CN108519147A - Multiple light courcess phase sensitive optical time domain reflectometer and its method - Google Patents
Multiple light courcess phase sensitive optical time domain reflectometer and its method Download PDFInfo
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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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Abstract
The invention discloses a kind of multiple light courcess phase sensitive optical time domain reflectometer and its methods,It includes multiple lasers,Multiple first couplers,Multiple second couplers,And multiple photodetectors,The wavelength for the continuous light that various lasers are sent out is different,The continuous light that laser is sent out is shunted to the second coupler and wavelength-division multiplex modulation module through the first coupler,Wavelength-division multiplex modulation module by the continuous light of multichannel be modulated into pulsed light and multiplex at export all the way to fiber amplifier be amplified after output to three port circulators,The backward Rayleigh scattering light of multichannel different wave length is matched to be input to and be interfered with continuous the second coupler of light of same wavelength by the second wavelength division multiplexer respectively,Multipath interference optical signal is converted to the perception information that electric signal is delivered to data collector and controls analysis module acquisition optical fiber by photodetector,The present invention uses the laser of multiple and different wavelength,Multiple photodetectors,Enhance the anti-polarization decay characteristic of system.
Description
Technical field
The present invention relates to distributed optical fiber vibration sensor technical fields, and it is quick to be in more detail related to a kind of multiple light courcess phase
Photosensitive domain reflectometer and its method.
Background technology
Backward Rayleigh scattering light that optical time domain reflectometer (OTDR) is generated when being propagated in a fiber using pulsed light obtains
Dampening information is optical cable construction, the essential tool of monitoring.But since traditional optical time domain reflectometer is using Low coherence
The wideband light source of property, can only detect the variation of intensity information in Rayleigh scattering light, therefore can only realize that fiber lengths, optical fiber decline
Subtract, fiber failure positioning etc. functions.H.F.Taylor et al. proposed phase sensitive optical time domain reflection technology (φ-in 1993
OTDR), which replaces the wideband light source in traditional optical time domain reflectometer using the high-coherence light source of super-narrow line width, not only can be with
The intensity information variation in Rayleigh scattering light is detected, and optical phase information variation can be detected, since light phase is believed
Breath variation is related with exterior part ambient vibration, to realize fiber-optic vibration signal measurement.Since the technology not only has monitoring simultaneously
It is accurately positioned the function of various vibration events, and with whole distributed measurement, remote, highly sensitive, the anti-electromagnetism of monitoring distance
The advantages that interference performance is strong, lightweight is small causes extensive concern and research, has been applied to long range optical cable guarantor at present
The fields such as shield, the tamper-proof excavation of oil-gas pipeline, circumference security protection, prevention of geological disaster.
Phase sensitive optical time domain reflectometer is the interference signal by backward Rayleigh scattering light in direct impulse width regions
And amplitude, phase, the various characteristic informations of frequency moved at position are obtained, interference signal makes phase sensitive optical time domain reflectometer have
The ability of standby phase measurement, but the problem of also bring interference fading simultaneously, that is to say, that spatially the amplitude of certain positions by
Become smaller in the reason of the interference, stablizes relatively or even close to zero, and on the time, interference fading problem has seriously affected these positions
The detectivity and rate of false alarm set.
In order to solve the problems, such as interference fading, 2013, Zhou Jun, Pan Zhenqing et al. were in document《It is integrated and is reflected based on multi-frequency
The Phase Demodulation Method of Optic of interference fading glitch in other φ-OTDR systems》One is proposed in (Vol.40, No.9, Chinese laser)
Method of the kind based on multi-frequency synthesis judgement, efficiently differentiates and eliminates wrong report, eliminates system caused by interference fading and misses
Report problem.The program produces multiple optical frequency signals using phase-modulator, and multichannel is realized by measuring different beat signals
Signal measurement, but multiple beat signals reduce the output power of light source, and the measurement of multiple and different frequency beat signals
It is extremely complex.
Frequency response range is also the key technical indexes of phase sensitive light time domain reflectometer system, shaking in actual environment
Dynamic signal can usually arrive material in kHz even order of megahertz, such as pipeline leakage, civil structure and be broken, it is desirable that vibration
Sensor have measure wideband vibration signal ability, however the measurement frequency of conventional phase sensitivity light time domain reflectometer system by
It is limited to measurement distance, because the light-triggered time interval of direct impulse cannot be less than the two-way time of light in a fiber, such as 10km
Optical fiber, signal probably need 100us, i.e. single measurement to need 100us back and forth, in the limiting case can only to the sample rate of single-point
The vibration signal of 5KHz can only be responded, and with the increase of accumulative frequency, the change of distance according to Sampling Theorem to 10KHz
Long, response frequency exponentially reduces.
