Scattering of a vector Bessel-Gaussian beam by a sphere

- The interaction of a vector Bessel-Gaussian beam with a dielectric sphere is investigated in the framework of GLMT.
- Analytical expressions of BSCs for vector Bessel-Gaussian beams with selected polarizations are derived using ASDM.
- The far-field scattered intensities are computed, and the effects of w0, x0, α0 and polarization type are investigated.
- The local enhancement of internal and near-surface fields is investigated.
- The polarization, half-cone angle and location of the beam affect the local enhancement.

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 w0, location of beam center, half-cone angle θb, 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 θb two curves formed by extreme peaks can be observed, and for larger θb 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.