保偏光纤基纠缠双光子态的产生及其相干操控研究

As the boundary between the worlds of the classical physics and quantum physics, quantum entanglement is widely used in quantum information science and technology, exploring the reliable and practical scheme for the generation and coherent manipulation of quantum entanglement is the cutting-edge of the related study. Taking the advantage of the polarization maintaining property of the polarization maintaining fiber (PMF), this project study on the generation and coherent manipulation of the entangled two-photon state with very high quality, which would solve the problem on the practical developing of the quantum light source due to the polarization disturbing in traditional single mode fiber based scheme. The study includes: building a theoretical model, which can be used to analyze the generation of entangled two-photon states in PMF and the its coherent manipulation scheme; experimental studying the high quality entangled two-photon state generation and its coherent manipulation; developing the techniques on the pump light source and filters for practical quantum light source. Based on those works, we can analyze the spontaneous nonlinear optical processes in PMF and the quantum interference phenomena for coherent manipulation of entangled two-photon states; clarifying and experimental demonstrating the physical factors which influence the generation quality of the entangled two-photon states; demonstrating the coherent manipulation of the photonic entanglement, such as controlled entanglement routing and coupling, based on quantum interference, and generating 1.5 micron spatial-path and frequency entangled two-photon states with a fidelity of greater than 0.95 and experimental measuring them; realizing the key techniques of picoseconds pulsed pump light source and optical filter with very high extinction ratio for practical quantum light source developing.

量子纠缠是区分经典和量子物理世界的基础物理资源，被广泛用于量子信息科学与技术的研究中，探索产生和操控量子纠缠的实用可靠方案是该领域的研究前沿。本项目发挥保偏光纤的双折射特性，研究高质量纠缠双光子态的产生和相干操控，突破普通单模光纤方案中偏振态扰动带来的量子光源实用化瓶颈。研究内容包括：建立分析保偏光纤中纠缠双光子态产生和相干操控的全量子理论模型；开展保偏光纤基高质量纠缠双光子态产生和相干操控的实验研究；研究发展实用化量子光源的泵浦光源和滤波技术。以期，明晰保偏光纤中纠缠双光子态产生的物理基础及其相干操控的量子干涉现象；阐明影响纠缠双光子态产生质量的物理因素和优化条件并进行实验验证；论证基于量子干涉实现光子纠缠资源的可控路由和耦合等相干操控过程；产生1.5微米保真度>0.95的空间-路径和频率纠缠双光子态并进行实验测量；研制皮秒脉冲泵浦光源和高消光比光学滤波器件等实用化量子光源关键技术。

本项目围绕保偏光纤基纠缠双光子态的产生与相干操控开展研究工作，并对光量子纠缠的量子信息应用进行扩展合作研究。作为区分经典和量子物理世界的基础物理资源，量子纠缠被广泛用于量子信息科学与技术的研究中。本项目正是在量子信息学科快速发展的背景下提出的，通过不断加深对光纤双折射特性的认识，我们探索出利用保偏光纤的双折射特性实现光量子纠缠资源产生和相干操控的可靠方案，这些方案有效的克服了普通单模光纤方案中偏振态扰动的瓶颈。主要的研究内容包括：(1) 建立了分析保偏光纤中纠缠双光子态的产生及其相干操控的全量子理论模型；(2) 开展了保偏光纤基纠缠双光子态的产生及其相干操控的实验研究，获得频率-路劲纠缠双光子态，测量得到其干涉条纹可见度大于95%；(3) 总结了发展实用化量子光源的泵浦光源和滤波技术，具体含高性能锁相激光器和10皮秒量级脉冲激光器等。更为重要的，得益于项目的支持，我们与加拿大卡尔加里大学开展合作研究，对光量子纠缠的量子信息应用进行扩展，研究工作包括：量子网络用场地光纤量子隐形传态、测量无关量子密钥分发、掺铒光纤基通讯波段多频道光-原子界面和频分复用宣布式单光子源的研究工作。以上工作进一步拓展了电子科技大学在量子信息方向的研究，帮助我们筹建‘信息与量子实验室’，并指明了我们在量子光源方向的具体研究，即复用宣布式单光子源和用于量子英特网的量子通道等。值得指出，我们申报的‘1.5微米波段主动频分复用宣布式单光子源’，作为本项目的后续研究，已经获得自然基金面上项目支持，为我们在电子科技大学继续开展量子信息的研究提供了持续资助。