量子密钥分发的网络化及关键器件的片上实验实现研究

It is necessary to build multi-node quantum communication network, in which arbitrary node can be used to distribute quantum key, in order to make quantum secure communication into real application. Although quantum communication based on physical principle is unconditionally secure, real quantum communication system consists of optical components and electrical components. There exist imperfection in real components, and there also exist imperfection in configuration of network and the combination of classical information and quantum information. The imperfection will bring the security loopholes in systems. In order to close the security loopholes arisen from detection, scientists proposed measurement devise independent quantum key distribution protocol (MDI-QKD), and its configuration can be naturally used in quantum communication network. This project is to carry out theoretical and experimental study in quantum communication network based on MDI-QKD and explore the integration on chip. Concretely, make deep theoretical and experimental research in the realization of MDI-QKD and build stable and efficient MDI-QKD system; build many nodes quantum network based on MDI-QKD and make security analysis; make use of integrated optics to integrate QKD on chip, and finally serve for the application of quantum communication network.

量子保密通信要真正走向实用化，必须要建立多节点的量子网络，该量子网络任意节点之间可以进行量子密钥分发。尽管建立在物理原理上的量子通信是无条件安全的， 但是实际的量子通信系统由光学元器件和电学元器件构成，实际器件会存在非完美性，同时网络的构型、经典和量子的融合也存在非完美性，这些非完美性会给系统带来安全漏洞。为了关闭探测器的安全漏洞，人们提出了测量设备无关的量子密钥分发协议（MDI-QKD），它的构型天然可以用于量子网络。本项目就是对基于MDI-QKD的量子网络进行深入的理论和实验研究，同时探索在芯片上进行集成。具体来说，对MDI-QKD协议的实现进行深入的理论和实验研究，搭建稳定和高效的MDI-QKD系统；基于MDI-QKD，搭建多节点的量子网络并进行安全性分析；利用集成光学把QKD系统进行片上集成，最终为量子保密通信实用化服务。

量子保密通信要真正走向实用化，必须要建立多节点的量子网络，该量子网络任意节点之间可以进行量子密钥分发。尽管建立在物理原理上的量子通信是无条件安全的， 但是实际的量子通信系统由光学元器件和电学元器件构成，实际器件会存在非完美性，同时网络的构型、经典和量子的融合也存在非完美性，这些非完美性会给系统带来安全漏洞。为了关闭探测器的安全漏洞，人们提出了测量设备无关的量子密钥分发协议（MDI-QKD），它的构型天然可以用于量子网络。项目搭建了偏振复用time-bin相位编码MDI-QKD的原理性验证系统，实现了一套全自稳的time-bin相位编码MDI-QKD系统，搭建了三节点的全自稳MDI-QKD网络系统。在片上设计了偏振起偏器，基于超薄透镜的超短耦合器和偏振无关的MMI分束器。这些研究为基于MDI-QKD的量子网络实用化和片上集成提供了理论和实验指导。