-field streaking facilitates extensive control over localized photoelectron sources for time-resolved imaging and diffraction.