CN108204857A - Vibration signal detection system and assembly method thereof - Google Patents
Vibration signal detection system and assembly method thereof Download PDFInfo
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- CN108204857A CN108204857A CN201611171524.2A CN201611171524A CN108204857A CN 108204857 A CN108204857 A CN 108204857A CN 201611171524 A CN201611171524 A CN 201611171524A CN 108204857 A CN108204857 A CN 108204857A
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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 vibration signal detection system and an assembly method thereof, and belongs to the field of vibration signal detection. The system comprises: the narrow-linewidth laser comprises a narrow-linewidth laser, a preamplifier, a photoelectric detector and at least two cascaded optical fiber filters positioned between the preamplifier and the photoelectric detector, wherein the narrow-linewidth laser is connected with the preamplifier, the bandwidths of the at least two optical fiber filters are equal and are x, and the narrow-linewidth laser can generate continuous laser; the passbands of at least two optical fiber filters have an overlapped part, and the bandwidth y of the overlapped part satisfies: n is more than or equal to y and less than x; wherein n is the linewidth of the narrow linewidth laser, the linewidth of the narrow linewidth laser being within the passband range of the coincident portion. The invention solves the problems that the ASE noise of the optical fiber filter is larger and the signal-to-noise ratio of the signal is reduced in the prior art, and improves the signal-to-noise ratio of the signal. The invention is used for detecting the vibration signal.
Description
Technical field
The present invention relates to vibration signal detection field, more particularly to a kind of vibration signal detecting system and its assembly method.
Background technology
Phase sensitive optical time domain reflection (English：phase-sensitive optical time-
domainreflectometer；Referred to as：Φ-OTDR) technology is otherwise known as the optical time domain reflection skill scattered based on coherent rayleigh
Art, the technology can be sent out rear to Rayleigh scattering optical signal, detection fiber using narrow linewidth continuous laser in sensor fibre
Ambient vibration signal, due to spy of the fiber-optic vibration detecting system based on Φ-OTDR technique with positioning accuracy height, high sensitivity
Point is widely used in the fields such as fence intrusion detection, long-distance oil ＆ gas pipeline detection, boundary security protection.
In the relevant technologies, the fiber-optic vibration detecting system based on Φ-OTDR technique generally comprises：Narrow linewidth laser, sound
Optical modulator, optical fiber circulator, preamplifier, optical fiber filter and photodetector, because with the extension of detecting distance,
Backward Rayleigh scattering optical signal can die down, and the backward Rayleigh scattering light weak output signal that photodetector receives causes to vibration
The detection difficult of signal, so usually preamplifier is set (generally to use two-stage Er-doped fiber in the port of optical fiber circulator
Amplifier), the intensity of detection signal is improved by preamplifier, then light is connected between preamplifier and photodetector
Fiber filter, for filtering out the spontaneous stimulated radiation generated during preamplifier amplifies backward Rayleigh scattering optical signal
(English：Amplified Spontaneous Emission；Referred to as：ASE) noise.
But since the bandwidth (generally in 50 Gigahertzs to 100 Gigahertzs) of optical fiber filter is much larger than narrow linewidth
The line width (be generally less than 3 kHz) of laser rear passes through optical fiber so that laser pulse is sent out to Rayleigh scattering optical signal
While wave filter, can also so that preamplifier generates when amplifying backward Rayleigh scattering optical signal in optical fiber filter
ASE noises in free transmission range pass through, and cause larger by the ASE noises of optical fiber filter, reduce the signal-to-noise ratio (English of signal
Text：SIGNAL-NOISE RATIO；Referred to as：SNR).
Invention content
In order to solve larger by the ASE noises of optical fiber filter in the prior art, the signal-to-noise ratio for reducing signal is asked
Topic, an embodiment of the present invention provides a kind of vibration signal detecting system and its assembly methods.The technical solution is as follows：
On the one hand, a kind of vibration signal detecting system is provided, including：
Narrow linewidth laser, preamplifier and photodetector and positioned at the preamplifier and the photoelectricity
Cascade at least two optical fiber filter between detector, the narrow linewidth laser are connect with the preamplifier, institute
The bandwidth for stating at least two optical fiber filters is equal, and is x, and the narrow linewidth laser can generate continuous laser；
The passband of at least two optical fiber filter is there are intersection, and the bandwidth y of the intersection meets：n
≤ y ＜ x；
Wherein, the n is the line width of the narrow linewidth laser, and the line width of the narrow linewidth laser is in the coincidence part
In the free transmission range divided.
Optionally, the system also includes：
Acousto-optic modulator, the power amplifier being connected in turn between the narrow linewidth laser and the preamplifier
With the first optical fiber circulator.
Optionally, at least two optical fiber filter includes：The fixed optical fiber filter of one centre wavelength and at least
One adjustable optical fiber filter of centre wavelength.
Optionally, the centre wavelength of the fixed optical fiber filter of one centre wavelength and the center of the continuous laser
Wavelength is equal.
