Polarization state persistence characteristics in wet haze within PM2.5 for forward transmission

摘要

This study evaluates the polarization state persistence of differently polarized light as they propagate through wet haze (PM2.5), inforward transmission. The investigated wavelength range extends from ultraviolet (UV) to short-wave infrared (SWIR) light. Using apolarization tracking Monte Carlo simulation for a range of particle sizes, wavelengths, relative refractive indices, and propagationdistances, we find that both vertically-linearly- and right-handed-circularly-polarized light show superior polarization state persistenceat a wavelength of 2.4μm. While the persistence increases gradually for increasing wavelengths, the study also reveals an anomaly, apersistence peak for wet haze with 2μm particles and 0.36μm wavelength. We further compare the polarization state persistencecharacteristics of vertically linearly and right circularly polarized light. Circular polarization persists better than linear for wet haze inwavelengths of 0.36, 0.543, and 1μm. While with the increase of wavelength and the decrease of particle size, linear polarizationgradually persisted better than circular polarization.