A control circuit for generating an optical output at a target frequency using a single-frequency laser is provided. The control circuit includes a micro-ring resonator configured to generate a frequency comb of a plurality of comb frequencies based on a source frequency, a carrier-envelope offset interferometer configured to determine a carrier-envelope offset frequency of the frequency comb, a tunable filter configured to select a subset of comb frequencies of the frequency comb based on the target frequency, and a spectrometer configured to resolve ambiguities in overlap between the subset of comb frequencies and the frequency comb, and refine the subset of comb frequencies to a single comb frequency for output.