Optionally, at least two optical fiber filter includes at least two fiber grating filters.
Optionally, the system also includes：At least two second optical fiber circulators, at least two fiber gratings filtering
Device is equal with the number of at least two second optical fiber circulator and connects one to one.
Optionally, optical fiber filter all at least two optical fiber filter is the adjustable optical fiber of centre wavelength
Wave filter.
Optionally, the x is 50 Gigahertzs.
Optionally, each optical fiber filter is bandpass-type optical fiber filter at least two optical fiber filter.
Optionally, the centre wavelength of the continuous laser is 1550 nanometers；
The line width of the narrow linewidth laser is less than 3 kHz.
Optionally, the system also includes：The sensor fibre being connect with first optical fiber circulator.
On the other hand, a kind of vibration signal detecting system assembly method is provided, including：
Narrow linewidth laser, preamplifier and photodetector are provided；
At least two optical fiber filters are provided, at least two optical fiber filter includes：First optical fiber filter and
Two optical fiber filters, the line width of the narrow linewidth laser is in the free transmission range of the first optical fiber filter, and described at least two
The bandwidth of optical fiber filter is equal, and is x；
The narrow linewidth laser is connect with the preamplifier；
At least two optical fiber filters grade is associated between the preamplifier and the photodetector, is adjusted
The centre wavelength of at least one optical fiber filter at least two optical fiber filter so that at least two optical fiber filtering
The passband of device is there are intersection, and the bandwidth y of the intersection meets：N≤y ＜ x；
Wherein, the n is the line width of the narrow linewidth laser.
Optionally, it is described to connect the narrow linewidth laser with the preamplifier, including：
The narrow linewidth laser is passed through into sequentially connected acousto-optic modulator, power amplifier and the first optical fiber circulator
Connect the preamplifier.
Optionally, at least two optical fiber filter includes：The fixed optical fiber filter of one centre wavelength and at least
One adjustable optical fiber filter of centre wavelength,
The centre wavelength of at least one optical fiber filter in adjustment at least two optical fiber filter, including：
Adjust the centre wavelength of the adjustable optical fiber filter of at least one centre wavelength.
Optionally, optical fiber filter all at least two optical fiber filter is the adjustable optical fiber of centre wavelength
Wave filter,
The centre wavelength of at least one optical fiber filter in adjustment at least two optical fiber filter, including：
Adjust the centre wavelength of each optical fiber filter at least two optical fiber filter.
The advantageous effect that technical solution provided in an embodiment of the present invention is brought is：
Vibration signal detecting system and its assembly method provided in an embodiment of the present invention, pass through at least two optical fiber filters
Cascade, it is and single using the intersection of the passband of at least two optical fiber filter as the passband of cascade optical fiber filter
Optical fiber filter is compared, and reduces the bandwidth of passband, rear passes through grade to Rayleigh scattering optical signal so that laser pulse is sent out
While the passband of the optical fiber filter of connection, the preposition amplification except the free transmission range in cascade optical fiber filter has been filtered out
The ASE noises that device generates, when being reduced by the noise of cascade optical fiber filter, correspondingly, the voltage effective value of noise
Reduce, so as to improve the signal-to-noise ratio of signal.
Description of the drawings
To describe the technical solutions in the embodiments of the present invention more clearly, make required in being described below to embodiment
Attached drawing is briefly described, it should be apparent that, the accompanying drawings in the following description is only some embodiments of the present invention, for
For those of ordinary skill in the art, without creative efforts, other are can also be obtained according to these attached drawings
Attached drawing.
Fig. 1-1 is a kind of structure diagram of vibration signal detecting system provided in an embodiment of the present invention；
Fig. 1-2 is the schematic diagram of the line width of narrow linewidth laser provided in an embodiment of the present invention；
Fig. 2-1 is the pass of a kind of line width of narrow linewidth laser provided in an embodiment of the present invention and the passband of optical fiber filter
It is schematic diagram；
Fig. 2-2 is another line width of narrow linewidth laser provided in an embodiment of the present invention and the passband of optical fiber filter
Relation schematic diagram；
Fig. 2-3 is the structure diagram of another vibration signal detecting system provided in an embodiment of the present invention；
Fig. 2-4 is a kind of line width of narrow linewidth laser provided in an embodiment of the present invention and the passband of fiber grating filter
Relation schematic diagram；
Fig. 3 is a kind of flow chart of vibration signal detecting system assembly method provided in an embodiment of the present invention.
Specific embodiment
To make the object, technical solutions and advantages of the present invention clearer, below in conjunction with attached drawing to embodiment party of the present invention
Formula is described in further detail.
An embodiment of the present invention provides a kind of vibration signal detecting system, as Figure 1-1, including：
Narrow linewidth laser 101, preamplifier 102 and photodetector 103 and positioned at 102 He of preamplifier
Cascade at least two optical fiber filter 104 between photodetector 103, narrow linewidth laser 101 and preamplifier 102
Connection, the bandwidth of at least two optical fiber filter 104 is equal, and is x, which can generate continuous sharp
Light.The continuous laser also refers to the laser more than 10 6 powers exported in 1 second.
