Abstract

A mode-locked laser photonic integrated circuit with a repetition rate of 10 GHz is optically synchronized to a tantala-based photonic crystal resonator comb with a repetition rate of 200 GHz. The synchronization is achieved through regenerative harmonic injection locking using a coupled optoelectronic oscillator loop resulting in an optical frequency division factor of 20. The repetition rate of the photonic crystal resonator comb is stabilized and locked through electro-optic division. This stability is transferred to the mode-locked laser where we measure a fractional frequency instability of $8\times 10^{-11}$ at an averaging time of 10 s for the repetition rate signal of the mode-locked laser. Furthermore, we also measure the near carrier phase noise of the pulse repetition rate and estimate the integrated rms timing jitter of the pulses to be 6 ps.