Phase-sensitive light time domain reflectometer based on 120-degree difference interferometer

A technology of time-domain reflectometry, phase-sensitive light, applied in the direction of transmitting sensing components using optical devices

Inactive Publication Date: 2016-01-06
NANJING PIONEER AWARENESS INFORMATION TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Protect the interferometer from external disturbances

Method used

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  • Phase-sensitive light time domain reflectometer based on 120-degree difference interferometer
  • Phase-sensitive light time domain reflectometer based on 120-degree difference interferometer
  • Phase-sensitive light time domain reflectometer based on 120-degree difference interferometer

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0053] Such as figure 2 As shown, the light emitted by the laser light source (1) is modulated into pulsed light by the optical pulse modulation module (2), and then amplified by the first optical amplifier (3), and then injected into the two ports of the first circulator (4). Into the sensing fiber, the backscattered light reflected from the sensing fiber is output through the three ports of the first circulator (4), and the output light is amplified by the second optical amplifier (5), and then transmitted from the second circulator One port of (6) is injected into the fiber grating (7), and the fiber grating (7) filters the scattered light and is injected into the third circulator (8) through two ports of the second circulator and three ports out. , the scattered light is injected into the left port of the 3×3 coupler (9) through the third circulator (8), and the scattered light is divided into three beams, one of which is reflected back by the first Faraday rotating mirro...

Embodiment 2

[0055] Such as image 3 As shown, a Mach-Zehnder interferometer based on 3×3 couplers with a phase difference of 120 degrees is used. The light emitted by the laser light source (1) is modulated into pulsed light by the optical pulse modulation module (2), amplified by the first optical amplifier (3), and then injected into the sensor by the two ports of the first circulator (4). In the optical fiber, the backscattered light reflected from the sensing optical fiber is output through the three ports of the first circulator (4), and the output light is amplified by the second optical amplifier (5) and then transmitted from the second circulator (6) The one-port input and the second-port output of the second circulator are injected into the fiber Bragg grating (7), and the scattered light is filtered by the fiber Bragg grating (7) and injected into the 1:1 coupler (88) through the two-port input and three-port output of the second circulator , the scattered light passes through ...

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Abstract

The invention discloses a phase-sensitive light time domain reflectometer based on a 120-degree difference interferometer. The reflectometer comprises a laser light source, a light pulse modulator, a first light amplifier, a first circulator, a second light amplifier, a second circulator, a fiber grating, the 120-degree difference interferometer, a first photoelectric detector, a second photoelectric detector, a third photoelectric detector, a data acquisition card and a data processing system. After light emitted by the laser light source is modulated to pulse light through the light pulse modulator, the pulse light is amplified through the first light amplifier, and then the pulse light goes into a second port from a first port of the first circulator so as to be injected into a sensing fiber; and the interferometer erected by use of a 3*3 coupler with a phase difference of 120 degrees is employed for performing distributed modulation on the phase of Rayleigh scattering light in the fiber and obtaining phase information along the fiber so that such information as vibration, temperature, strain and the like is sensed.

Description

technical field [0001] The invention relates to a phase-sensitive optical time-domain reflectometer, in particular to a phase-sensitive optical time-domain reflectometer based on a 120-degree phase difference interferometer. Background technique [0002] Phase-sensitive optical time domain reflectometer is a distributed optical fiber sensing technology based on Rayleigh scattering. It has the advantages of high sensitivity, sensitive response, long detection distance, and dynamic detection. Real-time monitoring of distance has received widespread attention. In addition to many characteristics of conventional distributed optical fiber sensing, this technology also has the advantages of high positioning accuracy and simple data processing. Such as health and safety monitoring of bridges, railway tracks, large buildings, etc. [0003] One of H.F.Taylor's prior technologies [H.F.TaylorandC.E.Lee.Apparatusandmethodforfiberopticintrusionsensing.U.S.Patent5,1993:194847.] proposed...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01D5/353
Inventor 曹玉龙杨飞
Owner NANJING PIONEER AWARENESS INFORMATION TECH CO LTD
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