Observation of self-pulsing in intracavity singly resonant second-harmonic generation with competing nonlinearities

Summary form only given. While working towards observing self-pulsing in doubly resonant SHG we discovered self-pulsing in a singly resonant cavity where the fundamental field alone, but not its second-harmonic, is resonant. This observation was unexpected since the mean field equation that describes singly resonant SHG only admits non-oscillatory linear instabilities. We therefore expect that the mechanism leading to the observed self-pulsing is qualitatively different than that found in the doubly resonant cavity. As we report here, self-pulsing in the singly resonant cavity only occurs due to a competing nonlinear parametric process, where the internally generated second-harmonic field drives a nondegenerate parametric oscillation.