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Optical Fiber Vibration Sensor Using Chaotic Laser

In this letter, a novel composite optical fiber sensor constructed with the combination of chaotic laser and non-balanced Sagnac/Mach–Zehnder structure is proposed and experimentally demonstrated for the distributed vibration measurement. With the help of a stable and low-coherence chaotic laser, higher order null-frequencies with accurate peaks can be successfully obtained, which reduces the location error, and thus improves the detection performance. The experimental results verify the effectiveness of the proposed sensor. It is able to detect vibration position over a total fiber length of 12.101 km, with a location error, which can be reduced to 22 m.