CN114577324A - Distributed optical fiber vibration monitoring system - Google Patents
Distributed optical fiber vibration monitoring system Download PDFInfo
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- CN114577324A CN114577324A CN202210145339.5A CN202210145339A CN114577324A CN 114577324 A CN114577324 A CN 114577324A CN 202210145339 A CN202210145339 A CN 202210145339A CN 114577324 A CN114577324 A CN 114577324A
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- 239000013307 optical fiber Substances 0.000 title claims abstract description 48
- 238000012544 monitoring process Methods 0.000 title claims abstract description 20
- 239000004065 semiconductor Substances 0.000 claims abstract description 20
- 230000003287 optical effect Effects 0.000 claims abstract description 19
- 230000000737 periodic effect Effects 0.000 claims abstract description 10
- 238000012545 processing Methods 0.000 claims abstract description 8
- 238000001514 detection method Methods 0.000 claims abstract description 6
- 238000006243 chemical reaction Methods 0.000 claims abstract description 4
- 238000001914 filtration Methods 0.000 claims abstract description 4
- 230000010355 oscillation Effects 0.000 claims abstract description 4
- 239000000835 fiber Substances 0.000 claims description 30
- 229910052691 Erbium Inorganic materials 0.000 claims 2
- UYAHIZSMUZPPFV-UHFFFAOYSA-N erbium Chemical compound [Er] UYAHIZSMUZPPFV-UHFFFAOYSA-N 0.000 claims 2
- 238000000034 method Methods 0.000 description 7
- 230000001427 coherent effect Effects 0.000 description 5
- 230000000630 rising effect Effects 0.000 description 3
- 230000003321 amplification Effects 0.000 description 2
- 230000035559 beat frequency Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000003199 nucleic acid amplification method Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008033 biological extinction Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000000253 optical time-domain reflectometry Methods 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01H—MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES
- G01H9/00—Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means
- G01H9/004—Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means using fibre optic sensors
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
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- Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
Abstract
The invention discloses a distributed optical fiber vibration monitoring system, which comprises: the device comprises a laser light source, an optical fiber coupler, a switch type semiconductor optical amplifier, an optical fiber circulator, a balance detector, a low-pass filter, a data acquisition and processing unit and a pulse driver; the continuous laser emitted by the laser source is divided into two paths by the optical fiber coupler; wherein, one path of continuous laser is used as local oscillation laser to enter a balance detector; the other path of continuous laser enters the switch type semiconductor optical amplifier and becomes periodic pulse laser under the drive of the pulse driver, and the periodic pulse laser is incident to the sensing optical fiber through the optical fiber circulator; the backward Rayleigh scattered light returned from the sensing optical fiber and the local oscillator laser enter the balance detector, enter the low-pass filter after photoelectric conversion and common-mode signal filtering, and are finally collected and analyzed by the signal collecting and processing unit, so that the vibration signal detection along the sensing optical fiber is realized.
Description
Technical Field
The invention belongs to the technical field of optical fiber sensing, and particularly relates to a distributed optical fiber vibration monitoring system.
Background
A distributed optical fiber vibration sensor is a novel optical fiber sensing technology based on phase-sensitive optical time domain reflectometry (phi-OTDR), and directly uses a single-core single-mode optical fiber as a sensor, so that the sensing and the sensing are integrated, the long-distance multipoint vibration monitoring can be realized, and the positioning precision can reach a meter level.
Because the backward Rayleigh scattering signal is weak, the demodulation method mainly comprises the following steps:
the method comprises the steps that firstly, a high-sensitivity avalanche photodiode or an erbium-doped fiber amplifier and a photodiode are used as a detector, backward Rayleigh scattered light signals are directly detected and collected, adjacent difference is carried out on scattered light interference signals obtained by sampling to detect vibration signals, the method can only simply judge position information of vibration points, and related amplitude and frequency information of vibration is difficult to collect;
and secondly, a coherent demodulation method, namely, enabling Rayleigh scattered light signals and local oscillator optical signals to enter a balanced detector, amplifying the local oscillator optical signals, collecting beat frequency signals by using a collecting card, and extracting amplitude and phase signals from the beat frequency signals to perform adjacent difference so as to realize the judgment of the vibration signals. Compared with a direct intensity demodulation method, the coherent demodulation method has higher technical implementation difficulty, higher measurement sensitivity and higher linearity, and can realize longer-distance monitoring.
