Summary of the invention
The present invention provides a kind of multiparameter distributed optical fiber sensing system, complicated to solve multi-parameter collecting system structure,
And build relatively costly problem.
First aspect according to embodiments of the present invention, it is provided that a kind of multiparameter distributed optical fiber sensing system, including light source,
Acousto-optic modulator, circulator, optical fiber, local oscillator optical signal generator, photoswitch, the first bonder and detector, wherein said light
The optical signal transmission that source produces gives described acousto-optic modulator, so that described acousto-optic modulator is after receiving described optical signal, and will
Described optical signal modulation becomes recurrent pulses light and is transferred to described circulator;
Described recurrent pulses optical transport is given described optical fiber by described circulator, so that described optical fiber is based on Brillouin scattering
Effect produces stokes light, produces Rayleigh scattering light based on Rayleigh scattering effect, and by described stokes light and described auspicious
Profit transmission of stray light gives described first bonder;
Described photoswitch carries out folding according to the amplitude size of pulse in described recurrent pulses light;
When described photoswitch disconnects, described stokes light and Rayleigh scattering light are transferred to institute by described first bonder
State detector and be converted into the signal of telecommunication, the signal of telecommunication reflection vibration information corresponding by described Rayleigh scattering light;Close at described photoswitch
During conjunction, the local oscillator optical signal that described local oscillator optical signal generator produces is transferred to described first bonder by described photoswitch,
Described first bonder, based on described local oscillator optical signal, carries out beat frequency to described stokes light, and by described Rayleigh scattering light
It is transferred to described detector with the stokes light after beat frequency and is converted into the signal of telecommunication, corresponding by stokes light after described beat frequency
Signal of telecommunication reflection temperature and strain information.
In the optional implementation of one, each cycle pulsed light of described recurrent pulses light includes multiple continuous print width
Being worth bigger pulse and the less pulse of an amplitude, described photoswitch is time in described recurrent pulses light, pulse amplitude is bigger
Disconnect, and Guan Bi when pulse amplitude is less in described recurrent pulses light.
In the optional implementation of another kind, described system also includes the second bonder, the light letter that described light source produces
Number carry out light-splitting processing through described second bonder, and spectroscopic signal is transferred to respectively described acousto-optic modulator and described local oscillator
Optical signal generator, so that described spectroscopic signal is modulated into recurrent pulses light by described acousto-optic modulator, described local oscillator light is believed
Number generator, after receiving described spectroscopic signal, produces local oscillator optical signal based on Brillouin scattering effect.
In the optional implementation of another kind, described system also includes the first fiber amplifier, described acousto-optic modulator
By described recurrent pulses optical transport to described first fiber amplifier;Described first fiber amplifier is to described periodicity arteries and veins
Wash off after being amplified processing, be transferred to described circulator.
In the optional implementation of another kind, described system also includes band filter, described first fiber amplifier
After being amplified described recurrent pulses light processing, it is transferred to described band filter;Described band filter is to institute
State after recurrent pulses light carries out bandpass filtering treatment, be transferred to described circulator.
In the optional implementation of another kind, described system also includes the second fiber amplifier, and described circulator is by institute
Stating stokes light and described Rayleigh scattering light is transferred to described second fiber amplifier, described second fiber amplifier is to institute
State stokes light and after described Rayleigh scattering light is amplified processing, be transferred to described first bonder.
In the optional implementation of another kind, described system also includes scrambler, and described local oscillator optical signal generator will
Described local oscillator optical signal transmission gives described scrambler;Described scrambler after disturbing process partially to described local oscillator optical signal, logical
Cross described photoswitch and be transferred to described first bonder.
