CN102496231A - Long-distance trunk line safety fiber wavelength division multiplexing type warning system - Google Patents
Long-distance trunk line safety fiber wavelength division multiplexing type warning system Download PDFInfo
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- CN102496231A CN102496231A CN2011103818259A CN201110381825A CN102496231A CN 102496231 A CN102496231 A CN 102496231A CN 2011103818259 A CN2011103818259 A CN 2011103818259A CN 201110381825 A CN201110381825 A CN 201110381825A CN 102496231 A CN102496231 A CN 102496231A
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Abstract
A long-distance trunk line safety fiber wavelength division multiplexing type warning system is formed by a light path and a signal processing module which collects light path signals. The light path comprises two aplanatic interferometers and one Michelson interferometer. The above three interferometers use three different wavelengths to concentratedly transmit to one fiber so as to form an induction fiber through a wavelength division multiplexer. Three light sources emit three lasers with different wavelengths and the lasers are taken as the light signals. The above three interferometers feel a vibration signal and divides the vibration signal into three paths through the wavelength division multiplexer. The three paths of the signals are transmitted to a photodiode respectively. The signal processing module processes the vibration signal collected by the photodiode, determines an abnormal disturbance position and emits an alarm signal.
Description
Technical field
The invention discloses a kind of optical fibre wavelength-division multiplex formula early warning system.
Background technology
Traditional length adopts the main line monitoring technology based on two Mach-Zehnder fiber optic interferometric principles apart from main line security optical fibre early warning system.
This know-why structure is as shown in Figure 1.Its monitoring principle is that the two-beam that in distributed sensing fiber, transmits is propagated in opposite direction; After influenced by same vibration event; Since two-beam from the incident nidus to separately check point the light path of process different, it is poor therefore to produce the regular hour, monitors the mistiming of the caused interference light signal variation of same incident according to the sensor two ends; Through relevant function method, just can confirm the position of abnormal disturbances.
The method need not be carried out phase demodulating to interference signal; But also there is weak point: because two sensor fibres are at a distance of nearer; The phase delay that sensor fibre vibration along the line possibly make two sensor fibres produce is consistent, causes not interfere, and produces the reciprocity effect; Long distance temperature variation on the way can cause system noise bigger, brings difficulty to signal Processing; At least need take three cores in the optical cable, under fiber resource situation seldom, be difficult to use; Higher to System Hardware Requirement in addition, require height like A/D switching rate to the data acquisition system, cause system cost to rise.
Summary of the invention
Technology of the present invention is dealt with problems and is: overcome the deficiency of prior art, provide a kind of high-precision length apart from main line security optical fibre wavelength-division multiplex formula early warning system.
Technical solution of the present invention is: long apart from main line security optical fibre wavelength-division multiplex formula early warning system; Form by light path and the signal processing module of gathering optical path signal; Described light path comprises two aplanatism interferometers and a Michelson interferometer, and above-mentioned three interferometers adopt three different wavelengths through forming induction optical fiber in wavelength division multiplexer concentration of transmissions to an optical fiber; Through three different wavelength of laser of three light emitted as light signal; Above-mentioned three interferometers are experienced vibration signal; Through wavelength division multiplexer vibration signal is divided into three tunnel, three road signals and transfers to photodiode respectively, signal processing module is handled the vibration signal of photodiode collection; Confirm the abnormal disturbances position, send alerting signal.
The demodulation mode of described aplanatism interferometer is: seek Frequency point ω through frequency spectrum
s, make cos ω
sτ
c=0, and then the time τ of definite light from disturbance point to the induction optical fiber connector
c, according to τ
cConfirm the position of disturbance point.
The basic structure of described two aplanatism interferometers is following: two light sources send two different wavelength of laser signals, and the two-way laser signal at first connects one road input end of 3 * 3 optical fiber splitters, and the two-way input end connects two photodiodes respectively in addition; One road output terminal of 3 * 3 optical fiber splitters is connected to one road input end of second 3 * 3 optical fiber splitter through fibre delay line, and another road output terminal of 3 * 3 optical fiber splitters directly connects another road input end of second 3 * 3 optical fiber splitter; One road output terminal of second 3 * 3 optical fiber splitter connects catoptron.
Described two light sources adopt ASE light source and SLD light source respectively.
