Articles techniques et présentations

Plasmonics has emerged as an important platform in nanophotonics over the past decades. Gold nanospheres act as optical antennas with absorption cross sections that can exceed their geometric cross sections by several times, resulting in exceptionally strong light absorption. As the particle size increases, light scattering becomes increasingly significant and eventually comparable to absorption. Consequently, optical coupling between neighboring plasmonic nanoparticles becomes an important factor. Periodic arrays of gold nanospheres exhibit collective lattice resonances when the wavelength of the incident light matches the lattice periodicity, giving rise to optical properties that differ significantly from those of isolated particles.

In this work, we employ the finite element method (FEM) in COMSOL Multiphysics to compare the optical response of individual gold nanospheres with that of periodic nanoparticle arrays. Simulations of isolated particles are based on the Optical Scattering off a Gold Nanosphere model from the COMSOL Application Library, while periodic arrays are modeled using periodic boundary conditions to represent infinite lattices. By systematically varying the lattice periodicity, we investigate its influence on the optical response and demonstrate how lattice resonances can enhance light absorption. The results provide insight into the design of plasmonic nanostructures with tailored optical properties for enhanced light–matter interaction.