title: Dispersion compensation in whispering-gallery modes.
abstract: We show that manipulation by a spatial profile of the refractive index of a circularly symmetric dielectric cavity results in a novel way of fine tuning frequency separations as well as spatial localizations of high-Q whispering-gallery modes excited in the cavity. The method permits dispersion compensation in the modes (spectrum equalization), diminishes the quality-factor limitation by surface roughness and contamination, and allows critical coupling to ultra-high-Q modes without maintaining an air gap with evanescent couplers.
authors.affiliation: Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109-8099, USA.
authors.forename: Vladimir S
authors.initials: VS
authors.lastname: Ilchenko
authors.forename: Anatoliy A
authors.initials: AA
authors.lastname: Savchenkov
authors.forename: Andrey B
authors.initials: AB
authors.lastname: Matsko
authors.forename: Lute
authors.initials: L
authors.lastname: Maleki