Interferometric Distributed Fiber Optic Sensing

This thesis studies single-arm frequency-shifted interferometry (SA-FSI), a simple, compact, practical and versatile fiber optic sensing technique which has many advantages over conventional techniques. We further developed the theory of SA-FSI, and successfully demonstrate that SA-FSI can achieve long distance and high sensitivity sensing multiplexing.In this thesis work, we also build a model of the working principle of a distributed vibration sensing system developed by QPS Photronics Inc., and explore its sensing features. Three different types of reflective terminations (a QPS VibroFibre sensor, a flat end fiber, and a loop mirror) have been used in our experiments. Experimental results for these three reflective terminations are consistent with simulation results based on our model.M.A.S