Improved calculation of the Mie solution and the geometrical optics approximation for large droplets

Abstract

This article considers energy distribution of light inside a uniformly illuminated transparent water droplet. Two methods are used: the geometrical optics approximation and the Mie solution derived from wave optics. The authors describe in detail calculation algorithms suitable for efficient computer implementation and ways to improve them. In the limit for large droplets, both similarities and differences between the methods are pointed out. Resonant states are discussed, when the usually dark regions of the droplet turn out to be illuminated.