Optimization of Timing Jitter Reduction by Optical Feedback for a Passively Mode-Locked Laser

We investigate the effect of optical self-feedback on the timing jitter of a passively mode-locked (ML) laser and compare the von Linde method with two pure time domain methods for calculating the timing jitter of such a system. We find that all three methods yield the same dependence of the timing jitter on the external cavity roundtrip time (delay time). Of these methods, the so-called long term jitter method is significantly less computationally expensive. We therefore use this method to investigate the influence of the delay time, feedback strength, and amplitude-phase coupling on the timing jitter. Our results show that, with vanishing amplitude-phase coupling, greater timing jitter reduction can be achieved with long delay times and larger feedback strengths, when feedback is near resonance. Off resonance, the timing jitter is increased. Non-vanishing amplitude-phase coupling can lead to destabilized pulse stream, even at the feedback main resonances.