Acoustic Far-Field Hypersonic Surface Wave Detection with Single Plasmonic Nanoantennas

Rodrigo Berte, Fabricio Della Picca, Martín Poblet, Yi Li, Emiliano Cortés, Richard V. Craster, Stefan A. Maier, Andrea V. Bragas

Research output: Contribution to journalArticleResearchpeer-review

24 Citations (Scopus)

Abstract

The optical properties of small metallic particles allow us to bridge the gap between the myriad of subdiffraction local phenomena and macroscopic optical elements. The optomechanical coupling between mechanical vibrations of Au nanoparticles and their optical response due to collective electronic oscillations leads to the emission and the detection of surface acoustic waves (SAWs) by single metallic nanoantennas. We take two Au nanoparticles, one acting as a source and the other as a receptor of SAWs and, even though these antennas are separated by distances orders of magnitude larger than the characteristic subnanometric displacements of vibrations, we probe the frequency content, wave speed, and amplitude decay of SAWs originating from the damping of coherent mechanical modes of the source. Two-color pump-probe experiments and numerical methods reveal the characteristic Rayleigh wave behavior of emitted SAWs, and show that the SAW-induced optical modulation of the receptor antenna allows us to accurately probe the frequency of the source, even when the eigenmodes of source and receptor are detuned.

Original languageEnglish
Article number253902
Number of pages6
JournalPhysical Review Letters
Volume121
Issue number25
DOIs
Publication statusPublished - 20 Dec 2018
Externally publishedYes

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