Beyond 200-Gb/s O-band intensity modulation and direct detection optics with joint look-uptable- based predistortion and digital resolution enhancement for low-cost data center interconnects  

作　　者：Qi Wu Zhaopeng Xu Yixiao Zhu Tonghui Ji Honglin Ji Yu Yang Junpeng Liang Chen Cheng Gang Qiao Zhixue He Jinlong Wei Qunbi Zhuge Weisheng Hu 

机构地区：[1]Peng Cheng Laboratory,Shenzhen,China [2]Shanghai Jiao Tong University,State Key Laboratory of Advanced Optical Communication Systems and Networks,Department of Electronic Engineering,Shanghai,China [3]University of L’Aquila,Department of Physical and Chemical Sciences,L’Aquila,Italy

出　　处：《Advanced Photonics Nexus》2024年第3期58-67,共10页先进光子学通讯（英文）

基　　金：supported by the National Key R&D Program of China(Grant No.2020YFB1806400);the China Scholarship Council(Grant No.202306230183);the National Natural Science Foundation of China(Grant Nos.62271305 and 62001287).

摘　　要：We propose a joint look-up-table(LUT)-based nonlinear predistortion and digital resolution enhancement scheme to achieve high-speed and low-cost optical interconnects using low-resolution digital-to-analog converters(DACs).The LUT-based predistortion is employed to mitigate the patterndependent effect(PDE)of a semiconductor optical amplifier(SOA),while the digital resolution enhancer(DRE)is utilized to shape the quantization noise,lowering the requirement for the resolution of DAC.We experimentally demonstrate O-band intensity modulation and direct detection(IM/DD)transmission of 124-GBd 4∕6-level pulse-amplitude modulation ePAMT-4∕6 and 112-GBd PAM-8 signals over a 2-km standard single-mode fiber(SSMF)with 3∕3.5∕4-bit DACs.In the case of 40-km SSMF transmission with an SOAbased preamplifier,124-GBd on-off-keying(OOK)/PAM-3/PAM-4 signals are successfully transmitted with 1.5∕2∕3-bit DACs.To the best of our knowledge,we have achieved the highest net data rates of 235.3-Gb∕s PAM-4,289.7-Gb∕s PAM-6,and 294.7 Gb∕s PAM-8 signals over 2-km SSMF,as well as 117.6-Gb∕s OOK,173.8-Gb∕s PAM-3,and−231.8 Gb∕s PAM-4 signals over 40-km SSMF,employing low-resolution DACs.The experimental results reveal that the joint LUT-based predistortion and DRE effectively mitigate the PDE and improve the signal-to-quantization noise ratio by shaping the noise.The proposed scheme can provide a powerful solution for low-cost IM/DD optical interconnects beyond 200 Gb∕s.

关 键 词：look-up-table digital resolution enhancer quantization noise semiconductor optical amplifier pattern-dependent effect pulse-amplitude modulation. 

分 类 号：TN9[电子电信—信息与通信工程]