采用CCD线阵的散射光强角分布测量系统, 测量了水、 酒精液柱、 光纤的彩虹角分布。 根据严格米氏理论, 数值研究了大尺寸参数圆柱的彩虹现象, 获得与实验相吻合的数值结果。 讨论了几何光学和艾里理论局限性, 将米氏理论和几何光学结合, 对彩虹现象给予了更为合理的解释。 利用第一级彩虹角反演折射率, 以及将彩虹强度导数角分布进行快速傅里叶变换获得了角谱反演圆柱粒子的直径。 并讨论了利用角谱反演粒子折射率和直径的精度。

The experimental results of the first and second rainbows for water, alcohol jet and fiber are measured by rainbow refractometer with a linear CCD camera. Based on Mie theory the rainbow intensity distribution is calculated, and numerical results agree with the experiment. The limitation of the geometric optics and Airy theory is discussed. And the rainbow phenomena are interpreted reasonably by using geometric optics and Mie theory. The refractive index can be determined by the first rainbow angle. Based on the fast Fourier transform of the derivative distribution of rainbow intensities, the diameter of a droplet is measured by the angular frequencies. The precision of measurement is also discussed by means of the angular frequency.