O-band quantum-dot mode-locked laser frequency comb for terabit optical transport

High-capacity data transmission for intra- and inter-data center links is essential to handle the massive increase in data traffic. To address the insatiable demands, IEEE has been working on creating specifications for 800 GbE (IEEE 802.3df) and 1.6 TbE (802.3dj) using a multi-lane distribution method by aggregating 100 Gbps and beyond lanes. Optical frequency comb sources based on semiconductor mode-locked laser (MLL) are cost- and energy-efficient optical sources that can enable multi-lane transmission systems. Here, we demonstrate 14×100 Gbps PAM4 signals and 10×100 Gbps probabilistically shaped PAM8 signals over 10 km SMF with an O-band InAs/InGaAs quantum dot mode-locked laser (QD-MLL) consuming only ∼284 fJ/bit. We also successfully demonstrated 128 Gbps/λ OOK signal transmission with four lines from the QD-MLL spaced at 160 GHz, with a single booster amplifier for multichannel amplification. We show that the performance of the ≥1 Tbps and 512 Gbps WDM signals is within the standard FEC limits with preamplifier and booster semiconductor optical amplifiers, respectively.