Strong and weak polarization-dependent interactions in connected and disconnected plasmonic nanostructures.

Area of Science:

• Plasmonics
• Nanophotonics
• Optical Metamaterials

Background:

• Hybridized plasmonic modes arise from the interaction between different metallic nanostructures.
• Understanding these modes is crucial for applications in sensing and light manipulation.

Purpose of the Study:

• To numerically and experimentally investigate hybridized modes between gold nanodiscs and nanorods.
• To compare plasmonic properties of connected versus disconnected nanostructure systems.
• To analyze the influence of metal junctions on charge redistribution and mode hybridization.

Main Methods:

• Numerical simulations including quasi-normal mode computation and coupled oscillator models.
• Experimental measurements of scattering spectra under oblique-incidence plane wave illumination.
• Fabrication techniques to control nanogap size and metal junction formation.

Main Results:

• Distinct plasmonic properties observed between connected and disconnected systems, particularly in longitudinal polarization.
• Disconnected systems consistently explained by QNM and coupled oscillator models.
• Connected systems show unique behavior due to charge redistribution at the metal junction.
• Excellent agreement between experimental scattering spectra and numerical predictions.

Conclusions:

• The study provides a comprehensive understanding of hybridized plasmonic modes in coupled and uncoupled nanostructures.
• The findings highlight the significant impact of metal junctions on plasmonic behavior.
• The presented methods are applicable to diverse systems for applications in light-matter interactions, biosensing, and strain monitoring.