Light scattering from an optically anisotropic particle illuminated by an arbitrary shaped beam

A solution for light scattering from an optically anisotropic particle illuminated by an arbitrary shaped beam is proposed in this paper, which is implemented using a combination of a recent developed T-matrix approach for anisotropic particles and the description of arbitrary shaped beam originally derived in the generalized Lorenz–Mie theory (GLMT). The internal fields inside anisotropic particle are expanded in terms of a series of quasi-spherical vector wave functions (qSVWFs) which are derived using an inverse Fourier transform operation, and the incident shaped beam is expanded in terms of the regular spherical vector wave functions (SVWFs), then the scattering transition matrix of an anisotropic particle is obtained using the extended boundary condition method (EBCM) technique. Verification computations are implemented for a uniaxial anisotropic particle illuminated by a focused Gaussian beam . Comparisons are made between the results obtained using the presented method and those calculated using other methods. Furthermore, numerical calculations are performed to study the influences of shaped beam parameters (beam waist radius, incident angles) and of particle parameters on the scattering properties.