Differentiation of soot particulates in air using polarized light scattering method.

Soot is the main light-absorbing particle in the visible range. Light scattering and absorption by air particulates can change their optical polarization state, and the information upon polarization can reflect the nature of particles. In this paper, a polarization scattering method has been developed for the feasibility study concerning differentiating soot from other typical air particulates. Simulation results indicate that S2/S0 at the scattering angle of 115° can identify the soot particles specifically. Single component experiments and double composition experiments are carried out, which confirm the validity of differentiating soot by a polarization indicator. These preliminary simulations, experiments, and field tests also imply the potential of polarization characterization applied in air pollutants analysis.