Coherent Frequency Comb Generation in a Silicon Nitride Microresonator   with Anomalous Dispersion
  We observe a transition to a coherent-comb state in a SiN-microresonator with anomalous dispersion. Although ~300 fs pulse trains are generated after line-by-line shaping, the intensity within the microring does not appear to be pulse-like. 
Pei-Hsun Wang, Yi Xuan, Jian Wang, Xiaoxiao Xue, Daniel E. Leaird,   Minghao Qi, and Andrew M. Weiner
physics.optics