Active fiber-loop method for improved performance assessment of Brillouin OTDR systems

We report on what we belive to be a new fiber-optical measurement artifact used to assess the performance of Brillouin optical time-domain reflectometry (BOTDR) devices. In our proposed configuration, a fast optical switch is employed to significantly reduce the round-trip loss of a fiber loop probed by the BOTDR interrogator. Through a series of experiments, we demonstrate that our modified fiber artifact enables detailed characterization of BOTDR devices, allowing simultaneous assessment of distance-dependent spatial resolution, distance-dependent measurement biases, and system configuration anomalies. Our approach, which can be readily extended to other distributed optical fiber sensing modalities, provides a practical method for validating and benchmarking device performance.