CN109163748A - Single-ended dynamic distributed Brillouin's reflection unit and method based on frequency agility technology - Google Patents
Single-ended dynamic distributed Brillouin's reflection unit and method based on frequency agility technology Download PDFInfo
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
- G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
- G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
- G01D5/353—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
- G01D5/35338—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using other arrangements than interferometer arrangements
- G01D5/35354—Sensor working in reflection
- G01D5/35358—Sensor working in reflection using backscattering to detect the measured quantity
- G01D5/35364—Sensor working in reflection using backscattering to detect the measured quantity using inelastic backscattering to detect the measured quantity, e.g. using Brillouin or Raman backscattering
Abstract
Single-ended dynamic distributed Brillouin's reflection unit and method based on frequency agility technology, are related to single-ended dynamic distributed Brillouin fiber optic sensing technology, in order to solve the problems, such as that the algorithm that existing Brillouin light domain reflectometer uses is complicated, the data of processing are more.Light is modulated to pulsed light through the 1st electrooptic modulator all the way, then pump light is used as after EDFA Erbium-Doped Fiber Amplifier power amplification, is inputted by one end of testing fiber；Another way light is modulated to the optics frequency agility signal light of lower sideband through the 2nd electrooptic modulator, and optics frequency agility signal light filters out lower sideband as reference light through the 1st filter；Spontaneous brillouin scattering occurs in testing fiber, the spontaneous Brillouin signal and reference light beat frequency of output, balanced detector detection beat signal simultaneously carries out photoelectric conversion, and electric signal is after filtering detection module is filtered detection, the output signal of acquisition module acquisition filtering detection module.The present invention is suitable for Fibre Optical Sensor.
Description
Technical field
The invention belongs to optical fields, and in particular to single-ended dynamic distributed Brillouin fiber optic sensing technology.
Background technique
It is known as Brillouin's reflectometer using the sensor-based system of spontaneous brillouin scattering, wherein Brillouin light domain reflectometer
(BOTDR) it is represented to be typical, has many advantages, such as that single-ended, system structure is simple and at low cost, be widely used to civil structure
The fields such as health monitoring, oil-gas pipeline monitoring, cable and fire monitoring.
In BOTDR system, pumping pulse is incident in testing fiber, by its backward spontaneous brillouin scattering signal and ginseng
Photo-beat frequency detection demodulation brillouin gain spectrum is examined, beat frequency can be effectively reduced detector bandwidth.The demodulation scheme of Brillouin's frequency spectrum
Have two classes: a kind of directly acquisition beat signal obtains Brillouin's frequency spectrum using Short Time Fourier Transform (STFT)；Another scheme
Brillouin's frequency spectrum is obtained by mixing, filtering and detection hardware analysis beat signal intensity, frequency sweep.Fitting Brillouin's frequency spectrum obtains
Brillouin shift carries out temperature according to the corresponding temperature of optical fiber and the coefficient of strain and strain demodulates.
Since spontaneous brillouin scattering signal is weaker, a large amount of averagely raising signal-to-noise ratio, existing frequency scanning scheme are needed
Dynamic is difficult to realize to measure, and STFT scheme can reduce required average time and carry out frequency demodulation down online, energy
It is enough to realize dynamic measurement (Guojie Tu, Yixin Zhang, Zhoufeng Ying, Xuping Zhang, and Lidong
Lv.Strain variation measurement with short-time Fourier transform-based
Brillouin optical time-domain reflectometry sensing system[J].Electronics
Letters,2014 50(22):1624-1626.).The small gain that equally can use in STFT-BOTDR system is excited in cloth
Deep pool scattering enhancing signal-to-noise ratio, further decrease average time improve dynamic sampling rate (Bo Li, Linqing Luo, Yifei Yu,
Kenichi Soga,and Jize Yan.Dynamic Strain Measurement Using Small Gain
Stimulated Brillouin Scattering in STFT-BOTDR[J].IEEE Sensors Journal,2017 17
(9):2718-2724.).In addition brillouin gain spectrum slope method avoids frequency scanning, and pump light and reference light difference on the frequency are fixed
So that brillouin gain spectrum slope is fallen in bandpass filter bandwidth, strain, same energy are directly demodulated according to signal power variations
It is enough to realize dynamic measurement (Damien Maraval, Renaud Gabet, Yves Jaouen, and Vincent
Lamour.Dynamic Optical Fiber Sensing With Brillouin Optical Time Domain
Reflectometry:Application to Pipeline Vibration Monitoring[J].Journal of
Lightwave Technology,2017 35(16):3296-3302.)。
However, algorithm complexity, the data of processing that existing Brillouin light domain reflectometer uses are more.
