Spectral extension and synchronization of microcombs in a single microresonator

Broadband frequency combs are a key enabling technology for frequency metrology and spectroscopy. Here, we demonstrate that the spectrum of a soliton microcomb can be extended by bi-chromatic pumping resulting in two combs that synchronize their repetition rate via cross-phase modulation. Read more: Nat Commun **11,**6384 (2020)