Transmission of 107-Gb/s PAM-4 Signal over 25 km of SSMF using O-band Commercial Off-the-Shelf DML

Demonstration of 112Gb/s PAM4/6 signal transmission in IM/DD systems using MLSE

“…Intensitymodulation/direct-detection (IM/DD) system can meet the cost-efficient and power-consuming requirement of such costsensitive scenarios [1] . Representatively, direct modulated lasers (DML) and electro-absorption modulated lasers (EML) are widely used in short-reach links because of their high integration, small size and low cost [2][3] . However, in many cases, the modulation bandwidth of DML and EML in limited, which poses a challenge to improving the data rate.…”

Low Complexity DSP for High Speed Optical Access Networking

“…High-volume PAM-4 chips are commercially available. However, at >25 Gb/s bit rates, implementing PAM-4 with simple linear equalizers [7,8,17,18] to support a transmission distance of 20 km over a single-mode fiber (SMF)-as required in access networks-using only 10-G optoelectronics [7], is extremely challenging, unless higher bandwidth transmitters or receivers (e.g., 25 G photodiodes [8]), or a dedicated chromatic dispersion compensation module [4] are adopted. It has been shown that reach extension is possible by mitigating system and component nonlinearities using DSP without changing the optical infrastructure [18,19].…”

“…However, the work presented in this paper is limited to simple direct detection (DD) applications using PAM-4 at the C-band. Although previous DD PAM-4 systems with improved capacity [24,25] have been demonstrated, they required the use of sophisticated neural network (NN) nonlinear equalization [24], or an O-band where chromatic dispersion is much smaller [25]. Moreover, none of the previous DD PAM-4 demonstrations considered a simpler nonlinear equalization architecture with noise suppression.…”