In this paper, we demonstrate the generation of high-performance entangled photon-pairs in different degrees of freedom from a single piece of fiber pigtailed periodically poled LiNbO₃ (PPLN) waveguide. We utilize cascaded second-order nonlinear optical processes, i.e., second-harmonic generation (SHG) and spontaneous parametric downconversion (SPDC), to generate photon-pairs. Previously, the performance of the photon-pairs is contaminated by Raman noise photons. Here by fiber-integrating the PPLN waveguide with noise-rejecting filters, we obtain a coincidence-to-accidental ratio (CAR) higher than 52,600 with photon-pair generation and detection rate of 52.36 kHz and 3.51 kHz, respectively. Energy-time, frequency-bin, and time-bin entanglement is prepared by coherently superposing correlated two-photon states in these degrees of freedom, respectively. The energy-time entangled two-photon states achieve the maximum value of CHSH-Bell inequality of S = 2.71 ± 0.02 with two-photon interference visibility of 95.74 ± 0.86%. The frequency-bin entangled two-photon states achieve fidelity of 97.56 ± 1.79% with a spatial quantum beating visibility of 96.85 ± 2.46%. The time-bin entangled two-photon states achieve the maximum value of CHSH-Bell inequality of S = 2.60 ± 0.04 and quantum tomographic fidelity of 89.07 ± 4.35%. Our results provide a potential candidate for the quantum light source in quantum photonics.

在本文中，我们展示了从单根光纤尾纤周期性极化的 LiNbO _{3 产生}不同自由度的高性能纠缠光子对(PPLN) 波导。我们利用级联二阶非线性光学过程，即二次谐波生成 (SHG) 和自发参数下变频 (SPDC)，来生成光子对。以前，光子对的性能受到拉曼噪声光子的污染。在这里，通过将 PPLN 波导与噪声抑制滤波器进行光纤集成，我们获得了高于 52,600 的重合与意外比 (CAR)，光子对生成和检测率分别为 52.36 kHz 和 3.51 kHz。能量-时间、频率-仓和时间-仓纠缠分别通过在这些自由度中相干叠加相关的双光子状态来制备。能量-时间纠缠的双光子态达到S的CHSH-Bell不等式的最大值 = 2.71 ± 0.02，双光子干涉能见度为 95.74 ± 0.86%。频率仓纠缠双光子态的保真度为 97.56 ± 1.79%，空间量子跳动可见度为 96.85 ± 2.46%。时间仓纠缠的双光子态实现了S  = 2.60 ± 0.04的 CHSH-Bell 不等式的最大值和 89.07 ± 4.35% 的量子断层扫描保真度。我们的结果为量子光子学中的量子光源提供了一个潜在的候选者。