National Laboratory of Solid State Microstructures, School of Physics, College of Engineering and Applied Sciences, Nanjing University, Nanjing, 210093, China.
Department of Electronic and Information Engineering, The Hong Kong Polytechnic University, Hong Kong.
Science. 2020 Jun 26;368(6498):1487-1490. doi: 10.1126/science.aba9779.
The development of two-dimensional metasurfaces has shown great potential in quantum-optical technologies because of the excellent flexibility in light-field manipulation. By integrating a metalens array with a nonlinear crystal, we demonstrate a 100-path spontaneous parametric down-conversion photon-pair source in a 10 × 10 array, which shows promise for high-dimensional entanglement and multiphoton-state generation. We demonstrate two-, three- and four-dimensional two-photon path entanglement with different phases encoded by metalenses with fidelities of 98.4, 96.6, and 95.0%, respectively. Furthermore, four-photon and six-photon generation is observed with high indistinguishability of photons generated from different metalenses. Our metalens-array-based quantum photon source is compact, stable, and controllable, indicating a new platform for integrated quantum devices.
二维超表面在量子光学技术中显示出巨大的潜力，因为它们在光场操控方面具有极好的灵活性。通过将一个透镜阵列与非线性晶体集成，我们在一个 10×10 的阵列中展示了一个 100 路自发参量下转换光子对源，这为高维纠缠和多光子态的产生提供了可能。我们通过金属透镜以不同的相位编码来演示二维、三维和四维双光子路径纠缠，其保真度分别为 98.4%、96.6%和 95.0%。此外，还观察到了四光子和六光子的产生，而且来自不同金属透镜的光子具有很高的不可分辨性。我们的基于透镜阵列的量子光子源具有紧凑、稳定和可控的特点，为集成量子器件提供了一个新的平台。
