Distributed magnetic sensing with high precision and long distance using polarization-sensitive optical frequency domain reflectometry

The fiber based distributed magnetic sensing has significant research and application value in strong magnetic measurement field, such as thunderstorm warning and nuclear reaction detection. The current polarization sensitive reflectometry technology has a limit of short measurement distance and low sensitivity. We proposed a sensing method based on polarization sensitive time-gated digital optical frequency domain reflectometry (TGDOFDR) to analyze the changes in state of polarization (SOP) before and after applying a magnetic field, for measuring the magnetic intensity. The sensing distance has been increased to 10 kilometers and the measurement error has been decreased to 5 mT.