The index of refraction of supercooled solutions determined by the analysis of optical rainbow scattering from levitated droplets

We present a novel method for the determination of the index of refraction of single droplets by light scattering measurements in the region of the first and second order rainbow. An inversion algorithm is proposed which allows to extract the refractive index with high precision from the position and width of both rainbow peaks. The method is applied to determine the index of refraction of supercooled levitated water droplets in the temperature region between 237 K and 273 K.