Revealing the Chiroptical Response of Plasmonic Nanostructures at the Nanofemto Scale

Autor: En Cao, Hiroaki Misawa, Tomoya Oshikiri, Quan Sun, Shuai Zu
Rok vydání: 2021
Předmět:
Zdroj: Nano Letters. 21:4780-4786
ISSN: 1530-6992
1530-6984
DOI: 10.1021/acs.nanolett.1c01322
Popis: The spatiotemporal origin of plasmonic chiroptical responses in nanostructures remains unexplored and unclear. Here, two orthogonally oriented Au nanorods as a prototype were investigated, with a giant chiroptical response caused by antisymmetric and symmetric mode excitations for obliquely incident left-handed circular polarization (LCP) and right-handed circular polarization (RCP) light. Time-resolved photoemission electron microscopy (PEEM) was employed to measure the near-field spatial distributions, spectra, and spatiotemporal dynamics of plasmonic modes associated with the chiroptical responses at the nanofemto scale, verifying the characteristic near-field distributions at the resonant wavelengths of the two modes and a very large spectral dichroism for LCP and RCP. More importantly, eigenmode excitations and their contributions to the ultrafast plasmonic chiroptical response in the space-time domain were directly revealed, promoting a full understanding of the ultrafast chiral origin in complex nanostructures. These findings open a way to design chiroptical nanophotonic devices for spatiotemporal control of chiral light-matter interactions.
Databáze: OpenAIRE