Ruifang Dong
dongruifang@ntsc.ac.cn
Education
2005-2009 Ph.D. in Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Germany
1998-2001 Master's Degree in Optics, Shanxi University, China
1994-1998 Bachelor's Degree in Optoelectronic Technology, Shanxi University, China
Experience
2022-Present Researcher, Hefei National Laboratory
2010-Present Professor, National Time Service Center, Chinese Academy of Sciences, Xi'an, China
2001-2005 Engineer, Optical Transmission R&D Department, Huawei Technologies Co., Ltd., Shenzhen, China
Overview of Academic Research
2001-2005 Engineer, Optical Transmission R&D Department, Huawei Technologies Co., Ltd., Shenzhen, China
Her major achievements include:
* Quantum-enhanced two-way time transfer architecture based on frequency-entangled biphoton sources were proposed and theoretically modeled, providing a quantum solution for high-precision and secure synchronization. Its practical implementations were advanced, achieving sub-picosecond time transfer in strong-noise environments (free-space and 100 km urban fibers), with a record 10-femtosecond-level synchronization stability over 50 km fibers. The high-sensitivity detection of spoofing delay attack as small as tens of picosecond was proposed and realized using frequency-entangled biphoton quantum nonlocality. These achievements highlight the high stability and security advantages of quantum time synchronization.
* To address dual challenges of noise suppression and signal regeneration in high-precision fiber time transfer, key technologies of integrated analog-digital hybrid feedback with time-frequency dual-loop phase-locking and optical-electrical-optical bidirectional relay with DWDM schemes were realized. Together with employed low-phase-noise oscillators and high-stability pulse generation, the world's first thousand-kilometers field fiber-based time transfer systems with picosecond-level stability were implemented, laying foundations for continental-scale precision fiber time networks.
* Breakthroughs were achieved for long-haul optical frequency transfer by developing 1.5μm sub-Hz-linewidth cavity-stabilized ultra-stable lasers alongside cost-effective Hz-level fiber-stabilized laser prototypes; conquering the fast and automatic locking for ultra-stable lasers in second-scale; and innovating large-dynamic-range fiber phase noise measurement and compensation. These culminated the pioneer domestic development in 1000 km-level field fiber-based optical frequency transfer system at the E-19 level, providing a foundational platform for quantum precision measurement research.
Research Directions/Fields:
Quantum Time Transfer and Synchronization
Fiber-Optic Time-Frequency Transfer Technology
Quantum Microwave Photonics, Quantum network
Major Honors and Awards
2013 "National Ten Thousand Talents Plan" Young Top-notch Talents
2015 Shaanxi Province Young & Middle-Aged Science and Technology Innovation Leading Talents
2016 Outstanding Awardee (20th Anniversary Implementation) of CAS "Western Light" Talent Cultivation Program
2017 Outstanding Young Scientist in National Time-Frequency Field
2019 CAS Outstanding Individual in Women's Contribution Award
2022 CAS "March 8th Red Banner Holder"
2022 CAS Outstanding Supervisor (Supervised recipient of 2022 CAS Top 100 Outstanding Doctoral Dissertations)
2022 CAS Regional Development Young Scholar
2023 14th Shaanxi Provincial Youth Science & Technology Award
2023 CAS Science and Technology Award for Development Advancement (Research and Application of High-Precision Optical-Fiber Time-Frequency Transfer, ranked 3rd of 8 contributors)
Representative Publications
1.Yuting Liu; Runai Quan; Xiao Xiang; Huibo Hong; Mingtao Cao; Tao Liu; Ruifang Dong Ruifang Dong; Shougang Zhang ; Quantum clock synchronization over 20-km multiple segmented fibers with frequency-correlated photon pairs and HOM interference, Applied Physics Letters, 2021, 119(14): 144003
2.Ye Yang; Yaqing Jin; Xiao Xiang; Tengfei Hao; Wei Li; Tao Liu; Shougang Zhang; Ninghua Zhu; Ruifang Dong; Ming Li ; Single-photon microwave photonics, Science Bulletin, 2022, 67(7): 700-706
3.Zhiguang Xia; Xiao Xiang; Runai Quan; Ruifang Dong (期 Ruifang Dong; Tao Liu; Shougang Zhang ; Dispersion broadening of the two-photon quantum interference width due to temporal filtering, Physical Review Applied, 2023, 20(4): 044080
4.Xiao Xiang; Bingke Shi; Runai Quan; Yuting Liu; Zhiguang Xia; Huibo Hong; Tao Liu; Jincai Wu; Jia Qiang; Jianjun Jia; Shougang Zhang; Ruifang Dong Ruifang Dong ; Quantum two-way time transfer over a hybrid free-space and fiber link, Quantum Science and Technology, 2023, 8: 045017
5.Bingke Shi; Xiao Xiang; Huibo Hong; Yuting Liu; Pengfei Zhang; Runai Quan; Mingtao Cao; Tao Liu; Shougang Zhang; Ruifang Dong Ruifang Dong ; Development of prototype system for quantum two-way clock synchronization, Applied Physics Letters, 2024, 124(10): 104001
6.Bingke Shi; Huibo Hong; Xiao Xiang; Runai Quan; Yuting Liu; Tao Liu; Shougang Zhang; Ruifang Dong Ruifang Dong; Quantum two-way time transfer over a 250 km direct fiber-optic link, Optics Express, 2024, 32(25): 43805
7.Xue Deng; Xiang Zhang; Qi Zang; Dong-dong Jiao; Dan Wang; Jie Liu; Jing Gao; Guan-jun Xu; Ruifang Dong Ruifang Dong; Tao Liu; Shou-gang Zhang ; Coherent optical frequency transfer via 972 km fiber link, Chinese Physics B, 2024, 33(2): 020602
8.Huibo Hong; Runai Quan; Xiao Xiang; Yuting Liu; Tao Liu; Mingtao Cao; Ruifang Dong Ruifang Dong; Shougang Zhang ; Quantum two-way time transfer over a 103 km urban fiber, Journal of Lightwave Technology, 2024, 42(5): 1479-1486
9.Bo Liu; Xinxing Guo; Jiang Chen; Yanli Zhou; Tao Liu; Ruifang Dong Ruifang Dong; Shougang Zhang ; Report on 3,143.6km Time and Frequency Transfer Fiber Link With Ps-level Stability, Chinese Physics Letters, 2025, 42: 014202
10.Xinqian Guo; Linbo Zhang; Jun Liu; Long Chen; Le Fan; Guanjun Xu; Tao Liu; Ruifang Dong Ruifang Dong; Shougang Zhang ; An automatic frequency stabilized laser with hertz-level linewidth, Optics & Laser Technology, 2022, 145: 107498