It is very attractive to apply a directly modulated laser (DML)-based intensity-modulation and direct-detection (IM/DD) system in future data centers and 5G fronthaul networks due to the advantages of low cost, low system complexity, and high energy efficiency, which perfectly match the application scenarios of the data centers and 5G fronthaul networks, in which a large number of high-speed optical interconnections are needed. However, as the data traffic in the data centers and 5G fronthaul networks continues to grow exponentially, the future requirements for data rates beyond 100 Gbaud are challenging the existing DML-based IM/DD system, and the main bottleneck is the modulation bandwidth of the DML. In this paper, the data rate demands and technical standards of the data centers and 5G fronthaul networks are reviewed in detail. With the modulation bandwidth requirements, the technical routes and achievements of recent DMLs are reviewed and discussed. In this way, the prospects, challenges, and future development of DMLs in the applications of future data centers and 5G fronthaul networks are comprehensively explored.

在未来的数据中心和 5G 前传网络中应用基于直接调制激光 (DML) 的强度调制和直接检测 (IM/DD) 系统具有成本低、系统复杂度低、能效，完美匹配需要大量高速光互连的数据中心和5G前传网络的应用场景。然而，随着数据中心和 5G 前传网络中的数据流量持续呈指数级增长，未来对 100 Gbaud 以上数据速率的要求正在挑战现有的基于 DML 的 IM/DD 系统，主要瓶颈是调制带宽。 DML。本文详细回顾了数据中心和5G前传网络的数据速率需求和技术标准。针对调制带宽的要求，回顾和讨论了近期DML的技术路线和成果。从而全面探讨了DML在未来数据中心和5G前传网络应用中的前景、挑战和未来发展。