CN107990997B - A kind of double light source self-correction formula fiber optic Distributed Temperature Fast measurement systems and method - Google Patents
A kind of double light source self-correction formula fiber optic Distributed Temperature Fast measurement systems and method Download PDFInfo
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- CN107990997B CN107990997B CN201711157684.6A CN201711157684A CN107990997B CN 107990997 B CN107990997 B CN 107990997B CN 201711157684 A CN201711157684 A CN 201711157684A CN 107990997 B CN107990997 B CN 107990997B
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K11/00—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00
- G01K11/32—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00 using changes in transmittance, scattering or luminescence in optical fibres
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K11/00—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00
- G01K11/32—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00 using changes in transmittance, scattering or luminescence in optical fibres
- G01K11/324—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00 using changes in transmittance, scattering or luminescence in optical fibres using Raman scattering
Abstract
A kind of double light source self-correction formula fiber optic Distributed Temperature Fast measurement systems and method, belong to technical field of optical fiber sensing.The system includes computer, multi-channel synchronous frequency sweep lock-in amplifier, light source driving circuit, short wavelength semiconductor laser, long wavelength semiconductor laser, optical fiber wave multiplexer, fiber coupler, Raman wavelength division multiplexer, optical detection module and temperature-measuring optical fiber.The two-way different frequency signals that multi-channel synchronous frequency sweep lock-in amplifier generates carry out step frequency modulation to two semiconductor lasers respectively simultaneously, double frequency cross-correlation test device synchronizes measurement to the backward Raman scattering light of two kinds of different frequencies, realizes that quick self-correcting districution temperature demodulates using incoherent optical frequency domain reflection technology.The optical fiber back scattering curved measurement of double light sources can be completed in a measurement period by the present invention, time of measuring than conventional method reduces half, and the fiber optic Distributed Temperature measurement for low cost, high-precision and high reliability provides a kind of technical solution of great competitiveness.
Description
Technical field
The invention belongs to technical field of optical fiber sensing, are related to a kind of double light source self-correction formula fiber optic Distributed Temperature rapid surveys
System and method.
Background technique
Fiber optic distributed temperature sensor (DTS) is to scatter light according to the backward anti-Stokes Raman of laser in a fiber
Intensity calculate fiber optic temperature, belong to a kind of intensity modulation type method for sensing, although the Stokes by measurement simultaneously is scattered
It penetrates luminous intensity and certain compensation has been carried out to the intensity of light source and optical transmission loss, but due to Stokes and anti-Stokes scattering
Channel spacing is in hundred nanometer scales, if fiber transmission attenuation can not occur in two kinds of scattering wave bands after system does temperature calibration
The variation of ratio, then temperature measurement result just will appear error.OH radical ion and hydrogen atom relatively hold under high temperature or hyperbaric environment
Easily enter fibre core through coat and generate a degree of added losses, makes essence of the fiber raman scattering DTS after long-term work
Degree is remarkably decreased, up to measured temperature distributed data Enlarging-Errors to absolutely not use value.Therefore, high temperature height can be inhibited
The drift of DTS is depressed, the long-time stability and measurement accuracy for improving DTS determine the long-term availability in its high temperature oil gas well
It is crucial.
In order to eliminate distributed temperaturing error caused by optical transmission loss changes, both-end penalty method and double Light Source Compensation methods
Equal automatic correcting methods are put forward one after another.Document Fernandez A F, Rodeghiero P, Brichard B, et
al.Radiation-tolerant Raman distributed temperature monitoring system for
large nuclear infrastructures[J].Ieee Transactions on Nuclear Science,2005.52
(6): 2689-2694 uses both-end penalty method, is distributed by the Raman scattering that photoswitch switching measures sensor fibre both ends respectively
Curve reduces the influence that fibre loss measures DTS.Document Hwang D, Yoon D J, Kwon I B, et al.Novel
auto-correction method in a fiber-optic distributed-temperature sensor using
reflected anti-Stokes Raman scattering[J].Optics Express,2010.18(10):9747-
9754 propose to realize self-correction with the anti-Stokes Raman scattering light of reflection, and the laser of the reflecting mirror reflection of optical fiber connector generates
Backward Raman scattering light be reflected by a reflector again after by optical fiber be incident on DTS host, using similar with both-end penalty method
Temperature demodulation method can be realized self-correction, but the increase of reflecting mirror has decayed the energy of pump light and anti-Stokes optical signal
Amount, reduces the Measurement Resolution of system.Document Suh K, Lee C.Auto-correction method for
differential attenuation in a fiber-optic distributed-temperature sensor[J]
.Optics Letters, 2008.33 (16): 1845-1847 proposes double Light Source Compensation methods, using the light of two different wave lengths
Source, the central wavelength of first light source is equal with the stokes scattering wavelength of second light source, the middle cardiac wave of second light source
Length is equal with the anti-Stokes scattering wavelength of first light source, reviews one's lessons by oneself to realize to loss difference variation in temperature demodulation
Just, this method has higher engineering practical value.However, both-end penalty method increase sensor in-site installation complexity and
Difficulty, although double Light Source Compensation methods can overcome the problems, such as this, the switch operating of light source makes the time of measuring of system increase 2
Times.Thus, design a kind of formal fiber optic Distributed Temperature Fast measurement system of the self-correcting that double light sources work at the same time have it is more extensive
Application value.