The passband of at least two optical fiber filter 104 is there are intersection, and the bandwidth y of intersection meets：n≤y
＜ x；Wherein, n is the line width of narrow linewidth laser 101, and the line width of the narrow linewidth laser 101 is in the free transmission range of intersection
It is interior.
It should be noted that the passband of optical fiber filter refers to the frequency passband that can be let the signal go through, optical fiber filter
Bandwidth refer to optical fiber filter passband width, that is to say that the frequency range of passband is poor；The line width of narrow linewidth laser
The frequency range for the laser that narrow linewidth laser generates is referred to, specifically, as shown in Figs. 1-2, being measured in frequency domain narrow
Line width laser generate laser spectral intensity, the peak value V of spectral intensity corresponding two frequencies of half (V/2) (w1,
W2 difference) is the line width n of narrow linewidth laser.The continuous laser that narrow linewidth laser generates can be in acousto-optic modulator
Laser pulse is converted under modulation.
In addition, the signal-to-noise ratio formula of signal is：SNR=20LOG (Vs/Vn)；Wherein, Vs represents that the voltage of signal is effective
Value, Vn represent the voltage effective value of noise, and the unit of SNR (signal-to-noise ratio) is dB (decibel), and LOG (Vs/Vn) expressions take (Vs/Vn)
Logarithm.
In conclusion vibration signal detecting system provided in an embodiment of the present invention, passes through at least two optical fiber filter grades
Connection, using the intersection of the passband of at least two optical fiber filter as the passband of cascade optical fiber filter, with single light
Fiber filter is compared, and reduces the bandwidth of passband, rear passes through cascade to Rayleigh scattering optical signal so that laser pulse is sent out
Optical fiber filter passband while, filtered out the preamplifier except the free transmission range in cascade optical fiber filter
The ASE noises of generation, when being reduced by the noise of cascade optical fiber filter, correspondingly, the voltage effective value of noise also subtracts
It is small, so as to improve the signal-to-noise ratio of signal.
It should be noted that the vibration signal detecting system can be Φ-OTDR systems.
Wherein, each optical fiber filter at least two optical fiber filter is bandpass-type optical fiber filter, and should
The bandwidth x of at least two optical fiber filters is fixed, can be 50GHz (Gigahertz)；Narrow linewidth laser generates
Continuous laser centre wavelength for 1550 nanometers, the line width of the narrow linewidth laser is less than 3kHz (kHz).Wherein, laser
Wavelength be inversely proportional with frequency：Wavelength=the light velocity/frequency.
Optionally, at least two optical fiber filters are provided in the vibration signal detecting system can include following three kinds of feelings
Condition：
The first situation, applied in vibration signal detecting system as Figure 1-1, at least two optical fiber filter
It can include：The fixed optical fiber filter of one centre wavelength and the adjustable optical fiber filter of at least one centre wavelength.Assuming that
At least two optical fiber filter includes：Fixed first optical fiber filter of centre wavelength and adjustable second optical fiber of centre wavelength
Wave filter, Fig. 2-1 is the line width n of narrow linewidth laser and the schematic diagram of the relationship of the passband of two optical fiber filters, such as Fig. 2-1
Shown, abscissa is frequency, and unit Hz, ordinate is spectral intensity, and unit is decibel (dB), wherein, the filtering of the first optical fiber
The passband of device 104a is M1, and the passband of the second optical fiber filter 104b is M2, the first optical fiber filter and the second optical fiber filter
Bandwidth be x.
It should be noted that the line width of narrow linewidth laser is in the free transmission range of the first optical fiber filter.
Optionally, as shown in Fig. 2-1, the centre wavelength of first optical fiber filter can be with the centre wavelength of continuous laser
Equal, the centre wavelength that is to say first optical fiber filter can be 1550 nanometers.Since bandpass-type optical fiber filter is in
Cardiac wave strong point is most weak to the inhibiting effect of signal, so when the centre wavelength of the first optical fiber filter and the middle cardiac wave of continuous laser
When long equal, it can so that signal is minimum by the loss of first optical fiber filter, that is to say to pass through to greatest extent
Backward Rayleigh scattering optical signal caused by laser pulse.
Specifically, first the first optical fiber filter can be connect with preamplifier, then in the defeated of the first optical fiber filter
Outlet concatenates the second optical fiber filter, after two optical fiber filters are cascaded, adjusts the centre wavelength of the second optical fiber filter, subtracts
The intersection y of the passband of small cascade optical fiber filter optionally, can cause y=n+x/2, wherein, n swashs for narrow linewidth
The line width of light device while ensureing optical signal by cascade optical fiber filter, can filter out preamplifier to greatest extent
The ASE noises of generation.In embodiments of the present invention, the position of the first optical fiber filter and the second optical fiber filter is not limited,
Second optical fiber filter with preamplifier can be connect, the first optical fiber filter is serially connected in the defeated of the second optical fiber filter
Outlet.
