High Accurate Optic Fiber Transfer Delay Measurement Using Software-Defined Radio

We propose and experimentally demonstrate a high accurate fiber transfer delay (FTD) measurement method based on software-defined radio (SDR) device. High-precision FTD measurement is an imperative technology for many scientific applications. Because of its merits such as low cost, high-frequency agility, and so on, SDR is an attractive platform to facilitate such demands. In cooperation with the characteristics of SDR, our FTD measurement prototype, which adopts a dedicated phase unwrapping-tracking scheme, is developed to achieve long-term, continuous measurement, and tracking without missing any abrupt changes. In addition to a FTD measurement accuracy of ±0.12 ps, it also can fulfill chromatic dispersion measurement. Owing to its low cost and ease of implementation, we hope our solution can provide new insight into the popularization of large-scale, low-cost FTD detection network for scientific applications like time and frequency dissemination, and radio interferometry.