Comparison of Rectangular and Hexagonal Periodic Unit Cells for Modeling Plasmonic Nanoparticle Arrays

The optical response of localized surface plasmon resonance (LSPR) principle-based nanostructures was studied with computational simulations using the finite element method (FEM). The refractive index sensitivity (RIS) of periodic rectangular and hexagonal nanoparticle layouts was compared to one another with linearly polarized electromagnetic waves at different angles of the incident light. The bulk RIS was calculated from the transmittance peak shifts caused by changing the dielectric medium surrounding the nanoparticles. The simulations were carried out using Comsol Multiphysics software. The aim of this research is to compare the optical response of rectangular and hexagonal unit cells for the gold nanoparticles with the same geometrical properties and distance between the periodically placed nanoparticles and to study the effect of changing the conditions of the incoming light.