Observations of structural resonances in the Raman spectra of optically levitated dielectric microspheres

Applying the technique of optical levitation by radiation pressure, it was possible to record Raman spectra from single microspheres of glass. Sharp intensity peaks are observed which are not present for a bulk sample of the glass. These peaks are shown to correspond to the natural resonant modes of the dielectric spher, and a good correlation is found between experimental and theoretically predicted spectra. The latter were calculated by making use of the Mie‐Debye theory.