Emerging services such as 8K/16K high-quality video streaming, virtual reality/augmented reality, beyond-5G mobile Internet, and edge computing are driving the need for even higher speed, capacity, and flexibility in optical access networks. Coherent passive optical networks (CPONs) have garnered significant attention in recent years due to their superior receiver sensitivity and high flexibility for 100G speeds and beyond. Research interest has surged in flexible, multi-dimensional multiplexing schemes that go beyond traditional time-division multiplexing (TDM). To further leverage the flexibility offered by CPONs, this paper proposes and experimentally demonstrates what we believe to be a novel three-dimensional flexible coherent PON (3D FLCS-CPON) for downstream applications. This system offers resource-allocation capabilities in the time, frequency, and power domains. By utilizing digital subcarrier multiplexing and power allocation in both the time and frequency domains, we achieve more flexible and adaptable access rates compared to traditional TDM and frequency-division multiplexing (FDM). We present in detail the operating principles of 3D FLCS-CPON in the downstream, along with steps for power calibration between subcarriers. As a proof of concept, we demonstrate the feasibility of 3D FLCS-CPON in the downstream using four subcarriers, achieving a peak data rate of 250Gb/s/λ${250}\;{\rm Gb/s/}\lambda$ over a 20-km fiber.

中文翻译：

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超越100G的三维灵活相干PON，具有时间、频率和功率资源分配能力

8K/16K 高质量视频流、虚拟现实/增强现实、超 5G 移动互联网和边缘计算等新兴业务正在推动光接入网络对更高速度、容量和灵活性的需求。近年来，相干无源光网络 (CPON) 因其卓越的接收器灵敏度和针对 100G 及更高速度的高灵活性而受到广泛关注。人们对超越传统时分复用 (TDM) 的灵活多维复用方案的研究兴趣激增。为了进一步利用 CPON 提供的灵活性，本文提出并通过实验演示了我们认为适用于下游应用的新型三维灵活相干 PON (3D FLCS-CPON)。该系统提供时域、频域和功率域的资源分配能力。通过在时域和频域中利用数字子载波复用和功率分配，与传统的 TDM 和频分复用 (FDM) 相比，我们实现了更灵活、适应性更强的接入速率。我们详细介绍了下游 3D FLCS-CPON 的工作原理，以及子载波之间的功率校准步骤。作为概念验证，我们展示了 3D FLCS-CPON 在下游使用四个子载波的可行性，实现了250的峰值数据速率Gb / s / λ​${250}\;{\rm Gb/s/}\lambda$超过20公里的光纤。