Summary of the invention
It is an object of the invention to propose a kind of double light source self-correction formula fiber optic Distributed Temperature Fast measurement systems and method,
It aims to solve the problem that the problem of switching of conventional method medium wavelength causes time of measuring to increase by twice, and reduces optical path loss, improve system
Performance indicator is the bigger space of application extension of the fibre optical sensor in fields such as oil gas well minings.
Technical solution of the present invention:
A kind of double light source self-correction formula fiber optic Distributed Temperature Fast measurement systems, including computer 1, multi-channel synchronous frequency sweep
Lock-in amplifier 2, light source driving circuit 3, short wavelength semiconductor laser 4, long wavelength semiconductor laser 5, optical fiber wave multiplexer
6, fiber coupler 7, Raman wavelength division multiplexer 8, optical detection module 9 and temperature-measuring optical fiber 10；
The computer 1 is issued to multi-channel synchronous frequency sweep lock-in amplifier 2 and is instructed；The light source driving circuit 3
After receiving the two-way modulated signal that multi-channel synchronous frequency sweep lock-in amplifier 2 generates, short wavelength semiconductor laser 4 is respectively driven
With long wavelength semiconductor laser 5；The output light of the short wavelength semiconductor laser 4 and long wavelength semiconductor laser 5
After optical fiber wave multiplexer 6, merging is input to fiber coupler 7, and the small part light separated in fiber coupler 7 enters as reference light
It is mapped to optical detection module 9, most of light is incident in temperature-measuring optical fiber 10 after being reflected by Raman wavelength division multiplexer 8；The thermometric
The backward Raman scattering light generated in optical fiber 10 is incident on optical detection module 9 after Raman wavelength division multiplexer 8 filters out；The survey
The portion that the backward Rayleigh scattering light generated in warm optical fiber 10 after the reflection of Raman wavelength division multiplexer 8, is separated by fiber coupler 7
Optical detection module 9 is incident in light splitting；The optical detection module 9 will receive after optical signal is converted into electric signal and be input to multi-pass
Road synchronizes frequency sweep lock-in amplifier 2；The multi-channel synchronous frequency sweep lock-in amplifier 2 is to include simultaneously in photosignal two
The small-signal of kind modulating frequency is carried out while being demodulated；The computer 1 exports multi-channel synchronous frequency sweep lock-in amplifier 2
Signal measurements be acquired, handle and show.