The centre wavelength of described ASE light source is 1550nm, the centre wavelength 1310nm of SLD light source.
Adopt the aplanatism interferometer of SLD light source to use phase modulation technique.
Described 3 * 3 optical fiber splitters are for dividing equally the light intensity coupling mechanism.
Described catoptron adopts faraday rotator mirror.
The present invention compared with prior art beneficial effect is:
(1) the native system light path adopts three independently interferometer formations, comprises two aplanatism interferometers and a Michelson interferometer.Compare with common single interferometer, taken into account the sensitivity and the accuracy of signal response.And ask average mode through weighting, and improved the degree of accuracy of location, be that bearing accuracy can reach 50m in the induction optical cable of 60km in length.
(2) native system adopts optical device such as wavelength division multiplexer, optical fiber circulator on light path design, and it is 1 optical fiber that the induction optical fiber of three interferometers is concentrated, and has practiced thrift valuable fiber resource, has improved the application power of system.
(3) aplanatism interferometer of the present invention adopts ASE, two kinds of light sources of SLD.The interference of every kind of light source has characteristics, and according to each interferometer design light source.Empirical tests, ASE adopts 1550nm, best results when SLD adopts 1310nm.
(4) the present invention's aplanatism interferometer of adopting the SLD light source obtains the phase change of abnormal disturbances through the phase-modulator high frequency modulated, has improved the contrast of interference signal.
(5) the conventional interference appearance adopts 2 * 2 optical fiber splitters, needs to use the phase-modulator of power supply power supply to carry out phase modulation (PM), avoids the low phenomenon of signal contrast.And adopt 3 * 3 optical fiber splitters; Constructing every road phase differential is the symmetrical beam electric signal of 120 degree, and the contrast of the signal of interference is high, can not use the phase-modulator of power supply power supply; Construct the light path of helping optical texture, strengthened reliability, the stability of practical application.
(6) all the induction optical fiber connector of interferometer has used faraday rotator mirror; The weak problem of polarization inducement signal of having avoided induction optical fiber to cause because of the fiber birefringence effect; Improved the stability of interference signal; Effectively offset the influence of environment, improved the antijamming capability of system, native system can be used under complicacy, rugged surroundings light path.
Description of drawings
Fig. 1 is traditional fiber orientation technical pattern synoptic diagram based on two M-Z principle of interferences;
Fig. 2 is a system light path synoptic diagram of the present invention.
Embodiment
Long apart from main line security optical fibre wavelength-division multiplex formula early warning system; Form by light path and the signal processing module of gathering optical path signal; Described light path comprises two aplanatism interferometers and a Michelson interferometer, and above-mentioned three interferometers adopt three different wavelengths through forming induction optical fiber in wavelength division multiplexer concentration of transmissions to an optical fiber; Through three different wavelength of laser of three light emitted as light signal; Above-mentioned three interferometers are experienced vibration signal; Through wavelength division multiplexer vibration signal is divided into three tunnel, three road signals and transfers to photodiode respectively, signal processing module is handled the vibration signal of photodiode collection; Confirm the abnormal disturbances position, send alerting signal.
The demodulation mode of aplanatism interferometer is: seek Frequency point ω through frequency spectrum
s, make cos ω
sτ
c=0, and then the time τ of definite light from disturbance point to the induction optical fiber connector
c, according to τ
cConfirm the position of disturbance point.Can seek a series of ω in the actual application
s, confirm τ again through averaging
c
The basic structure of two aplanatism interferometers is following: two light sources send two different wavelength of laser signals, and the two-way laser signal at first connects one road input end of 3 * 3 optical fiber splitters, and the two-way input end connects two photodiodes respectively in addition; One road output terminal of 3 * 3 optical fiber splitters is connected to one road input end of second 3 * 3 optical fiber splitter through fibre delay line, and another road output terminal of 3 * 3 optical fiber splitters directly connects another road input end of second 3 * 3 optical fiber splitter; One road output terminal of second 3 * 3 optical fiber splitter connects catoptron.
Two light sources of above-mentioned aplanatism interferometer adopt ASE light source and SLD light source respectively, and the light source of Michelson interferometer adopts the DFB light source.
Introduce implementation procedure of the present invention in detail below in conjunction with object lesson.