The second situation, applied in vibration signal detecting system as Figure 1-1, at least two optical fiber filter
In all optical fiber filter all can be the adjustable optical fiber filter of centre wavelength.Assuming that there are two centers for setting in the system
The optical fiber filter of Wavelength tunable, Fig. 2-2 is the line width n of narrow linewidth laser and the relationship of the passband of two optical fiber filters
Schematic diagram, as shown in Fig. 2-2, abscissa is frequency, and unit Hz, ordinate is spectral intensity, and unit is decibel (dB),
In, the passband of two optical fiber filters is respectively M3 and M4, and the bandwidth of two optical fiber filters is x.
Specifically, first by an optical fiber filter (being described for the ease of distinguishing, referred to as optical fiber filter 1) and preposition amplification
Device connects, and adjusts the centre wavelength of optical fiber filter 1 so that the line width of narrow linewidth laser is in the passband model of optical fiber filter 1
In enclosing.Another optical fiber filter (being known as optical fiber filter 2) is connected on the output terminal of optical fiber filter 1 again, by two optical fiber
After wave filter cascade, the centre wavelength of cascade optical fiber filter 1 and optical fiber filter 2 is adjusted, reduces cascade two optical fiber
The intersection of the passband of wave filter, while ensureing optical signal by cascade optical fiber filter, before filtering out to greatest extent
Put the ASE noises of amplifier generation.
The third situation, applied in vibration signal detecting system as Figure 2-3, at least two optical fiber filter
All can be fiber grating filter, the system can also include at least two second optical fiber circulators, fiber grating filter
Number it is identical with the number of the second optical fiber circulator and connect one to one.Assuming that there are two fiber grating filters for setting in system
Wave device, then there are two the second optical fiber circulators for setting in the system, are denoted as the second optical fiber circulator 1091 and the second optical fiber respectively
Circulator 1092.Fig. 2-4 is the relation schematic diagram of the line width n of narrow linewidth laser and the passband of two fiber grating filters,
As in Figure 2-4, abscissa is frequency, and unit Hz, ordinate is spectral intensity, and unit is decibel (dB), wherein, two light
The reflection passbands of fine grating filter are respectively M5 and M6, and two fiber grating filter reflectance spectrum bandwidth are x.
It is specifically, first that a fiber grating filter (being described for the ease of distinguishing, referred to as fiber grating filter 1) is logical
It crosses the second optical fiber circulator (describing for the ease of distinguishing, referred to as the second optical fiber circulator 1) to connect with preamplifier so that narrow
The line width of line width laser is in the range of the reflectance spectrum of fiber grating filter 1.Another fiber grating filter (is known as again
Fiber grating filter 2) the second optical fiber circulator 1 is connected to by the second optical fiber circulator (be known as the second optical fiber circulator 2)
Output terminal, after two fiber grating filters are cascaded by two the second optical fiber circulators, adjust fiber grating filter 1
With the reflectance spectrum centre wavelength of fiber grating filter 2, reduce the coincidence part of cascade two fiber grating filter reflectance spectrums
Point, while ensureing optical signal by cascade fiber grating filter, the ASE of preamplifier generation is filtered out to greatest extent
Noise.
Further, as Figure 1-1, which can also include being connected to narrow linewidth laser 101 and preposition in turn
Acousto-optic modulator 105,106 and first optical fiber circulator 107 of power amplifier between amplifier 102.
It should be noted that the system further includes：The sensor fibre 108 being connect with the first optical fiber circulator 107.
Specifically, in vibration signal detecting system as Figure 1-1, narrow linewidth laser 101 is continuous for generating
Laser；Acousto-optic modulator 105 is connect with narrow linewidth laser 101, for the continuous laser tune for generating narrow linewidth laser 101
It is made as laser pulse；Power amplifier 106 is connect with acousto-optic modulator 105, for being amplified to laser pulse；It is amplified
Laser pulse is transmitted to by the port 107a of the first optical fiber circulator 107 in the first optical fiber circulator 107, using the first light
The port 107b of fine circulator 107 is transmitted in the sensor fibre 108 being connect with the first optical fiber circulator 107, and laser pulse exists
In sensor fibre 108 during transmission, backward Rayleigh scattering optical signal can be generated, the optical signal that laser pulse generates can pass through first
The port 107b of optical fiber circulator 107 is transmitted in the first optical fiber circulator 107, using the end of the first optical fiber circulator 107
Mouth 107c is transmitted in the preamplifier 102 being connect with the first optical fiber circulator 107, and preamplifier 102, which is realized, believes light
Number amplification；Amplified optical signal passes through cascade at least two optical fiber filter 104, is transmitted in photodetector 103；
Optical signal is converted to digital signal by photodetector 103, digital signal is transmitted to by output terminal in host computer, by upper
Position machine is detected the digital signal.