A kind of double light source self-correction formula fiber optic Distributed Temperature method for fast measuring, using incoherent optical frequency domain reflection technology,
Simultaneously to two light sources with carrying out different frequencies intensity modulated, through cross-correlation test algorithm to the backward Raman scattering of two kinds of frequencies
Light is carried out while being demodulated, and realizes high-precision and rapid survey to districution temperature；Specific step is as follows:
Computer 1 is issued to multi-channel synchronous frequency sweep lock-in amplifier 2 and is instructed first；Light source driving circuit 3 receives multi-pass
The step frequency scanning modulated signal for the two-way different frequency that the synchronous frequency sweep lock-in amplifier 2 in road generates drives shortwave simultaneously respectively
Long semiconductor laser 4 and long wavelength semiconductor laser 5；Then short wavelength semiconductor laser 4 and long wavelength semiconductor swash
The output light of light device 5 merges after optical fiber wave multiplexer 6 is input to fiber coupler 7, and the small part light separated enters as reference light
It is mapped to optical detection module 9, most of light is incident in temperature-measuring optical fiber 10 after being reflected by Raman wavelength division multiplexer 8；Temperature-measuring optical fiber 10
The backward Raman scattering light of middle generation is incident on optical detection module 9 after Raman wavelength division multiplexer 8 filters out；Temperature-measuring optical fiber 10 simultaneously
After the backward Rayleigh scattering light of middle generation is reflected by Raman wavelength division multiplexer 8, the part light separated after fiber coupler 7 enters
It is mapped to optical detection module 9；The reference light received, Raman diffused light and Rayleigh scattering light are converted into telecommunications by optical detection module 9
Number it is input to multi-channel synchronous frequency sweep lock-in amplifier 2；Multi-channel synchronous frequency sweep lock-in amplifier 2 wraps simultaneously in photosignal
After the small-signal of the two kinds of modulating frequencies contained is carried out while being demodulated, the measurement result after all frequency scannings is transferred to calculating
Machine 1；Last computer 1 recovers two Rayleigh scattering curves and two backward Raman scattering songs by inversefouriertransform algorithm
After line, carries out the demodulation of self-correcting districution temperature and show.
The multi-channel synchronous frequency sweep lock-in amplifier 2 has the function of step frequency scanning measurement, frequency sweeping ranges
For 1kHz-100MHz.
There are two frequencies to measure function simultaneously for the tool of multi-channel synchronous frequency sweep lock-in amplifier 2, i.e., single input is logical
The amplitude and phase of two frequency signals in road can be measured simultaneously out, and the cross jammings of two frequency measurements is less than-
60dB。
The central wavelength difference of the short wavelength semiconductor laser 4 and the long wavelength semiconductor laser 5 is
100nm makes the Stokes Raman of the short wavelength semiconductor laser 4 scatter light and the long wavelength semiconductor laser 5
Anti-Stokes Raman scattering light peak wavelength it is equal.
The optical fiber wave multiplexer 6 is a kind of optical fibre wavelength division multiplexer.
The splitting ratio of the fiber coupler 7 is 10:90 to 50:50.
The optical detection module 9 is amplified by 2 PIN photodiodes, 1 avalanche photodide and low noise mutual conductance
Circuit composition.
The principle of the present invention is as follows: using non-phase to the positioning of the spatial position of Raman (Rayleigh) backward in optical fiber scattering light
Dry probe beam deflation (IOFDR) technology measures while realizing double light sources.The two of multi-channel synchronous frequency sweep lock-in amplifier generation
Road different frequency signals carry out step frequency modulation to two semiconductor lasers respectively, and two laser light sources worked at the same time enter
It is mapped to backward Raman (Rayleigh) the scattering light for generating two kinds of respective frequencies in temperature-measuring optical fiber, multi-channel synchronous is input in the same time and sweeps
The photosignal comprising two kinds of different frequencies of frequency lock-in amplifier and two inside multi-channel synchronous frequency sweep lock-in amplifier
The reference signal of different frequency carries out computing cross-correlation simultaneously, after completing frequency scanning, can calculate separately out two light sources
The frequency response of the Raman diffused light of generation.Computer recovers two backward Raman scattering songs by inversefouriertransform algorithm
After line and two backward Raman scattering curves, a self-correcting districution temperature demodulation is completed.
Beneficial effects of the present invention: the optical fiber back scattering curved measurement of double light sources can be completed in a measurement period, than
The time of measuring of traditional double light source self-correction methods reduces half.The double light sources of small-power continuous semiconductor laser substitution tradition
High peak power pulse light source in DTS, since the development of semiconductor laser reaches its maturity, alternative wavelength is very rich
Richness keeps implementation of the invention very easy, and reduces system cost and complexity.The present invention is low cost, high-precision and height
The fiber optic Distributed Temperature measurement of reliability provides a kind of technical solution of great competitiveness.
Detailed description of the invention
Attached drawing 1 is structural schematic diagram of the invention.
Attached drawing 2 is double modulation of source frequencies variation schematic diagram of single measurement.
Attached drawing 3 is the schematic illustration that triple channel steps in synchronization frequency scanning formula lock-in amplifier.
