The present paper may be viewed as built from comments concerning a recently published paper in Journal of Quantitative Spectroscopy and Radiative Transfer, and actually constitutes as well a rebuttal of some of the claims it contains. The issue considered concerns the computation of scattering properties of the interaction between an arbitrary electromagnetic shaped beam and a homogeneous sphere. Our discussion of the issue may be easily extended as well to more general cases, beyond the simplest case of a homogeneous spherical scatterer, up to the case of arbitrary shaped particles in the framework of T-matrix formulation. Finally, we take the opportunity of the present paper to review the use of the angular spectrum decomposition in light scattering.

Efficient computation of arbitrary beam scattering on a sphere: Comments and rebuttal, with a review on the angular spectrum decomposition

Propagation of Lorentz-Gaussian elliptical multi-Gaussian correlated Schell-Model beam in anisotropic turbulence

An analytical expression of an elliptical Bessel beam (EBB) is deduced on the basis of the angular spectrum decomposition (ASD) method, starting from an elliptical Bessel-like profile in the initial transverse plane. The angular spectrum representation is also obtained for another approximate EBB that is produced by the refraction of a circular Bessel beam at an interface in oblique incidence. The expressions are further expanded into a series of vector spherical harmonic functions for describing the scattering of the beams by a spherical particle. Numerical calculations are implemented with different parameters and the results are discussed. A length parameter is obtained for evaluating the variation of the EBB along the propagation. It is confirmed that the refracted CBB at small incident angle behaves in a similar way to the EBB. When the incident angle increases, the asymmetry of the transverse beam profile becomes serious and the propagation of the beam deviates gradually from the predicted direction.

Yide Zhang

Papers

Comparison of a standard elliptical Bessel beam and a refracted circular Bessel beam at oblique incidence