In the optional implementation of another kind, described system also includes waveform generator, and described waveform generator produces
Waveshape signal be sent to described acousto-optic modulator and described photoswitch so that described acousto-optic modulator receiving described light letter
After number, based on described waveshape signal, described optical signal modulation is become recurrent pulses light;Described photoswitch is receiving described ripple
After shape signal, if described waveshape signal reflects that in described recurrent pulses light, pulse amplitude is relatively big, disconnects, if described waveform letter
Number reflect that pulse amplitude is less in described recurrent pulses light, closes.
In the optional implementation of another kind, described optical fiber is a signal mode fiber cable.
The invention has the beneficial effects as follows:
1, the present invention is by using acousto-optic modulator, the optical signal modulation that light source produces is become recurrent pulses light, and makes
In recurrent pulses light, the amplitude of pulse varies in size, and when pulse amplitude is bigger, vibration information is acquired to external world, at arteries and veins
Rush amplitude less time temperature and strain information are acquired to external world, it is ensured that be acquired the time at vibration information to external world
The light intensity change of the fine Rayleigh scattering light produced becomes apparent from, and can avoid adopting in temperature to external world and strain information
During collection, the stokes light that optical fiber produces introduces nonlinear noise, such that it is able to improve the degree of accuracy of information gathering;
2, by the present invention in that and disconnect when photoswitch pulse amplitude in recurrent pulses light is bigger, and at recurrent pulses
In light pulse amplitude less time Guan Bi, can make system when temperature to external world and strain detect, to optical fiber produce this
Lentor light carries out beat frequency, and can avoid local oscillator optical signal transmission being coupled to first when carrying out vibration information and gathering
Device, the collection to vibration information impacts, thus improves information gathering accuracy;
3, the distributed multiparameter that the present invention uses single channels of information acquisition can realize vibration, temperature and strain is adopted
Collection, relatively simple for structure, and system cost of manufacture can be reduced;
4, by the present invention in that each recurrent pulse light of recurrent pulses light can include that multiple continuous print amplitude is bigger
Pulse and the less pulse of an amplitude, when pulse amplitude is bigger, vibration information is acquired, when pulse amplitude is less
Being acquired temperature and strain information, the pace of change that can meet vibration information is very fast, and the change of temperature and strain is slow
Feature, it is achieved vibration, the timely collection of temperature and strain information, such that it is able to improve the degree of accuracy of information gathering further;
5, the present invention is by using the second bonder, and the optical signal producing light source carries out light-splitting processing, and a part provides
To acousto-optic modulator, a part is supplied to local oscillator optical signal generator, can avoid the local oscillator that local oscillator optical signal generator produces
Optical signal cannot carry out beat frequency to the stokes light that optical fiber produces, such that it is able to improve integrity and the stability of system;
6, the present invention is by using the first fiber amplifier to be amplified recurrent pulses light processing, and uses bandwidth to filter
The radiated noise introduced in processing and amplifying is filtered by ripple device, can improve information gathering degree of accuracy;
7, optical fiber is produced by the present invention by using the second fiber amplifier stokes light and Rayleigh scattering light are carried out
Processing and amplifying, can improve the degree of accuracy of information gathering further;
8, the present invention by disturbing process partially to local oscillator optical signal, and interference when can eliminate Brillouin scattering detection declines
Weak phenomenon, such that it is able to improve the degree of accuracy of information gathering;The present invention partially process by local oscillator optical information is disturbed rather than
Transmission to the recurrent pulses light of optical fiber is disturbed process partially, can avoid recurrent pulses light is disturbed partially process time
Rayleigh scattering light is impacted, such that it is able to improve the degree of accuracy of information gathering further;
9, the present invention is by using waveform generator, controls the generation of recurrent pulses light and the folding of photoswitch
System, can improve integrity and the stability of system further;
10, the present invention is by using simple optical fiber, produces based on Rayleigh scattering effect and can reflect that the Rayleigh of vibration information dissipates
Penetrate light, and produce the stokes light that can reflect temperature and strain information based on Brillouin scattering effect, be possible not only to collect
Vibration information, it is also possible to collect temperature and strain information, the strain information herein collected includes extraneous strain and light
The fine strain occurred due to variations in temperature self;As can be seen here, the present invention collects temperature and strain information can reflect
Go out the impact of temperature on fiber self-deformation, such that it is able to the correction of the strain information for truly collecting provides foundation.
