CN108759882A - Semiconductor laser mutually pouring-in Distributed optical fiber sensor system and localization method - Google Patents
Semiconductor laser mutually pouring-in Distributed optical fiber sensor system and localization method Download PDFInfo
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- CN108759882A CN108759882A CN201810412141.2A CN201810412141A CN108759882A CN 108759882 A CN108759882 A CN 108759882A CN 201810412141 A CN201810412141 A CN 201810412141A CN 108759882 A CN108759882 A CN 108759882A
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- 239000013307 optical fiber Substances 0.000 title claims abstract description 37
- 239000004065 semiconductor Substances 0.000 title claims abstract description 24
- 238000000034 method Methods 0.000 title claims abstract description 14
- 230000004807 localization Effects 0.000 title claims abstract description 13
- 239000000835 fiber Substances 0.000 claims abstract description 26
- 230000010287 polarization Effects 0.000 claims abstract description 21
- 238000012545 processing Methods 0.000 claims abstract description 12
- 230000003287 optical effect Effects 0.000 claims abstract description 6
- 230000008878 coupling Effects 0.000 claims description 4
- 238000010168 coupling process Methods 0.000 claims description 4
- 238000005859 coupling reaction Methods 0.000 claims description 4
- 230000035945 sensitivity Effects 0.000 abstract description 3
- 238000002347 injection Methods 0.000 abstract description 2
- 239000007924 injection Substances 0.000 abstract description 2
- 238000001514 detection method Methods 0.000 description 7
- 238000005516 engineering process Methods 0.000 description 7
- 238000000253 optical time-domain reflectometry Methods 0.000 description 6
- 238000012544 monitoring process Methods 0.000 description 3
- 230000008901 benefit Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 230000005611 electricity Effects 0.000 description 2
- 230000003321 amplification Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- 230000036039 immunity Effects 0.000 description 1
- 238000005312 nonlinear dynamic Methods 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 238000000181 polarisation optical time-domain reflectometry Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 230000001953 sensory effect Effects 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
- G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
- G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
- G01D5/353—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
- G01D5/35306—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using an interferometer arrangement
- G01D5/35322—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using an interferometer arrangement using interferometer with one loop with several directions of circulation of the light, e.g. Sagnac interferometer
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- General Physics & Mathematics (AREA)
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Abstract
The invention discloses a kind of semiconductor laser mutually pouring-in Distributed optical fiber sensor system and localization methods, sensor-based system includes sequentially connected laser one, Polarization Controller one, fiber optic loop, Polarization Controller two, laser two, and the laser one and laser two are connect with signal processing with collecting unit respectively.Fiber optic loop is made of 2x2 couplers and a single-mode fiber, and the half optical fiber of single mode optical fiber is as sensor fibre.Two Polarization Controllers are used to control the polarization state of the light of two lasers of injection.The optical signal of system is transformed into electric signal and enters data acquisition and procession unit by the photodetector built in two lasers.Localization method includes the steps that the virtual value Location perturbation according to the virtual value of difference and the difference of the relation curve of disturbance location and this two path signal measured of the two-way output electric signal measured in advance.Present system structure and signal processing are simple, high sensitivity, real-time are good, can detect and position various time-varying disturbances.
Description
Technical field
The present invention relates to a kind of Distributed optical fiber sensor system and localization method, especially a kind of semiconductor laser mutually injects
Formula Distributed optical fiber sensor system and localization method, belong to sensory field of optic fibre.
Background technology
Distributed optical fiber sensor system has electromagnetism interference, corrosion-resistant, unregulated power supply, high sensitivity, can supervise at a distance
Full automatic security monitoring may be implemented in many advantages, such as survey, it the safety monitoring of circumference, oil-gas pipeline leak detection,
Structural health monitoring of building etc. has broad application prospects.
Currently, Distributed optical fiber sensor system mainly has optical time domain reflection（OTDR）Type and interference-type two major classes.OTDR type skills
Art is ripe, only need to be laid with a sensor fibre, easy to use, but system can detect distance and limited resolution, and real-time
It is poor.Therefore, on the basis of traditional OTDR, a variety of profile fiber sensing technologies based on OTDR structures, such as base are developed
In the profile fiber sensing technology of Brillouin scattering（BOTDR）, polarization-optical time domain reflectometry（POTDR）Technology and phase sensitive
Optical time domain reflectometer（ϕ-OTDR）.BOTDR sensing technology structures are relatively easy, but to light source requirements height, and distance sensing by
Limit.POTDR sensing technologies positioning accuracy is high, but its distance sensing is shorter.- OTDR sensing technologies are in long range detection, high frequency
Response has great advantage with these three aspect tools are accurately measured, but requires high-coherence light source, and interference free performance is poor.Interference-type point
Cloth optical fiber sensing system basic structure mainly has mach zhender（M-Z）Interferometer and Sarnia gram（Sagnac）Interferometer two
Kind.M-Z interference-type sensor-based system two-way operations are positioned using the cross-correlation of the output signal of both direction, and signal processing is simple,
But cause system easily affected by environment due to the use of arm structure.And Sagnac interference-type sensor-based systems use single light path, increase
Strong system becomes environment the immunity of influence slowly, but need to generally carry out phase demodulating could utilize zero frequency method to position, and
It is only limitted to the positioning to broadband disturbing signal.
