自从1984年第一个量子密钥分发协议提出后，它已经逐渐发展成为量子信息应用中最有实用化应用前景的技术。随着量子密钥分发的发展，如何构建面向具有复杂连接的多用户网络成为量子密钥分发技术走向实际应用的重要课题。为此，本论文基于纠缠基色散光学量子密钥分发技术，系统研究了基于量子纠缠分配的大用户规模量子密钥分发组网方案和实验实现，论文取得的主要研究成果有：实验实现了光纤传输的长距离纠缠基色散光学量子密钥分发协议，光纤传输距离为20公里。实验中基于单模硅波导中的自发四波混频过程实现了高质量的时间能量纠缠量子光源的制备，通过三层划分的高维时间编码提升原始密钥成码率并有效减少了误码率，采用非局域色散补偿技术解决了时间能量纠缠光子对在光纤传输过程中光纤色散的影响。通过对高维时间编码参数的综合优化，20公里光纤传输条件下的安全密钥产生率达到104 kbps。提出并实验论证了一种基于1×N多端口分束器的大用户规模量子密钥分发网络。为了实现该网络，提出了一种对称式纠缠基色散光学量子密钥分发方案，解决了传统方案无法应用于基于1×N多端口分束器的量子纠缠分配网络的问题。利用单模硅波导实现了宽频带时间能量纠缠量子光源，并提取出16组纠缠资源。对于每组纠缠资源，采用1×N多端口分束器形成一个全连接的量子密钥分发子网。各子网中分别取一个用户终端安置在中心可信中继节点实现子网之间的安全密钥生成。实验实现了包含112用户（16个子网，每子网包含7用户和一个置于可信节点的终端）的大规模量子密钥分发网络。网络中用户之间利用对称式纠缠基色散光学量子密钥分发生成安全密钥，平均的安全密钥产生率为60 bps。提出并实验论证了一种无可信节点辅助的全连接量子密钥分发网络。通过综合运用波分复用和空分复用技术灵活的分配纠缠资源，使得网络中每两个用户间都分配到相应纠缠资源，并利用对称式纠缠基色散光学量子密钥分发生成安全密钥，形成全连接网络。实验上利用5组纠缠资源通过1×N多端口分束器构建5个包含8个用户的全连接子网。利用10组纠缠资源通过波分复用的方式实现5个子网之间的用户连接。最终利用一个量子光源实现了支持40个用户的网型全连接量子密钥分发网络，网络中同时实现的量子密钥分发连接数达到780，子网内两用户之间的平均安全码率为51 bps，不同子网的两用户之间平均安全码率为22 bps。
Quantum key distribution (QKD) has gradually developed into the most promising quantum information technology for practical applications, since it was first proposed in 1984. With the development of QKD, how to build multi-user QKD network with complex connections has become an important issue for QKD’s development towards practical applications. In this thesis, the networking schemes and their experimental implementations of large scale QKD network were investigated based on the entanglement-based dispersive optics QKD (DO-QKD). The main results achieved in this thesis includes:The long-distance entanglement-based DO-QKD over optical fiber transmission of 20 km was experimentally realized. In the experiment, a high-quality energy-time entanglement photon pair source was realized based on the spontaneous four wave mixing process in a single mode silicon waveguide. By a format of three-level high dimensional time encoding, the raw key rate was enhanced and the quantum bit error rate was also reduced effectively. Besides, the dispersion influences induced by the long fiber transmission of energy-time photon pairs was eliminated by the nonlocal dispersion cancellation technology. Finally, by the optimization of high dimensional time encoding, a secret key rate of 104 kbps was achieved under the fiber transmission of 20 km.A large scale QKD network based on 1×N multi-port beam splitter was proposed and experimentally demonstrated. To fulfill this network, a symmetric entanglement-based DO-QKD scheme was proposed resolving the problem that the conventional DO-QKD scheme cannot be applied to the proposed quantum entanglement distribution network. A broadband quantum light source of energy-time entanglement was realized based on a single mode silicon waveguide and sixteen sets of entanglement resources were extracted from the quantum light source. For each set of entanglement resource, a fully connected QKD subnet was established based on a 1×N multi-port beam splitter. A specific user from each subnet was kept at the central trusted relay node to realize the key generation between the users in different subnets. At the end, a large scale QKD network with 112 users (16 subnets, each subnet includes 7 end users and an end user placed at the trusted node) was experimentally realized. The symmetric entanglement-based DO-QKD was used for the secret key generation in the network with an average of secret key rate was 60 bps.A fully connected QKD network without the assistance of trusted node was proposed and experimentally demonstrated. By wavelength division multiplexing and space division multiplexing technologies, the entanglement resources from broadband energy-time entanglement photon pair source were flexibly distributed to the users in the network. Each two users in the network were allocated the corresponding entanglement resource which could be used for secret key generation between them by the symmetric entanglement-based DO-QKD, forming a fully connected network. In the experiment, five sets of entanglement resources were utilized for establishing five QKD subnets by 1×N multi-port beam splitters, and each subnet contained eight users. Ten sets of entanglement resources were used for the connections between users in different subnets. Ultimately, a forty-user mesh-type fully connected QKD network based on only one quantum light source was realized. The simultaneous QKD connections between the users in the network reached 780 with an average secret key rate of 51 bps between two users in the same subnet and 22 bps between two users in different subnets.
