China News Agency, Hefei, May 5 (Reporter Wu Lan) The reporter learned from the University of Science and Technology of China on the 5th that the school's Pan Jianwei, Zhang Qiang, etc. cooperated with Jinan Institute of Quantum Technology Wang Xiangbin, Liu Yang, etc., which greatly broke through the traditional optical fiber vibration sensing. The technical distance is difficult to exceed the limit of 100 kilometers, and the long-distance optical fiber vibration sensing of 658 kilometers has been successfully realized, and the positioning accuracy has reached 1 kilometers.
Relevant research results are published in the form of "Editor's Recommendation" in Physical Review Letters.
Optical fiber vibration sensing uses optical fiber as a sensor for vibration sensing. Due to its advantages of high sensitivity, fast response, simple structure and uniform distribution, it is widely used in engineering fields such as structural health monitoring, oil and gas pipeline leakage monitoring, perimeter protection and earthquake monitoring. prospect.
At present, fiber-optic vibration sensing mostly uses distributed acoustic wave sensing technology, and its sensing distance is limited to less than 100 kilometers. An important technical challenge is how to overcome the distance limitation and realize long-distance fiber-optic vibration sensing.
Quantum key distribution (QKD) is based on the basic principles of quantum mechanics, combined with the "one-time-one-pad" encryption method, which can realize unconditionally secure and confidential communication.
Because of its important practical significance, QKD has been a research hotspot in the international academic community in the past few decades.
The TF-QKD protocol proposed in 2018 is considered to be the optimal solution for realizing ultra-long-distance optical fiber QKD.
However, in practical applications, noises such as sound and vibration along the optical fiber link are unavoidable.
In this study, the researchers integrated the experimental system of long-distance quantum key distribution and optical fiber vibration sensing. While completing the optical fiber dual-field quantum key distribution (TF-QKD), they finally realized a 658-kilometer optical fiber dual-field Quantum key distribution and optical fiber vibration sensing locate the disturbance position of the artificial vibration source on the link with an accuracy better than 1 km.
The above research results show that the TF-QKD network architecture can not only realize ultra-long-distance distribution of security keys, but also can be applied to ultra-long-distance vibration sensing to realize the fusion of wide-area quantum communication network and optical fiber sensor network.
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