Summary of the invention
The data that the algorithm used the purpose of the present invention is to solve existing Brillouin light domain reflectometer is complicated, handles
More problem, to provide single-ended dynamic distributed Brillouin's reflection unit based on frequency agility technology.
The first single-ended dynamic distributed Brillouin's reflection unit based on frequency agility technology of the present invention, including swash
Light device, the 1st electrooptic modulator, pulse module, EDFA Erbium-Doped Fiber Amplifier 1, circulator 2, the 2nd electrooptic modulator, agile frequency module,
1st filter 3, balanced detector, filtering detection module and acquisition module；
The laser of laser output is divided into 2 tunnels, and light is used to generate the pump light of pulse all the way, under another way light is for generating
Frequency displacement reference light；
The light all the way is modulated to pulsed light through the 1st electrooptic modulator, and the pulse signal of the 1st electrooptic modulator is by pulse mode
Block provides, and pulsed light is used as pump light after 1 power amplification of EDFA Erbium-Doped Fiber Amplifier, then in turn through 1 port of circulator 2
With 2 ports, then one end input by testing fiber 4；
The another way light is modulated to the optics frequency agility signal light of lower sideband, the 2nd electric light tune through the 2nd electrooptic modulator
The optics frequency agility signal of device processed is provided by agile frequency module, and optics frequency agility signal light filters out lower sideband through the 1st filter 3 and makees
For reference light；
Spontaneous brillouin scattering occurs in testing fiber 4, the spontaneous Brillouin signal of back scattering is by the one of testing fiber 4
2 ports of end input circulator 2, then exported by 3 ports of circulator 2, the spontaneous Brillouin signal and reference light beat frequency of output,
Balanced detector detection beat signal simultaneously carries out photoelectric conversion, and electric signal is after filtering detection module is filtered detection, acquisition
The output signal of module acquisition filtering detection module.
It preferably, further include single side-band modulator and microwave source；
The light all the way is used to generate the pump light of fixed upshift pulse；
The light all the way is modulated to the signal light of fixed upshift through single side-band modulator, then through the 1st electrooptic modulator tune
It is made as pulsed light, the fixing frequency displacement microwave signal of single side-band modulator is provided by microwave source.
Preferably, the 1st filter 3 is realized using fiber bragg grating.
Second of the present invention single-ended dynamic distributed Brillouin's reflection unit based on frequency agility technology, including swash
Light device, the 3rd electrooptic modulator, agile frequency module, the 4th electrooptic modulator, pulse module, the 2nd filter 5, erbium-doped fiber amplification
Device 1, circulator 2, balanced detector, filtering detection module and acquisition module；
The laser of laser output is divided into 2 tunnels, and light is used to generate the pump light of upshift pulse all the way, and another way light is direct
As reference light；
The light all the way is modulated to the optics frequency agility signal light of lower sideband through the 3rd electrooptic modulator, through the 4th electric light tune
Device processed is modulated to pulsed light, filters out upper side band through the 2nd filter 5, then as pumping after 1 power amplification of EDFA Erbium-Doped Fiber Amplifier
Light is inputted then in turn through the 1 and 2 port of circulator 2, then by one end of testing fiber 4；3rd electrooptic modulator
Optics frequency agility signal is provided by agile frequency module, and the pulse signal of the 4th electrooptic modulator is provided by pulse module；
Spontaneous brillouin scattering occurs in testing fiber 4, the spontaneous Brillouin signal of back scattering is by the one of testing fiber 4
2 ports of end input circulator 2, then exported by 3 ports of circulator 2, the spontaneous Brillouin signal and reference light beat frequency of output,
Balanced detector detection beat signal simultaneously carries out photoelectric conversion, and electric signal is after filtering detection module is filtered detection, acquisition
The output signal of module acquisition filtering detection module.
