Analyzing morphology-dependent resonances observed in optical processes, like Raman scattering or fluorescence emission from single microparticles, allows an exact determination of size, refractive index, and optical dispersion. The main feature of the method discussed here is an exact Mie calculation combined with an optimization program. The results obtained from a gradient-trapped emulsion particle and those from an optically levitated droplet are discussed to show the advantages of the method. It is further demonstrated that only by a precise analysis of the observed morphology-dependent resonances is it possible to describe the droplet evolution.
J. Popp, M. Lankers, M. Trunk, I. Hartmann, E. Urlaub, and W. Kiefer, "High-Precision Determination of Size, Refractive Index, and Dispersion of Single Microparticles from Morphology-Dependent Resonances in Optical Processes," Appl. Spectrosc. 52, 284-291 (1998)