Electromagnetic Scattering Of A Composite Material Sphere By An Arbitrarily Incident Gaussian Beam

The interactions of the anisotropic, bi-isotropic and many other complex material particles with a laser beam are of great theoretical significance and wide applications in the fields of atmosphere optics, radar remote sensing, laser fusion, biomedicine and nanometer material science. The main work and results in this paper are as follows:1. The scattering characteristics of a uniaxial anisotropic sphere in a Gaussian beam are developed when the beam propagates nonparallel to the primary optical axis. Based on the Fourier transform and spherical vector wave functions, both the scattering and internal field coefficients are analytically derived. The angular distributions of the scattering intensities, near-surface fields, as well as the two eigen modes for the internal fields are calculated. The effects of the beam width, beam waist center position and the anisotropy ratio on scattering properties are discussed.2. Based on the addition theorem for spherical vector wave functions under coordinate rotations, scattering characteristics of an anisotropic sphere in an obliquely incident Gaussian beam are also proposed for both on-axis and off-axis cases. The influences of the incident angle, the anisotropy ratio, as well as the beam waist center position on the field distributions are numerically analyzed in the case of oblique incidence.3. An analytical solution to the scattering of an anisotropic coated sphere in a Gaussian beam with arbitrary illumination is presented, too. The scattering properties of a plasma anisotropic-coated conducting sphere, a uniaxial anisotropic-coated spherical shell, as well as a nucleated blood cell in a Gaussian beam are obtained. The applications of this theoretical development in the fields of biomedicine, target shielding and anti-radar coating are discussed.4. The stable and accurate recursive formulas are proposed to calculate scattering coefficients for a chiral sphere in a Gaussian beam.The angular distributions of the far-scattered fields, near-surface fields, as well as the two eigen modes for the internal fields are analyzed. The scattering characteristics of a chiral-coated conducting sphere are further discussed.