Extended Data Fig. 1: Comb generation simulation at low optical power.

Shown is the simulated optical spectrum of a soliton comb generated with 700 µW optical pump power (Pin) in the bus waveguide before the microresonator. The microresonator dimensions used in the model are 730 nm × 1,800 nm with a radius of 120 µm, corresponding to a 194 GHz FSR.