Optical frequency comb with ultra-stable repetition rate generated in a micro-ring resonator

By applying an appropriate amplitude modulation to the pump laser, a Kerr frequency comb with ultra-stable repetition-rate is generated in a micro-ring resonator. Two parameters are adjusted: the modulation frequency that matches the micro-ring resonating frequency, and the modulation depth to optimize the shape of the input pulse. With this approach, the frequency comb exhibits 400 lines within +/- 10 dB power range. The repetition rate is 28.55 GHz which can be tuned by a few hundreds of MHz before the becoming unstable.