In recent years, the mutual injected system of semiconductor laser receives the extensive concern of people.The present invention is by means of semiconductor
The non-linear dynamic characteristic and reflection type optical fiber ring interferometer structure of the mutual injected system of laser carry out system design, it is proposed that
A kind of novel semiconductor laser mutually pouring-in Distributed optical fiber sensor system and localization method.
Invention content
It is an object of the invention to be directed to deficiency in the prior art, a kind of semiconductor laser mutually pouring-in distribution is provided
Optical fiber sensing system and localization method.
In order to achieve the above objectives, the technical solution adopted in the present invention is：
A kind of semiconductor laser mutually pouring-in Distributed optical fiber sensor system, including sequentially connected laser one, Polarization Control
Device one, fiber optic loop, Polarization Controller two, laser two, the laser one and laser two respectively with signal processing with acquisition
Unit connects；The Polarization Controller one and Polarization Controller two are for controlling the light for injecting the laser one and laser two
Polarization state；The optical signal of system is transformed into electric signal and entered by the photodetector built in the laser one and laser two
The signal processing and collecting unit, the virtual value of the difference for exporting electric signal according to the two-way measured in advance and disturbance location
Relation curve and this two path signal measured difference virtual value, determine disturbance location.
The fiber optic loop is made of a 2x2 coupler and a single-mode fiber, and the both ends of the single mode optical fiber connect respectively
It connects the ports II of the coupler and its ports III of coupling output, the length of the single mode optical fiber is much larger than two laser
The coherence length of device, and the half optical fiber of the single mode optical fiber is as sensor fibre.
The laser one and laser two are all distributed feed-backs（DFB）The frequency detuning of semiconductor laser, the two is big
In 100GHz, other parameters may be the same or different.
A kind of localization method of the mutual pouring-in Distributed optical fiber sensor system of semiconductor laser, swashs for above-mentioned semiconductor
The mutual pouring-in Distributed optical fiber sensor system of light device, includes the following steps：
Step 1：Whether changed according to the waveform of the arbitrary electric signal all the way acquired, it is determined whether have disturbance；
Step 2：Calculate the virtual value of the difference of two path signal；
Step 3：According to the relation curve and this survey of the virtual value of the difference of the two path signal measured in advance and disturbance location
The virtual value of the difference of the two path signal obtained, determines disturbance location.
Using above-mentioned technical proposal, the present invention obtains following advantageous effect：
1, the present invention makees detection structure using reflective ring interferometer, and utilizes semiconductor laser nonlinear amplification interference letter
Number, improve the detection sensitivity of system.
2, the present invention utilizes the detection based on luminous intensity and localization method so that the signal processing of system is very simple, real
When property is also enhanced, meanwhile, system is also no longer limited by broadband disturbance to the detection of disturbance, can also be detected to narrowband disturbance
With positioning.
3, the present invention is based on the mutual injected system of semiconductor laser, detection and the localization method of difference can be utilized, make be
The output of system is not influenced by light source power fluctuation, and the stability of work is good.
Description of the drawings
Fig. 1 is the structure chart of the embodiment of the present invention 1.
Fig. 2 is the fiber optic loop structure chart in the embodiment of the present invention 1.
Fig. 3 is in the embodiment of the present invention 3, when undisturbed, from laser one（On）With laser two（Under）Electricity output end
The collected two-way signal output waveform of mouth.
Fig. 4 be the embodiment of the present invention 3 in, disturbance point apart from coupler be 120m when, from laser one（On）And laser
Two（Under）The two-way signal output waveform that arrives of electricity output port processing.
Fig. 5 is the relation curve of the virtual value and disturbance location for the difference that two-way exports electric signal in the embodiment of the present invention 3.
Specific implementation mode
Below in conjunction with the accompanying drawings, specific embodiments of the present invention are described further.
