Development of Fiber Optic BOTDA Sensor for Intrusion Detection

We present a compact fiber optic Brillouin optical time domain analysis (BOTDA) sensor system, which has the capability of detecting and locating intrusion attempts over several tens of kilometers long paths. The system employs a laser diode and two electro-optic modulators. Simulation of an intrusion effect was achieved by use of a strain-inducing setup. Distance resolution of 3 m was obtained for a 4.81 km long optical fiber within 1.5 s. Actual intrusion detection experiment was also performed using a step-on stage setup and clearly discernable detection signals were obtained in less than 1.5 s. # 2002 Published by Elsevier Science B.V.