Cai Chun, Sun Yongmei, Zhang Yongrui, Zhang Peng, Niu Jianing, Ji Yuefeng
Opt Express. 2019 Feb 18;27(4):5125-5135. doi: 10.1364/OE.27.005125.
We demonstrate quantum key distribution (QKD) with classical signals in a seven-core fiber using dense wavelength division multiplexing. Quantum signals are transmitted in an outer core separately and intercore crosstalk (IC-XT) is the main impairment of them. In order to alleviate IC-XT, we propose a quantum-classical interleave scheme. Then the properties of IC-XT are analyzed based on the measurement results, which indicate counter-propagation is a better co-existence method than co-propagation. Finally, we perform QKD experiments in the presence of two classical channels with a channel spacing of 100 GHz between quantum channel and the nearest classical channels. The experiment results prove counter-propagation almost immune to IC-XT, which is consistent with our analysis. Also, the feasibility of the transmission over the range of metropolitan area networks is validated with our scheme.
我们利用密集波分复用在七芯光纤中通过经典信号实现了量子密钥分发（QKD）。量子信号在外层芯中单独传输，芯间串扰（IC-XT）是其主要损伤因素。为了减轻IC-XT，我们提出了一种量子-经典交织方案。然后根据测量结果分析了IC-XT的特性，结果表明反向传播是比同向传播更好的共存方法。最后，我们在存在两个经典信道的情况下进行了QKD实验，量子信道与最近的经典信道之间的信道间距为100 GHz。实验结果证明反向传播几乎不受IC-XT影响，这与我们的分析一致。此外，我们的方案验证了在城域网范围内传输的可行性。
