| In this dissertation,the scattering properties of aerosol particles illuminated with a plane wave/shaped beam are studied.The haze particles mainly includes ammonium sulfate,sulfuric acid,ammonium nitrate and carbon particles.The research of scattering characteristics mainly includes that scattering phase function,scattering intensity and differential scattering cross section change with the scattering angle,and that the extinction efficiency factor,scattering efficiency factor and absorption efficiency factor change with the size parameters of particle.The main results are as follows: 1.Based on Mie theory,the scattering properties of homogeneous spherical and water-containing stratified spherical aerosol particles of haze illuminated with plane wave are studied,and their difference were compared.And then the scattering properties of the aerosol particles of haze with homogeneous rotationally symmetric ellipsoid,cylinder and Chebyshev shapes illuminated by a plane wave were studied by using the T matrix method.The scattering properties of the sphere particle are compared with the scattering properties of spheroidal particle.It is concluded that the spheroidal particle can be equivalent to the sphere particle when the axis ratio of the spheroidal is close to 1,and when the rotation ellipsoid particles is close to the needle shape,it can’t be equivalent to the sphere particles to calculate the scattering properties.Finally,the scattering properties of the different shapes of the rotationally symmetric particles are compared.2.The scattering properties of cluster aerosol particles of haze illuminated by plane waves were studied by generalized multi-particles Mie theory(GMM).The scattering properties of single component cluster and mixtures component cluster are compared.And the scattering properties of the cluster illuminated by plane waves with different incident direction are compared.And the scattering properties of the aggregation fractal clusters are calculated by using the generalized multi-particles Mie theory(GMM),there clusters are produced by the software of the diffusion limited aggregation(DLA)model.The effect of the incident wave direction and the aggregation fractal cluster component on the scattering properties are analyzed and compared.3.The scattering properties of homogeneous spherical and water-containing stratified spherical aerosol particles of haze illuminated by shaped beam are studied by using generalized Lorenz-Mie theory(GLMT),and their difference were compared.(1)Based on the localized approximation method in generalized Lorenz-Mie theory,the expression of Gaussian beam shaped coefficients is given.A program for numerically calculating the scattering properties of homogeneous spherical and stratified spherical particles illuminated by Gaussian beams is designed.The difference of the scattering properties of homogeneous spherical and water-containing stratified spherical aerosol particles of haze illuminated by plane wave and Gaussian beam are compared.(2)The expression of beam shaped coefficients of the Bessel vortex beam is deduced by the integral localized approximation method in the generalized Lorenz-Mie theory.Based on the above derivation,a program for numerically calculating the scattering properties of homogeneous spherical and stratified spherical particles illuminated by Bessel vortex beams is designed,The differential scattering cross section changing with the scattering angle of a spherical particle illuminated by the zero-order Bessel vortex beam are compared with the results of the references,and the correctness of the program is proved.The scattering properties of homogeneous spherical and water-containing stratified spherical aerosol particles illuminated by different topological charge Bessel vortex beams are studied.(3)The expression of the electromagnetic field of the Laguerre Gaussian beam in the space Cartesian coordinate system is deduced by using the angular spectrum method.The expression of the beam shaped coefficients of a spherical particle illuminated by Laguerre Gaussian beam is deduced by the integral localized approximation method.A simulation program for numerically calculating the scattering properties of spherical particles illuminated by Laguerre Gaussian beam is designed.The correctness of the simulation program is verified by comparing the scattering properties of homogeneous spherical particles illuminated by zero order Laguerre Gauss beam with x axis polarized Gauss beam.In the end,the scattering properties of the homogeneous spherical and water-containing stratified spherical aerosol particles illuminated by different topological charge Laguerre gauss beams are studied. |
PDF Full Text Request