Effects of environment variation of glycerol smoke particles on the persistence of linear and circular polarization.

ABSTRACT

Environment variation is an important factor affecting the polarization propagation through the smoke. In this paper, we investigate the effects of the relative humidity and optical thickness on polarization transmission character, as well as the persistence of the linear and circular polarization of artificial smoke particles with simulations and experiments. We develop an environment modulation system to control the environment variation and measure the transmission degree of polarization (DOP). Correspondingly, by building the relation between the smoke filling time and optical thickness, as well as between the relative humidity and particle size and refractive index, we utilize the Monte Carlo program to track photon scattering process through varying the radius, refractive index and optical thickness. Both the simulation and the experimental results show that the DOP of both linear and circular polarizations are constantly decreased with the increasing of the optical thickness. However, at the same optical thickness, both the linear and circular polarization's persistence benefits with the increasing of the relative humidity. Moreover, circular polarization persists better than linear polarization in the larger optical thickness and the higher humidity environment under the wavelength of 532 nm. These works can verify the persistence of circular polarization and broaden the application range of polarized lights in a variable artificial smoke environment.