不同湿度环境下可见光波段激光偏振特性研究

Abstract

Haze weather interferes with the visible light imaging effect, and the polarization characteristic of visible light can effectively improve the detection efficiency. Haze environment is affected by aerosol particle humidity, which is an important physical parameter of haze environment. In order to obtain the polarization characteristics of visible light in haze environment, the influence of humidity in haze environment on polarization characteristics was analyzed. Based on the single particle scattering characteristics of non-polarized light aerosol, the polarization transmission model was established by improved Monte Carlo method, research on transmission characteristics of polarized light in visible bands under different humidity and water mist was conducted, the influence of humidity change in water mist environment on polarization characteristics of polarized light in different visible bands was analyzed, and a near-real water mist environment was built. The polarization model was verified by laboratory experiments, the change of polarization degree and polarization state of linear polarized light on 450, 532 and 671 nm was compared and analyzed under different humidity conditions, the confidence of simulation model was more than 60%. The results show that the polarization degree of polarized light decreases with the increase of humidity of water-fog environment. With the increase of the wavelength, the polarization tends to be flat, while the exit polarization degree increases with the increase of wavelength. The humidity values of the descending point of polarization degree are 50%, 70% and 90% when the laser wavelengths are 450, 532, 671 nm, respectively. For water mist, which is easily affected by humidity, polarized light with longer wave length should be selected as far as possible for transmission detection in visible band. Because humidity has a greater influence on shorter wavelengths than longer wavelengths, circularly polarized light with longer wavelengths has the best polarization retention characteristics in environments with higher humidity. In the environment with high humidity, polarized light imaging with long wavelength should be selected as far as possible to achieve better imaging effect.