Scattering characteristics of silicon nanoprisms: A theoretical investigation across monomeric to hexameric structures

Abstract

Dielectric nanostructures exhibit intriguing optical properties and outstanding advantages in designing optical nanoantennas and metasurfaces compared to plasmonic nanostructures. This study employs classical electrodynamic methods to comprehensively explore the scattering characteristics of silicon triangular nanoprisms in monomer and oligomer forms. For monomeric nanoprisms, the scattering spectra reveal two distinct and prominent resonance peaks attributed to magnetic dipole (MD) and electric dipole (ED) modes. Reducing interparticle gaps within dimeric structures leads to noticeable blueshifts in MD resonance peaks with stable intensities, in contrast to the nearly constant position and significantly reduced intensities of the ED resonance peaks. A pronounced Fano-like resonance was observed upon transitioning to tetrameric and hexameric configurations, resulting from the coupling between MD and ED modes. A broad resonance peak also emerges in the long-wavelength region due to MD-to-MD coupling. The simulations conducted herein hold significant theoretical implications, advancing our comprehension of the scattering properties of dielectric nanoparticles and contributing valuable insights into fundamental nanophotonics.