AI 中文总结
提出一种表征携带宽带量子信号的偏振光纤信道的方法，利用带平均旋转矩阵奇异值分解得出最优输入态等，其奇异值提供信道特征，还给出不忠度带宽及应用示例。
AI 中文摘要
我们提出一种用于表征承载宽带量子信号的偏振光纤信道的方法，其中窄带滤波会浪费光子通量。波长相关的偏振模色散（PMD）将每个输入态映射到庞加莱球面上的一条轨迹；我们表明，带平均旋转矩阵的奇异值分解以封闭形式给出了最优输入态、相互无偏测量基及其不忠度。三个奇异值提供了一个紧凑的、与带宽相关的信道特征，它将一阶与高阶PMD分开，由此产生的5%不忠度带宽给出了一个实际的滤波预算。我们对马斯达尔城已部署的光纤链路进行了表征，并通过一个偏振控制器串联两个信道来演示PMD缓解。
英文摘要
We present a method for characterizing depolarization in fiber channels carrying broadband polarization-encoded optical signals. Wavelength-dependent polarization mode dispersion (PMD) maps each input polarization to a trajectory on the Poincaré sphere; we show that the singular value decomposition of the band-averaged rotation matrix yields, in closed form, the optimal input states, the associated mutually unbiased measurement bases, and the resulting projection error probabilities. The three singular values provide a compact, bandwidth-dependent channel signature that distinguishes first- from higher-order PMD, and yield the bandwidth at which the worst-case error probability reaches 3% as a practical filtering budget. We characterize twelve deployed fiber links in Masdar City and demonstrate PMD mitigation by concatenating two channels through a single polarization controller, a step towards nonlocal PMD compensation.
Comments18 pages, 4 figures
