We demonstrate a four-lane wavelength division multiplexing (WDM) intensity modulation and direct detection (IM/DD) system at O-band. The 3-dB bandwidth of directly modulated lasers (DMLs) in this experiment is only 15 GHz. To support 100-Gbit/s/lane PAM-4 transmission in each lane, digital pre-equalization and advanced receiver-side DSPs are adopted to compensate for bandwidth limitation. Moreover, semiconductor optical amplifier (SOA) is utilized at the receiver to compensate for the optical power loss during fiber transmission so that 40-km transmission distance can be achieved. To the best of our knowledge, it is the first time to successfully transmit 400-Gbit/s PAM-4 signals over 40-km SSMF with 15-GHz DMLs.

中文翻译：

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基于窄带DML的IM/DD系统4×100Gbit/s PAM-4传输40km演示

我们展示了 O 波段的四通道波分复用 (WDM) 强度调制和直接检测 (IM/DD) 系统。本实验中直接调制激光器 (DML) 的 3-dB 带宽仅为 15 GHz。为了在每个通道中支持 100-Gbit/s/通道 PAM-4 传输，采用数字预均衡和先进的接收端 DSP 来补偿带宽限制。此外，在接收端利用半导体光放大器（SOA）来补偿光纤传输过程中的光功率损耗，从而实现40公里的传输距离。据我们所知，这是第一次使用 15-GHz DML 在 40 公里 SSMF 上成功传输 400-Gbit/s PAM-4 信号。