Detailed description of the invention
For the technical scheme making those skilled in the art be more fully understood that in the embodiment of the present invention, and make the present invention real
Execute the above-mentioned purpose of example, feature and advantage can become apparent from understandable, below in conjunction with the accompanying drawings to technical side in the embodiment of the present invention
Case is described in further detail.
In describing the invention, unless otherwise prescribed and limit, it should be noted that term " connects " should do broad sense manage
Solve, for example, it may be mechanically connected or electrical connection, it is also possible to be the connection of two element internals, can be to be joined directly together, it is possible to
To be indirectly connected to by intermediary, for the ordinary skill in the art, can understand as the case may be above-mentioned
The concrete meaning of term.
See Fig. 1, for an embodiment circuit block diagram of multiparameter distributed optical fiber sensing system of the present invention.These many ginsengs
Number distributed optical fiber sensing system can include that light source 110, acousto-optic modulator 120, circulator 130, optical fiber 140, local oscillator light are believed
Number generator 150, photoswitch the 160, first bonder 170 and detector 180, wherein the outfan of light source 110 connects acousto-optic and adjusts
The input of device 120 processed, the outfan of acousto-optic modulator 120 connects the first end 1 of circulator 130, the second end of circulator 130
Mouthfuls 2 connect optical fiber 140, and the 3rd port 3 connects the first input end of the first bonder 170, local oscillator optical signal generator 150 defeated
Going out end and connected the second input of the first bonder 170 by photoswitch 160, the outfan of the first bonder 170 connects detection
Device 180.
In the present embodiment, light source 110 can produce optical signal and by the optical signal transmission of generation to acousto-optic modulator 120,
This optical signal modulation, after receiving optical signal, can be become recurrent pulses light and be transferred to circulator by acousto-optic modulator 120
First port 1 of 130, wherein this recurrent pulses light can include the pulse that amplitude varies in size.Hereafter, circulator 130
Second port 2 can be by this recurrent pulses optical transport to optical fiber 140, so that optical fiber 140 produces based on Brillouin scattering effect
Stokes light, produces Rayleigh scattering light based on Rayleigh scattering effect, and this stokes light and Rayleigh scattering light is transferred to
The first input end of the first bonder 170.
When photoswitch 160 disconnects, the first bonder 170 receives only stokes light and Rayleigh scattering light, therefore its
Directly stokes light and Rayleigh scattering light can be transferred to detector 180 and be converted into the signal of telecommunication.Owing to making when extraneous vibration
When optical fiber, it will cause the phase place generation significant change of the Rayleigh scattering light that optical fiber produces based on Rayleigh scattering effect, enter
And (the light intensity change that stokes light occurs can be ignored to cause the interference light intensity between Rayleigh scattering light that significant change also occurs
Disregard), therefore light intensity based on Rayleigh scattering light can reflect vibration information.In order to make extraneous vibration produce when acting on optical fiber
The light intensity change that raw Rayleigh scattering light can become apparent from, needs defeated to optical fiber when carrying out extraneous vibration information gathering
Enter the pulse that amplitude is bigger.
When photoswitch 160 closes, the local oscillator optical signal that local oscillator optical signal generator 150 produces can pass through photoswitch
160 are transferred to the first bonder 170, and hereafter stokes light can be carried out by the first bonder 170 based on this local oscillator optical signal
Beat frequency, and the stokes light after Rayleigh scattering light and beat frequency is transferred to detector 180 is converted into the signal of telecommunication.Due to when the external world
Temperature and effects of strain are when optical fiber, it will cause the frequency displacement of the stokes light that optical fiber produces based on Brillouin scattering effect to send out
Raw significant change, therefore frequency displacement based on stokes light can reflect temperature and strain information.Due to when inputting to optical fiber
Pulse amplitude bigger time, the nonlinear noise of the stokes light that optical fiber produces based on Brillouin scattering effect is relatively big, therefore
When carrying out temperature and strain information gathers to the pulse that optical fiber input amplitude is less.