Attached drawing 4 is the amplitude-frequency response of the double light source Raman rear orientation lights measured simultaneously.
In figure: 1 computer；2 multi-channel synchronous frequency sweep lock-in amplifiers；3 light source driving circuits；
4 short wavelength semiconductor lasers；5 long wavelength semiconductor lasers；6 optical fiber wave multiplexers；
7 fiber couplers；8 Raman wavelength division multiplexers；9 optical detection modules；10 temperature-measuring optical fibers；
The modulating frequency of 11 short wavelength semiconductor lasers；The modulating frequency of 12 long wavelength semiconductor lasers；
13 field programmable gate arrays；14 Raman scattering optical channel double frequency cross-correlation test devices；
15 Rayleigh scattering optical channel double frequency cross-correlation test devices；16 refer to optical channel double frequency cross-correlation test device；
17 short wavelength light source modulated digital signal generators；18 long wavelength's light source modulated digital signal generators；
19 digital communication controllers；20 communication interfaces；21 Raman scattering photosignal input interfaces；
22 Rayleigh scattering photosignal input interfaces；23 refer to photosignal input interface；
24 short wavelength light source modulated signal output interfaces；25 long wavelength's light source modulated signal output interfaces；
26 Raman scattering photosignal analog-digital converters；27 Rayleigh scattering photosignal analog-digital converters；
28 refer to photosignal analog-digital converter；29 short wavelength light source modulated signal digital analog converters；
30 long wavelength's light source modulated signal digital analog converters；
The amplitude-frequency response for the Stokes Raman scattering light that 31 short wavelength lasers generate；
The amplitude-frequency response for the anti-Stokes Raman scattering light that 32 long wavelength lasers generate.
Specific embodiment
A specific embodiment of the invention is described in detail below in conjunction with technical solution and attached drawing.
A kind of double light source self-correction formula fiber optic Distributed Temperature Fast measurement systems mainly include computer 1, multi-channel synchronous
Frequency sweep lock-in amplifier 2, light source driving circuit 3, short wavelength semiconductor laser 4, long wavelength semiconductor laser 5, optical fiber close
Wave device 6, fiber coupler 7, Raman wavelength division multiplexer 8, optical detection module 9 and temperature-measuring optical fiber 10.
Computer 1 is issued to multi-channel synchronous frequency sweep lock-in amplifier 2 and is instructed；It is same that light source driving circuit 3 receives multichannel
The step frequency scanning modulated signal for the two-way different frequency that step frequency sweep lock-in amplifier 2 generates drives short wavelength simultaneously respectively
Semiconductor laser 4 and long wavelength semiconductor laser 5；Short wavelength semiconductor laser 4 and long wavelength semiconductor laser 5
Output light merges after optical fiber wave multiplexer 6 is input to fiber coupler 7, and the small part light separated, which is incident on light as reference light, to be visited
Module 9 is surveyed, most of light is incident in temperature-measuring optical fiber 10 after being reflected by Raman wavelength division multiplexer 8；It is generated in temperature-measuring optical fiber 10
Backward Raman scattering light is incident on optical detection module 9 after Raman wavelength division multiplexer 8 filters out；What is generated in temperature-measuring optical fiber 10 is backward
After Rayleigh scattering light is reflected by Raman wavelength division multiplexer 8, the part light separated after fiber coupler 7 is incident on optical detection mould
Block 9；The reference light received, Raman diffused light and Rayleigh scattering light are converted into electric signal and are input to multi-pass by optical detection module 9
Road synchronizes frequency sweep lock-in amplifier 2；Multi-channel synchronous frequency sweep lock-in amplifier 2 measures reference light, Rayleigh scattering light and drawing simultaneously
After the amplitude and phase of two frequency signals in graceful scattering light, the amplitude and phase that cross correlation algorithm is calculated are transmitted to meter
Calculation machine 1；Computer 1 is demodulated and is shown according to inversefouriertransform algorithm and automatic correcting method realization high-precision districution temperature.
Wherein, multi-channel synchronous frequency sweep lock-in amplifier 2 is that a kind of triple channel steps in synchronization the amplification of frequency scanning formula locking phase
Device, frequency measurement range are 1kHz-100MHz.The most higher modulation current that light source driving circuit 3 is is 1A, bandwidth 100MHz.
