We describe a procedure for identifying morphology-dependent resonances observed in various optical processes in micrometer-sized droplets. This capability results from the use of a vibrating-orifice aerosol generator in which the radius a of a droplet stream is repeatedly ramped between fixed values, providing characteristic size spectra. When acquired in conjunction with other optical data (such as fluorescence, lasing, and Raman scattering), fixed-angle elastic scattering provides a fiducial spectrum from which mode positions are assigned and transferred. From Lorenz–Mie theory calculations, spectral spans of ≈0.1a are shown to be sufficient to yield unambiguous mode identification, given an initial experimental uncertainty of ±1.5° in the scattering angle and ±6% in the refractive index.
© 1990 Optical Society of America
Original Manuscript: February 20, 1990
Manuscript Accepted: July 6, 1990
Published: December 1, 1990
J. D. Eversole, H.-B. Lin, A. L. Huston, and A. J. Campillo, "Spherical-cavity-mode assignments of optical resonances in microdroplets using elastic scattering," J. Opt. Soc. Am. A 7, 2159-2168 (1990)