Broad-Band Transmission Characteristics of Polarizations in Foggy Environments

Abstract

Based on the Monte Carlo (MC) algorithm, we simulate the evolutions of different types of the polarized lights in the broad-band range from visible to infrared in foggy environments. Here, we have constructed two scattering systems to simulate the transmission characteristics of the polarized lights: (1) A monodisperse system based on five types of particles with the sizes of 0.5, 1.0, 2.5, 4, and 5 µm, respectively; (2) a polydisperse system based on scattering particles with a mean value (size) of 2.0 μm. Our simulation results show that linearly polarized light (LPL) and circularly polarized light (CPL) exhibit different advantages in different wavelengths and different scattering systems. The polarization maintenances (PM) of the degree of circular polarizations (DoCPs) are better than those of the degree of linear polarizations (DoLPs) for most incident wavelengths. CPL is not superior to LPL in the strong-absorption wavelengths of 3.0µm, 6.0µm, and long infrared. Here, when the wavelength is closer to the particle sizes in a system, the influence on propagating polarizations will be more obvious. However, the difference in the degree of polarization (DoP) between the resulting CPL and LPL is positive at these points, which means the penetrating ability of CPL is superior to that of LPL in these scattering systems. We have also simulated the extinction efficiency Qext and the scattering index ratio Qratio as functions of both wavelength and particle size for analyzing polarization’s transmission characteristics. Our work paves the way of selecting the optimal incident wavelengths and polarizations for concrete scattering systems.