The third single-ended dynamic distributed Brillouin's reflection unit based on frequency agility technology of the present invention, including swash
Light device, the 5th electrooptic modulator, pulse module, EDFA Erbium-Doped Fiber Amplifier 1, circulator 2, the 6th electrooptic modulator, microwave source, the 3rd
Filter 6, balanced detector, frequency mixer, agile frequency module, low-pass filter and acquisition module；
The laser of laser output is divided into 2 tunnels, and light is used to generate the pump light of pulse all the way, and another way light is solid for generating
Fix the reference light of frequency displacement；
The light all the way is modulated to pulsed light through the 5th electrooptic modulator, and pulsed light is through 1 power amplification of EDFA Erbium-Doped Fiber Amplifier
It is used as pump light afterwards, is inputted then in turn through the 1 and 2 port of circulator 2, then by one end of testing fiber 4；5th electricity
The pulse signal of optical modulator is provided by pulse module；
The another way light is modulated to the signal light of the lower sideband of fixing frequency displacement through the 6th electrooptic modulator, through the 3rd filtering
Device 6 filters out lower sideband as reference light, and the fixing frequency displacement microwave signal of the 6th electrooptic modulator is provided by microwave source；
Spontaneous brillouin scattering occurs in testing fiber 4, the spontaneous Brillouin signal of back scattering is by the one of testing fiber 4
2 ports of end input circulator 2, then exported by 3 ports of circulator 2, the spontaneous Brillouin signal and reference light beat frequency of output,
Balanced detector detection beat signal simultaneously carries out photoelectric conversion, and the output signal of balanced detector is inputted as microwave signal to be mixed
Device, the output signal of agile frequency module as local oscillation signal input mixer, the low-pass filtered device of the output signal of frequency mixer into
After row filtering, acquisition module acquires the output signal of low-pass filter.
Preferably, agile frequency module and/or pulse module are replaced using arbitrary waveform generator.
Single-ended dynamic distributed Brillouin's reflection unit and method based on frequency agility technology of the invention, utilizes frequency agility
Technology realizes being switched fast for frequency, and the frequency of required scanning is written to agile frequency module in advance, primary all output, simultaneously
A pulse train is exported, each pulse pair answers a microwave frequency signal.There are three types of schemes to realize the fast of spontaneous Brillouin gain spectral
Speed demodulation: 1) the quick scanning of light frequency is referred to；2) the quick scanning of pumping light frequency；3) frequency mixer local oscillation signal is quickly swept
It retouches.Its time of measuring is determined that filtering detection module has the gain energy of tens dB by fiber lengths, frequency sweep number and average time
Average time is enough effectively reduced.The present invention completes the demodulating process of brillouin gain spectrum in hardware components, and data are effectively reduced
Collection capacity and later data processing difficulty, while hardware provides tens dB signal gains, can be realized the single-ended dynamic point of high-precision
Cloth Brillouin's temperature and strain sensing.
Detailed description of the invention
Fig. 1 is single-ended dynamic distributed Brillouin's reflection unit described in specific embodiment one based on frequency agility technology
Schematic diagram；
Fig. 2 is pumping pulse sequence and optics frequency agility signal sequence relational graph in specific embodiment one；
Fig. 3 is single-ended dynamic distributed Brillouin's reflection unit described in specific embodiment one based on frequency agility technology
Structural schematic diagram；
Fig. 4 is single-ended dynamic distributed Brillouin's reflection unit described in specific embodiment two based on frequency agility technology
Structural schematic diagram；
Fig. 5 is single-ended dynamic distributed Brillouin's reflection unit described in specific embodiment three based on frequency agility technology
Structural schematic diagram；
Fig. 6 is single-ended dynamic distributed Brillouin's reflection unit described in specific embodiment four based on frequency agility technology
Structural schematic diagram.