Optionally, each optical fiber filter in above-mentioned at least two optical fiber filter can be single F-P resonant cavity group
Into spectrum be Lorentz spectral line optical fiber filter.Optionally, in order to preferably inhibit the passband of cascade optical fiber filter
Outer ASE noises, each optical fiber filter in above-mentioned at least two optical fiber filter can be multiple F-P resonant cavity superposition groups
Into failing edge is more precipitous and bandpass-type optical fiber filter that top is smooth.
Alternatively, as Figure 2-3, which can include being connected to narrow linewidth laser 101 and preamplifier in turn
Acousto-optic modulator 105,106 and first optical fiber circulator 107 of power amplifier between 102.
Specifically, in vibration signal detecting system as Figure 2-3, narrow linewidth laser 101 is continuous for generating
Laser；Acousto-optic modulator 105 is connect with narrow linewidth laser 101, for the continuous laser tune for generating narrow linewidth laser 101
It is made as laser pulse；Power amplifier 106 is connect with acousto-optic modulator 105, for being amplified to laser pulse；It is amplified
Laser pulse is transmitted to by the port 107a of the first optical fiber circulator 107 in the first optical fiber circulator 107, using the first light
The port 107b of fine circulator 107 is transmitted in the sensor fibre 108 being connect with the first optical fiber circulator 107, and laser pulse exists
In sensor fibre 108 during transmission, backward Rayleigh scattering optical signal can be generated, the optical signal that laser pulse generates can pass through first
The port 107b of optical fiber circulator 107 is transmitted in the first optical fiber circulator 107, using the end of the first optical fiber circulator 107
Mouth 107c is transmitted in the preamplifier 102 being connect with the first optical fiber circulator 107, and preamplifier 102, which is realized, believes light
Number amplification；Amplified optical signal is transmitted to the second optical fiber circulator by 1091 a of port of the second optical fiber circulator 1091
In 1091, the light being connect with the second optical fiber circulator 1091 is transmitted to using 1091 b of port of the second optical fiber circulator 1091
In fine grating filter 104, after fiber grating filter 104 filters out optical signal, optical signal is passed by port 1091b
It transports in the second optical fiber circulator 1091, enters the second fiber annular using the port 1091c of the second optical fiber circulator 1091
In device 1092, the second optical fiber circulator 1092 is also there are three port, respectively port 1092a, port 1092b and port 1092c,
Specific work process can refer to the course of work of the second optical fiber circulator 1091, and this will not be repeated here；Optical signal passes through second
The port 1092c of optical fiber circulator 1092 is transmitted to photodetector 103；Optical signal is converted to number by photodetector 103
Digital signal is transmitted to by output terminal in host computer by signal, and the digital signal is detected by host computer.
In conclusion vibration signal detecting system provided in an embodiment of the present invention, passes through at least two optical fiber filter grades
Connection, using the intersection of the passband of at least two optical fiber filter as the passband of cascade optical fiber filter, with single light
Fiber filter is compared, and reduces the bandwidth of passband, rear passes through cascade to Rayleigh scattering optical signal so that laser pulse is sent out
Optical fiber filter passband while, filtered out the preamplifier except the free transmission range in cascade optical fiber filter
The ASE noises of generation, when being reduced by the noise of cascade optical fiber filter, correspondingly, the voltage effective value of noise also subtracts
Small, so as to improve the signal-to-noise ratio of signal, the data collecting card that the reduction of ASE noises is also improved in photodetector collects
Signal data precision, convenient for the processing of follow-up data.
An embodiment of the present invention provides a kind of vibration signal detecting system assembly method, as shown in figure 3, including：
Step 301 provides narrow linewidth laser, preamplifier and photodetector.
Step 302 provides at least two optical fiber filters, which includes：First optical fiber filters
Device and the second optical fiber filter, the line width of the narrow linewidth laser is in the free transmission range of the first optical fiber filter, this at least two
The bandwidth of a optical fiber filter is equal, and is x.
Narrow linewidth laser is connect by step 303 with preamplifier.
At least two optical fiber filter grades are associated between preamplifier and photodetector by step 304, adjust this extremely
The centre wavelength of at least one optical fiber filter in few two optical fiber filters so that the passband of at least two optical fiber filter
There are intersection, and the bandwidth y of intersection meets：N≤y ＜ x.
Wherein, the n is the line width of the narrow linewidth laser.
It should be noted that narrow linewidth laser can generate continuous laser, which can be in acousto-optic modulator
Modulation under be converted to laser pulse.
In conclusion vibration signal detecting system assembly method provided in an embodiment of the present invention, by by least two light
Fiber filter cascades, using the intersection of the passband of at least two optical fiber filter as the logical of cascade optical fiber filter
Band compared with single optical fiber filter, reduces the bandwidth of passband, is sent out rear to Rayleigh scattering light letter causing laser pulse
While number by the passband of cascade optical fiber filter, filter out except the free transmission range in cascade optical fiber filter
The ASE noises that preamplifier generates, when being reduced by the noise of cascade optical fiber filter, correspondingly, the voltage of noise
Virtual value also reduces, so as to improve the signal-to-noise ratio of signal.
