在入射自然光和线偏振光两种常见情况下,基于Mie理论和Debye级数展开,模拟了整体散射光和各阶散射光的偏振度和偏振比分布。研究结果表明:自然光入射时的散射光一般为部分偏振光,当粒径小于波长时,偏振度分布与Rayleigh散射的一致;当粒径大于波长时,整体散射光的偏振度在前向散射角很低,随着散射角的增加逐渐增高但变化频繁,在彩虹角处有很高的值。当入射光为线偏振光时,散射光一般为椭圆偏振光,整体散射光和各阶散射光的偏振比都很高,只有当方位角远离0°、90°、180°时才会出现极小值。

Under the two common conditions of incident natural light and linearly polarized light, we simulate the polarization degree and polarization ratio distributions of whole scattered light and various orders scattered light based on Mie theory and Debye series expansion. The results show that the scattered light is usually partially polarized when incident light is natural light. The distribution of polarization degree is consistent with Rayleigh scattering when the particle size is less than the wavelength. When the particle size is larger than the wavelength, the polarization degree of the whole scattered light is very low at the forward scattering angle, and increases with the increase of scattering angle but changes frequently, and get a high value at the rainbow angle. The scattered light is commonly elliptically polarized light when the incident light is linearly polarized light. In this case, the polarization ratios of the whole scattered light and various orders scattered light are high. A minimum value occurs only when the azimuth angle is far from 0°, 90° and 180°.