Specific embodiment
Specific embodiment 1: present embodiment is illustrated in conjunction with Fig. 1 to Fig. 3, based on victory described in present embodiment
Single-ended dynamic distributed Brillouin's reflection unit of converter technique, including laser, the 1st electrooptic modulator, pulse module, mix bait
Fiber amplifier 1, circulator 2, the 2nd electrooptic modulator, agile frequency module, the 1st filter 3, balanced detector, filtering detection mould
Block and acquisition module；
Testing fiber 4 is general single mode fiber, and distributed feedback fibre laser of the wavelength near 1550nm is as light
Source.
The laser of laser output is divided into 2 tunnels through 50:50 coupler, and 50% light all the way is used to generate the pumping of pulse
Light, 50% another way light is for generating downshift reference light；
Described 50% light all the way is modulated to 10ns pulsed light sequence, the arteries and veins of the 1st electrooptic modulator through the 1st electrooptic modulator
It rushes signal to be provided by pulse module, the 1st electrooptic modulator works in minimum operating point.Pulsed light is through EDFA Erbium-Doped Fiber Amplifier
(EDFA) the high frequency pumping pulse light sequence that peak power is 1W is obtained after power amplification, then in turn through 1 end of circulator 2
Mouth and 2 ports, then inputted by one end of testing fiber 4；
Described 50% another way light is modulated to the optics frequency agility signal light of lower sideband through the 2nd electrooptic modulator, and the 2nd
The optics frequency agility signal of electrooptic modulator is provided by agile frequency module, and optics frequency agility signal light filters out down through the 1st filter 3
Sideband is as reference light；1st filter 3 is realized using fiber bragg grating.
Spontaneous brillouin scattering occurs in testing fiber 4, the spontaneous Brillouin signal of back scattering is by the one of testing fiber 4
2 ports of end input circulator 2, then exported by 3 ports of circulator 2, the spontaneous Brillouin signal and reference light beat frequency of output,
Balanced detector detection beat signal simultaneously carries out photoelectric conversion, improves signal-to-noise ratio, and electric signal is filtered through filtering detection module
After wave detection, the output signal of acquisition module acquisition filtering detection module, the spontaneous brillouin scattering spectrum after directly obtaining demodulation.
The principle of the present invention is illustrated in conjunction with Fig. 1, the spontaneous Brillouin signal and optics agile frequency modulation of back scattering
The reference optical signal beat frequency of system carries out spectrum analysis using the scheme of filtering and detection.Fixed filters frequency and bandwidth.With
When frequency reference photo-beat frequency, the two difference on the frequency is larger, and the low-frequency component of spontaneous back scattering is fallen in filter bandwidht, wave detector
Respective strengths are obtained after intensity demodulation；When with high frequency references photo-beat frequency, the two difference on the frequency is smaller, the high frequency of spontaneous back scattering
Ingredient is fallen in filter bandwidht, and respective strengths are obtained after wave detector intensity demodulation, finally in entire optics frequency agility signal
Realize that spontaneous Brillouin gain spectral is reconfigured quickly.
Pumping pulse sequence and optics frequency agility signal sequence relationship are illustrated in conjunction with Fig. 2, in reference light optical path
The radiofrequency signal of the modulated terminal input of 2nd electrooptic modulator is the wave train f of N number of frequency step variationm(t):
Wherein: fm0For the original frequency of the wave train, fsFor number of frequency steps, T is any frequency sweep cycle,To take
Whole, t is the time；
The beam of laser of input is modulated into the reference light of upper lower side frequency output by the 2nd electrooptic modulator；
fr(t)=f0±fm(t),
Wherein, f0The frequency of laser is exported for laser；
The reference light is that the light for the different frequency for being T by N number of period forms, while each microwave frequency corresponds to a square wave
Pulse signal, pulse train are loaded on the 1st electrooptic modulator of pump light optical path, output pumping pulsed light.
Guarantee that reference the light frequency range of optics frequency agility, while can be with compared to pump light covering optical fiber Brillouin frequency displacement
Optics frequency agility range is improved, strain and temperature demodulation range are increased.Pumping pulse optical width decision systems spatial resolution is surveyed
The amount time is related with fiber lengths, frequency sweep number and signal averaging number, realizes the survey of single-ended dynamic distributed strain and temperature
Amount.