Fig. 2 is the structural representation of a concrete light path of the present invention, and each label is represented following implication among the figure
HY01, HY02, HY04, HY05, HY07, HY08, HY14: photodetector;
The HY03:ASE laser instrument, 1550nm; The HY13:DFB laser instrument, 1490nm; The HY16:SLD laser instrument, 1310nm;
HY10, HY23: wide window 3 * 3 is divided equally optical fiber splitter;
HY09: optical fiber circulator, 1550nm; HY17: optical fiber circulator, 1490nm;
HY11, HY19, HY24: fibre delay line;
HY25: phase-modulator;
HY12, HY27, HY31: faraday rotator mirror, 1310nm; HY32: faraday rotator mirror, 1550nm; HY29, HY33: faraday rotator mirror, 1490nm;
HY15, HY26, HY18: wavelength division multiplexer, 1310&1550nm;
HY20, HY22, HY30, HY28: wavelength division multiplexer, 1310&1550nm&1490nm;
HY21: wavelength division multiplexer, 1310&1490nm;
Being called fibre optic interferometer 1 under two aplanatism interferometers respectively introduces with fibre optic interferometer 2.
(1) fibre optic interferometer 1
Article 2, interfere the path to be respectively:
(1)HY03-HY09-HY10-HY11-HY15-HY20-HY23-HY30-HY32-HY30-HY23-HY22-HY18-HY10
(2)HY03-HY09-HY10-HY18-HY22-HY23-HY30-HY32-HY30-HY23-HY20-HY15-HY11-HY10
The light path of 2 paths is with different identical optical fiber and the devices of order process; Equivalent optical path; Be similar to the Sagnac fibre optic interferometer, owing to adopt the low-coherence light source of this C-band of ASE (centre wavelength 1550nm), so the light path in other path can not form effective interference in the optical fiber.
Understand for convenient, suppose that the abnormal disturbances signal is a simple signal on the main line, angular frequency is ω
sThough actual conditions are effects that induction optical fiber will receive the wideband disturbance; Its frequency spectrum is output as the output combination of each frequency disturbance signal, and each component of wideband disturbing signal all can be come out by demodulation in dynamic range, so the phase change that first hypothetical anomaly perturbation action produces on induction optical fiber is φ
sSin ω
sT, wherein φ
sAmplitude for phase change.
When propagate optical routing path (1) and path (2), all can be modulated by abnormal disturbances, the light output expression formula that obtains is respectively:
Wherein: P
10And P
20For being respectively the amplitude of 2 road light,
With
Be the initial phase of light, τ
MnBe the n time time of light of path m through abnormal disturbances point.
Make P=P
1+ P
2, then the light intensity of interferometer output is I=PP
*, owing to adopt 3 * 3 optical fiber splitters of dividing equally, then P
10=P
20, get its interference term:
I
12＝P
10 2cos[4φ
Ssinω
sτ
acosω
s(t-τ
b)cosω
sτ
c]
Wherein, τ
aBe the time of light through fibre delay line HY11; τ
bBe the time of light through fibre delay line HY11 and whole section induction optical fiber GL26; τ
cBe the time of light from the disturbance point to HY30.
Through HY02, HY04, HY05 three road phase differential is the symmetrical photoelectric conversion signal of 120 degree, can demodulate the light path phase differential that abnormal disturbances causes.Because to the τ that confirms
c1 even a plurality of ω are arranged
sMake cos ω
sτ
c=0, can calculate out the position of abnormal disturbances point thus.The aforementioned calculation process realizes through signal processing module.
(2) fibre optic interferometer 2
Article 2, light path interferes the path to be respectively
(1)HY16-HY21-HY23-HY24-HY25-HY26-HY27-HY26-HY25-HY24-HY23-HY20-HY15-HY12-HY15-HY20-HY23-HY30-HY31-HY23-HY22-HY18-HY19
(2)HY16-HY21-HY23-HY30-HY31-HY30-HY23-HY20-HY15-HY12-HY15-HY20-HY23-HY24-HY25-HY26-HY27-HY26-HY25-HY24-HY23-HY22-HY18-HY19
The light path of 2 paths is with different identical optical fiber and the devices of order process; Equivalent optical path; Also be similar to the Sagnac fibre optic interferometer, owing to adopt SLD broad spectrum light source (centre wavelength 1310nm), the light path in other path has formed not effective interference in the optical fiber.
