Frequency stabilization circuit, frequency stabilization method, and optical comb generator

A frequency stabilization circuit comprising:

• an offset frequency detection unit which detects a carrier envelope offset frequency in an optical comb output from a resonator of a mode-locked fiber laser;
• a beat frequency detection unit which detects a beat frequency generated by interference between an optical spectrum as a reference in the optical comb and wavelength reference laser light;
• a first feedback control unit which controls a resonator length in the mode-locked fiber laser based on a first error signal indicating an error of the carrier envelope offset frequency with respect to a reference frequency;
• a second feedback control unit which controls excitation light power in the mode-locked fiber laser based on a second error signal indicating an error of the carrier envelope offset frequency with respect to the reference frequency;
• and
• a third feedback control unit which controls a resonator length in the mode-locked fiber laser based on a third error signal indicating an error of the beat frequency with respect to the reference frequency.