Embodiment 1：
As shown in Figure 1, a kind of semiconductor laser mutually pouring-in Distributed optical fiber sensor system, including sequentially connected laser
One, Polarization Controller one, fiber optic loop, Polarization Controller two, laser two, the laser one and laser two respectively with signal
Processing is connect with collecting unit；The Polarization Controller one and Polarization Controller two inject the laser one and swash for controlling
The polarization state of the light of light device two；Photodetector built in the laser one and laser two is transformed into the optical signal of system
Electric signal enters the signal processing and collecting unit, the virtual value of the difference for exporting electric signal according to the two-way measured in advance
With the relation curve of disturbance location and the virtual value of the difference of this two path signal measured, disturbance location is determined.
As shown in Fig. 2, the fiber optic loop is made of a 2x2 coupler and a single-mode fiber, the single mode optical fiber
Both ends are separately connected the ports II of the coupler and its ports III of coupling output, the length of the single mode optical fiber are much larger than
The coherence length of the two-laser, and the half optical fiber of the single mode optical fiber is as sensor fibre.
The laser one and laser two are all distributed feed-backs（DFB）The frequency detuning of semiconductor laser, the two is big
In 100GHz, other parameters may be the same or different.
Embodiment 2：
In the present embodiment, two semiconductor lasers select the Distributed Feedback Laser module of Mianyang, Sichuan ultraphotic communication Co., Ltd.
Their parameter is slightly different, and one output wavelength of laser is 1528.308nm, output power 1.232mW.Laser two is defeated
It is 1529.172nm, output power 1.372mW to go out wavelength.Coupler is the 2x2 fiber couplers that coupling ratio is 20/80.Two
A Polarization Controller all uses the optical fiber squeezer (PLC-001) of General Photonics companies of the U.S..Signal processing with adopt
Collection unit is made of 5203 digital oscilloscopes of PicoScope of a conventional microcomputer and PICO companies of Britain, oscillograph
The data transmission of acquisition to computer, handle to obtain disturbance location with Matlab software programmings.G.652 all optical fiber are all made of
Standard single-mode fiber, wherein the fiber lengths of fiber optic loop are 2.032km.
Embodiment 3：
A kind of localization method of the mutual pouring-in Distributed optical fiber sensor system of semiconductor laser, includes the following steps：
Step 1：Whether changed according to the waveform of the arbitrary electric signal all the way acquired, it is determined whether have disturbance；
Step 2：Calculate the virtual value of the difference of two path signal；
Step 3：According to the relation curve and this survey of the virtual value of the difference of the two path signal measured in advance and disturbance location
The virtual value of the difference of the two path signal obtained, determines disturbance location.
When undisturbed, Polarization Controller is adjusted, keeps the light in injection laser most strong, the collected two paths of signals of oscillograph
Waveform is as shown in Figure 3.Add a piezoelectric ceramics between two sections of sensor fibres（PZT）Phase-modulator utilizes Agilent companies
Signal generator（33250A）, it is 26 kHz to generate a frequency, and amplitude is the sinusoidal signal of 50 mVpp, drives PZT phases
Modulator is to simulate external disturbance.Sinusoidal signal is operated in burst patterns, and parameter is as follows：Period is 5ms, 1 cycle.Show
The collected two paths of signals waveform of wave device is as shown in figure 4, with Fig. 3 comparisons as can be seen that the generation significant change of its waveform, accordingly may be used
Know and is disturbed on sensor fibre.Change disturbance point position, measures the virtual value and disturbing potential of the difference of two-way output signal
The relation curve set is as shown in Figure 5.It can be calculated, the virtual value of the difference of two-way output signal shown in Fig. 4 is 0.498V, according to
Relation curve shown in fig. 5 can know that the disturbance point is 120m with a distance from coupler.
Claims (4)
1. a kind of mutual pouring-in Distributed optical fiber sensor system of semiconductor laser, it is characterised in that：Including sequentially connected laser
Device one, Polarization Controller one, fiber optic loop, Polarization Controller two, laser two, the laser one and laser two respectively with letter
Number processing is connect with collecting unit；The Polarization Controller one and Polarization Controller two inject one He of laser for controlling
The polarization state of the light of laser two；Photodetector built in the laser one and laser two changes the optical signal of system
Enter the signal processing and collecting unit at electric signal, for exported according to the two-way that measures in advance electric signal difference it is effective
Value and the relation curve of disturbance location and the virtual value of the difference of this two path signal measured, determine disturbance location.
2. the mutual pouring-in Distributed optical fiber sensor system of semiconductor laser according to claim 1, it is characterised in that：It is described
Fiber optic loop is made of a 2x2 coupler and a single-mode fiber, and the both ends of the single mode optical fiber are separately connected the coupler
The ports II and its coupling output the ports III, the length of the single mode optical fiber is much larger than the coherence length of the two-laser,
And the half optical fiber of the single mode optical fiber is as sensor fibre.
3. the mutual pouring-in Distributed optical fiber sensor system of semiconductor laser according to claim 1, it is characterised in that：It is described
Laser one and laser two are all distributed feedback semiconductor lasers, and the frequency detuning of the two is more than 100GHz.
