Polarization-dependent multipolar plasmon resonances in anisotropic multiscale au particles

Area of Science:

• Nanophotonics
• Plasmonics
• Materials Science

Background:

• Three-dimensional (3D) anisotropic nanoparticles exhibit unique optical properties.
• Controlling particle geometry is crucial for tuning plasmonic resonances.

Purpose of the Study:

• Fabricate and characterize 3D multiscale gold particles with varying aspect ratios.
• Investigate the relationship between particle geometry and plasmonic excitation modes.
• Understand the influence of structural asymmetry on optical responses.

Main Methods:

• Fabrication of 3D multiscale gold particles.
• Optical characterization of fabricated particles.
• Finite-difference time-domain (FDTD) calculations.

Main Results:

• Increasing particle aspect ratio excited longitudinal and transverse plasmon modes.
• Higher aspect ratios correlated with increased multipolar orders for both modes.
• Structural asymmetry was identified as the cause for distinct transverse plasmon resonances.
• Modifying particle ends resulted in two longitudinal and one transverse resonance.

Conclusions:

• Particle aspect ratio and structural asymmetry are key factors in determining plasmonic behavior.
• Tailoring 3D gold particle geometry allows for control over longitudinal and transverse plasmon resonances.
• This research provides insights into designing plasmonic nanostructures for specific optical applications.