A system includes a first optical frequency comb generator that generates a first parametrically generated comb using parametric mixing comprising a first plurality of optical waves including at least one first optical wave. The system includes a second optical frequency comb generator that generates a second parametrically generated comb using parametric mixing comprising a second plurality of optical waves. The second optical frequency comb generator receives the at least one first optical wave and generates the second plurality of optical waves using the at least one first optical wave. Respective center frequencies of one or more optical waves of the first plurality of optical waves are aligned in frequency with respective center frequencies of one or more optical waves of the second plurality of optical waves.