Short wavelength semiconductor laser 4 is the semiconductor laser diode that central wavelength is 974nm.Long wavelength semiconductor swashs
Light device 5 is the semiconductor laser diode that central wavelength is 1064nm.Optical fiber wave multiplexer 6 is the wavelength-division that transmission peak wavelength is 1064nm
Multiplexer.The splitting ratio of fiber coupler 7 is 10:90.The central wavelength of 8 transmission end of Raman wavelength division multiplexer is 1020nm, band
Width is 20nm.Optical detection module 9 is by 2 PIN photodiodes, 1 avalanche photodide and low noise mutual conductance amplifying circuit
Composition, bandwidth 100MHz.Temperature-measuring optical fiber 10 uses 50/125 μm of multimode sensor fibre.
Attached drawing 2 is double modulation of source frequencies variation schematic diagram of single measurement.The modulation frequency of short wavelength semiconductor laser
The variation range of rate 11 and the modulating frequency of long wavelength semiconductor laser 12 is all 50kHz-50MHz, and step frequency is
50kHz；The difference on the frequency of the modulating frequency 12 of the modulating frequency 11 and long wavelength semiconductor laser of short wavelength semiconductor laser
For 50kHz.
Attached drawing 3 is the schematic illustration that triple channel steps in synchronization frequency scanning formula lock-in amplifier.Field-programmable gate array
Digital communication controllers 19 in column 13 receive the control instruction of communication interface 20；Short wavelength in field programmable gate array 13
Modulation of source digital signal generator 17 and long wavelength's light source modulated digital signal generator 18 generate two-way different modulating simultaneously
The step frequency modulated signal of frequency, respectively by short wavelength light source modulated signal output interface 24 and long wavelength's light source modulated signal
Output interface 25 exports；Raman scattering photosignal input interface 21, Rayleigh scattering photosignal input interface 22 and reference light
Electric signal input interface 23 is respectively connected to Raman scattering photosignal, Rayleigh scattering photosignal and the ginseng of optical detection module output
After examining photosignal, respectively by Raman scattering photosignal analog-digital converter 26, Rayleigh scattering photosignal analog-digital converter 27
Digital signal is converted to reference photosignal analog-digital converter 28；Field programmable gate array 13 acquire digital signal and
The difference that short wavelength light source modulated digital signal generator 17 and long wavelength's light source modulated digital signal generator 18 generate respectively
The reference sine/cosine signals of frequency, while being input to Raman scattering optical channel double frequency cross-correlation test device 14, Rayleigh scattering light
The cross-correlation inspection synchronous with reference to bifrequency is carried out in optical channel double frequency cross-correlation test device 16 of channel double frequency cross-correlation test device 15
It surveys and calculates；Calculated amplitude and phase value is transferred to communication interface 20 by digital communication controllers 19.
Attached drawing 4 is the amplitude-frequency response of the double light source Raman rear orientation lights measured simultaneously.Stokes Raman scatters light
Amplitude-frequency response 31 is short wavelength's semiconductor laser 4 under the modulation of step frequency electric signal, multi-channel synchronous frequency sweep lock-in amplifier 2
The amplitude of the frequency response of the Stokes Raman scattering light generated in the optical fiber of measurement；The width of anti-Stokes Raman scattering light
It is long wavelength semiconductor laser 5 under different step frequency electric signal modulation that frequency response, which answers 32, and multi-channel synchronous frequency sweep locking phase is put
The amplitude of the frequency response of the anti-Stokes Raman scattering light generated in the optical fiber that big device 2 measures.
The above description is only a preferred embodiment of the present invention, is not intended to restrict the invention, for those skilled in the art
For member, the invention may be variously modified and varied.All within the spirits and principles of the present invention, it is made it is any modification,
Equivalent replacement, improvement etc., should all be included in the protection scope of the present invention.
