光量子信息科学技术是新一代信息技术发展的重要方向。随着光量子信息系统向更大的规模和更贴近实用的方向发展，光量子器件/系统的芯片集成化成为重要的发展趋势。基于晶体硅的光量子芯片具有稳定性高、集成度高、扩展性强、工作波段宽以及与微电子学CMOS工艺兼容等优点，有潜力实现光量子态产生、调控和探测的全功能集成，近年来引起广泛关注。本论文结合国家重点研发计划课题“功能集成的有源光量子芯片研究与应用（2017YFA0303704）”，在1.5 μm光通信波段，发展硅光量子芯片上集成量子光源和单光子探测器的关键技术，研究综合运用硅光量子器件实现复杂量子信息功能的方法和手段。主要研究成果如下：提出并实现了光通信波段硅浅脊波导集成超导纳米线单光子探测器。理论计算了硅浅脊波导和氮化铌超导纳米线结合结构的光子吸收特性，完成了实验样品设计。突破了硅光子器件和超导纳米线器件混合集成的工艺难点，发展出完整的工艺流程，制备出器件样品。对器件样品的电学特性和单光子探测特性进行实验测试，测得单光子探测系统整体探测效率为3.1%，平均每秒暗计数低达2.1个，时间抖动为93.1 ps。去除系统附加光学损耗后，样品片上探测效率达到18.5%。面向含有量子光源的硅光量子芯片中泵浦光引入噪声光子的问题，提出了一种硅条形-浅脊混合波导结构用以抑制噪声光子的影响。理论分析了此结构对硅光量子芯片设计和实现的简化作用，通过数值计算对波导进行了优化设计。制备出论证该结构功能的器件样品，并实验验证了其抑制硅光量子芯片中噪声光子影响的工作原理。提出并理论分析了基于该结构的两个光量子芯片设计：（1）实现时间片纠缠产生的硅量子光源芯片；（2）实现路径纠缠产生/分发/测量的硅光量子芯片。提出并设计制备了一种可调控的偏振纠缠贝尔态产生芯片。该芯片通过自发四波混频产生高质量的频率简并关联光子对，通过量子干涉实现双光子的反聚束输出，并通过量子态叠加实现偏振纠缠产生。对两路频率简并光子的反聚束输出采用洪-欧-曼德尔干涉实验进行论证，测得干涉条纹可见度分别达到97.5%和93.7%。在两非正交偏振基下测量输出光子对的双光子干涉条纹，可见度分别达到90.7%与72.2%。简化贝尔基实验下测得条纹可见度达到85.8%。论证了芯片的偏振纠缠贝尔态产生及可调控特性。
Quantum photonic information science and technology is important for the new-generation information technology. As the quantum photonic information system scales up and goes practical, integration of quantum photonic devices and systems becomes an important trend. Crystalline-silicon-based quantum photonic circuits raise widespread concern with the advantages of high stability, high integration, strong scalability, wide working wavelength range, CMOS compatibility and the potential to realize full integration of quantum photonic state generation, manipulation and detection. This dissertation is supported by the National Key Research and Development Project "Research and application of functional integrated active quantum photonic circuit (2017YFA0303704)", aiming to develop the key technology in integrating quantum light sources and single photon detectors on silicon quantum photonic circuits in 1.5 μm telecom band, and to study the method of realizing complex quantum information functions with silicon photonic quantum devices. The main research results are as follows:A silicon shallow-ridge waveguide integrated superconducting nanowire single photon detector working in telecom band is proposed and implemented. The core composite structure consists of a silicon waveguide and a niobium nitride nanowire. The photon absorption characteristics of the composite structure is calculated theoretically. The detector device is designed and fabricated successfully. In the research, we solve the technical difficulties of the hybrid integration and develop a complete fabrication process. The electrical and single-photon detection properties of the device are measured. The result shows the system detection efficiency of 3.1% with the low dark count of 2.1 count per second and the timing jitter of 93.1 ps. After removing the loss brought by the detection system, the on-chip detection efficiency is extracted as 18.5%.A hybrid silicon waveguide scheme is proposed to solve the pump light induced noise problem in the silicon quantum photonic circuit with quantum light source. The scheme is composed of strip waveguide and shallow-ridge waveguide structures. The simplification in the design and implementation of the circuit is analyzed theoretically. The waveguide parameters are optimized by numerical calculation. To verify the working principle of the scheme, the corresponding chip is fabricated and experiments are conducted. Two designs based on the scheme are proposed and analyzed. (1) The silicon quantum light source circuit for time-bin entanglement generation, (2) The silicon photonic circuit for path entanglement generation, distribution and analysis. A tunable polarization-entangled Bell state generator circuit is proposed, designed and fabricated. The circuit generates high-quality frequency-degenerate photon pairs by spontaneous four-wave mixing, realizes the biphoton anti-bunching output through quantum interference, and realizes polarization entanglement through quantum state superposition. The Hong-Ou-Mandel interference experiment is conducted to demonstrate the two sets of the anti-bunching outputs, with the interference fringe visibilities of 97.5% and 93.7%, respectively. The two-photon interference fringes of the output photon pairs under two sets of non-orthogonal polarization groups are measured, with the visibility of 90.7% and 72.2%, respectively. The simplified BSM is conducted, with the visibility of 85.8%. These verify that the designed circuit can output polarization-entangled Bell state. Its output state can be switched between two frequency-degenerate Bell states.
