Study Of Rainbow For Homogeneous And Inhomogeneous Particles

On the basis of Lorenz-Mie theory, this paper is devoted to the research oncharacteristics of intensity and spectrum distributions of each order rainbow for ahomogeneous particle, with the usage of geometric optics theory, Airy theory andDebye theory. The results show that for some refractive index, the intensity distributionof the first or second rainbow is not single, but the interference intensity distributionwith other high order rainbow (the fourth or the fifth rainbow). Each order rainbow canbe separated and reconstructed from the interference intensity distribution, using Lowor band pass filtering for the interference spectrum of the intensity and IFFT. Thesimulation of Debye theory and the experimental results can prove the results obtained.The relation of ripple frequency of the second rainbow with the diameter of particle issimulated by Lorenz-Mie theory, and used in particle sizing with high precision.The characteristics of each rainbow for an inhomogeneous particle are studied hereusing Lorenz-Mie theory. The relation of the positions of Airy peaks to each orderrainbow with the profile of refractive index is simulated and discussed, which iscompared with the results simulated by ray tracing theory.