Elastic and Inelastic Light Scattering at Wavelengths On and Off Structure Resonances of Spheres and Cylinders

摘要

Elastic and inelastic light scattering at wavelengths on and off structure resonances of micrometer sized spheres and cylinders are investigated. Spectral and angular distributions are examined both experimentally and theoretically. Structure resonances in the elastic scattering occur when the incident wavelength corresponds to a discrete natural mode of oscillation of the sphere. Based on previous studies indicating that structure resonances are expected to occur for inelastic emission from fluorescent dipoles within the sphere, such structure resonances were observed at specific fluorescent wavelengths from a single dye-impregnated polystyrene sphere (32 micrometers in diameter) suspended in a fluid. Conditions for resonance are the same for both elastic and inelastic scattering, and excellent agreement is obtained between the experimental results and a calculation based on the Lorenz/Mie theory. Fluorescent uranium doped glass fibers (5 micrometers in diameter) were used for angular distribution measurement as well as for wavelength measurements.