Optionally, as Figure 1-1, narrow linewidth laser 101 is connect with preamplifier 102, including：By narrow linewidth
Laser 101 is connected preposition by sequentially connected acousto-optic modulator 105,106 and first optical fiber circulator 107 of power amplifier
Amplifier 102.
Optionally, which can include：The fixed optical fiber filter of one centre wavelength and extremely
A few adjustable optical fiber filter of centre wavelength, adjusts at least one optical fiber filter at least two optical fiber filter
Centre wavelength, including：Adjust the centre wavelength of the adjustable optical fiber filter of at least one centre wavelength.
It is exemplary, it is assumed that at least two optical fiber filter includes：Fixed first optical fiber filter of centre wavelength is in
Cardiac wave grows adjustable second optical fiber filter.Specifically, can first connect the first optical fiber filter with preamplifier, then
The output terminal of first optical fiber filter concatenates the second optical fiber filter, after two optical fiber filters are cascaded, adjusts the second optical fiber
The centre wavelength of wave filter reduces the intersection y of the passband of cascade optical fiber filter, optionally, can cause y=n+ then
2, wherein, n is the line width of narrow linewidth laser, can be with maximum limit while ensureing optical signal by cascade optical fiber filter
The ASE noises for filtering out preamplifier generation of degree.In embodiments of the present invention, the first optical fiber filter and the second light are not limited
Second optical fiber filter with preamplifier can also connect, the first optical fiber filter be serially connected in by the position of fiber filter
The output terminal of second optical fiber filter.
Optionally, optical fiber filter all at least two optical fiber filter all can be the adjustable light of centre wavelength
Fiber filter adjusts the centre wavelength of at least one optical fiber filter at least two optical fiber filter, including：Adjust this extremely
The centre wavelength of each optical fiber filter in few two optical fiber filters.
It is exemplary, it is assumed that there are two the adjustable optical fiber filters of centre wavelength for setting in the system.Specifically, first by one
Optical fiber filter (being described for the ease of distinguishing, referred to as optical fiber filter 1) is connect with preamplifier, adjusts optical fiber filter 1
Centre wavelength so that the line width of narrow linewidth laser is in the free transmission range of optical fiber filter 1.Another optical fiber is filtered again
Device (being known as optical fiber filter 2) is connected on the output terminal of optical fiber filter 1, and after two optical fiber filters are cascaded, adjustment is cascade
The centre wavelength of optical fiber filter 1 and optical fiber filter 2 reduces the intersection of the passband of cascade two optical fiber filters,
While ensureing optical signal by cascade optical fiber filter, the ASE noises of preamplifier generation are filtered out to greatest extent.
Optionally, as Figure 2-3, it is assumed that there are two fiber grating filters for setting in the system.Specifically, first by one
A fiber grating filter (being described for the ease of distinguishing, referred to as fiber grating filter 1) by the second optical fiber circulator (in order to
Described convenient for distinguishing, referred to as the second optical fiber circulator 1) it is connect with preamplifier.Another fiber grating filter (is claimed again
For fiber grating filter 2) pass through the second optical fiber circulator (being known as the second optical fiber circulator 2) and the second optical fiber circulator 1
Output port is connected.Reduce the intersection of the passband of cascade two fiber grating filters, ensure that optical signal passes through cascade
Fiber grating filter while, filter out to greatest extent preamplifier generation ASE noises.
In conclusion vibration signal detecting system provided in an embodiment of the present invention, passes through at least two optical fiber filter grades
Connection, using the intersection of the passband of at least two optical fiber filter as the passband of cascade optical fiber filter, with single light
Fiber filter is compared, and reduces the bandwidth of passband, rear passes through cascade to Rayleigh scattering optical signal so that laser pulse is sent out
Optical fiber filter passband while, filtered out the preamplifier except the free transmission range in cascade optical fiber filter
The ASE noises of generation, when being reduced by the noise of cascade optical fiber filter, correspondingly, the voltage effective value of noise also subtracts
Small, so as to improve the signal-to-noise ratio of signal, the data collecting card that the reduction of ASE noises is also improved in photodetector collects
Signal data precision, convenient for the processing of follow-up data.
About the vibration signal detecting system assembly method in above-described embodiment, wherein each step performs the specific of operation
Mode is described in detail in the embodiment in relation to the system, and explanation will be not set forth in detail herein.
The foregoing is merely presently preferred embodiments of the present invention, is not intended to limit the invention, it is all the present invention spirit and
Within principle, any modification, equivalent replacement, improvement and so on should all be included in the protection scope of the present invention.
Claims (15)
1. a kind of vibration signal detecting system, which is characterized in that including：
Narrow linewidth laser, preamplifier and photodetector and positioned at the preamplifier and the photodetection
Cascade at least two optical fiber filter between device, the narrow linewidth laser are connect with the preamplifier, it is described extremely
The bandwidth of few two optical fiber filters is equal, and is x, and the narrow linewidth laser can generate continuous laser；
The passband of at least two optical fiber filter is there are intersection, and the bandwidth y of the intersection meets：N≤y ＜
x；
Wherein, the n is the line width of the narrow linewidth laser, and the line width of the narrow linewidth laser is in the intersection
In free transmission range.
