Light scattering by an infinite cylinder of arbitrarily smooth cross section based on vectorial complex ray model

Abstract

This paper reports the extension of vectorial complex ray model allowing to account, in the high-frequency limit, for the direction, polarization, curvature of wave front, amplitude, phase and scattered intensity of the light rays interacting with an infinite cylinder of arbitrary while smooth cross section. Based on the proposed method, a numerical study is performed on the scattering patterns of composite elliptical cylinders (CEC). The effects of shape deformation, refractive index and the direction of incident wave on the scattering patterns of the CEC whose cross sections approximate the shapes of realistic raindrops are investigated and quantitatively analyzed, which provides insight into how these factors affect the appearance of a natural rainbow. Being flexible and numerically efficient (a full scattering diagram is obtained in few seconds on a laptop computer), the method proposed in this paper is thought to have important applications in calculating and analyzing the scattering characteristics of light by cylindrical objects of cross sections ranging from simple to complex.