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

Abstract

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 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim 1.1$ </tex-math></inline-formula> THz.