多层球对高斯波束散射的德拜级数研究

Debye Series of Gaussian Beam Scattering by a Multi-Layered Sphere

基于广义洛伦兹-米氏理论,利用多层球粒子散射系数的德拜级数展开公式,提出了一种新的研究多层球粒子对高斯波束散射的方法。计算结果与已有的广义洛伦兹-米氏理论算法的计算结果吻合得很好。利用该方法有效分离了折射率分布满足指数变化规律的多层球粒子对高斯波束散射的远区散射场中多阶彩虹的干涉强度分布。数值模拟了双层球的归一化双一阶彩虹强度分布以及各层的一阶彩虹艾里结构。最后分析讨论了高斯波束的入射位置和束腰半径对多层球单阶彩虹强度分布的影响。

On the basis of the generalized Lorenz-Mie theory, a new method to study Gaussian beam scattering by a multi-layered sphere is presented by the formula of the Debye series decomposition for scattering coefficients. The results calculated by this method and by the generalized Lorenz-Mie theory agree well. The scattered field distribution in the far-zone of a multi-layered sphere illuminated by Gaussian beam is simulated and the interference intensity distribution of mixed order rainbows is separated efficiently. The refractive index profile of the multilayered sphere is exponential versus the radial position. The intensity distribution of the twin first-order rainbow and the Airy structure of each layer by a two-layered sphere are simulated. At last, the influence of incident position and beam waist on scattering intensity distribution is discussed.