Scattering of a vector Bessel-Gaussian beam by a sphere

The interaction of a vector Bessel-Gaussian beam (VBGB) with a dielectric sphere is investigated in the framework of generalized Lorenz-Mie theory (GLMT). The electric field of a VBGB is derived using the angular spectrum decomposition method (ASDM), and the analytical expressions of beam shape coefficients (BSCs) are derived utilizing multipole expansion method using vector spherical harmonics. Various polarizations including linear, circular, radial, and azimuthal polarizations are considered. The far-field scattered intensities are numerically computed, and numerical results show that the beam parameters (including beam-waist radius w(0), location of beam center, half-cone angle theta(b), and polarization type) strongly affect the far-field scattered intensities. The internal and near-surface fields are also calculated, and numerical results show that for smaller theta(b) two curves formed by extreme peaks can be observed, and for larger theta(b) such curves disappear and local enhancement of electric fields on the surface can be observed. Such results have important applications in various fields, including particle sizing, optical trapping and manipulation, etc. (C) 2017 Elsevier Ltd. All rights reserved.