We have demonstrated up to 56-Gb/s cost-efficient transmission for intra-data center interconnection over 10-km SMF-28 with negative power penalty. This 56-Gb/s transmitter comprises a low-cost 10-G-class directly-modulated distributed-feedback (DFB) laser without requiring expensive digital to analog converter (DAC), analog-to-digital converter (ADC) and power-consumptive digital signal processing (DSP).
Fang, K., Yu, J., Wang, H., & Li, X. (2017). 56 Gbps signal generation from one 10-G class laser diode for 400G intra-data center interconnection. Optical Fiber Technology, 36, 210–214. https://doi.org/10.1016/j.yofte.2017.04.002