We have achieved the longest three mode-multiplexed full C-band transmission yet attained over 3060 km. In wideband mode-multiplexed transmission over weakly-coupled fewmode fibers (FMFs), the width of signal impulse responses is dependent on wavelength, and also exhibits a linear growth with increased transmission distance because of the presence of differential mode delay (DMD). Those properties are technically challenging issues for future deployable space division multiplexing (SDM) transport systems since they make a system design complicated, especially for terrestrial FMF transmission links. In this article, we describe how we applied a cyclic mode permutation (CMP) technique to achieve wideband long-haul FMF transmission where spatial channels are cyclically interchanged in each span to suppress DMD-induced pulse broadening. The CMP technique enabled DMD-unmanaged long-haul transmission across 4.4-THz optical bandwidth over two-mode FMF whose DMD varied in the range from 33.7–44.3 ps/km, resulting in 3060-km FMF transmission with a net capacity of 40.2 Tb/s.

中文翻译：

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全 C 波段 3060 公里 DMD 非托管 3 模式传输，容量为 40.2 Tb/s，使用循环模式排列

我们实现了最长的三模复用全 C 波段传输，传输距离超过 3060 公里。在弱耦合少模光纤 (FMF) 上的宽带模式复用传输中，信号脉冲响应的宽度取决于波长，并且由于差模延迟 (DMD) 的存在，还随着传输距离的增加呈线性增长。这些特性是未来可部署空分复用 (SDM) 传输系统的技术挑战问题，因为它们使系统设计变得复杂，尤其是对于地面 FMF 传输链路。在本文中，我们描述了我们如何应用循环模式置换 (CMP) 技术来实现宽带长途 FMF 传输，其中空间信道在每个跨度中循环交换以抑制 DMD 引起的脉冲展宽。