Phase-stable and selectable repetition-rate division of an optical frequency comb

We present a phase-stable and selectable repetition-rate (frep) divider (PSRD) of an optical frequency comb (OFC) by down-picking a train of pulses from the fundamental OFC phase coherently. The PSRD operating at the integer pulse-picking order p uses an acousto-optic modulator driven by a train of phase-synchronized single-cycle wave packets oscillating at the carrier frequency of fcfrep and the gating frequency of fgpfrep/p. The demonstrated PSRD can selectively pick a train of pulses with p=2 to 25 from the fundamental OFC with frep=250 MHz at 530 nm. Integrated phase noises from 10 Hz to 25 kHz offset frequency from the optical beat note between each down-picked OFC and the fundamental OFC are measured to be about (59±6) mrad through the whole pulse picking order. The phase-coherent down-picked OFC could be of use for various applications where phase-stable and repetition-rate selectable OFCs are the essential radiation sources.