FIELD: measuring equipment.
SUBSTANCE: invention relates to measuring equipment, namely to fiber-optic security detectors. An optical circuit of a fiber-optic security detector with combined interferometers is a combined interferometers implementing an optical circuit containing closed loops forming reflection signals, in which the same segments of optical fiber of a cable are sensitive elements of interferometers, in which a phase shift of a probing pulse is created in accordance with the physical impact, the same for both loops – one is a closed-loop Mach-Zehnder interferometer, the other is a closed-loop Sagnac interferometer.
EFFECT: increase in the accuracy of the determination of a point of impact on a sensitive element due to the use of a combined interferometer method; provision of uniform sensitivity of a sensitive part of a fiber-optic security detector; increase in the reliability of the fiber-optic security detector; simplification of the installation due to the elimination of the need to use compensation coils in its composition.
5 cl, 12 dwg
