Since optical submarine cable systems are a part of the global communications infrastructure, their total capacity must be continuously and dramatically enlarged. Recently, methods how to maximize the transmission capacity under electrical power limitations have been studied, and it has been reported that a single band (C-band only) transmission system with more fiber pairs (FPs) could be a promising technology. This finding has triggered work on submarine cables with more FPs. For a further increase in FPs in optical submarine cable systems, which also have space limitations in existing cable designs, space-division multiplexing (SDM) technologies such as multi-core fibers (MCFs) and multi-mode fibers (MMFs) could be promising solutions. In particular, 125-μm standard cladding SDM fibers are attractive for early deployment in submarine cable systems since they are expected to have high productivity and high mechanical reliability similar to existing single-mode fibers (SMFs) with the same cladding diameter. In this paper, we report transpacific MCF transmission over a 30-nm bandwidth using standard cladding ultralow-loss coupled 4-core fibers, extending our previous work. The Q ² -factors of 608 (4 core × 152 WDM) SDM/WDM channels modulated with 24-Gbaud DP (dual polarization)-QPSK (quadrature phase shift keying) exceeded the assumed forward error correction (FEC) limits after a 9,150-km transmission. As a result, transmission capacity of 50.47 Tbit/s and a capacity-distance product of 461.8 Pbit/s·km were achieved for standard cladding diameter SDM fibers.

中文翻译：

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50.47-Tbit/s 标准包层耦合 4 芯光纤传输超过 9,150 公里

由于海底光缆系统是全球通信基础设施的一部分，它们的总容量必须不断地大幅扩大。最近，研究了如何在电力限制下最大化传输容量的方法，据报道，具有更多光纤对 (FP) 的单频段（仅 C 频段）传输系统可能是一项有前途的技术。这一发现引发了对具有更多 FP 的海底电缆的研究。为了进一步增加海底光缆系统中的 FP，现有光缆设计也存在空间限制，多芯光纤 (MCF) 和多模光纤 (MMF) 等空分复用 (SDM) 技术可能很有前景解决方案。特别是，125-μm 标准包层 SDM 光纤对于海底电缆系统的早期部署很有吸引力，因为它们预计具有与具有相同包层直径的现有单模光纤 (SMF) 类似的高生产率和高机械可靠性。在本文中，我们报告了使用标准包层超低损耗耦合 4 芯光纤在 30 纳米带宽上的跨太平洋 MCF 传输，扩展了我们之前的工作。问 在 9,150 公里传输后，使用 24 Gbaud DP（双极化）-QPSK（正交相移键控）调制的 608 个（4 核 × 152 WDM）SDM/WDM 信道的^{2 个}因子超过了假定的前向纠错 (FEC) 限制. 结果，标准包层直径SDM光纤实现了50.47 Tbit/s的传输容量和461.8 Pbit/s·km的容量-距离积。