Elastic light scattering of a single sphere in a Gaussian light sheet

Abstract

Elastic light scattering has been proven to be an effective tool to characterize particles in a non-contact manner for the advantage of sub-wavelength resolution and ability of retrieving optical properties. But measurements based on plane wave scattering usually yield to weak scattering light, which poses strict requirements on the sensitivity of detection system. Gaussian light sheet that converges in one dimension can greatly enhance the intensity of scattering light, but it leads to the position dependence of light scattering. In this paper, characteristics of light scattering of a sphere in a Gaussian light sheet are numerically studied. Influences of sphere radius, refractive index, waist radius and sphere positions are systematically investigated via parametric study. Results show that the structure and optical information of the sphere are encoded into the scattering light. When the sphere radius is much less than the waist radius of light sheet, the angular distribution of scattering light of Gaussian light sheet is similar to that of plane wave scattering. The similarity decreases with increase of sphere radius and deviation from the optical axis. The proposed numerical method has the advantage of high efficiency and precision, providing the theoretical basis for inverse modeling.