Self-injection Locked Time Domain Mode-locked Optoelectronic Oscillator

A high-quality frequency comb generator based on self-injection locked time domain mode-locked optoelectronic oscillator (SIL-TDML-OEO) is demonstrated. The scheme applies a self-injection locked TDML-OEO structure, in which a long optical fiber delay loop without oscillation is used to inject-locked the TDML-OEO. The spur suppression ratio (SSR) of the generated frequency comb was obviously enhanced by ~21 dB under SIL. The phase noise of the proposed SIL-TDML-OEO is -125.86 dBc/Hz@10 kHz which is improved by ~7.91 dB compared with that of free-running TDML-OEO. In addition, the tunability of central frequency of the frequency comb generator is also discussed.