PROJECT TITLE :

High-Precision Time Transfer Over 2000-km Fiber Link

ABSTRACT:

The 2-approach fiber-optic time transfer based mostly on bidirectional time-division multiplexing transmission over one fiber with the same wavelength (BTDM-SFSW) is a good approach to eliminate the result of Rayleigh backscattering and reach the maximum bidirectional symmetry at the same time. During this paper, a BTDM-SFSW-based time transfer testbed is built with the employment of loop configuration within the laboratory to guage the performance of fiber-optic time transfer over thousands of kilometers, which is confronted with worse signal-to-noise ratio (SNR), a lot of serious fiber dispersion, and thus on. The contributions of various factors, as well as the precision and stability of transmitted wavelengths, the facility dependence of transceivers' receiving delays, Sagnac effect, etc., to the uncertainty of time transfer are investigated by theoretical analyses and experimental measurements. A full uncertainty budget for the BTDM-SFSW-based time transfer is provided. Experimental results show that the stabilities of less than 89 ps/s and twenty three ps/one hundred and five s will be achieved for the time transfer over a 200zero-km fiber link. The theoretical expanded uncertainty with the coverage factor will be but one hundred ps while not the necessity of a fiber link calibration, which is validated by experimental results still.