近日，意大利拉奎拉大学Antonelli, Cristian团队研究了现场部署多芯光纤中量子密钥分配与高吞吐量经典通信的集成。相关论文发表在2025年8月13日出版的《光：科学与应用》杂志上。

量子密钥分发（QKD）是一种基于量子物理原理的对称密码密钥共享的安全通信方法。将其集成到光纤网络基础设施中对于确保光通信的私密性非常重要。多芯光纤（MCF）可能是未来高容量光网络的基石，为这种集成提供了新的机会。

研究组首次通过实验证明，在工业标准包层直径为125 μm的现场部署MCF上，离散变量QKD和C波段高通量经典通信共存。具体来说，他们演示了在25.2公里非耦合核心MCF的一个核心中成功建立安全密钥，同时以110.8 Tb/s的总净速率加载其余三个核心的全c波段反传播经典流量。

通过提出并实验验证核间自发拉曼散射噪声的改进分析模型，研究组发现这种配置对于部署的MCF链路是最佳的，因为它不受量子和经典信号在同一方向传播时产生的波混频的影响。该发现在展示下一代光通信网络中非耦合多芯光纤中QKD和经典传输的集成方面迈出了重要的一步。

附：英文原文

Title: Integration of quantum key distribution and high-throughput classical communications in field-deployed multi-core fibers

Author: Wu, Qi, Ribezzo, Domenico, Di Sciullo, Giammarco, Cocchi, Sebastiano, Ann Shaji, Divya, Alves Zischler, Lucas, Luis, Ruben, Serena, Paolo, Lasagni, Chiara, Bononi, Alberto, Hayashi, Tetsuya, Gagliano, Alessandro, Martelli, Paolo, Gatto, Alberto, Parolari, Paola, Boffi, Pierpaolo, Bacco, Davide, Zavatta, Alessandro, Zhu, Yixiao, Hu, Weisheng, Xu, Zhaopeng, Shtaif, Mark, Marotta, Andrea, Graziosi, Fabio, Mecozzi, Antonio, Antonelli, Cristian

Issue&Volume: 2025-08-13

Abstract: Quantum key distribution (QKD) is a secure communication method for sharing symmetric cryptographic keys based on the principles of quantum physics. Its integration into the fiber-optic network infrastructure is important for ensuring privacy in optical communications. Multi-core fibers (MCFs), the likely building blocks of future high-capacity optical networks, offer new opportunities for such integration. Here, we experimentally demonstrate, for the first time, the coexistence of discrete-variable QKD and high-throughput classical communication in the C-band over a field-deployed MCF with industry standard cladding diameter of 125μm. Specifically, we demonstrate successful secure-key establishment in one core of a 25.2-km uncoupled-core MCF, while simultaneously loading the remaining three cores with full C-band counter-propagating classical traffic at an aggregate net rate of 110.8Tb/s. By proposing and experimentally validating an improved analytical model for inter-core spontaneous Raman scattering noise, we find that this configuration is optimal for our deployed MCF link as it is immune to four-wave mixing, that becomes relevant when the quantum and classical signals are propagating in the same direction. Our findings make an important step forward in demonstrating the integration of QKD and classical transmission in uncoupled-core multi-core fibers for next-generation optical communication networks.

DOI: 10.1038/s41377-025-01982-z

Source: https://www.nature.com/articles/s41377-025-01982-z