OPTICAL CIRCUIT OF FIBER-OPTIC SECURITY DETECTOR, WHICH USES CLOSED INTERFEROMETER WITH TWO ARMS, PLACED IN CONNECTING COUPLING Russian patent published in 2022 - IPC G01D5/353 G02B6/42 

FIELD: measuring equipment.

SUBSTANCE: invention relates to measuring equipment using optical fiber, to fiber-optic security detectors. An optical circuit of a fiber-optic security detector, which uses a closed interferometer with two arms, contains a closed loop forming a reflection signal, in which the same segments of optical fiber of a cable are sensitive elements of the interferometer, in which a phase shift of a probing pulse is created in accordance with the exerted physical impact. The closed loop is a Mach-Zehnder interferometer, the length of one of arms of the interferometer is compensated by an optical delay line, the optical delay line is made by means of connection into an optical circuit of reserve cores of a fiber-optic cable or is made in the form of a coil of optical fiber, while the optical circuit is placed in a connecting coupling.

EFFECT: provision of uniform sensitivity of part of a fiber-optic security detector, increase in the reliability of a fiber-optic security detector, simplification of mounting.

3 cl, 12 dwg