Experimental observations of spectral changes produced by individual microscopic spheres

Spectral changes in individual micrometer-sized scatters are experimentally measured. Using an interferometric microscope equipped with a wavelength-swept illumination, the optical fields diffracted from the individual scatters are measured precisely, from which 2D light scattering spectra were retrieved as functions of the wavelength and scattering angle. In the measured scattering spectra of individual scatters, spectral shifts were clearly observed, which is also directly explained using the Mie scattering theory.