Adding a spin to Kerker's condition: arbitrary scattering direction tuning of nano-antennas with designed excitation

TL;DR

This paper presents a method to dynamically control the scattering direction of dielectric nanospheres using tailored optical excitation, enabling arbitrary in-plane scattering tuning over a broad wavelength range.

Contribution

It introduces a novel optical excitation technique employing azimuthally and radially polarized beams to independently excite magnetic and electric dipoles inside a nanosphere, allowing precise scattering direction control.

Findings

Scattering direction can be tuned within a plane.

Method works across a broad wavelength spectrum.

Independent excitation of magnetic and electric dipoles achieved.

Abstract

We describe a method to control the directional scattering of a high index dielectric nanosphere, which utilizes the unique focusing properties of an azimuthally polarized phase vortex and a radially polarized beam to independently excite insde the nanosphere a spinning magnetic dipole and a linearly polarized electric dipole mode normal to the magnetic dipole. We show that by simply adjusting the phase and amplitude of the field on the exit pupil of the optical system, the scattering of the nanosphere can be tuned to any direction within a plane and the method works over a broad wavelength range.