Prior art Patent《Distributed optical fiber vibration sensor》(application number 201210349310.5) discloses one kind
Distributed optical fiber vibration sensor introduces MZ interferometers in phase sensitive light time domain reflectometer system, improves the sound of system
Answer frequency.But cause system sufficiently complex, it is unfavorable for functionization.
Document《Ultra-broadband phase-sensitive optical time-domain
reflectometry with a temporally sequenced multi-frequency source》(Vol.40,
15 2015/Optics Letters of No.22/November) using a kind of technology of time domain sequence multifrequency source, it can sweep
N number of fiber phase information is obtained in the repetition period retouched, to substantially increase the responsive bandwidth of system.The program uses electric light
Modulator EOM carries out shift frequency to light source, generates the optical signal of different frequency one by one.But control of this mode to EOM shift frequencies
It is required that it is very high, and usually will produce two frequency-shift signalings up and down after EOM shift frequencies, it is adversely affected to normally measuring.
Prior art Patent《Phase sensitive type optical time domain reflection sensing system and method》(application number
A kind of phase sensitive type optical time domain reflection sensing system and method for double light source packages 201210060043.X) are disclosed, but should
Double light sources are merely used to provide different pulse luminous powers in scheme, are used for the measurement of different length optical fiber, can not realize
The promotion of detectivity and response frequency.
In conclusion there is an urgent need for a kind of new phase sensitive optical time domain reflectometers and its method to solve above-mentioned ask for this field
Topic.
Invention content
It is an object of the present invention to provide a kind of multiple light courcess phase sensitive optical time domain reflectometer and its methods, overcome
Interference fading is adversely affected caused by detection, enhances the anti-polarization decay characteristic of system, solves phase sensitive optical time domain
In reflectometer the problem of polarization decay.
It is another object of the present invention to provide a kind of multiple light courcess phase sensitive optical time domain reflectometer and its methods, pass through
It controls the triggering moment of optical signal modulator and increases the pendulous frequency to spatially identical point, improve phase sensitive optical time domain
The frequency response range of reflectometer solves the problems, such as that phase sensitive optical time domain reflectometer frequency response is not high.
Therefore, to achieve the goals above, the present invention provides a kind of multiple light courcess phase sensitive optical time domain reflectometer, packet
It includes：
At least two send out the laser of the continuous light of different wave length, one of them is to send out λ1The laser of the continuous light of wavelength
Device, another is to send out λ2The laser of the continuous light of wavelength, λ1Not equal to λ2；
At least two first couplers, each first coupler are corresponded with each laser respectively, institute
The first coupler is stated for the continuous light that the laser is sent out to be divided into two-way；
At least two second couplers, wavelength-division multiplex modulation module, wherein each second coupler respectively with it is each
First coupler corresponds, and the continuous light of two-way is divided by first coupler, and to be input to the wavelength-division all the way multiple
With modulation module, another way is input to second coupler, and the wavelength-division multiplex modulation module is set to be come what is received
It is modulated into pulsed light from the continuous light of at least two-way of first coupler and multiplex at exporting all the way；
Fiber amplifier, the fiber amplifier receive at least two-way difference wave from the wavelength-division multiplex modulation module
Long pulsed light is simultaneously amplified output；
Three port circulators, three port circulator has first port, second port and third port, from institute
The pulsed light for stating at least two-way different wave length of fiber amplifier output inputs three port circulator from the first port,
Then it is output in test optical fiber by the second port, at least the pulsed light of two-way different wave length transmits in testing optical fiber
When at least two back scattering occur respectively, wherein backward Rayleigh scattering is identical as input optical wavelength, therefore at least two-way is different
The pulsed light of wavelength corresponds to the backward Rayleigh scattering light for generating at least two-way different wave length, and at least two-way different wave length is backward auspicious
Profit scattering light is exported by the second port back to three port circulator and from the third port；
Second wavelength division multiplexer, second wavelength division multiplexer receive at least two-way exported from three port circulator
The backward Rayleigh scattering light of different wave length simultaneously separates the backward Rayleigh scattering light of at least two-way different wave length, respectively from least two
A port output, the backward Rayleigh scattering light of at least two-way different wave length is matched to be input to respectively to be connected with same wavelength
Second coupler of continuous light, therefore the light of two input ports input of each second coupler is by same
What laser generated, i.e. the wavelength of two-beam is identical, meets coherent condition and interferes；
At least two photodetectors, data collector and control analysis module, wherein each photodetector
It is corresponded with each second coupler, the interference light signal after second coupler interferes is input into institute
Photodetector is stated, interference light signal is converted into interference electric signal and is input to the data collector by the photodetector,
The data collector by interference signal after electric signal progress high-speed sampling to being input to the control analysis module, the control
The interference signal that analysis module processing analysis receives, to know the perception information of optical fiber.
