Laser diode comb spectrum amplification preserving low RIN for WDM applications

Quantum dot-based diode comb lasers enable a single multi-channel-laser source for short-reach, high-speed WDM interconnects. In this paper, we demonstrate for the first time a 15 channel low RIN comb laser with 80 GHz channel spacing. We show that all the FP modes can be simultaneously directly modulated simply by modulating the pump current at 3.2 Gb/s, which indicates that the comb laser may be an ideal broadband light source in WDM-PON applications.We demonstrate that the whole comb laser spectrum can be amplified by a quantum dot SOA without increasing the relative intensity noise (RIN). Small signal amplification factor was measured as high as 30 dB and the saturated output power was as high as 15 dBm.