Scattering of Gaussian beam by a large nonspherical particle based on vectorial complex ray model

To describe the interaction of a shaped beam with a particle, the well-known generalized Lorenz-Mie theory (GLMT) has been developed in the past three decades. However, because of the dependence on the method of separation of variables, it is limited to particles of simple shapes such as spheres. In recent years, the vectorial complex ray model (VCRM) has been developed for the light/electromagnetic wave interaction with a particle/object of any shape with a smooth surface. Considering the asymmetry of the scattered field by nonspherical particles, we have extended the VCRM for the three-dimensional scattering problems (VCRM3D). Nevertheless, the numerical implementations of VCRM3D were focused on the plane wave scattering. In this paper, we extend the VCRM3D for the Gaussian beam scattering by large nonspherical particles. A careful examination on the calculation results is made by comparing with the GLMT for spherical particles and good agreement is found. The proposed method is then applied to the calculation for the 3D scattered intensity of Gaussian beam by a large dielectric spheroid. This work opens perspectives for exploring the shaped beam scattering by a large particle/object of any smooth surface in 3D space.