Study On Scattering Of Bessel Beam By Typical Particles With Shell

The study of light scattering by various particles has always been an important subject of research in many areas of practical applications, such as grain size analysis, environmental monitoring, combustion technology, and particle capture. For the case of an incident plane wave or Gaussian beam, there have been many investigations of light scattering properties by particles. As a typical non-diffracting beam, the scattering of Bessel beam by particles deserves widely study. Over the past few years, the studies on the scattering of particles by Bessel beam have been reported several times. However, as we have already observed, these studies mainly focused on the cases of homogeneous spheres, and the scattering analysis of Bessel beam by particles with other structures has not been reported in the existing literatures.Within the Generalized Lorenz-Mie theory (GLMT), the scattering of an on-axis zero-order Bessel beam by typical particles with shell is theoretically investigated by the method of expansion of spherical vector wave functions (SVWFs) and spheroidal vector wave functions. Specially, the typical particles with shell include concentric spheres, multilayered spheres, eccentric spheres, conducting spheroids with dielectric coating. The main work and results are summarized as follows:1. In the research on the study of shape beam scattering by particles, the calculation of beam-shape coefficients (BSCs) is a key point. According to the integral localized approximation (ILA), an analytical formula for BSCs of the on-axis zero-order Bessel beam is given in the spherical coordinate system. The BSCs is validated by three methods, including the convergence analysis, the comparison of the scattering results of degradation Bessel beam and plane wave, and the comparison of the analytical result and the numerical result obtained from the surface integral equation method (SIEM).2. Using the BSCs, the scattering properties of Bessel beam by a homogeneous sphere is investigated. The difference and sameness among the scattering results of plane wave, Gaussian beam and Bessel beam by a homogeneous sphere are analyzed. The effects of the beam half-angle, the sphere radius, the refractive index of medium in the sphere on the scattering are analyzed in detail.3. The scattering of Bessel beam by a concentric sphere, a multilayered sphere is firstly studied. And the analytic solutions to the scattering of Bessel beam by two different particles are presented in detail respectively. The corresponding calculation program is proved to be credible using the method of comparison between the analytical result and numerical result of SIEM. The detailed results on the effects of the beam half-angle, geometric parameters, the refractive index of medium on the scattering are given.4. The scattering of Bessel beam by an eccentric sphere is investigated for the first time. And the analytical solution to the beam scattering is presented in detail. Also, the corresponding program of the scattering calculation is validated by the comparison between analytical solution and numerical solution. Some numerical results on the effects of several corresponding parameters on the scattering are also given.5. Based on the BSCs of Bessel beam in spherical coordinate system, the corresponding formula of BSCs for Bessel beam in spheroidal coordinated system is given with the aid of the relationship between SVWFs and spheroidal vector wave functions. The scattering of Bessel beam by a conducting spheroid with dielectric coating is firstly studied. Using the calculation program of the scattering for the conducting spheroid with dielectric coating by Bessel beam, the scattering result of plane wave by conducting sphere with dielectric coating is given. Comparing our results to those in other references, the program is validated. Some numerical results for the scattering of Bessel beam by a spheroid with dielectric coating are presented.