The distributed optical fiber vibration sensor based on phase sensitive optical time domain reflection needs high-coherence laser pulses, so an external modulation mode needs to be adopted. Currently, external modulation is mainly achieved by using acousto-optic modulators. The acousto-optic modulator is mature in technology and high in extinction ratio, but the driving is complex, the rising edge of a pulse is generally in the order of tens of nanoseconds, high spatial resolution cannot be achieved, the laser has frequency shift from tens of mega to hundreds of mega after passing through the acousto-optic modulator, a heterodyne coherent demodulation method is needed at the moment, and signal demodulation difficulty is high.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a distributed optical fiber vibration monitoring system.
The purpose of the invention is realized by the following technical scheme:
a distributed fiber optic vibration monitoring system, comprising: the device comprises a laser light source, an optical fiber coupler, a switch type semiconductor optical amplifier, an optical fiber circulator, a balance detector, a low-pass filter, a data acquisition and processing unit and a pulse driver; the continuous laser emitted by the laser source is divided into two paths by the optical fiber coupler; wherein, one path of continuous laser is used as local oscillation laser to enter a balance detector; the other path of continuous laser enters the switch type semiconductor optical amplifier and becomes periodic pulse laser under the drive of the pulse driver, and the periodic pulse laser is incident to the sensing optical fiber through the optical fiber circulator; the backward Rayleigh scattered light returned from the sensing optical fiber and the local oscillator laser enter the balance detector, enter the low-pass filter after photoelectric conversion and common-mode signal filtering, and are finally collected and analyzed by the signal collecting and processing unit, so that the vibration signal detection along the sensing optical fiber is realized.
According to a preferred embodiment, the fiber vibration monitoring system further comprises a first erbium-doped fiber amplifier, which is disposed between the switch-type semiconductor optical amplifier and the fiber circulator and is used for amplifying the periodic pulse laser.
According to a preferred embodiment, the fiber vibration monitoring system further comprises a second erbium-doped fiber amplifier, the second erbium-doped fiber amplifier is arranged between the fiber circulator and the balanced detector, backward rayleigh scattered light returning from the sensing fiber passes through the fiber circulator and is amplified by the second erbium-doped fiber amplifier, and the amplified backward rayleigh scattered light is input to the balanced detector.
According to a preferred embodiment, the laser light source is a narrow linewidth semiconductor laser light source. The narrow linewidth semiconductor laser light source has stronger shock resistance and wider working temperature range.
According to a preferred embodiment, the fiber coupler is not limited to standard couplers, direct-connect couplers, star/tree couplers, and wavelength multiplexers.
According to a preferred embodiment, the low-pass filter is not limited to butterworth and chebyshev filters.
The aforementioned main aspects of the invention and their respective further alternatives can be freely combined to form a plurality of aspects, all of which are aspects that can be adopted and claimed by the present invention. The skilled person in the art can understand that there are many combinations, which are all the technical solutions to be protected by the present invention, according to the prior art and the common general knowledge after understanding the scheme of the present invention, and the technical solutions are not exhaustive herein.
The invention has the beneficial effects that: the distributed optical fiber vibration monitoring system utilizes the switch type semiconductor optical amplifier as an external modulator to realize pulse laser without frequency shift and finally realize homodyne coherent detection. Because the switch type semiconductor optical amplifier is used as an external modulator, the rising edge of the pulse laser is very fast (less than 1ns), so that the pulse laser with the pulse width of tens of nanoseconds can be realized, and the high spatial resolution performance can be improved; and the switch type semiconductor optical amplifier has a certain signal gain function, so that the requirement on the amplification performance of the first erbium-doped optical fiber amplifier at the back is lowered.
Drawings
Fig. 1 is a schematic structural diagram of a distributed optical fiber vibration monitoring system according to the present invention.
Detailed Description
The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It is to be noted that the features in the following embodiments and examples may be combined with each other without conflict.
It should be noted that, in order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments.