F in Fig. 21To fNFor frequency corresponding to each period.
Specific embodiment 2: present embodiment is illustrated in conjunction with Fig. 4, based on frequency agility skill described in present embodiment
Single-ended dynamic distributed Brillouin's reflection unit of art, including laser, the 3rd electrooptic modulator, agile frequency module, the 4th electric light
Modulator, pulse module, the 2nd filter 5, EDFA Erbium-Doped Fiber Amplifier 1, circulator 2, balanced detector, filtering detection module and
Acquisition module；
Testing fiber 4 is general single mode fiber, and distributed feedback fibre laser of the wavelength near 1550nm is as light
Source.
The laser of laser output is divided into 2 tunnels through 90:10 coupler, and 90% light all the way is for generating upshift pulse
Pump light, 10% another way light is directly as reference light；
Described 90% light all the way is modulated to the optics frequency agility signal light of lower sideband through the 3rd electrooptic modulator, through the 4th
Electrooptic modulator is modulated to 10ns pulsed light sequence, filters out upper side band through the 2nd filter 5, then through 1 power of EDFA Erbium-Doped Fiber Amplifier
The pumping pulse light sequence that the optics frequency agility that peak power is 1W is modulated is obtained after amplification, then in turn through the 1 of circulator 2
Port and 2 ports, then inputted by one end of testing fiber 4；The optics frequency agility signal of 3rd electrooptic modulator is by agile frequency module
It provides, the pulse signal of the 4th electrooptic modulator is provided by pulse module；
Spontaneous brillouin scattering occurs in testing fiber 4, the spontaneous Brillouin signal of back scattering is by the one of testing fiber 4
End input circulator 22 ports, then by circulator 23 ports export, the spontaneous Brillouin signal of output and 10% reference
Photo-beat frequency, balanced detector detection beat signal simultaneously carry out photoelectric conversion, improve signal-to-noise ratio, electric signal is through filtering detection module
After being filtered detection, the output signal of acquisition module acquisition filtering detection module, the spontaneous Brillouin after directly obtaining demodulation
Scattering spectra.
Using pump light optics frequency agility and impulse modulation in present embodiment.
Specific embodiment 3: present embodiment is illustrated in conjunction with Fig. 5, based on frequency agility skill described in present embodiment
Single-ended dynamic distributed Brillouin's reflection unit of art, including laser, the 5th electrooptic modulator, pulse module, erbium-doped fiber are put
It is big device 1, circulator 2, the 6th electrooptic modulator, microwave source, the 3rd filter 6, balanced detector, frequency mixer, agile frequency module, low
Bandpass filter and acquisition module；
Testing fiber 4 is general single mode fiber, and distributed feedback fibre laser of the wavelength near 1550nm is as light
Source.
The laser of laser output is divided into 2 tunnels through 50:50 coupler, and 50% light all the way is used to generate the pumping of pulse
Light, 50% another way light are used to generate the reference light of fixed downshift；
Described 50% light all the way is modulated to 10ns pulsed light through the 5th electrooptic modulator, and pulsed light amplifies through erbium-doped fiber
The high frequency pumping pulse light sequence that peak power is 1W is obtained after device (EDFA) power amplification, then in turn through the 1 of circulator 2
Port and 2 ports, then inputted by one end of testing fiber 4；The pulse signal of 5th electrooptic modulator is provided by pulse module；
Described 50% another way light is modulated to the signal light of the lower sideband of fixing frequency displacement through the 6th electrooptic modulator, warp
3rd filter 6 filters out lower sideband as reference light, and the fixing frequency displacement microwave signal of the 6th electrooptic modulator is provided by microwave source；
Spontaneous brillouin scattering occurs in testing fiber 4, the spontaneous Brillouin signal of back scattering is by the one of testing fiber 4
2 ports of end input circulator 2, then exported by 3 ports of circulator 2, the spontaneous Brillouin signal and reference light beat frequency of output,
Balanced detector detection beat signal simultaneously carries out photoelectric conversion, improves signal-to-noise ratio, the output signal of balanced detector is as micro-
Wave signal input mixer, the output signal of agile frequency module is as local oscillation signal input mixer, the output signal of frequency mixer
After low-pass filtered device filtering, acquisition module acquires the output signal of low-pass filter, in the publication certainly after directly obtaining demodulation
Deep scattering spectra.
