Lateral shifts of linearly- and radially-polarized Bessel beams scattered by a nanosphere.

Abstract

We report the investigation on the lateral shifts that linearly-polarized (LP) and radially-polarized (RP) Bessel beams experience during the Mie scattering by a nanosphere. A numerical procedure based on the angular spectrum theory is developed to solve the scattered electromagnetic field and subsequent lateral shifts with a high computational efficiency, which can be easily applied to an arbitrary shaped polarized beam. The influences of different factors, including conical angle, nanosphere radius and position, on the lateral shifts are systematically investigated. The results demonstrate that for on-axis scattering, a LP Bessel beam can be regarded as a plane wave with the same polarization state but an equivalent longer wavelength, while a RP Bessel beam can be regarded as a plane wave with a polarization state along the propagation direction exhibiting independence on the conical angle. The findings help deepen our understandings of lateral shifts in light scattering of vectorial non-diffractive beams.