The final interference signal that forms:
I
12＝P
10 2cos[4φ
Ssinω
sτ
acosω
s(t-τ
b)cosω
sτ
c]
This interferometer obtains the phase change of abnormal disturbances through the phase-modulator high frequency modulated, obtains the high interference signal of contrast, so after signal processing module need carry out demodulation according to above-mentioned high frequency frequency, adopts said method again, calculates τ
c, and then the position of definite abnormal disturbances point.The aforementioned calculation process realizes through signal processing module.
(3) fibre optic interferometer 3 (Michelson interferometer)
Article 2, light path interferes the path to be respectively:
(1)HY13-HY17-HY21-HY23-HY28-HY29-HY28-HY23
(2)HY13-HY17-HY21-HY23-HY30-HY33
Article two, light path forms interference at optical fiber splitter HY23 through different paths after the faraday rotator mirror reflection; Belong to Michelson interferometer; Owing to use the DFB light source (wavelength 1490nm) of narrow linewidth,, still can form effective interference although two optical path lengths differ bigger.And because full light path has been used faraday rotator mirror, so there is not the problem of polarization decay.
After two-beam formed in optical fiber splitter HY23 and interferes, being divided into three road phase differential through HY20-HY01, HY21-HY17-HY14, HY22-HY08 path was the symmetrical beam electric signal of 120 degree, thereby demodulated the phase place of abnormal disturbances.Different with the above two is; Phase differential that preceding two interferometers obtain and abnormal disturbances physical characteristics are also not quite identical; Identification brings very big difficulty to signal, and both interferometers of front are owing to being similar to the sagnac interferometer, so insensitive to gradual factor; Influenced the sensitivity of system on certain program; And the phase signal that Michelson interferometer obtains can direct corresponding abnormal disturbances signal characteristic, and Michelson interferometer sensitivity is high, has effectively replenished the deficiency of preceding two kinds of interferometers.
Signal processing module carries out weighted mean with the disturbance location that above-mentioned aplanatism interferometer calculates; And then the position of definite abnormal disturbances; Obtain the abnormal disturbances signal characteristic through Michelson interferometer; (can adopt traditional modes such as eigenwert extraction) discerned in the disturbance behavior, sent alerting signal.
The single core distributing optical fiber sensing technology of system applies of the present invention; Through actual test shows; Can carry out 24 hours on-line monitoring to the main line safe condition that reaches 60 kilometers; The abnormal disturbances of any point and carry out effective early warning on the perception main line, bearing accuracy can reach 50 meters, and the protection of railway line, highway, boundary line, long distance pipeline, communications optical cable is had the major application meaning.
The unspecified part of the present invention belongs to general knowledge as well known to those skilled in the art.
Claims (8)
1. long apart from main line security optical fibre wavelength-division multiplex formula early warning system; It is characterized in that: form by light path and the signal processing module of gathering optical path signal; Described light path comprises two aplanatism interferometers and a Michelson interferometer, and above-mentioned three interferometers adopt three different wavelengths through forming induction optical fiber in wavelength division multiplexer concentration of transmissions to an optical fiber; Through three different wavelength of laser of three light emitted as light signal; Above-mentioned three interferometers are experienced vibration signal; Through wavelength division multiplexer vibration signal is divided into three tunnel, three road signals and transfers to photodiode respectively, signal processing module is handled the vibration signal of photodiode collection; Confirm the abnormal disturbances position, send alerting signal.
2. length according to claim 1 is apart from main line security optical fibre wavelength-division multiplex formula early warning system, and it is characterized in that: the demodulation mode of described aplanatism interferometer is: seek Frequency point ω through frequency spectrum
s, make cos ω
sτ
c=0, and then the time τ of definite light from disturbance point to the induction optical fiber connector
c, according to τ
cConfirm the position of disturbance point.
3. length according to claim 1 is apart from main line security optical fibre wavelength-division multiplex formula early warning system; The basic structure that it is characterized in that described two aplanatism interferometers is following: two light sources send two different wavelength of laser signals; The two-way laser signal at first connects one road input end of 3 * 3 optical fiber splitters, and the two-way input end connects two photodiodes respectively in addition; One road output terminal of 3 * 3 optical fiber splitters is connected to one road input end of second 3 * 3 optical fiber splitter through fibre delay line, and another road output terminal of 3 * 3 optical fiber splitters directly connects another road input end of second 3 * 3 optical fiber splitter; One road output terminal of second 3 * 3 optical fiber splitter connects catoptron.