In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
In addition, it should be noted that, in the present invention, if the specific structures, connection relationships, position relationships, power source relationships, and the like are not written in particular, the structures, connection relationships, position relationships, power source relationships, and the like related to the present invention can be known by those skilled in the art without creative work on the basis of the prior art.
Referring to fig. 1, the present invention discloses a distributed optical fiber vibration monitoring system, which includes: the device comprises a laser light source, an optical fiber coupler, a switch type semiconductor optical amplifier, a first erbium-doped optical fiber amplifier, an optical fiber circulator, a second erbium-doped optical fiber amplifier, a balance detector, a low-pass filter, a data acquisition and processing unit and a pulse driver.
Preferably, the laser light source is a narrow linewidth semiconductor laser light source, the central wavelength is 1550nm, the linewidth is less than 5kHz, and the laser light source can stably work for a long time at the temperature range of-10 ℃ to +50 ℃. The fiber optic couplers are not limited to standard couplers, direct-connect couplers, star/tree couplers, and wavelength multiplexers. The low-pass filter is not limited to the butterworth filter and the chebyshev filter.
The continuous laser emitted by the laser source is divided into two paths by the optical fiber coupler. Wherein, one path of continuous laser enters the balance detector as local oscillation laser. And the other path of continuous laser enters the switch type semiconductor optical amplifier and becomes periodic pulse laser under the drive of the pulse driver, and the periodic pulse laser is amplified by the first erbium-doped fiber amplifier and then enters the sensing fiber through the fiber circulator.
The backward Rayleigh scattered light returned from the sensing fiber passes through the fiber circulator and is amplified by the second erbium-doped fiber amplifier. The amplified back Rayleigh scattering light and the local oscillator laser enter a balance detector, enter a low-pass filter after photoelectric conversion and common-mode signal filtering, and are finally collected and analyzed by a signal collecting and processing unit, so that the vibration signal detection along the sensing optical fiber is realized.
The distributed optical fiber vibration monitoring system utilizes the switch type semiconductor optical amplifier as an external modulator to realize pulse laser without frequency shift and finally realize homodyne coherent detection.
Because the switch type semiconductor optical amplifier is used as an external modulator, the rising edge of the pulse laser is very fast (less than 1ns), so that the pulse laser with the pulse width of tens of nanoseconds can be realized, and the high spatial resolution performance can be improved; and the switch type semiconductor optical amplifier has a certain signal gain function, so that the requirement on the amplification performance of the first erbium-doped optical fiber amplifier at the back is lowered.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.
Claims (6)
1. A distributed fiber optic vibration monitoring system, comprising: the device comprises a laser light source, an optical fiber coupler, a switch type semiconductor optical amplifier, an optical fiber circulator, a balance detector, a low-pass filter, a data acquisition and processing unit and a pulse driver;
the continuous laser emitted by the laser source is divided into two paths by the optical fiber coupler;
wherein, one path of continuous laser is used as local oscillation laser to enter a balance detector;
the other path of continuous laser enters the switch type semiconductor optical amplifier and becomes periodic pulse laser under the drive of the pulse driver, and the periodic pulse laser is incident to the sensing optical fiber through the optical fiber circulator;
the backward Rayleigh scattered light returned from the sensing optical fiber and the local oscillator laser enter the balance detector, enter the low-pass filter after photoelectric conversion and common-mode signal filtering, and are finally collected and analyzed by the signal collecting and processing unit, so that the vibration signal detection along the sensing optical fiber is realized.
2. The distributed fiber optic vibration monitoring system of claim 1 further comprising a first erbium doped fiber amplifier,
the first erbium-doped optical fiber amplifier is arranged between the switch-type semiconductor optical amplifier and the optical fiber circulator and is used for amplifying periodic pulse laser.
3. A distributed fibre optic vibration monitoring system according to claim 1 or claim 2 further comprising a second erbium doped fibre amplifier disposed between the fibre optic circulator and the balanced detector,
and the backward Rayleigh scattered light returned from the sensing optical fiber passes through the optical fiber circulator and is amplified by the second erbium-doped optical fiber amplifier, and the amplified backward Rayleigh scattered light is input to the balanced detector.
