>100-GHz Bandwidth Directly-Modulated Lasers and Adaptive Entropy Loading for Energy-Efficient >300-Gbps/λ IM/DD Systems

We demonstrate DML-based net 325-Gb/s at back-to-back and 321.24-Gb/s after 2-km standard single-mode fiber transmissions for >300-Gbps/λ short-reach optical interconnects. Our net rate performance denotes an increase of ∼34% compared to our previous works, while the pre-FEC rates are >400 Gbps. The DML transmitter is based on a PPR-enhanced, >100-GHz-bandwidth DML, fabricated by our novel membrane-III-V-on-SiC technology. Also wide-band, entropy-loaded DMT modulation is utilized based on a novel adaptive algorithm and via a digitally-preprocessed analog multiplexer. These results pave the way towards low-cost and energy-efficient Terabit Ethernet and a significant step towards achieving DML-based 400-Gbps/λ IM/DD systems in the future.