Plasmon transmutation: inducing new modes in nanoclusters by adding dielectric nanoparticles

Area of Science:

• Nanophotonics and Plasmonics
• Materials Science

Background:

• Planar plasmonic nanoparticle clusters exhibit nanoscale electromagnetic "hot spots" and Fano resonances.
• These properties are of significant interest for advanced sensing applications.

Purpose of the Study:

• To investigate how incorporating discrete dielectric nanoparticles modifies the plasmonic properties of metallic nanoclusters.
• To explore the creation of new plasmon modes and the transmutation of existing ones in metallodielectric nanocomplexes.

Main Methods:

• Fabrication of metallodielectric nanocomplexes by depositing dielectric nanoparticles (e.g., carbon) onto plasmonic nanocluster arrays.
• Characterization of optical responses to identify and analyze induced plasmon modes.

Main Results:

• A single carbon nanoparticle in a nanodisk junction induced a metal-dielectric-metal quadrupolar plasmon mode.
• In a ten-membered cluster, multiple carbon nanoparticles introduced a collective magnetic plasmon mode into the Fano dip.
• This resulted in an additional subradiant mode in the metallodielectric nanocluster's optical response.

Conclusions:

• The addition of dielectric nanoparticles to metallic nanoclusters significantly expands the diversity and types of supported plasmon modes.
• This strategy offers a versatile pathway for designing novel nanoscale assemblies with tailored optical properties for sensing and other applications.