Light scattering by a charged infinite cylinder in a transparent medium

Although charged particles exist widely in a plasma environment or an electrolyte, the problem of electromagnetic scattering by a charged cylinder has remained unsolved. In this paper, using the tangential boundary conditions with a surface current induced by excess surface charges, we calculate the extinction, scattering and absorption efficiencies for a charged infinite cylinder upon which a plane wave is normally incident. For two polarizations of the incident light, we show the different effects of the excess surface charges on the optical efficiencies. For p- polarization, the extinction efficiencies own a platform structure where the extinction is in proportion to the density of surface charges, which corresponds to the light absorption by the excess surface charges. For s- polarization, the excess surface charges will induce a new resonance at the dielectric function of the cylinder larger than - 1 and a shift on the anomalous resonance which can only exist for the dielectric function near and smaller than - 1. The increasing surface charge density can shift these resonances to a larger size parameter and broaden the widths of the anomalous resonances. Furthermore, considering a specific case of a charged MgO cylinder, we identify a blue shift of the resonances near the longitudinal optical phonon frequency. (C) 2020 Elsevier Ltd. All rights reserved.