Preferably, the λ1For 1550.12nm, the λ2For 1550.92nm.
Preferably, first coupler is 1*2 couplers, and second coupler is 2*2 couplers.
According to a preferred embodiment of the present invention, the wavelength-division multiplex modulation module include one first wavelength division multiplexer and
One optical signal modulator, before first wavelength division multiplexer is arranged on the optical signal modulator, first wavelength-division multiplex
Device by the photosynthetic wave of at least two-way exported from first coupler at being input to afterwards in the optical signal modulator all the way, it is described
The continuous light of at least two-way different wave length is modulated into pulsed light simultaneously and is input in the fiber amplifier by optical signal modulator.
Preferably, the optical signal modulator is acousto-optic modulator.
According to a further advantageous embodiment of the invention, the wavelength-division multiplex modulation module includes one first wavelength-division multiplex
Device, at least two optical signal modulators, after first wavelength division multiplexer is arranged at least two optical signal modulators
Side, each optical signal modulator are corresponded with each first coupler, what each first coupler separated
Light is input to the corresponding optical signal modulator respectively all the way, and each optical signal modulator will come from first coupling
At first wavelength division multiplexer is input to after pulsed light, first wavelength division multiplexer is near to lack two for the continuous light modulation of clutch
Road pulsed light multiplex at being input in the fiber amplifier afterwards all the way.
According to a further advantageous embodiment of the invention, each optical signal modulator analyzes mould with the control respectively
Block communicates to connect, and the triggering moment difference for controlling the different optical signal modulators is set in the control analysis module, often
The triggering moment of one optical signal modulator is controlled the optical signal modulator triggered relative to upper one
Triggering moment is sequentially delayed backward, and delay time is less than trigger pulse cycle T.
Preferably, in the case of two optical signal modulators, the delay time is the half for triggering cycle T.
Other side under this invention, the present invention further provides it is a kind of improve vibration measurement frequency method,
It includes the following steps：
(A) optical signal modulator that an optical signal modulator sends out pulsed light as first is set；
(B) the control analysis module control triggers first optical signal modulator for sending out pulsed light and sends out pulse
Light, while triggering the data collector and acquiring the electric signal of the photodetector output, and it is T to record triggering moment；
(C) from T delay (T/N) * (n-1), the control analysis module controls n-th of optical signal modulator hair of triggering successively
Go out pulsed light, while triggering the signal that the data collector acquires the photodetector output, N is optical signal modulator
Quantity, n are the serial number for being carrying out the optical signal modulator for sending out pulsed light；
(D) cycle executes step (C) until N number of optical signal modulator, photodetector are all triggered and acquired；
(E) the control analysis module obtains from the data collector and analyzes N group data.
In this way, it realizes spatially each point and has been sampled n times during one-shot measurement, sample rate carries
N times is risen, N times of vibration measurement frequency upgrading.
The above and other purposes of the present invention, feature, advantage will in the following detailed description, attached drawing and appended
Claim it is further clear.
Description of the drawings
Fig. 1 is the configuration signal of multiple light courcess phase sensitive optical time domain reflectometer according to a preferred embodiment of the present invention
Figure；
Fig. 2 is that the configuration of multiple light courcess phase sensitive optical time domain reflectometer according to a further advantageous embodiment of the invention is shown
It is intended to；
Fig. 3 is the method flow signal of raising vibration measurement frequency according to a further advantageous embodiment of the invention
Figure；
In figure：Laser 10；Send out λ1The laser 11 of the continuous light of wavelength；Send out λ2The laser 12 of the continuous light of wavelength；The
One coupler 20；Wavelength-division multiplex modulation module 30；First wavelength division multiplexer 31；Optical signal modulator 32；Fiber amplifier 40；Three
Port circulator 50；First port 51；Second port 52；Third port 53；Second wavelength division multiplexer 60；Second coupler 70；
Photodetector 80；Data collector 90；Control analysis module 100；Laser 10A；Send out λ1The laser of the continuous light of wavelength
11A；Send out λ2The laser 12A of the continuous light of wavelength；First coupler 20A；Wavelength-division multiplex modulation module 30A；First wavelength-division is multiple
With device 31A；Optical signal modulator 32A；Fiber amplifier 40A；Three port circulator 50A；First port 51A；Second port
52A；Third port 53A；Second wavelength division multiplexer 60A；Second coupler 70A；Photodetector 80A；Data collector 90A；
Control analysis module 100A.
Specific implementation mode
In the following, in conjunction with attached drawing and specific implementation mode, invention is described further, it should be noted that in not phase
Under the premise of conflict, new implementation can be formed between various embodiments described below or between each technical characteristic in any combination
Example.