4. The distributed fiber optic vibration monitoring system of claim 1 wherein the laser light source is a narrow linewidth semiconductor laser light source.
5. The distributed fiber optic vibration monitoring system of claim 1 wherein the fiber optic coupler is not limited to standard couplers, direct-connect couplers, star/tree couplers, and wavelength multiplexers.
6. A distributed fibre optic vibration monitoring system as claimed in claim 1 wherein said low pass filter is not limited to butterworth and chebyshev filters.
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Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102645268A (en) * | 2012-04-26 | 2012-08-22 | 中国科学院上海光学精密机械研究所 | Optical frequency division multiplexing phase-sensitive optical time domain reflectometer |
| CN102778800A (en) * | 2012-08-16 | 2012-11-14 | 电子科技大学 | Method and device for generating light pulse by direct current light |
| WO2017142443A2 (en) * | 2016-02-19 | 2017-08-24 | Общество с ограниченной ответственностью "БГ-ОПТИКС" | Method of evaluating vibration signals along long objects |
| CN109163748A (en) * | 2018-09-17 | 2019-01-08 | 哈尔滨工业大学 | Single-ended dynamic distributed Brillouin's reflection unit and method based on frequency agility technology |
| CN111307054A (en) * | 2020-02-29 | 2020-06-19 | 太原理工大学 | High-precision dynamic strain monitoring device and method based on time-delay-free chaotic laser |
| CN111609918A (en) * | 2020-06-09 | 2020-09-01 | 重庆大学 | Optical fiber distributed vibration sensing system based on envelope detection circuit |
| CN111928938A (en) * | 2020-09-10 | 2020-11-13 | 无锡科晟光子科技有限公司 | Long-distance distributed optical fiber vibration detection system |
| WO2020237129A1 (en) * | 2019-05-22 | 2020-11-26 | Nec Laboratories America, Inc. | Single mode fiber distributed temperature sensing with improved noise characteristics |
| CN113310563A (en) * | 2021-04-22 | 2021-08-27 | 成都海恒之星科技合伙企业(有限合伙) | Distributed optical fiber vibration sensing device and method for improving positioning accuracy |
| CN214372659U (en) * | 2021-04-02 | 2021-10-08 | 广西师范大学 | Rayleigh-Raman fusion type distributed optical fiber sensing system |
-
2022
- 2022-02-17 CN CN202210145339.5A patent/CN114577324A/en active Pending
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102645268A (en) * | 2012-04-26 | 2012-08-22 | 中国科学院上海光学精密机械研究所 | Optical frequency division multiplexing phase-sensitive optical time domain reflectometer |
| CN102778800A (en) * | 2012-08-16 | 2012-11-14 | 电子科技大学 | Method and device for generating light pulse by direct current light |
| WO2017142443A2 (en) * | 2016-02-19 | 2017-08-24 | Общество с ограниченной ответственностью "БГ-ОПТИКС" | Method of evaluating vibration signals along long objects |
| CN109163748A (en) * | 2018-09-17 | 2019-01-08 | 哈尔滨工业大学 | Single-ended dynamic distributed Brillouin's reflection unit and method based on frequency agility technology |
| WO2020237129A1 (en) * | 2019-05-22 | 2020-11-26 | Nec Laboratories America, Inc. | Single mode fiber distributed temperature sensing with improved noise characteristics |
| CN111307054A (en) * | 2020-02-29 | 2020-06-19 | 太原理工大学 | High-precision dynamic strain monitoring device and method based on time-delay-free chaotic laser |
| CN111609918A (en) * | 2020-06-09 | 2020-09-01 | 重庆大学 | Optical fiber distributed vibration sensing system based on envelope detection circuit |
| CN111928938A (en) * | 2020-09-10 | 2020-11-13 | 无锡科晟光子科技有限公司 | Long-distance distributed optical fiber vibration detection system |
| CN214372659U (en) * | 2021-04-02 | 2021-10-08 | 广西师范大学 | Rayleigh-Raman fusion type distributed optical fiber sensing system |
| CN113310563A (en) * | 2021-04-22 | 2021-08-27 | 成都海恒之星科技合伙企业(有限合伙) | Distributed optical fiber vibration sensing device and method for improving positioning accuracy |
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