So far, acousto-optic modulator 120, when the optical signal modulation that light source produces is become recurrent pulses light, can make the cycle
In property pulsed light, the amplitude of pulse varies in size, and when pulse amplitude is bigger, vibration information is acquired to external world, in pulse
When amplitude is less, temperature and strain information are acquired to external world, thereby may be ensured that when vibration information is acquired to external world
The light intensity change of the Rayleigh scattering light that optical fiber produces becomes apparent from, and can avoid carrying out in temperature to external world and strain information
During collection, the stokes light that optical fiber produces introduces nonlinear noise, and then can improve the degree of accuracy of information gathering.
Wherein, photoswitch 160 can carry out folding according to the amplitude size of pulse in recurrent pulses light.Due to vibration letter
The change of breath is rapid, and the change of temperature and strain is slow, and therefore each recurrent pulse light of this recurrent pulses light can include
Pulse that multiple continuous print amplitudes are bigger and the less pulse of an amplitude, and the frequency of each pulse is the most identical with dutycycle.
For each recurrent pulse light, when the pulse that multiple continuous print amplitudes are bigger is transmitted to optical fiber, this system can be to acting on
Extraneous vibration information on optical fiber detects;When the pulse that this amplitude is less is transmitted to optical fiber, this system can be to effect
Ambient temperature and strain on optical fiber detect.Photoswitch 160 can be time in recurrent pulses light, pulse amplitude be bigger
Disconnect, and Guan Bi when pulse amplitude is less in recurrent pulses light, such system detects in temperature to external world and strain
Time, the stokes light that optical fiber produces can be carried out beat frequency, and can avoid local oscillator when carrying out vibration information and gathering
Optical signal transmission gives the first bonder, and the collection to vibration information impacts, such that it is able to improve information gathering accuracy.
It addition, above-mentioned optical fiber can be general single mode fiber optical cable.Owing to optical fiber himself can when temperature changes
Can also can occur to deform accordingly, therefore the present invention be by using simple optical fiber, can reflect based on the generation of Rayleigh scattering effect and shake
The Rayleigh scattering light of dynamic information, and the stokes light that can reflect temperature and strain information is produced based on Brillouin scattering effect,
Being possible not only to collect vibration information, it is also possible to collect temperature and strain information, the strain information herein collected includes
The strain that extraneous strain and optical fiber are occurred due to variations in temperature self.As can be seen here, the temperature that the present invention collects and should
Change information can reflect the impact of temperature on fiber self-deformation, such that it is able to the correction of the strain information for truly collecting
Foundation is provided.
As seen from the above-described embodiment, the present invention uses single channels of information acquisition can realize vibration, temperature and strain
Distributed multi-parameters sampling, relatively simple for structure, system cost of manufacture can be reduced, and it is high to gather accuracy.