It is described below for disclosing the present invention so that those skilled in the art can realize the present invention.It is excellent in being described below
Embodiment is selected to be only used as illustrating, it may occur to persons skilled in the art that other obvious modifications.It defines in the following description
The present invention basic principle can be applied to other embodiments, deformation scheme, improvement project, equivalent program and do not carry on the back
Other technologies scheme from the spirit and scope of the present invention.
It will be understood by those skilled in the art that the present invention exposure in, term " longitudinal direction ", " transverse direction ", "upper",
The orientation or position of the instructions such as "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outside"
Relationship is to be based on the orientation or positional relationship shown in the drawings, and is merely for convenience of description of the present invention and simplification of the description, rather than
Indicate or imply that signified device or element must have a particular orientation, with specific azimuth configuration and operation, therefore above-mentioned
Term is not considered as limiting the invention.
It is understood that term " one " is interpreted as " at least one " or " one or more ", i.e., in one embodiment,
The quantity of one element can be one, and in a further embodiment, the quantity of the element can be multiple, and term " one " is no
It can be interpreted as the limitation to quantity.
Referring to Fig. 1 of attached drawing, multiple light courcess phase sensitive optical time domain reflectometer according to a preferred embodiment of the present invention
It will be elucidated in following description, wherein the multiple light courcess phase sensitive optical time domain reflectometer includes：
At least two send out the laser 10 of the continuous light of different wave length, one of them is to send out λ1The continuous light of wavelength swashs
Light device 11, another is to send out λ2The laser 12, λ of the continuous light of wavelength1Not equal to λ2；
At least two first couplers 20, each first coupler 20 are a pair of with each laser 10 1 respectively
It answers, first coupler 20 is used to the continuous light that the laser 10 is sent out being divided into two-way；
At least two second couplers 70, wavelength-division multiplex modulation module 30, wherein each second coupler 70 is distinguished
It is corresponded with each first coupler 20, the continuous light that two-way is divided by first coupler 20 is input to all the way
The wavelength-division multiplex modulation module 30, another way are input to second coupler 70, and the wavelength-division multiplex modulation module 30 wraps
One first wavelength division multiplexer 31 and an optical signal modulator 32 are included, first wavelength division multiplexer 31 is arranged on the optical signal
Before modulator 32, first wavelength division multiplexer 31 is by the photosynthetic wave of at least two-way exported from first coupler 20 at all the way
After be input in the optical signal modulator 32, the optical signal modulator 32 by the continuous light of at least two-way different wave length simultaneously
It is modulated into pulse light output；
Fiber amplifier 40, the fiber amplifier 40 receive at least two-way from the wavelength-division multiplex modulation module 30
The pulsed light of different wave length is simultaneously amplified output；
Three port circulators 50, three port circulator 50 have first port 51, second port 52 and third end
Mouthfuls 53, the pulsed light of at least two-way different wave length exported from the fiber amplifier 40 inputs described from the first port 51
Then three port circulators 50 are output to by the second port 52 in test optical fiber, at least pulse of two-way different wave length
When being transmitted in testing optical fiber at least two back scattering occur respectively for light, wherein backward Rayleigh scattering and input optical wavelength phase
Together, therefore the pulsed light of at least two-way different wave length corresponds to the backward Rayleigh scattering light for generating at least two-way different wave length, at least
The backward Rayleigh scattering light of two-way different wave length is by the second port 52 back to three port circulator 50 and from institute
State the output of third port 53；
Second wavelength division multiplexer 60, second wavelength division multiplexer 60 receive exported from three port circulator 50 to
The backward Rayleigh scattering light of few two-way different wave length simultaneously separates the backward Rayleigh scattering light of at least two-way different wave length, respectively from
At least two ports export, and the backward Rayleigh scattering light of at least two-way different wave length is matched respectively to be input to same
Second coupler 70 of the continuous light of wavelength, therefore the light of two input ports input of each second coupler 70
It is generated by the same laser 10, i.e. the wavelength of two-beam is identical, meets coherent condition and interferes；
At least two photodetectors 80, data collector 90 and control analysis module 100, wherein each light
Electric explorer 80 is corresponded with each second coupler 70, the interference light after second coupler 70 interferes
Signal is input into the photodetector 80, and interference light signal is converted into interference electric signal and inputted by the photodetector 80
To the data collector 90, the data collector 90 carries out after high-speed sampling interference signal being input to described to electric signal
Control analysis module 100, the interference signal that the control analysis module 100 processing analysis receives, to know the sense of optical fiber
Know information.