In present embodiment, frequency agility signal performs a scan at frequency mixer, reduces system for agile frequency module
The requirement of bandwidth.
Specific embodiment 4: present embodiment is illustrated in conjunction with Fig. 6, based on frequency agility skill described in present embodiment
Single-ended dynamic distributed Brillouin's reflection unit of art, including laser, single side-band modulator, microwave source, the 1st Electro-optical Modulation
Device, pulse module, EDFA Erbium-Doped Fiber Amplifier 1, circulator 2, the 2nd electrooptic modulator, agile frequency module, the 1st filter 3, balance
Detector, filtering detection module and acquisition module；Testing fiber 4 is general single mode fiber, distribution of the wavelength near 1550nm
Formula feedback fibre laser is as light source.
The laser of laser output is divided into 2 tunnels through the coupler of 90:10, and 90% light all the way is for generating fixed upshift
The pump light of pulse, 10% another way light is for generating downshift reference light；
Described 90% light all the way enters single side-band modulator (SSBM), and carrier wave and single order lower side frequency are suppressed and export
The signal light of the fixed upshift of 8.3GHz, then 10ns pulsed light, the fixation of single side-band modulator are modulated to through the 1st electrooptic modulator
Frequency displacement microwave signal is provided by microwave source, and the pulse signal of the 1st electrooptic modulator is provided by pulse module, and pulsed light is mixed bait light
The high frequency pumping pulse light sequence that peak power is 1W is obtained after fiber amplifier (EDFA) power amplification, then in turn through annular
The 1 and 2 port of device 2, then inputted by one end of testing fiber 4；
Described 10% another way light is modulated to the optics frequency agility signal light of lower sideband through the 2nd electrooptic modulator, and the 2nd
The optics frequency agility signal of electrooptic modulator is provided by agile frequency module, and optics frequency agility signal light filters out down through the 1st filter 3
Sideband is as reference light；
Spontaneous brillouin scattering occurs in testing fiber 4, the spontaneous Brillouin signal of back scattering is by the one of testing fiber 4
2 ports of end input circulator 2, then exported by 3 ports of circulator 2, the spontaneous Brillouin signal and reference light beat frequency of output,
Balanced detector detection beat signal simultaneously carries out photoelectric conversion, and electric signal is after filtering detection module is filtered detection, acquisition
The output signal of module acquisition filtering detection module, the spontaneous brillouin scattering spectrum after directly obtaining demodulation.
Present embodiment uses two-way frequency modulating technology, reduces requirement of the system for frequency agility module bandwidth.
Specific embodiment 5: present embodiment is described in above-mentioned any one specific embodiment based on optics Zhou
The single-ended fast distributed Brillouin Optical Time Domain Reflectometry device of chain of singing is described further, agile frequency module and/or pulse mode
Block is replaced using arbitrary waveform generator.
Specific embodiment 6: the single-ended dynamic distributed Brillouin described in present embodiment based on frequency agility technology is anti-
The frequency of required scanning is written agile frequency module, and primary all output, while exporting pumping light pulse sequence by shooting method,
Each pump light pulse pair answers the microwave frequency of an agile frequency module；
Using one of following three kinds of modes when frequency agility is modulated:
Frequency agility module drive electrooptic modulator, electrooptic modulator modulate reference light；Corresponding specific embodiment one and four
The device；
Frequency agility module drive electrooptic modulator, electrooptic modulator modulated pumping light；Described in corresponding specific embodiment two
Device；
Electric signal after spontaneous Brillouin signal and reference light beat frequency is as microwave signal input mixer, agile frequency module
Output signal as local oscillation signal input mixer；Device described in corresponding specific embodiment three.