Claims (10)
1. a kind of double light source self-correction formula fiber optic Distributed Temperature Fast measurement systems, which is characterized in that including computer (1), more
Channel Synchronous frequency sweep lock-in amplifier (2), light source driving circuit (3), short wavelength semiconductor laser (4), long wavelength semiconductor
Laser (5), optical fiber wave multiplexer (6), fiber coupler (7), Raman wavelength division multiplexer (8), optical detection module (9) and temperature measuring optical
Fine (10)；
The computer (1) is issued to multi-channel synchronous frequency sweep lock-in amplifier (2) and is instructed；The light source driving circuit
(3) it after receiving the two-way modulated signal that multi-channel synchronous frequency sweep lock-in amplifier (2) generate, respectively drives short wavelength's semiconductor and swashs
Light device (4) and long wavelength semiconductor laser (5)；The short wavelength semiconductor laser (4) and long wavelength semiconductor laser
After optical fiber wave multiplexer (6), merging is input to fiber coupler (7) output light of device (5), is separated in fiber coupler (7)
Small part light is incident on optical detection module (9) as reference light, and most of light is incident on after being reflected by Raman wavelength division multiplexer (8)
In temperature-measuring optical fiber (10)；The backward Raman scattering light generated in the temperature-measuring optical fiber (10) is filtered through Raman wavelength division multiplexer (8)
Optical detection module (9) are incident on after out；The backward Rayleigh scattering light generated in the temperature-measuring optical fiber (10) is answered by Raman wavelength-division
After device (8) reflection, optical detection module (9) are incident on by the part light that fiber coupler (7) separates；The optical detection mould
Block (9) will receive after optical signal is converted into electric signal and be input to multi-channel synchronous frequency sweep lock-in amplifier (2)；The multi-pass
Road synchronous frequency sweep lock-in amplifier (2) is carried out while being solved to the small-signal for two kinds of modulating frequencies for including simultaneously in photosignal
It adjusts；The signal measurements that the computer (1) exports multi-channel synchronous frequency sweep lock-in amplifier (2) are acquired, handle
And display.
2. a kind of double light source self-correction formula fiber optic Distributed Temperature Fast measurement systems according to claim 1, feature exist
In the multi-channel synchronous frequency sweep lock-in amplifier (2) has the function of step frequency scanning measurement, and frequency sweeping ranges are
1kHz-100MHz；There are two frequencies to measure function simultaneously for multi-channel synchronous frequency sweep lock-in amplifier (2) tool, i.e., individually
The amplitude and phase of two frequency signals in input channel can be measured simultaneously out, and the cross jamming of two frequency measurements is small
In -60dB.
3. a kind of double light source self-correction formula fiber optic Distributed Temperature Fast measurement systems according to claim 1 or 2, feature
It is, the short wavelength semiconductor laser (4) and the central wavelength difference of the long wavelength semiconductor laser (5) are
100nm makes the Stokes Raman of the short wavelength semiconductor laser (4) scatter light and the long wavelength semiconductor laser
(5) peak wavelength of anti-Stokes Raman scattering light is equal.
4. a kind of double light source self-correction formula fiber optic Distributed Temperature Fast measurement systems according to claim 3, feature exist
In, the central wavelength difference of the short wavelength semiconductor laser (4) and the long wavelength semiconductor laser (5) is 100nm,
The Stokes Raman of the short wavelength semiconductor laser (4) is set to scatter light and the long wavelength semiconductor laser (5)
The peak wavelength that anti-Stokes Raman scatters light is equal.
5. a kind of double light source self-correction formula fiber optic Distributed Temperature Fast measurement systems according to claim 1,2 or 4, special
Sign is that the optical fiber wave multiplexer (6) is a kind of optical fibre wavelength division multiplexer.
6. a kind of double light source self-correction formula fiber optic Distributed Temperature Fast measurement systems according to claim 3, feature exist
In the optical fiber wave multiplexer (6) is a kind of optical fibre wavelength division multiplexer.
7. a kind of according to claim 1, double light source self-correction formula fiber optic Distributed Temperature Fast measurement systems described in 2,4 or 6,
It is characterized in that, the splitting ratio of the fiber coupler (7) is 10:90 to 50:50.
8. a kind of double light source self-correction formula fiber optic Distributed Temperature Fast measurement systems according to claim 5, feature exist
In the splitting ratio of the fiber coupler (7) is 10:90 to 50:50.
9. a kind of double light source self-correction formula fiber optic Distributed Temperature Fast measurement systems according to claim 7, feature exist
In the optical detection module (9) amplifies electricity by 2 PIN photodiodes, 1 avalanche photodide and low noise mutual conductance
Road composition.
