Tuning Kerr-Soliton Frequency Combs to Atomic Resonances

Dissipative-Kerr-soliton (DKS) frequency combs in nonlinear microresonators, which offer small footprints and low power consumption, can be used for optical metrology and communication. Ultrabroadband DKS combs at near-infrared frequencies remain largely unexplored, though, for lack of suitable group-velocity dispersion, reliable fabrication, and a robust method for soliton generation. Using microresonators from a commercial foundry that yield the right dispersion, the authors reliably produce stable DKSs by ultrafast pump-frequency modulation. With tuning, this work can directly connect the C and L telecommunication bands to the electronic transitions used for optical atomic clocks.