For the process of the signal of telecommunication that detector 180 detects, vibration detection principle is: sampled in multiple sampling periods
The analogue signal obtained is converted to digital signal, and this digital signal moves average and mobile difference processing, it is possible to
Obtain the positional information of vibration;The information taking out vibration position corresponding point relevant position in Different sampling period lines up one
OK, obtain the time-domain information of vibration position, then the time-domain information of vibration position is done Nonuniform fast Fourier transform, it is possible to
Frequency of vibration information to oscillation point.Temperature detection principle is: when ambient temperature is applied on long-distance sensing optical fiber, it will
The optical frequency shift of backward Brillouin scattering light in pulsed light width range is caused to change, due to backward spontaneous brillouin scattering
Light frequency and temperature line relationship, when ambient temperature change act on long on sensor fibre time, backward Brillouin dissipates
Penetrate light frequency to change, after the reference laser beat frequency that Brillouin scattering exports with annular Brillouin laser at bonder
Light frequency along with the change of temperature and linear change, collect in the sampling period according to certain space resolution subdivisions
Brillouin's local oscillator optical signal carry out Fourier transformation, the spectral line of Fourier transformation is carried out Lorentz fit, takes out in frequency
Center value, then the center frequency obtaining Different sampling period is only averaged and difference processing, just can obtain long-distance sensing
The temperature information of optical fiber.Strain detecting principle is: when in extraneous effects of strain to long-distance sensing optical fiber, it will cause
In pulsed light width range, the optical frequency shift of backward Brillouin scattering light changes, due to the optical frequency of backward spontaneous brillouin scattering
Rate is linear with strain, when external world's strain change act on long on sensor fibre time, backward Brillouin scattering light
Frequency changes, the light after the reference laser beat frequency that Brillouin scattering exports with annular Brillouin laser at bonder
Frequency is linear change along with the change strained, according to the certain space resolution subdivisions cloth to collecting in the sampling period
In deep pool local oscillator optical signal carry out Fourier transformation, the spectral line of Fourier transformation is carried out Lorentz fit, takes out center frequency value,
The center frequency obtained Different sampling period is more only averaged and difference processing, just can obtain long-distance sensing optical fiber
The change information of strain.
See Fig. 2, for another embodiment circuit block diagram of multiparameter distributed optical fiber sensing system of the present invention.Fig. 2
Difference with multiparameter distributed optical fiber sensing system shown in Fig. 1 is, also includes the second bonder 210, this second bonder
210 can be arranged on light source 110 and between acousto-optic modulator 120, and light source 110 and local oscillator optical signal generator 150.Light source
110 optical signals produced carry out light-splitting processing through the second bonder 210, and spectroscopic signal is transferred to acousto-optic modulator respectively
120 and local oscillator optical signal generator 150, so that spectroscopic signal is modulated into recurrent pulses light, local oscillator light by acousto-optic modulator 110
Signal generator 150, after receiving spectroscopic signal, produces local oscillator optical signal based on Brillouin scattering effect.The present invention is by adopting
Using the second bonder, the optical signal producing light source carries out light-splitting processing, and a part is supplied to acousto-optic modulator, and a part provides
To local oscillator optical signal generator, the local oscillator optical signal that local oscillator optical signal generator can be avoided to produce optical fiber cannot be produced this
Lentor light carries out beat frequency, such that it is able to improve the accuracy of the local oscillator optical signal that local oscillator optical signal generator produces, it is ensured that be
The integrity of system and stability.
The difference of multiparameter distributed optical fiber sensing system shown in Fig. 2 with Fig. 1 is, also includes the first fiber amplifier
220 and band filter 230, the outfan of this acousto-optic modulator 120 connects the input of the first fiber amplifier 220, and first
The outfan of fiber amplifier 220 connects the input of band filter 230, and the outfan of band filter 230 connects annular
First port 1 of device 130.Acousto-optic modulator 120 by recurrent pulses optical transport to the first fiber amplifier 220;First optical fiber
Amplifier 220, after being amplified recurrent pulses light processing, is transferred to band filter 230.Band filter 230 is right
After recurrent pulses light carries out bandpass filtering treatment, it is transferred to the first port 1 of circulator 130.The present invention is by periodically
Pulsed light is amplified processing and being filtered by the radiated noise introduced in processing and amplifying, can improve the degree of accuracy of information gathering.
