A Distributed Optical Fiber Disturbance Detection Device

Abstract

The invention discloses a distributed optical fiber disturbance detection device. The output end of a DFB laser is connected to the input end of a first coupler through a first polarizer, and the first output end of the first coupler is connected to the first third through a first delay optical fiber. Port 1 port of the circulator is connected, port 2 of the first three-port circulator is connected to the first sensing fiber, port 3 of the first three-port circulator is connected to the first input end of the second coupler through the third delay fiber, and the first The second output end of the coupler is connected to the port 1 of the second three-port circulator through the second delay fiber, the port 2 of the first three-port circulator is connected to the second sensing fiber, and the port 3 of the first three-port circulator is connected to the fourth The delay fiber is connected to the second input end of the second coupler, the first output end of the second coupler is connected to the input end of the signal detection module, and the second output end of the second coupler is input to the signal detection module through the second polarizer end connected. The invention solves the problem that the false alarm rate and the false alarm rate of the existing distributed optical fiber sensing system are too large.

Description

technical field [0001] The invention belongs to the technical field of optical fiber sensing and sensing network, and in particular relates to a distributed optical fiber disturbance detection device. Background technique [0002] Since Dr. Gao Yun proposed the prophecy of using optical fibers to transmit optical signals in 1966, human research on optical fiber materials and transmission signals has developed rapidly. At the end of the 20th century, with the practicability of optical fiber and the development of optical communication technology, people began to focus on the application of optical fiber in the field of sensing, forming a new research direction - optical fiber sensor technology. When light is transmitted in an optical fiber, its intensity, phase, frequency, polarization state and other parameters are easily affected by the external environment, such as temperature, stress, electric field, magnetic field, etc. The technology of obtaining the change of the corr...

AI Technical Summary

Problems solved by technology

However, due to the complex actual application environment of the system, the sensing optical cable is exposed to the external environment, which is easily affected by harsh environments such as strong winds and heavy rains, and generates unnecessary vibrations, which makes the disturbance event signals sensed by the distributed optical fiber vibration sensing system changeable. and unstable, causing the system to generate a large number of false positives

In order to reduce false positives, researchers usually choose to reduce the sensitivity of the system through complex disturbance discrimination algorithms

However, this reduction in sensitivity may in turn underreport true perturbations

At the same time, the complex disturbance discrimination algorithm will also reduce the real-time performance of the system

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