Research on High Stability Time-Frequency Transmission Over a 22.5 km 7-Core Fiber

We experimentally demonstrated time-frequency transmission over a 7-core optical fiber and achieved a long-term frequency stability of${9.48 \times 10^{\wedge}}{-}{17 {@} 1000} \mathrm{s}$, time stability of 1.17ps@1000s, and time synchronization accuracy of 33.8 ps.