Experimental Demonstration of Conjugate-Franson Interferometry
Experimental Demonstration of Conjugate-Franson Interferometry
复制标题
共轭弗朗森干涉测量的实验演示
DOI：
10.1103/physrevlett.127.093603
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发表时间：
2021
影响因子：
8.6
通讯作者：
Wong, Franco N. C.
中科院分区：
文献类型：
--
作者：
Chen, Changchen;Shapiro, Jeffrey H.;Wong, Franco N. C.
弗兰森干涉测量是一种众所周知的量子测量技术，用于探测光子对频率相关性，通常用于验证时间-能量纠缠。我们首次展示了称为共轭弗朗森干涉测量的时间基础互补技术。它测量光子对到达时间的相关性，从而为量子工具箱提供了有价值的补充。我们获得了自发参量下转换生成的纠缠光子对的共轭弗朗森干涉可见度，无需背景扣除。我们的测量结果超出了量子经典阈值 25 个标准差，并验证了共轭弗朗森干涉仪 (CFI) 作为验证时间能量纠缠的替代方法。此外，CFI 可见度是双光子联合时间强度的函数，因此对该状态的光谱相位变化敏感：弗兰森干涉仪或红欧曼德尔干涉仪的情况并非如此。我们通过测量两种不同双光子状态的可见性来强调 CFI 的实用性：一种没有光谱相位变化，另一种有光谱相位变化，观察到后者的 CFI 可见性降低了 21%。 CFI 对于光子纠缠、量子通信和量子网络领域的应用可能有用。
Franson interferometry is a well-known quantum measurement technique for probing photon-pair frequency correlations that is often used to certify time-energy entanglement. We demonstrate, for the first time, the complementary technique in the time basis called conjugate-Franson interferometry. It measures photon-pair arrival-time correlations, thus providing a valuable addition to the quantum toolbox. We obtain a conjugate-Franson interference visibility ofwithout background subtraction for entangled photon pairs generated by spontaneous parametric down-conversion. Our measured result surpasses the quantum-classical threshold by 25 standard deviations and validates the conjugate-Franson interferometer (CFI) as an alternative method for certifying time-energy entanglement. Moreover, the CFI visibility is a function of the biphoton’s joint temporal intensity, and is therefore sensitive to that state’s spectral phase variation: something that is not the case for Franson interferometry or Hong-Ou-Mandel interferometry. We highlight the CFI’s utility by measuring its visibilities for two different biphoton states: one without and the other with spectral phase variation, observing a 21% reduction in the CFI visibility for the latter. The CFI is potentially useful for applications in areas of photonic entanglement, quantum communications, and quantum networking.