4. the localization method of the mutual pouring-in Distributed optical fiber sensor system of a kind of semiconductor laser, for described in claim 1
The mutual pouring-in Distributed optical fiber sensor system of semiconductor laser, which is characterized in that include the following steps：
Step 1：Whether changed according to the waveform of the arbitrary electric signal all the way acquired, it is determined whether have disturbance；
Step 2：Calculate the virtual value of the difference of two path signal；
Step 3：According to the relation curve and this survey of the virtual value of the difference of the two path signal measured in advance and disturbance location
The virtual value of the difference of the two path signal obtained, determines disturbance location.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110146116A (en) * | 2019-06-19 | 2019-08-20 | 南昌航空大学 | The localization method of Sagnac Fibre Optical Sensor under a kind of multipoint disturbance |
| CN112525374A (en) * | 2020-12-10 | 2021-03-19 | 中红外激光研究院(江苏)有限公司 | Temperature sensor based on non-reciprocal fiber intracavity singularity effect |
| CN113488836A (en) * | 2021-06-23 | 2021-10-08 | 成都飞机工业（集团）有限责任公司 | Narrow linewidth light source |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6490045B1 (en) * | 1998-10-09 | 2002-12-03 | University Of Southhampton | Fibre optic sensor |
| US20090002712A1 (en) * | 2007-06-26 | 2009-01-01 | Huang Hung-Chia | Passively biased fiber-optic gyroscope and current sensor |
| CN101813238A (en) * | 2010-04-20 | 2010-08-25 | 上海大学 | Sagnac/Mach-Zehnder interferometer profile fiber sensing system and time domain positioning method thereof |
| CN103065407A (en) * | 2013-01-09 | 2013-04-24 | 新疆美特智能安全工程股份有限公司 | Optical fiber intelligent monitoring system and monitoring method based on phase signal carrier technology |
| CN104459676A (en) * | 2014-11-05 | 2015-03-25 | 上海大学 | System and method for simultaneously measuring lengths of two optical fibers |
| CN104729549A (en) * | 2015-03-26 | 2015-06-24 | 上海大学 | Two-way chaos ring laser distributed optical fiber sensing system and time difference positioning method thereof |
| CN106452570A (en) * | 2016-09-22 | 2017-02-22 | 北京交通大学 | Optical fiber fault detection system and detection method based on optical fiber phase mediation principle |
| CN107843248A (en) * | 2017-09-01 | 2018-03-27 | 长春理工大学 | Self-injection locking resonance type optical gyroscope and its method of work |
-
2018
- 2018-05-03 CN CN201810412141.2A patent/CN108759882B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6490045B1 (en) * | 1998-10-09 | 2002-12-03 | University Of Southhampton | Fibre optic sensor |
| US20090002712A1 (en) * | 2007-06-26 | 2009-01-01 | Huang Hung-Chia | Passively biased fiber-optic gyroscope and current sensor |
| CN101813238A (en) * | 2010-04-20 | 2010-08-25 | 上海大学 | Sagnac/Mach-Zehnder interferometer profile fiber sensing system and time domain positioning method thereof |
| CN103065407A (en) * | 2013-01-09 | 2013-04-24 | 新疆美特智能安全工程股份有限公司 | Optical fiber intelligent monitoring system and monitoring method based on phase signal carrier technology |
| CN104459676A (en) * | 2014-11-05 | 2015-03-25 | 上海大学 | System and method for simultaneously measuring lengths of two optical fibers |
| CN104729549A (en) * | 2015-03-26 | 2015-06-24 | 上海大学 | Two-way chaos ring laser distributed optical fiber sensing system and time difference positioning method thereof |
| CN106452570A (en) * | 2016-09-22 | 2017-02-22 | 北京交通大学 | Optical fiber fault detection system and detection method based on optical fiber phase mediation principle |
| CN107843248A (en) * | 2017-09-01 | 2018-03-27 | 长春理工大学 | Self-injection locking resonance type optical gyroscope and its method of work |
Non-Patent Citations (1)
| Title |
|---|
| SPAMMER SJ: "Interferometric distributed", 《APPLIED OPTICS》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110146116A (en) * | 2019-06-19 | 2019-08-20 | 南昌航空大学 | The localization method of Sagnac Fibre Optical Sensor under a kind of multipoint disturbance |
| CN112525374A (en) * | 2020-12-10 | 2021-03-19 | 中红外激光研究院(江苏)有限公司 | Temperature sensor based on non-reciprocal fiber intracavity singularity effect |
| CN113488836A (en) * | 2021-06-23 | 2021-10-08 | 成都飞机工业（集团）有限责任公司 | Narrow linewidth light source |
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