Resonance structures in elastic and Raman scattering from microspheres

Abstract

To study the interactions between Mie scattering and Raman emissions of spherical particles, we measured the Raman spectra together with the elastically scattered light of the excitation source of an evaporating aqueous sodium nitrate droplet. Resonance structures were observed in the temporal profiles of the elastically scattered light and Raman nitrate and water emissions. The resonance structures in these three profiles occurred in a concerted mode but sometimes occurred independently of each other. A model of inelastic scattering by microspheres by Kerker et al. ["Raman and Fluorescent Scattering by Molecules Embedded in Spheres with Radii up to Several Multiples of the Wavelength," Appl. Opt. 18, 1172-1179 (1979); "Lorenz-Mie Scattering by Spheres: Some Newly Recognized Phenomena," Aerosol Sci. Technol. 1, 275-291 (1982); "Inelastic Light Scattering," in Aerosol Microphysics I: Particle Interaction, W. H. Marlow, Ed. (Springer-Verlag, New York, 1980); "Model for Raman and Fluorescent Scattering by Molecules Embedded in Small Particles," Phys. Rev. A 13, 396-404 (1976)] and the behavior of low order Mie resonances were used to explain the data. This type of data can be used for the determination of chemical compositions of spherical particles.