Quantifying the Selective Excitation-Free Enhancement of Chiral Plasmonic Nanocavities by Raman Scattering

Area of Science:

• Photonics and Nanotechnology
• Plasmonics
• Materials Science

Background:

• Chiral plasmonic nanocavities exhibit significant electromagnetic field enhancement and chiroptical properties.
• Accurate characterization of their selective enhancement is crucial for advancing photonic applications.

Purpose of the Study:

• To introduce a novel method for quantifying the selective enhancement of chiral plasmonic nanocavities.
• To utilize the Raman 2D band of graphene as a probe for evaluating nanocavity performance.
• To provide a new perspective for assessing and improving chiral plasmonic nanocavity designs.

Main Methods:

• Fabrication of chiral gold nanocube-on-mirror structures.
• Integration of few-layer graphene and thin-film graphite within the nanocavities.
• Modulation of graphene's 2D band using linearly polarized light.
• Analysis of the 2D band chirality to reflect selective nanocavity enhancement.

Main Results:

• The Raman 2D band of graphene serves as an effective probe for 'excitation-free' quantification of chiral plasmonic nanocavity enhancement.
• The chirality of the 2D band accurately reflects the selective total enhancement, excluding excitation rate contributions.
• Demonstrated modulation of graphene's 2D bands within chiral plasmonic structures.

Conclusions:

• Graphene's 2D band chirality offers a unique approach to assess chiral plasmonic nanocavity performance.
• This strategy provides a valuable tool for the development and optimization of advanced plasmonic devices.
• The findings facilitate a deeper understanding and improvement of chiral plasmonic nanocavity functionalities.