Novel architecture for ultra-stable micro-ring resonator based optical   frequency combs
  We report a novel geometry for OPOs based on nonlinear microcavity resonators. This approach relies on a self-locked scheme that enables OPO emission without the need for thermal locking of the pump laser to the microcavity resonance. By exploiting a CMOS-compatible microring resonator, we achieve oscillation with a complete absence of shutting down, or self-terminating behavior, a very common occurrence in externally pumped OPOs. Further, this scheme consistently produces very wide bandwidth (>300nm, limited by our experimental set-up) combs that oscillate at a spacing of the FSR of the micro cavity resonance. 
Alessia Pasquazi, Lucia Caspani, Marco Peccianti, Matteo Clerici,   Marcello Ferrera, Luca Razzari, David Duchesne, Brent E....
physics.optics