Defense area optical fiber distribution type vibration sensor and perimeter alarm system adopting same

Abstract

The invention discloses a defense area optical fiber distribution type vibration sensor comprising a light source, a first transmission optical fiber, a second transmission optical fiber, a coupler provided with at least four coupling arms, a first depolarizer, a second depolarizer, a delay loop, a U-shaped sensing optical fiber loop and a signal receiving and processing module, wherein two ends of the first transmitting optical fiber are respectively connected with the light source and the first coupling arm of the coupler; two ends of the second transmitting optical fiber are respectively connected with the signal processing module and the second coupling arm of the coupler; the third coupling arm of the coupler is connected with one end of the first depolarizer; the fourth coupling armof the coupler is connected with one end of the second depolarizer; and the delay loop and the U-shaped sensing optical fiber loop are connected in series between the other end of the first depolarizer and the other end of the second depolarizer. The sensor avoids the phenomena of polarization and fading caused by stress double refraction in the single mode fiber and provides a new feasible scheme for an optical fiber perimeter alarm system.

Description

technical field [0001] The invention relates to the technical field of photoelectric sensing, in particular to an area-defense optical fiber distributed vibration sensor and a perimeter alarm system using the sensor. Background technique [0002] As a new generation of perimeter alarm system, the fiber optic perimeter alarm system has strong military and civilian value. It can be used for perimeter security monitoring of prisons, important military targets, weapon depots, etc., and can also be used for perimeter security monitoring of important facilities such as communities, government agencies, nuclear power plants, and airports. [0003] The optical fiber perimeter alarm system mainly adopts optical fiber distributed vibration sensor, which analyzes the intrusion vibration information by monitoring the impact of environmental stress changes in a small boundary area on the optical fiber, and judges and alarms it. The fiber optic perimeter alarm system has the advantages t...

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Problems solved by technology

[0016] The embodiment of the present invention provides an anti-zone optical fiber distributed vibration sensor to solve the problem that the optical fiber cannot be reliably used for vibration sensing in the prior art

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