Xiang Xiao, Dong Ruifang, Li Baihong, Hou Feiyan, Quan Runai, Liu Tao, Zhang Shougang
Opt Express. 2020 Jun 8;28(12):17697-17707. doi: 10.1364/OE.390149.
Benefiting from the unique quantum feature of nonlocal dispersion cancellation (NDC), the strong temporal correlation of frequency-entangled photon pair source can be maintained from the unavoidable dispersive propagation. It has thus played a major role in many fiber-based quantum information applications. However, the limit of NDC due to finite frequency entanglement has not been quantified. In this study, we provide a full theoretical analysis of the NDC characteristics for the photon pairs with finite frequency entanglement. Experimental examinations were conducted by using two spontaneous parametric down-conversion photon pair sources with frequency correlation and anticorrelation properties. The excellent agreement demonstrates the fundamental limit on the minimum temporal correlation width by the nonzero two-photon spectral correlation width of the paired photons, which introduces an inevitable broadening by interaction with the dispersion in the signal path. This study provides an easily accessible tool for assessing and optimizing the NDC in various quantum information applications.
得益于非局域色散抵消（NDC）这一独特的量子特性，频率纠缠光子对源的强时间相关性能够在不可避免的色散传播过程中得以保持。因此，它在许多基于光纤的量子信息应用中发挥了重要作用。然而，由于有限频率纠缠导致的NDC极限尚未得到量化。在本研究中，我们对具有有限频率纠缠的光子对的NDC特性进行了全面的理论分析。通过使用两个具有频率相关和反相关特性的自发参量下转换光子对源进行了实验检测。出色的一致性证明了配对光子非零的双光子光谱相关宽度对最小时间相关宽度的基本限制，这会通过与信号路径中的色散相互作用而不可避免地导致展宽。本研究为评估和优化各种量子信息应用中的NDC提供了一个易于使用的工具。
