Stability of Optical Frequency Comb Generated With InAs/InP Quantum-Dash-Based Passive Mode-Locked Lasers

In this paper, we present a systematic investigation of passive mode-locked InAs/InP quantum-dash lasers in terms of frequency and timing stability. Mode-locking features are analyzed using the frequency domain approach based on the concept of supermodes. It is shown that the phase of adjacent longitudinal modes is correlated over 1.3-THz frequency span. The observed strong coherence between modes enables low timing jitter and a long-term stability of the repetition rate frequency within 5×10-8 over 100 s.