FIELD: physics.
SUBSTANCE: invention relates to measuring equipment using optical fibre, namely, to fibre-optic security detectors, as well as to products, methods and means related to fibre-optic security detectors and their aspects. Claimed enclosure with the linear part of the security fibre-optic detector, which is an enclosure formed by a discontinuous obstacle stretched between the pillars installed on the foundations, wherein the discontinuous obstacle comprises a sensitive element of the security fibre-optic detector, placed along the discontinuous obstacle along a curved path, which provides vibration sensitivity and additional connectivity of the elements of the discontinuous obstacle, wherein the security fibre-optic detector is a security fibre-optic detector, which includes combined interferometers, having a station part with a transceiving device connected to the linear part of said detector. At that, the linear part is a branched optical circuit based on splitters and a fibre-optic cable, which by means of connecting sleeves and a transport cable connect the transceiving device and the sensitive elements of the detector of the security fibre-optic cable, the latter comprises closed circuits generating reflection signals, the same sections of the optical fibre of the cable being the sensitive elements of interferometers, in which a phase shift of the probing pulse is created in accordance with the physical effect, which is the same for both circuits. One closed circuit is a Mach-Zehnder interferometer, and the other closed circuit is a Sagnac interferometer.
EFFECT: high accuracy of determining the point of action on the sensitive element; providing uniform sensitivity of the sensitive part of the security fibre-optic detector; high reliability of the security fibre-optic detector; simplification of installation due to elimination of necessity to use compensation coils in its composition, which are necessary for compensation of length of fibres of the sensitive element, as well as implementation of its purpose.
10 cl, 12 dwg
