Open AccessDimer of dielectric nanospheres as a generalized Huygens element
Author(s) -
Alexey A. Dmitriev,
Mikhail V. Rybin
Publication year - 2022
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/2227/1/012016
Subject(s) - multipole expansion , dipole , dimer , scattering , physics , discrete dipole approximation , wavelength , molecular physics , optics , coupling (piping) , plane wave , light scattering , scattering amplitude , optical theorem , amplitude , dielectric , materials science , optoelectronics , quantum mechanics , nuclear magnetic resonance , metallurgy
We study the conditions of suppressed backward scattering in optical oligomers. Optical oligomers are closely packed clusters of nanoparticles which support multiple resonances, allowing to achieve scattering phase rotation by 2π necessary for metalenses. In this paper we consider the simplest oligomer — a dimer, which is irradiated by a normally-incident plane wave with the magnetic field oriented along the dimer axis. Using the dipole approximation, we have derived analytically the generalized Kerker condition for this system. Similarly to a single sphere case, the electric and magnetic dipole have to be of the same amplitude to suppress the backward scattering. However, due to the inter-particle coupling, the full coupled-dipole problem must be solved to find the wavelength of the backscattering suppression. Using the coupled-dipole and coupled-multipole methods, we have found that the Kerker condition wavelength for the considered dimer is red-shifted compared to a single sphere.