FIELD: measuring equipment.
SUBSTANCE: invention relates to measuring equipment using optical fibre, to fibre-optic security detectors. A fence with a linear part of a fibre-optic security detector constitutes a fence formed by a non-continuous obstacle extending between poles installed on foundations, with sensing elements of the detector placed along the non-continuous obstacle along a curvilinear trajectory providing vibration sensitivity and additional connectivity of the obstacle elements, wherein included in the detector is a closed interferometer with two arms, with a station part with a transceiver apparatus connected with the linear part of the detector, the linear part constitutes a branched optical circuit based on splitters and a fibre-optic cable, containing a closed contour forming reflection signals, segments of the optical fibre constitute sensing elements of the interferometer and create a phase shift in the probing pulse for the contour, wherein the closed contour constitutes a Mach-Zehnder interferometer.
EFFECT: ensured uniform sensitivity of the fibre-optic security detector; increased reliability of the fibre-optic security detector.
10 cl, 12 dwg