4. length according to claim 3 is characterized in that apart from main line security optical fibre wavelength-division multiplex formula early warning system: described two light sources adopt ASE light source and SLD light source respectively.
5. length according to claim 4 is apart from main line security optical fibre wavelength-division multiplex formula early warning system, and it is characterized in that: the centre wavelength of described ASE light source is 1550nm, the centre wavelength 1310nm of SLD light source.
6. length according to claim 4 is characterized in that apart from main line security optical fibre wavelength-division multiplex formula early warning system: adopt the aplanatism interferometer of SLD light source to use phase modulation technique.
7. length according to claim 3 is apart from main line security optical fibre wavelength-division multiplex formula early warning system, and it is characterized in that: described 3 * 3 optical fiber splitters are for dividing equally the light intensity coupling mechanism.
8. length according to claim 3 is characterized in that apart from main line security optical fibre wavelength-division multiplex formula early warning system: described catoptron adopts faraday rotator mirror.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2015051758A1 (en) * | 2013-10-12 | 2015-04-16 | 复旦大学 | Method and system using wavelength division multiplexing for eliminating and reducing light diffusion and light reflection interference in interferometric path |
| CN104111127B (en) * | 2014-07-28 | 2017-01-25 | 北京航天易联科技发展有限公司 | Optical wavelength division multiplexer bandwidth selecting device |
| CN113176581A (en) * | 2021-03-15 | 2021-07-27 | 北京华信科创科技有限公司 | Doppler pulse laser wind measuring device, method and system |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2005012942A1 (en) * | 2003-07-25 | 2005-02-10 | Klaus Wolter | Speed measurement |
| CN1862239A (en) * | 2006-06-15 | 2006-11-15 | 华中科技大学 | Distributed optical fiber vibration sensing method and apparatus thereof |
| CN101382441A (en) * | 2008-10-16 | 2009-03-11 | 北京邮电大学 | Double interference ring perimeter safety protecting and positioning system |
| CN101465052A (en) * | 2007-12-21 | 2009-06-24 | 陈玉凤 | Safety monitoring system and method for circumference |
| CN102064884A (en) * | 2010-11-25 | 2011-05-18 | 复旦大学 | Long-distance distributed optical fiber positioning interference structure based on wavelength division multiplexing (WDM) |
| CN102157044A (en) * | 2011-04-07 | 2011-08-17 | 杨峰 | Full-optical fiber system for locating and alarming |
-
2011
- 2011-11-25 CN CN201110381825.9A patent/CN102496231B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2005012942A1 (en) * | 2003-07-25 | 2005-02-10 | Klaus Wolter | Speed measurement |
| CN1862239A (en) * | 2006-06-15 | 2006-11-15 | 华中科技大学 | Distributed optical fiber vibration sensing method and apparatus thereof |
| CN101465052A (en) * | 2007-12-21 | 2009-06-24 | 陈玉凤 | Safety monitoring system and method for circumference |
| CN101382441A (en) * | 2008-10-16 | 2009-03-11 | 北京邮电大学 | Double interference ring perimeter safety protecting and positioning system |
| CN102064884A (en) * | 2010-11-25 | 2011-05-18 | 复旦大学 | Long-distance distributed optical fiber positioning interference structure based on wavelength division multiplexing (WDM) |
| CN102157044A (en) * | 2011-04-07 | 2011-08-17 | 杨峰 | Full-optical fiber system for locating and alarming |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2015051758A1 (en) * | 2013-10-12 | 2015-04-16 | 复旦大学 | Method and system using wavelength division multiplexing for eliminating and reducing light diffusion and light reflection interference in interferometric path |
| US10024697B2 (en) | 2013-10-12 | 2018-07-17 | Fudan University | Method and system using wavelength division multiplexing for eliminating and reducing light diffusion and light reflection interference in interference path |
| CN104111127B (en) * | 2014-07-28 | 2017-01-25 | 北京航天易联科技发展有限公司 | Optical wavelength division multiplexer bandwidth selecting device |
| CN113176581A (en) * | 2021-03-15 | 2021-07-27 | 北京华信科创科技有限公司 | Doppler pulse laser wind measuring device, method and system |
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