10. a kind of using any double light source self-correction formula fiber optic Distributed Temperature Fast measurement systems of claim 1-9
Measurement method, which is characterized in that use incoherent optical frequency domain reflection technology, while to two light sources progress different frequencies intensity
Modulation is carried out while being demodulated through backward Raman scattering light of the cross-correlation test algorithm to two kinds of frequencies, realizes to districution temperature
High-precision and rapid survey；Specific step is as follows:
Computer (1) is issued to multi-channel synchronous frequency sweep lock-in amplifier (2) and is instructed first；Light source driving circuit (3) receives more
The step frequency scanning modulated signal for the two-way different frequency that Channel Synchronous frequency sweep lock-in amplifier (2) generates drives simultaneously respectively
Short wavelength semiconductor laser (4) and long wavelength semiconductor laser (5)；Then short wavelength semiconductor laser (4) and long wave
The output light of long semiconductor laser (5) merges after optical fiber wave multiplexer (6) is input to fiber coupler (7), the few portion separated
Light splitting is incident on optical detection module (9) as reference light, and most of light is incident on thermometric after being reflected by Raman wavelength division multiplexer (8)
In optical fiber (10)；The backward Raman scattering light generated in temperature-measuring optical fiber (10) is incident on after Raman wavelength division multiplexer (8) filters out
Optical detection module (9)；The backward Rayleigh scattering light generated in temperature-measuring optical fiber (10) simultaneously is reflected by Raman wavelength division multiplexer (8)
Afterwards, the part light separated after fiber coupler (7) is incident on optical detection module (9)；Optical detection module (9) is by what is received
Reference light, Raman diffused light and Rayleigh scattering light are converted into electric signal and are input to multi-channel synchronous frequency sweep lock-in amplifier (2)；It is more
Channel Synchronous frequency sweep lock-in amplifier (2) carries out simultaneously the small-signal for two kinds of modulating frequencies for including simultaneously in photosignal
After demodulation, the measurement result after all frequency scannings is transferred to computer (1)；Last computer (1) is become by anti-Fourier
After scaling method recovers two Rayleigh scattering curves and two backward Raman scattering curves, the demodulation of self-correcting districution temperature is carried out simultaneously
Display.
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| CN113405577B (en) * | 2018-05-30 | 2022-11-11 | 华为技术有限公司 | Measuring method and measuring device |
| CN111006786B (en) * | 2019-11-22 | 2021-01-29 | 太原理工大学 | Double-path high-precision temperature demodulation method based on distributed optical fiber Raman sensing system |
| CN113447158B (en) * | 2021-06-28 | 2024-01-26 | 中国人民解放军国防科技大学 | Method for measuring full-link fiber core temperature distribution of high-power fiber laser |
| CN113507317A (en) * | 2021-07-09 | 2021-10-15 | 电子科技大学中山学院 | Optical fiber fault monitoring device and method based on incoherent optical frequency domain reflection |
| CN113916498A (en) * | 2021-09-30 | 2022-01-11 | 电子科技大学中山学院 | Wavelength division multiplexing incoherent optical frequency domain reflected optical fiber quality detection device and method |
| CN115235367B (en) * | 2022-07-26 | 2023-04-25 | 北京理工大学 | High-precision double-frequency optical frequency domain reflectometer with large strain measurement range |
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| CN101825498B (en) * | 2010-04-13 | 2012-03-21 | 中国计量学院 | Distributed optical fiber Raman temperature sensor (DOFRTS) with self-correction of dispersion and loss spectra |
| CN201876324U (en) * | 2010-11-12 | 2011-06-22 | 湖北擎宇科技有限公司 | Double-light source light path structure of distributed optical fiber Raman temperature sensor |
| CN102062649B (en) * | 2010-11-26 | 2012-11-21 | 中国计量学院 | Dual wavelength light source self-correcting distributed optical fiber Raman temperature sensor for optical fiber Raman frequency shifter |
| CN102322976B (en) * | 2011-08-09 | 2013-01-02 | 中国计量学院 | Fiber Raman frequency shifter double-wavelength pulse coding light source self-correcting distribution type fiber Raman temperature sensor |
| CN106768278B (en) * | 2017-01-06 | 2020-07-31 | 天津大学 | Distributed optical fiber vibration and temperature dual-physical quantity sensing and positioning system |
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