A high-precision bidirectional time-transfer system over a single fiber based on wavelength-division multiplexing and time-division multiplexing

Abstract

In this paper, a high-precision bidirectional time-transfer system over a single fiber based on wavelength-division multiplexing and time-division multiplexing (SFWDM-TDM) is proposed, which combines the advantages of wavelength-division multiplexing and time-division multiplexing. It uses two dense wavelength-division channels to effectively suppress the problem of optical fiber reflection. At the same time, the time-division multiplexing method is used in combination with sampling and holding the time to complete the multi-user task. In hardware, we optimized the carrier processing and the high-precision time-delay control module of the SFWDM-TDM system to complete high-precision time-transfer equipment. In software and algorithm, the optical fiber time-interval measurement method and measurement times are optimized, and the SFWDM-TDM system reaches a synchronization accuracy of 8.9 ps at 1 s. Finally, a real-time detection mechanism with self-recovery ability is added to the system. This lays the foundation for a reliable, long-distance, high-precision, and multi-user mode optical fiber time- and frequency-transfer network.

Time Transfer in a 1839-km Telecommunication Fiber Link Demonstrating a Picosecond-Scale Stability

“…Numerous groups have been conducting research on highperformance TTOF technology since as early as 2006, resulting in continuous breakthrough progress. [7][8][9][10][11][12] As of the present time, long-distance fiber-optic time transfer has been implemented both in laboratory fibers [13][14][15][16][17] and in field telecom fiber links. [18][19][20][21] Specifically, the TTOF demonstration in laboratory fibers has been extended to cover 2000 km distance.…”

Time transfer in a 1839 km telecommunication fiber link demonstrating a picosecond-scale stability

“…Since as early as 2006, research on high-performance TTOF technology has been conducted by numerous groups, leading to continuous breakthrough progress [7][8][9][10][11][12]. As of the present time, long-distance fiber-optic time transfer has been implemented both in laboratory fibers [13][14][15][16] and in field telecom fiber links [17][18][19][20]. Specifically, the TTOF demonstration in laboratory fibers has been extended to cover a distance of 2000 km.…”

Time transfer in a 1839 km telecommunication fiber link demonstrating a picosecond-scale stability

“…Since as early as 2006, research on high-performance TTOF technology has been conducted by numerous groups, leading to continuous breakthrough progress [7][8][9][10][11][12]. As of the present time, long-distance fiber-optic time transfer has been implemented both in laboratory fibers [13][14][15][16] and in field telecom fiber links [17][18][19][20]. Specifically, the TTOF demonstration in laboratory fibers has been extended to cover a distance of 2000 km.…”