Since 10 line width of laser is very narrow, 90 collected interference electric signal of the data collector is not a routine
Damped exponential signals, but signal amplitude spatially has the interference deamplification of substantially fluctuation, when amplitude fading is to approaching
Detectivity can be seriously affected when zero.In multiple light courcess phase sensitive optical time domain reflectometer provided by the present invention, adopt respectively
The laser 10 for the continuous light for sending out different wave length at least two, due to wavelength difference, to obtain the dry decaying of two-way
Signal, and due to the difference of wavelength, spatially the interference signal of same position all decay to zero probability it is very small, therefore can
To enhance anti-interference fading ability, ensure the sensitivity of system.
It is noted that the laser 10, first coupler 20, second coupler 70, the photoelectricity
The quantity of detector 80 is unrestricted in the multiple light courcess phase sensitive optical time domain reflectometer of the present invention, for example, in this reality
It applies in example with the quantity of the laser 10, first coupler 20, second coupler 70, the photodetector 80
Be illustrate and disclose the content and feature of the multiple light courcess phase sensitive optical time domain reflectometer of the present invention for two, but
The laser 10, first coupler 20, second coupler 70, the photodetector 80 quantity be two
It can not be considered as the limitation of the content and range of the multiple light courcess phase sensitive optical time domain reflectometer to the present invention.It is optional
Ground, under the premise of following two：The wavelength for the continuous light that the different lasers 10 is sent out is different；First coupler
20, second coupler 70, the quantity of the photodetector 80 are corresponding with the quantity of the laser 10 respectively.At this
In other possible examples of the multiple light courcess phase sensitive optical time domain reflectometer of invention, the laser 10, described first
Coupler 20, second coupler 70, the photodetector 80 quantity can also but be not limited to be implemented as 3,4,5
Deng.
It will be appreciated by persons skilled in the art that the laser 10, first coupler 20, second coupling
Device 70, the quantity of the photodetector 80 are more, spatially the interference signal of same position all decay to zero probability it is smaller.
Preferably, the wavelength X1For 1550.12nm, the wavelength X2For 1550.92nm.
Preferably, first coupler 20 is 1*2 couplers, and second coupler 70 is 2*2 couplers.
Preferably, the optical signal modulator 32 is acousto-optic modulator.
It will be readily appreciated by those skilled in the art that the optical signal modulator 32 is implemented as acousto-optic in the present embodiment
Modulator can not be considered as the limitation of the content and range of the multiple light courcess phase sensitive optical time domain reflectometer to the present invention.
Optionally, in other possible examples of the multiple light courcess phase sensitive optical time domain reflectometer of the present invention, the optical signal
Modulator 32 can also be implemented as electrooptic modulator.
It will be appreciated by persons skilled in the art that the data collector 90 can be polylith capture card, or
Multiple data acquisition channels with independent triggers function in same capture card.
Referring to Fig. 2 of attached drawing, multiple light courcess phase sensitive optical time domain reflection according to a further advantageous embodiment of the invention
Meter will be elucidated in following description, wherein the multiple light courcess phase sensitive optical time domain reflectometer includes：
At least two send out the laser 10A of the continuous light of different wave length, one of them is to send out λ1The continuous light of wavelength
Laser 11A, another is to send out λ2The laser 12A, λ of the continuous light of wavelength1Not equal to λ2；
At least two first coupler 20A, each first coupler 20A respectively with each laser 10A mono-
One corresponds to, and the first coupler 20A is used to the laser 10A continuous light sent out being divided into two-way；
At least two second coupler 70A, wavelength-division multiplex modulation module 30A, wherein each the second coupler 70A points
It is not corresponded with each first coupler 20A, the continuous light for being divided into two-way by the first coupler 20A is defeated all the way
Enter to the wavelength-division multiplex modulation module 30A, another way is input to the second coupler 70A, not with above preferred embodiment
With in the present embodiment, the wavelength-division multiplex modulation module 30A includes one first wavelength division multiplexer 31A, at least two light
Signal modulator 32A, the first wavelength division multiplexer 31A are arranged on at least two optical signal modulator 32A rear sides, often
A optical signal modulator 32A is corresponded with each first coupler 20A, each the first coupler 20A points
The light all the way gone out is input to the corresponding optical signal modulator 32A respectively, and each optical signal modulator 32A will come from
The continuous light modulation of the first coupler 20A is at being input to the first wavelength division multiplexer 31A, the first wave after pulsed light
Division multiplexer 31A will at least two-way pulsed light multiplex at exporting afterwards all the way；
Fiber amplifier 40A, the fiber amplifier 40A are received from the wavelength-division multiplex modulation module 30A at least
The pulsed light of two-way different wave length is simultaneously amplified output；
Three port circulator 50A, the three ports circulator 50A have first port 51A, second port 52A, Yi Ji
Three port 53A, the pulsed light of at least two-way different wave length exported from the fiber amplifier 40A is from the first port 51A
The three ports circulator 50A is inputted, is then output in test optical fiber by the second port 52A, at least two-way is different
