Fiber-Optic UTC(k) Timescale Distribution With Automated Link Delay Cancelation

In this paper, we describe the idea and practical realization of an automated calibrator of fiber-optic UTC(k) distribution system, along with a high-resolution shifter of 1 PPS signal, which allows us to cancel the propagation delay and, thus, to produce the 1 PPS at the remote system output with practically zero offset. The solution was experimentally verified with 10 different optical paths, up to 300 km long. The rms offset of the output timescale in our experiments was 7.1 ps, and maximum absolute value did not exceed 15 ps.