Identification method of atmospheric non-spherical aerosol based on vortex light scattering

Vortex laser beams carrying orbital angular momentum (OAM) have extensive research value and application prospects in the fields of optical communication, particle micromanipulation, and high-precision measurement. In this study, the scattering and polarization characteristics of vortex beams interacting with non-spherical particles are explored, and multiple polarization parameters are obtained and used as indicators to realize the identification of different shapes and different types of non-spherical aerosol particles, which are different from the currently used P 11 index under plane wave incidence. First, taking the ellipsoid and cylinder shapes of carbonaceous aerosols as an example, the scattering matrix is numerically simulated based on the discrete dipole approximation (DDA) method, and the variation curves of individual polarization characteristics elements with scattering angle are obtained under vortex beams with different topological charges L . The results showed that, at the scattering angles of 0°, 90°, and 180°, multiple polarization parameters related to particle shape have been discovered, and the values of P 33 / P 11 , P 34 / P 11 , and P 44 / P 11 under L = 0, 2, and 3 are opposite, and most of the absolute deviation were valued > 0.8 for the two shapes in the direction of 90° scattering angle. Furthermore, the polarization characteristics of dust and black carbon (BC) are investigated under different vortex beams. Several indicators related to aerosols were also found, and at the scattering angle of 180°, the polarization parameters P 22 / P 11 , P 34 / P 11 , and P 44 / P 11 , can effectively identify the dust and BC aerosol particles under the topological charge L = 3. This study will provide an important theoretical basis for the development and application of vortex light lidar in the atmospheric field, and has great potential and application prospects in aerosol identification, classification, and climate numerical simulation.