2. system according to claim 1, which is characterized in that the system also includes：
Acousto-optic modulator, the power amplifier and being connected in turn between the narrow linewidth laser and the preamplifier
One optical fiber circulator.
3. system according to claim 1, which is characterized in that at least two optical fiber filter includes：One center
The fixed optical fiber filter of wavelength and the adjustable optical fiber filter of at least one centre wavelength.
4. system according to claim 3, which is characterized in that in one fixed optical fiber filter of centre wavelength
Cardiac wave length is equal with the centre wavelength of the continuous laser.
5. system according to claim 1, which is characterized in that at least two optical fiber filter includes at least two light
Fine grating filter.
6. system according to claim 5, which is characterized in that the system also includes：At least two second fiber annulars
Device, at least two fiber grating filter is equal with the number of at least two second optical fiber circulator and corresponds
Connection.
7. system according to claim 1, which is characterized in that all optical fiber filter at least two optical fiber filter
Wave device is the adjustable optical fiber filter of centre wavelength.
8. system according to any one of claims 1 to 7, which is characterized in that the x is 50 Gigahertzs.
9. system according to any one of claims 1 to 7, which is characterized in that each at least two optical fiber filter
Optical fiber filter is bandpass-type optical fiber filter.
10. system according to claim 1, which is characterized in that
The centre wavelength of the continuous laser is 1550 nanometers；
The line width of the narrow linewidth laser is less than 3 kHz.
11. system according to claim 2, which is characterized in that the system also includes：With first optical fiber circulator
The sensor fibre of connection.
12. a kind of vibration signal detecting system assembly method, which is characterized in that including：
Narrow linewidth laser, preamplifier and photodetector are provided；
At least two optical fiber filters are provided, at least two optical fiber filter includes：First optical fiber filter and the second light
Fiber filter, the line width of the narrow linewidth laser is in the free transmission range of the first optical fiber filter, at least two optical fiber
The bandwidth of wave filter is equal, and is x；
The narrow linewidth laser is connect with the preamplifier；
At least two optical fiber filters grade is associated between the preamplifier and the photodetector, described in adjustment
The centre wavelength of at least one optical fiber filter at least two optical fiber filters so that at least two optical fiber filter
Passband is there are intersection, and the bandwidth y of the intersection meets：N≤y ＜ x；
Wherein, the n is the line width of the narrow linewidth laser.
13. according to the method for claim 12, which is characterized in that
It is described to connect the narrow linewidth laser with the preamplifier, including：
The narrow linewidth laser is connected by sequentially connected acousto-optic modulator, power amplifier and the first optical fiber circulator
The preamplifier.
14. according to the method for claim 12, which is characterized in that at least two optical fiber filter includes：In one
Cardiac wave grows fixed optical fiber filter and the adjustable optical fiber filter of at least one centre wavelength,
The centre wavelength of at least one optical fiber filter in adjustment at least two optical fiber filter, including：
Adjust the centre wavelength of the adjustable optical fiber filter of at least one centre wavelength.
15. according to the method for claim 12, which is characterized in that all optical fiber at least two optical fiber filter
Wave filter is the adjustable optical fiber filter of centre wavelength,
The centre wavelength of at least one optical fiber filter in adjustment at least two optical fiber filter, including：
Adjust the centre wavelength of each optical fiber filter at least two optical fiber filter.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112201126A (en) * | 2020-10-10 | 2021-01-08 | 长春理工大学 | Optical fiber amplifier spontaneous radiation noise suppression experimental device, system and process |
Citations (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001051975A (en) * | 1999-08-11 | 2001-02-23 | Nippon Telegr & Teleph Corp <Ntt> | Band width variable digital filter bank |
| CN1669220A (en) * | 2002-07-15 | 2005-09-14 | 神经网路处理有限公司 | Digital filter designing method, digital filter designing program, digital filter |