When being transmitted in testing optical fiber at least two back scattering occur respectively for the pulsed light of wavelength, wherein backward Rayleigh scattering and input
Optical wavelength is identical, therefore the pulsed light of at least two-way different wave length corresponds to the backward Rayleigh scattering for generating at least two-way different wave length
Light, at least backward Rayleigh scattering light of two-way different wave length return to three port circulator by the second port 52A
50A is simultaneously exported from the third port 53A；
Second wavelength division multiplexer 60A, the second wavelength division multiplexer 60A is received to be exported from the three ports circulator 50A
At least two-way different wave length backward Rayleigh scattering light and the backward Rayleigh scattering light of at least two-way different wave length is separated, point
It is not exported from least two ports, the backward Rayleigh scattering light of at least two-way different wave length is matched respectively to be input to therewith
The second coupler 70A of the continuous light of phase co-wavelength, therefore two input ports input of each second coupler 70A
Light be all to be generated by the same laser 10A, i.e. the wavelength of two-beam is identical, meets coherent condition and interferes；
At least two photodetector 80A, data collector 90A and control analysis module 100A, wherein each described
Photodetector 80A is corresponded with each second coupler 70A, after the second coupler 70A is interfered
Interference light signal is input into the photodetector 80A, and interference light signal is converted into interference electricity by the photodetector 80A
Signal is input to the data collector 90A, and the data collector 90A carries out interference signal after high-speed sampling electric signal
It is input to the control analysis module 100A, the interference signal received is analyzed in the control analysis module 100A processing, to
Know the perception information of optical fiber.
It is noted that in the present embodiment, each optical signal modulator 32A analyzes mould with the control respectively
The triggering for controlling the different optical signal modulator 32A is set in block 100A communication connections, the control analysis module 100A
Moment is different, the triggering moment of each optical signal modulator 32A controlled relative to upper one trigger described in
The triggering moment of optical signal modulator 32A is sequentially delayed backward, and delay time is less than trigger pulse cycle T.
For more specifically, the control analysis module 100A sets an optical signal modulator 32A as first
The optical signal modulator 32A of pulsed light is sent out, described first of the control analysis module 100A controls triggering sends out pulsed light
Optical signal modulator 32A send out pulsed light, while triggering the data collector 90A to acquire the photodetector 80A defeated
The electric signal gone out, and it is T to record triggering moment, then from T delay T/N* (N-1), the control analysis module 100A controls are touched
Optical signal modulator 32A sends out pulsed light described in hair n-th, while triggering the data collector 90A and acquiring the photoelectricity spy
The signal of device 80A outputs is surveyed, N is the quantity of the optical signal modulator 32A.That is, the adjacent light triggered
The interval time of signal modulator 32A is T/N.
In the present embodiment, with the quantity of the optical signal modulator 32A the present embodiment is illustrated and discloses for two
The content and feature of the multiple light courcess phase sensitive optical time domain reflectometer.Therefore, the delay time is trigger cycle T one
Half.Such as the measurement optical fiber triggering period of 10km long is 100us, second optical signal modulator 32A's triggered
The triggering moment delay 50us for the optical signal modulator 32A that triggering moment is triggered relative to first.Therefore one
In secondary measurement, the data collector 90A collects two paths of signals, i.e., has done measuring twice to same point on spatial position, surveys
Amount interval 50us, and the mode of single light source is only surveyed space same point once, measurement interval 100us, therefore the present invention is by phase
The response frequency of the sensitive optical time domain reflectometer in position improves 2 times.
It is noted that the laser 10A, the first coupler 20A, the optical signal modulator 32A, described
Second coupler 70A, the photodetector 80A quantity the present invention the multiple light courcess phase sensitive optical time domain reflectometer
In it is unrestricted, for example, in the present embodiment with the laser 10A, the first coupler 20A, the optical signal modulation
Device 32A, the second coupler 70A, the photodetector 80A quantity be to illustrate and disclose the present invention for two
The multiple light courcess phase sensitive optical time domain reflectometer content and feature, but the laser 10A, first coupler
20A, the optical signal modulator 32A, the second coupler 70A, the photodetector 80A quantity be two not
It can be considered as the limitation of the content and range of the multiple light courcess phase sensitive optical time domain reflectometer to the present invention.Optionally, exist
Under the premise of following two：The wavelength for the continuous light that the different laser 10A is sent out is different；The first coupler 20A, institute
State optical signal modulator 32A, the second coupler 70A, the photodetector 80A quantity respectively with the laser
The quantity of 10A is corresponding.In other possible examples of the multiple light courcess phase sensitive optical time domain reflectometer of the present invention, institute
State laser 10A, the first coupler 20A, the optical signal modulator 32A, the second coupler 70A, the photoelectricity
The quantity of detector 80A can also but be not limited to be implemented as 3,4,5 etc..
