Cascaded Fiber-Optic Interferometers for Multi-Perimeter-Zone Intrusion Detection With a Single Fiber Used for Each Defended Zone

A new fiber-optic perimeter intrusion detection system employing only one single-mode fiber as a disturbance sensor for each zone is presented. signal generated through interference between lights from two resonators, i.e., linear laser cavity and an extended resonator, was used determining defended zone. not sensing the intrusion-induced but also transmission of pump lights. Although many papers have reported multi-perimeter-zone systems, study presents, first time, with all along that in line pattern sectioned into multiple zones. An outdoor test four perimeter-zone carried out short section attached on netted fence Experimental results demonstrated there no cross any defended-zone light circuits, high alarm-upon-intrusion rate zero false alarm could be reached by using presented algorithm.