Morphology-dependent Resonances Research Articles

Morphology–Dependent Resonances in Raman Scattering, Fluorescence Emission, and Elastic Scattering from Microparticles

Morphology-dependent resonances in a 10-μm-diam silicate glass fiber have been found to enhance Raman emission from the glass at discrete wavelengths, giving rise to structure in the Raman spectrum from the fiber that is not present for a bulk sample of the glass. Enhancement occurs at emission wavelengths that correspond to natural resonant modes of the fiber. Since similar effects are expected for microparticles with other well-defined geometries, e.g., spheres and spheroids, these results have important implications in the use of Raman spectroscopy for analysis of single or highly monodispersed microparticles. Resonance-induced peaks in a Raman spectrum could lead to incorrect interpretation of the spectrum if their origin is not understood. Previous work in this laboratory has shown that morphology-dependent resonances also give rise to peaks in fluorescence emission and elastic scattering spectra from dielectric microparticles. Insight into the physical nature of these resonances has been gained by s...