Stokes parameters measurement system designed by symmetric division of amplitude with double quarter-wave plate

Abstract

In order to accurately detect the full Stokes parameters of atmospheric aerosol, a Stokes parameters measurement system is designed by symmetric division of amplitude with double quarter-wave plate in this paper. The system adopts light normal incidence, amplitude symmetric dividing and two quarter-wave plates fixed at 45°. The design makes the structure of the system optical path simple. The polarization effect and intensity loss of the optical path is low. The system is calibrated using eight-point method. The results of experimental show that the system matrix A is more accurate after eight-point calibration, and the total RMS (Root-Mean-Square) deviation of Stokes parameters is reduced by 57.8% and 43.3% compared with four-point and six-point calibration method, respectively. This shows that the system can accurately measure the full Stokes parameters of any incident light in real time. We used this system to measure and invert the full Stokes parameters of dust aerosol particles using six different concentrations. The backscattering matrix of dust aerosol was inverted using its Stokes parameters. It was found that the Stokes parameters of the same dust aerosol particles varied with concentration. The elements values of the backscattering matrix F22/F11, F33/F11 and F44/F11 almost unchanged with concentration. This system can measure the full Stokes parameters of aerosols accurately. It can be used to study the polarization characteristics and microphysical properties of the atmospheric aerosols. It also has a good practical guiding significance for the remote sensing of atmospheric aerosols.