cw Nonlinear Optics in Droplet Microcavities Displaying Enhanced Gain

Abstract
A variety of stimulated nonlinear optical processes are observed under relatively low intensity cw excitation in droplet spherical microcavities. These include stimulated Raman and Rayleigh-wing scattering as well as four-wave parametric oscillation. The low thresholds for these stimulated processes are accounted for by all waves being in resonance with high-Q droplet modes and by the existence of a significant cavity QED enhancement (> 100 times) in the nonlinear gain coefficients.