Intensity and Polarization of Light Scattered by Some Permanent Gases and Vapors

A light-scattering instrument has been developed and used to determine the polarization ratios and scattering powers of nitrogen, oxygen, carbon dioxide, air, a 79.6% nitrogen–20.4% oxygen mixture, propane, butane, and dimethyl ether. Measurements were made with three types of incident light—unpolarized, horizontally plane polarized, and vertically plane polarized. Three methods were used to measure the polarization ratio for unpolarized incident light, ρu; two to measure that with vertically plane-polarized light, ρυ; and one for horizontally polarized light, ρh. Good agreement was obtained between experimental results and predictions from Rayleigh's theory of anisotropic scattering by small particles.