Study On Multi-Time Reflection Induced By In-Line Fiber Connector In Engineering Applied Distributed Single-Fiber Interferometer Sensing System

In this article, multi-time reflection phenomenon induced by fiber connector at the connection point of device module in engineering applied all-fiber long-distance distributed vibration sensing system is analyzed and discussed. Despite the application of phase generated carrier (PGC) technology, this multi-time reflection phenomenon severely degrades the performance of the system. Through theoretical analysis and experiments on the basis of PGC technology, it is found that the influence of multi-time reflection on the system can be suppressed by selecting appropriate modulation frequency according to the position of the reflection point, and the distortion of the phase retrieved signal is effectively eliminated.