It will be appreciated by persons skilled in the art that when N number of institute using N number of laser 10A and respective numbers
When stating optical signal modulator 32A, the interval time of the adjacent optical signal modulator 32A triggered is T/N, n-th of hair
When the delay for the optical signal modulator 32A that the optical signal modulator 32A of raw triggering is triggered relative to first
Between be (T/N) * (n-1), i.e., n times have been surveyed to spatially same point in one-shot measurement, by response frequency promoted N times.N is indicated
The serial number for the optical signal modulator 32A for sending out pulsed light is executed, when for example, when n being 1,2,3 ..., indicates the 1st respectively
It is a, the 2nd, the 3rd ... the optical signal modulator 32A triggered.Illustratively, it when it is 3 that N, which is 5, n, indicates altogether
There are 5 optical signal modulator 32A, wherein the 3rd optical signal modulator 32A triggered is sent out relative to the 1st
The delay time of the optical signal modulator 32A of raw triggering is (T/5) * (3-1).
Preferably, the wavelength X1For 1550.12nm, the wavelength X2For 1550.92nm.
Preferably, the first coupler 20A is 1*2 couplers, and the second coupler 70A is 2*2 couplers.
Preferably, the optical signal modulator 32A is acousto-optic modulator.
It will be readily appreciated by those skilled in the art that the optical signal modulator 32A is implemented as sound in the present embodiment
Optical modulator can not be considered as the limit of the content and range of the multiple light courcess phase sensitive optical time domain reflectometer to the present invention
System.Optionally, in other possible examples of the multiple light courcess phase sensitive optical time domain reflectometer of the present invention, the light letter
Number modulator 32A can also be implemented as electrooptic modulator.
It will be appreciated by persons skilled in the art that the data collector 90A can be polylith capture card, or
Multiple data acquisition channels with independent triggers function in same capture card.
As shown in Fig. 3, the present invention further provides a kind of methods improving vibration measurement frequency comprising following
Step：
(A) the optical signal modulator 32A that an optical signal modulator 32A sends out pulsed light as first is set；
(B) the control analysis module control 100A triggers the described first optical signal modulator 32A for sending out pulsed light
Pulsed light is sent out, while triggering the data collector 90A and acquiring the electric signal of the photodetector 80A outputs, and is recorded
Triggering moment is T；
(C) n-th of optical signal modulation of triggering is controlled successively from T delay (T/N) * (n-1), the control analysis module 100A
Device 32A sends out pulsed light, while triggering the signal that the data collector 90A acquires the photodetector 80A outputs, and N is
The quantity of optical signal modulator 32A, n is the serial number for being carrying out the optical signal modulator 32A for sending out pulsed light, for example, when n is
When 1,2,3 ..., expression the 1st respectively, the 2nd, the 3rd ... the optical signal modulator 32A triggered；
(D) cycle executes step (C) until N number of optical signal modulator 32A, photodetector 80A are triggered and adopted
Collection；And
(E) the control analysis module 100A is obtained from the data collector 90A and is analyzed N group data.
In this way, it realizes spatially each point and has been sampled n times during one-shot measurement, sample rate carries
N times is risen, N times of vibration measurement frequency upgrading.
It should be understood by those skilled in the art that the embodiment of the present invention shown in foregoing description and attached drawing is only used as illustrating
And it is not intended to limit the present invention.The purpose of the present invention has been fully and effectively achieved.The function and structural principle of the present invention exists
It shows and illustrates in embodiment, under without departing from the principle, embodiments of the present invention can have any deformation or modification.
