Optical pulling of chiral Rayleigh particle due to coupling effect

Abstract

The presence of strong near-field coupling interactions is shown in significant alterations to the electromagnetic field distribution of the nearby nanoparticles (NPs) in recent research studies, resulting in the formation of unique optical force behavior. Through interactions with plasmonic, glass, and anisotropic metamaterial substrates, chiral Rayleigh particles show not only unique optical force behaviors in this article but also a strong capacity to change the surrounding electromagnetic environment, which can be a novel approach. To date, as far as we know, no report has identified numerical and analytic solutions of the chiral NP pulling force behavior due to coupling with another NP on plasmonic and anisotropic metamaterial substrates. Counterintuitive force direction reversal is observed on chiral Rayleigh particle when plane-wave illumination is applied to not only an isolated chiral Rayleigh particle but also when chiral with nearby dielectric and plasmonic NPs, resulting in an individual chiral experiencing a pushing force, the introduction of nearby other NPs induces an optical pulling force on variation in wavelength, incidence angle, and radius. It is unfortunate that this pulling behavior does not work on a glass substrate. The intrinsic chiral nature influences the configuration of the surrounding electromagnetic fields, thereby increasing the system’s susceptibility to environmental variations. To interpret these phenomena, the coupled electric and magnetic dipole approximation method was employed in this paper, and this study establishes the crucial role in achieving precision manipulation of chiral NP that offers new pathways for control in nanophotonics, optical trapping, and optimizing metamaterials.