长距离多用户光纤光频高精度传递研究

The fiber-based optical frequency transfer has high stability, and can provide an precious and real-time observation method for high-tech application field such as dark matter detection and VLBI radio astronomy. Ultra-long distance, ultra-high precision and multi-user networking are several important development directions of optical frequency transfer and comparison. According to the characteristics of long distance, multi-node and multi-user high complexity of the actual optical fiber network, this project will focus on improving the optical frequency transmission distance and transmission accuracy and realizes the multi-node and multi-user network optical frequency transmission in the optical fiber network. It is expected to demonstrate multi-stage cascade transfer of optical frequency and multi-user network optical frequency transfer in a 600 km urban optical fiber network, and the instability of optical frequency transmission can reach the order of E-19. Through the research of this project, it will promote the application of optical fiber frequency transmission in related fields, and promote the development of related research and application fields.

利用光纤传递光学频率信号具有较高的传输稳定度，可以为暗物质探测，VLBI射电天文学等高技术应用领域提供一种超高精度的，实时的观测手段。超远距离、超高精度、多用户网络化是光纤光学频率传递和比对的几个重要发展方向。本项目面向我国高精度地基授时系统的建设需求，针对实际光纤网络的长距离、多节点、多用户的高复杂度特点，研究进一步提高光频传递距离和传递精度以及实现光纤网络中多节点多用户的网络化光学频率传递。预期在总长600km的实地光纤传递网中演示光学频率多级级联传递和多用户网络化传递，光频传递的日稳定度达到E-19量级。通过本项目研究，将促进光纤光频传递在相关领域的应用，推动相关研究及应用领域的发展。

光纤光学频率传递是新一代时间频率体系和地基授时系统的重要组成部分，利用光纤实现高精度光学频率传递具有明显的精度优势和应用前景。本项目面向我国高精度地基授时系统的建设需求，针对实际光纤网络的长距离、多节点、多用户的高复杂度特点，研究进一步提高光频传递距离和传递精度以及实现光纤网络中多节点多用户的网络化光学频率传递。通过光相位锁定、偏振自动控制、传递系统非对称光路优化、多级级联传递和被动式光纤光频传递等关键技术突破，实现了972km光纤光频级联传递，以及150km+120km的多用户分支网络光频传递，测量频率传输稳定度均达到E-19量级。达到了高精度地基授时系统的设计要求，也为高精度光纤授时网建设提供更多可能性。