Claims (9)
1. multiple light courcess phase sensitive optical time domain reflectometer, which is characterized in that including：
At least two send out the laser of the continuous light of different wave length；
At least two first couplers, each first coupler are corresponded with each laser respectively, and described the
One coupler is used to the continuous light that the laser is sent out being divided into two-way；
At least two second couplers, wavelength-division multiplex modulation module, wherein each second coupler respectively with it is each described
First coupler corresponds, and the continuous light that two-way is divided by first coupler is input to the wavelength-division multiplex tune all the way
Molding block, another way are input to second coupler, and the wavelength-division multiplex modulation module is set comes from institute by what is received
The continuous light of at least two-way for stating the first coupler is modulated into pulsed light and multiplex at exporting all the way；
Fiber amplifier, the fiber amplifier receive at least two-way different wave length from the wavelength-division multiplex modulation module
Pulsed light is simultaneously amplified output；
Three port circulators, three port circulator has first port, second port and third port, from the light
The pulsed light of at least two-way different wave length of fiber amplifier output inputs three port circulator from the first port, then
It is output in test optical fiber by the second port, at least the pulsed light of two-way different wave length transmits the time-division in testing optical fiber
At least two back scattering do not occur, wherein backward Rayleigh scattering is identical as input optical wavelength, therefore at least two-way different wave length
Pulsed light correspond to the backward Rayleigh scattering light for generating at least two-way different wave length, at least backward Rayleigh of two-way different wave length dissipates
Light is penetrated to export by the second port back to three port circulator and from the third port；
Second wavelength division multiplexer, it is different that second wavelength division multiplexer receives at least two-way exported from three port circulator
The backward Rayleigh scattering light of wavelength simultaneously separates the backward Rayleigh scattering light of at least two-way different wave length, respectively from least two ends
Mouth output, the backward Rayleigh scattering light of at least two-way different wave length is matched respectively to be input to the continuous light of same wavelength
Second coupler interfered；
At least two photodetectors, data collector and control analysis module, wherein each photodetector with it is every
A second coupler corresponds, and the interference light signal after second coupler interferes is input into the light
Electric explorer, interference light signal is converted into interference electric signal and is input to the data collector by the photodetector, described
Data collector by interference signal after electric signal progress high-speed sampling to being input to the control analysis module, the control analysis
Resume module analyzes the interference signal received, to know the perception information of optical fiber.
2. source phase sensitivity optical time domain reflectometer as many as described in claim 1, which is characterized in that the wavelength-division multiplex modulation
Module includes one first wavelength division multiplexer and an optical signal modulator, and first wavelength division multiplexer is arranged on the optical signal
Before modulator, first wavelength division multiplexer is by the photosynthetic wave of at least two-way exported from first coupler at inputting afterwards all the way
Into the optical signal modulator, the continuous light of at least two-way different wave length is modulated into pulse by the optical signal modulator simultaneously
Light is input to the fiber amplifier.
3. source phase sensitivity optical time domain reflectometer as many as described in claim 1, which is characterized in that the wavelength-division multiplex modulation
Module includes one first wavelength division multiplexer, at least two optical signal modulators, and first wavelength division multiplexer is arranged at least
On rear side of two optical signal modulators, each optical signal modulator is corresponded with each first coupler, often
The light all the way that a first coupler separates is input to the corresponding optical signal modulator, each optical signal respectively
Modulator by the continuous light modulation from first coupler at being input to first wavelength division multiplexer after pulsed light, it is described
The near few two-way pulsed light multiplex of first wavelength division multiplexer at being input in the fiber amplifier afterwards all the way.
4. source phase sensitivity optical time domain reflectometer as many as claimed in claim 3, which is characterized in that each optical signal tune
Device processed is communicated to connect with the control analysis module respectively, and the control analysis module, which is set, controls the different optical signals
The triggering moment of modulator is different, and the triggering moment of each optical signal modulator is controlled to be occurred to touch relative to upper one
The triggering moment of the optical signal modulator of hair is sequentially delayed backward, and delay time is less than trigger pulse cycle T.
5. source phase sensitivity optical time domain reflectometer as many as claimed in claim 4, which is characterized in that the adjacent institute triggered
The interval time for stating optical signal modulator is T/N, and N is the quantity of the optical signal modulator.
6. such as claim 1, source phase sensitivity optical time domain reflectometer as many as described in any one of 2,3,4, which is characterized in that institute
It is 1*2 couplers to state the first coupler, and second coupler is 2*2 couplers.
7. such as claim 1, source phase sensitivity optical time domain reflectometer as many as described in any one of 2,3,4, which is characterized in that institute
It is acousto-optic modulator to state optical signal modulator.
8. such as claim 1, source phase sensitivity optical time domain reflectometer as many as described in any one of 2,3,4, which is characterized in that institute
It is electrooptic modulator to state optical signal modulator.
9. the method for improving vibration measurement frequency, anti-suitable for source phase sensitivity optical time domain as many as described in claim 5
Penetrate meter, which is characterized in that include the following steps：
(A) optical signal modulator that an optical signal modulator sends out pulsed light as first is set；
(B) the control analysis module control triggers first optical signal modulator for sending out pulsed light and sends out pulsed light,
The data collector is triggered simultaneously and acquires the electric signal of the photodetector output, and it is T to record triggering moment；
(C) from T delay (T/N) * (n-1), the control analysis module controls n-th of optical signal modulator of triggering and sends out arteries and veins successively
It washes off, while triggering the signal that the data collector acquires the photodetector output, N is the number of optical signal modulator
Amount, n is the serial number for being carrying out the optical signal modulator for sending out pulsed light；
(D) cycle executes step (C) until N number of optical signal modulator, photodetector are all triggered and acquired；And
(E) the control analysis module obtains from the data collector and analyzes N group data.
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