| CN101158591A (en) * | 2007-10-15 | 2008-04-09 | 北京航空航天大学 | Detecting method suitable for optical fiber distributed temperature and stress sensing device |
| CN201096589Y (en) * | 2007-06-27 | 2008-08-06 | 中国石油天然气股份有限公司 | Distributed Optical Fiber Pipeline Safety Early Warning System Based on Phase Interference |
| CN101246983A (en) * | 2008-03-17 | 2008-08-20 | 南京大学 | Ultra-wideband filter based on simplified left hand transmission line structure |
| CN101359902A (en) * | 2008-09-25 | 2009-02-04 | 炬才微电子（深圳）有限公司 | Equalizing method and system for audio signal |
| CN101424621A (en) * | 2008-11-12 | 2009-05-06 | 西安金和光学科技有限公司 | Optical fibre grating sensor |
| CN102096158A (en) * | 2010-11-24 | 2011-06-15 | 北京交通大学 | All-fiber flat filter and fabricating method thereof |
| CN102460122A (en) * | 2009-04-17 | 2012-05-16 | 丹佛斯Ixa股份有限公司 | Sensor utilizing band pass filters |
| US20120129480A1 (en) * | 2010-11-22 | 2012-05-24 | Motorola, Inc. | Apparatus for receiving multiple independent rf signals simultaneously and method thereof |
| CN102706437A (en) * | 2012-06-13 | 2012-10-03 | 扬州森斯光电科技有限公司 | Super-long distance phase-sensitive optical time domain reflectometer (Phi-OTDR) system |
| CN203069504U (en) * | 2012-11-23 | 2013-07-17 | 姜利军 | Adjustable filter and non-dispersive gas detector |
| CN104198030A (en) * | 2014-08-29 | 2014-12-10 | 中国石油天然气股份有限公司 | Multi-path vibration detection method and system based on coherent Rayleigh scattering |
| CN104317068A (en) * | 2014-10-29 | 2015-01-28 | 中国科学院半导体研究所 | Integrated optical filter with center wavelength and filter bandwidth both adjustable independently |
| CN105222815A (en) * | 2015-09-18 | 2016-01-06 | 南京派光信息技术有限公司 | Based on the phase sensitive optical time domain reflectometer of 120 degree of difference interferometers |
| US20170188359A1 (en) * | 2012-12-05 | 2017-06-29 | Origin Wireless, Inc. | Method, Apparatus, Server, and Systems of Time-Reversal Technology |
-
2016
- 2016-12-17 CN CN201611171524.2A patent/CN108204857B/en active Active
Patent Citations (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001051975A (en) * | 1999-08-11 | 2001-02-23 | Nippon Telegr & Teleph Corp <Ntt> | Band width variable digital filter bank |
| CN1669220A (en) * | 2002-07-15 | 2005-09-14 | 神经网路处理有限公司 | Digital filter designing method, digital filter designing program, digital filter |
| CN201096589Y (en) * | 2007-06-27 | 2008-08-06 | 中国石油天然气股份有限公司 | Distributed Optical Fiber Pipeline Safety Early Warning System Based on Phase Interference |
| CN101158591A (en) * | 2007-10-15 | 2008-04-09 | 北京航空航天大学 | Detecting method suitable for optical fiber distributed temperature and stress sensing device |
| CN101246983A (en) * | 2008-03-17 | 2008-08-20 | 南京大学 | Ultra-wideband filter based on simplified left hand transmission line structure |
| CN101359902A (en) * | 2008-09-25 | 2009-02-04 | 炬才微电子（深圳）有限公司 | Equalizing method and system for audio signal |
| CN101424621A (en) * | 2008-11-12 | 2009-05-06 | 西安金和光学科技有限公司 | Optical fibre grating sensor |
| CN102460122A (en) * | 2009-04-17 | 2012-05-16 | 丹佛斯Ixa股份有限公司 | Sensor utilizing band pass filters |
| US20120129480A1 (en) * | 2010-11-22 | 2012-05-24 | Motorola, Inc. | Apparatus for receiving multiple independent rf signals simultaneously and method thereof |
| US8320858B2 (en) * | 2010-11-22 | 2012-11-27 | Motorola Solutions, Inc. | Apparatus for receiving multiple independent RF signals simultaneously and method thereof |
| CN102096158A (en) * | 2010-11-24 | 2011-06-15 | 北京交通大学 | All-fiber flat filter and fabricating method thereof |
| CN102706437A (en) * | 2012-06-13 | 2012-10-03 | 扬州森斯光电科技有限公司 | Super-long distance phase-sensitive optical time domain reflectometer (Phi-OTDR) system |
| CN203069504U (en) * | 2012-11-23 | 2013-07-17 | 姜利军 | Adjustable filter and non-dispersive gas detector |
| US20170188359A1 (en) * | 2012-12-05 | 2017-06-29 | Origin Wireless, Inc. | Method, Apparatus, Server, and Systems of Time-Reversal Technology |
| CN104198030A (en) * | 2014-08-29 | 2014-12-10 | 中国石油天然气股份有限公司 | Multi-path vibration detection method and system based on coherent Rayleigh scattering |
| CN104317068A (en) * | 2014-10-29 | 2015-01-28 | 中国科学院半导体研究所 | Integrated optical filter with center wavelength and filter bandwidth both adjustable independently |
| CN105222815A (en) * | 2015-09-18 | 2016-01-06 | 南京派光信息技术有限公司 | Based on the phase sensitive optical time domain reflectometer of 120 degree of difference interferometers |
Non-Patent Citations (1)
| Title |
|---|
| 许欧 等: "重叠写入啁啾光纤光栅型滤波器的", 《光电器件》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112201126A (en) * | 2020-10-10 | 2021-01-08 | 长春理工大学 | Optical fiber amplifier spontaneous radiation noise suppression experimental device, system and process |
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