Interference type optical fiber distribution disturbance sensor and disturbance location method thereof

Abstract

The invention discloses an interference type optical fiber distribution disturbance sensor and a disturbance location method thereof, which relate to the technical field of optical fiber distribution disturbance sensors. The sensor comprises a light source, two detectors, a first Mach-Zehnder interferometer and a second Mach-Zehnder interferometer. The first Mach-Zehnder interferometer comprises a first optical coupling device and a second optical coupling device, wherein the first coupling device divides light emitted by the light source into two beams and sends the beams into the second optical coupling device, the light beams are interfered in the second optical coupling device, and the interfered light is respectively transmitted to a first detector and the second Mach-Zehnder interferometer. The second Mach-Zehnder interferometer comprises a third optical coupling device and a fourth optical coupling device, wherein the third optical coupling device divides the interfered light into two beams and transmits the beams to the fourth coupling device, the light beams are interfered in the fourth optical coupling device, and the interfered light is transmitted to a second detector. The interference type optical fiber distribution disturbance sensor and the disturbance location method of the disturbance sensor are simple in hardware structure, low in cost, high in accuracy, easy to achieve and capable of being used for long-distance monitoring.

Description

technical field [0001] The invention relates to the technical field of optical fiber distributed disturbance sensors, in particular to an interference type optical fiber distributed disturbance sensor and a disturbance positioning method thereof. Background technique [0002] Due to its high sensitivity, small size, light weight, intrinsic safety, electrical insulation, anti-electromagnetic interference, relatively low cost, versatility, high reliability, hardware matching optical fiber communication interface, easy networking, especially can realize Excellent features such as distributed measurement have a wide range of applications in industrial, civil and military fields. Among them, the optical fiber distributed disturbance sensor is of great significance in the fields of perimeter security, oil and gas pipeline monitoring, large structure monitoring and communication line monitoring. [0003] The optical fiber distributed disturbance sensor can monitor the disturbance ...

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Problems solved by technology

[0024] However, when this is applied to long-distance monitoring, the backward Rayleigh scattering and stimulated Brillouin scattering in the sensing fiber and the guiding fiber will make the interference light intensity of the interferometer superimposed with noise terms, resulting in the counterclockwise Mach-Zero The optical signal-to-noise ratio of the German interferometer is reduced, resulting in positioning errors

Among them, the influence of stimulated Brillouin scattering can be effectively suppressed or eliminated by means of optical path compensation, while the influence of backward Rayleigh scattering cannot be eliminated, and it will still affect the disturbance positioning accuracy of long-distance monitoring. This defect limits this type of sensor The application in long-distance monitoring reduces the practical performance of the sensor

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