Amplitude and Phase Noise of Frequency Combs Generated by Single-Section InAs/InP Quantum-Dash-Based Passively and Actively Mode-Locked Lasers

We investigate the amplitude and phase noise of an optical frequency comb based on InAs/InP quantum-dash mode-locked laser. The laser demonstrates low relative intensity noise (< −125 dB/Hz) and phase noise in the passive mode-locking regime. By actively mode-locking the laser, we observe a reduction in the flicker FM noise and timing jitter, as a result of which the optical linewidth decreases, and hence the effective bandwidth compatible with optical coherent systems increases by more than 50% to
$\sim 1.1$
THz.