Generation of Low-Timing-Jitter Optical Pulses Based on Two-Point Optical Frequency Division

• 1、School of Electronic Engineering, Beijing University of Posts and Telecommunications, Beijing 100876

Abstract：Low-timing-jitter optical pulses have important applications in precision measurement, optoelectronic frequency synthesis, and low-noise microwave generation. To address the limited repetition-rate stability and pronounced low-frequency phase fluctuations of free-running pulsed lasers, a method for generating low-timing-jitter optical pulses based on two-point optical frequency division is proposed and experimentally demonstrated. In this method, two lasers locked to different longitudinal modes of the same Fabry-Pérot cavity serve as optical references. Through two-point optical frequency division, the relative frequency stability of the two optical references is transferred to the repetition rate of a mode-locked laser, thereby enabling closed-loop stabilization of the output pulse train. Experimental results show that, compared with the free-running state, the phase noise of the photodetected 1 GHz microwave signal is reduced by 36 dB at a 1 Hz offset frequency and by 26 dB at a 1 kHz offset frequency after locking. The integrated root-mean-square timing jitter over the offset-frequency range from 10 Hz to 100 kHz is reduced from 252.78 fs to 8.39 fs. This method effectively suppresses the low-frequency phase fluctuations of the mode-locked pulse train and provides an effective approach for generating low-timing-jitter optical pulses.

Keywords： optical engineering optical frequency division optical frequency comb phase noise timing jitter