PAM4(四阶脉冲幅度调制)为100/400 Gbit/s以太网提供了一种有效可行的解决方案。介绍了400 Gbit/s以太网的技术标准进展和两种400 Gbit/s光模块的封装形式, 阐述了PAM4光收发模块的基本原理和结构框图, 通过分析不同速率的技术方案和参数,表明28 GBaud PAM4是实现400 Gbit/s以太网传输较好的方案;综述了模块设计所需的器件、芯片、测试仪器和测试方案的现有技术水平, 为100/400 Gbit/s PAM4光收发模块的设计和实现提供参考。

PAM4 format provides an effective solution for 100/400 Gbit/s Ethernet. In this paper, the standard development of 400 Gbit/s Ethernet and two form factors of 400 Gbit/s optical modules are introduced. The basic principle and structure diagram of PAM4 optical transceiver module are described and the technical scheme and parameters of different rate are analyzed. It shows that 28 GBaud PAM4 is a good solution to achieve 400 GEthernet. Then the technical level of device, chip, test instrument and test solution is summarized, which provides a guidance for the design and implementation of PAM4 optical transceiver module.