128 Gbit/s high speed optical interconnection networks in data centers by a 30 GHz Mach-Zehnder modulator

摘要

A decision feedback equalization(DFE)algorithm is proposed by simplifying Volterra structure.The simplification principle and process of the proposed Volterra-based equalization algorithm are presented.With the support of this algorithm,the signal damage for four-level pulse amplitude modulation signal(PAM-4)is compensated,which is caused by device bandwidth limitation and dispersion during transmission in C-band intensity modulation direct detection(IM-DD)fiber system.Experiments have been carried out to demonstrate that PAM-4 signals can transmit over 2 km in standard single-mode fiber(SSMF)based on a 30 GHz Mach-Zehnder modulator(MZM).The bit error rate(BER)can reach the threshold of hard decision-forward error correction(HD-FEC)(BER=3.8×10-3)and its sensitivity is reduced by 2 d Bm compared with traditional feedforward equalization(FFE).Meanwhile,the algorithm complexity is greatly reduced by 55%,which provides an effective theoretical support for the commercial application of the algorithm.