Low-threshold parametric nonlinear optics with quasi-phase-matched whispering-gallery modes

Abstract

We propose to fabricate a toroidal dielectric cavity from a periodically poled χ(2) nonlinear material (e.g., LiNbO3) to achieve efficient interaction among high-Q whispering-gallery modes. We show that the periodic poling allows for suppression of both material and cavity dispersion. Such a cavity might be a basic element of a family of efficient nonlinear devices operating at a broad range of optical wavelengths.