Multi-Zone Fiber-Optic Intrusion Detection System With Active Unbalanced Michelson Interferometer Used for Security of Each Defended Zone

Autor: Tai-Lang Jong, Likarn Wang, Kai-Shuo Hsu, Hsin Hsieh
Rok vydání: 2020
Předmět:
Zdroj: IEEE Sensors Journal. 20:1607-1618
ISSN: 2379-9153
1530-437X
DOI: 10.1109/jsen.2019.2946904
Popis: A new fiber-optic system with an active unbalanced Michelson interferometer (AUMI) was designed for multi-zone perimeter intrusion detection by employing only two single-mode fibers for each sensing zone. A pump laser at the monitor site was used to remotely pump the erbium-doped fibers located, respectively, at the two arms of the AUMI for each sensing zone. Configured into a fiber laser cavity, the AUMI served as an optical switch that would modulate the optical power when one arm of the AUMI was perturbed by intrusion to induce a phase offset variation. In the study, an armored cable with a length of 200 meters in total was divided into four sections each guarding a perimeter zone. The experimental results showed that the AUMI system correctly responded to perturbations induced by footstepping on a fiber cable buried underground, vibrating a netted fence, or knocking a window. A high alarm-upon-intrusion rate and zero false alarm rate could be reached by using the presented detection algorithm.
Databáze: OpenAIRE