The difference of multiparameter distributed optical fiber sensing system shown in Fig. 2 with Fig. 1 is, also includes the second fiber amplifier
240, the 3rd port 3 of circulator 130 connects the input of the second fiber amplifier 240, the output of the second fiber amplifier 240
End connects the first input end of the first bonder 170.Stokes light and Rayleigh scattering light are transferred to the second light by circulator 130
Fiber amplifier 240, the second fiber amplifier, after being amplified stokes light and Rayleigh scattering light processing, is transferred to first
Bonder 170.The present invention is amplified processing by the stokes light producing optical fiber and Rayleigh scattering light, can be further
Improve the degree of accuracy of information gathering.
The difference of multiparameter distributed optical fiber sensing system shown in Fig. 2 with Fig. 1 is, also includes scrambler 250, and it is permissible
It is arranged between local oscillator optical signal generator 150 and photoswitch 160.Local oscillator optical signal generator 150 is by local oscillator optical signal transmission
To scrambler 250;Scrambler 250, after local oscillator optical signal is disturbed process partially, is transferred to the first coupling by photoswitch 160
Second input of device 170.The present invention by disturbing process partially to local oscillator optical signal, when can eliminate Brillouin scattering detection
The weak phenomenon of interference, such that it is able to improve information gathering degree of accuracy.It addition, the present invention is by disturbing local oscillator optical information
Partially process rather than the recurrent pulses light of transmission to optical fiber is disturbed process partially, can avoid to recurrent pulses light
Carry out disturbing when partially processing and Rayleigh scattering light is impacted, such that it is able to improve the degree of accuracy of information gathering.
The difference of multiparameter distributed optical fiber sensing system shown in Fig. 2 with Fig. 1 is, also includes waveform generator 260, should
The outfan of waveform generator 260 is connected with the control end of acousto-optic modulator 120 and photoswitch 160 respectively.Waveform generator 260
The waveshape signal produced is sent to acousto-optic modulator 110 and photoswitch 160, so that acousto-optic modulator 110 is receiving optical signal
After, based on this waveshape signal, optical signal modulation become recurrent pulses light;Photoswitch 160 after receiving this waveshape signal, if
In waveshape signal reflection recurrent pulses light, pulse amplitude then disconnects relatively greatly, if pulse in waveshape signal reflection recurrent pulses light
Amplitude is less, closes.The present invention is by using waveform generator, simultaneously to the generation of recurrent pulses light and photoswitch
Folding is controlled, and can improve integrity and the stability of system further.
As seen from the above-described embodiment, the present invention uses single channels of information acquisition can realize vibration, temperature and strain
Distributed multi-parameters sampling, relatively simple for structure, system cost of manufacture can be reduced, and it is high to gather accuracy.
It is to be noted that light source can be narrow linewidth light source, owing to bigger pulsed light can inspire four ripple in optical fiber
The nonlinear noises such as mixing, therefore can reduce the non-linear of light pulse after amplification by controlling the electric current of the first fiber amplifier
Noise.Wherein, waveform generator connect acousto-optic modulator port produce repetition rate be 9KHz, shift frequency be the height of 110MHz
Pulsed light, high impulse level magnitude is 1V, pulsewidth is 30ns, and low pulse amplitude is 0.5V, pulsewidth is 10ns, measures the cycle for one
Interior high impulse is 100:1 with the number ratio of low pulse, as shown in Figure 3;The a length of 10km of long-distance sensing optical fiber;Detector
The a width of 1.5GHz of band, a width of 2GHz of band of data collecting card, sample rate is 2GS/s.
Those skilled in the art, after considering description and putting into practice invention disclosed herein, will readily occur to its of the present invention
Its embodiment.The application is intended to any modification, purposes or the adaptations of the present invention, these modification, purposes or
Person's adaptations is followed the general principle of the present invention and includes the undocumented common knowledge in the art of the present invention
Or conventional techniques means.Description and embodiments is considered only as exemplary, and true scope and spirit of the invention are by following
Claim is pointed out.
It should be appreciated that the invention is not limited in precision architecture described above and illustrated in the accompanying drawings, and
And various modifications and changes can carried out without departing from the scope.The scope of the present invention is only limited by appended claim.