It is obvious to a person skilled in the art that invention is not limited to the details of the above exemplary embodiments, Er Qie
In the case where without departing substantially from spirit or essential attributes of the invention, the present invention can be realized in other specific forms.Therefore, no matter
From the point of view of which point, the present embodiments are to be considered as illustrative and not restrictive, and the scope of the present invention is by appended power
Benefit requires rather than above description limits, it is intended that all by what is fallen within the meaning and scope of the equivalent elements of the claims
Variation is included within the present invention.
Claims (7)
1. single-ended dynamic distributed Brillouin's reflection unit based on frequency agility technology, which is characterized in that including laser, the 1st
Electrooptic modulator, pulse module, EDFA Erbium-Doped Fiber Amplifier (1), circulator (2), the 2nd electrooptic modulator, agile frequency module, the 1st
Filter (3), balanced detector, filtering detection module and acquisition module；
The laser of laser output is divided into 2 tunnels, and light is used to generate the pump light of pulse all the way, and another way light is for generating downshift
Reference light；
The light all the way is modulated to pulsed light through the 1st electrooptic modulator, and the pulse signal of the 1st electrooptic modulator is mentioned by pulse module
For pulsed light is used as pump light after EDFA Erbium-Doped Fiber Amplifier (1) power amplification, then in turn through 1 port of circulator (2)
With 2 ports, then one end input by testing fiber (4)；
The another way light is modulated to the optics frequency agility signal light of lower sideband, the 2nd electrooptic modulator through the 2nd electrooptic modulator
Optics frequency agility signal provided by agile frequency module, optics frequency agility signal light filters out lower sideband conduct through the 1st filter (3)
Reference light；
Spontaneous brillouin scattering occurs in testing fiber (4), the spontaneous Brillouin signal of back scattering is by the one of testing fiber (4)
2 ports of end input circulator (2), then exported by 3 ports of circulator (2), the spontaneous Brillouin signal and reference light of output
Beat frequency, balanced detector detection beat signal simultaneously carry out photoelectric conversion, electric signal through filtering detection module be filtered detection after,
The output signal of acquisition module acquisition filtering detection module.
2. single-ended dynamic distributed Brillouin's reflection unit according to claim 1 based on frequency agility technology, feature
It is, further includes single side-band modulator and microwave source；
The light all the way is used to generate the pump light of fixed upshift pulse；
The light all the way is modulated to the signal light of fixed upshift through single side-band modulator, then is modulated to through the 1st electrooptic modulator
The fixing frequency displacement microwave signal of pulsed light, single side-band modulator is provided by microwave source.
3. single-ended dynamic distributed Brillouin's reflection unit according to claim 1 based on frequency agility technology, feature
It is, the 1st filter (3) is realized using fiber bragg grating.
4. single-ended dynamic distributed Brillouin's reflection unit based on frequency agility technology, which is characterized in that including laser, the 3rd
Electrooptic modulator, agile frequency module, the 4th electrooptic modulator, pulse module, the 2nd filter (5), EDFA Erbium-Doped Fiber Amplifier (1),
Circulator (2), balanced detector, filtering detection module and acquisition module；
The laser of laser output is divided into 2 tunnels, and light is used to generate the pump light of upshift pulse all the way, another way light directly as
Reference light；
The light all the way is modulated to the optics frequency agility signal light of lower sideband through the 3rd electrooptic modulator, through the 4th electrooptic modulator
It is modulated to pulsed light, filters out upper side band through the 2nd filter (5), then as pumping after EDFA Erbium-Doped Fiber Amplifier (1) power amplification
Light is inputted then in turn through the 1 and 2 port of circulator (2), then by one end of testing fiber (4)；3rd Electro-optical Modulation
The optics frequency agility signal of device is provided by agile frequency module, and the pulse signal of the 4th electrooptic modulator is provided by pulse module；
Spontaneous brillouin scattering occurs in testing fiber (4), the spontaneous Brillouin signal of back scattering is by the one of testing fiber (4)
2 ports of end input circulator (2), then exported by 3 ports of circulator (2), the spontaneous Brillouin signal and reference light of output
Beat frequency, balanced detector detection beat signal simultaneously carry out photoelectric conversion, electric signal through filtering detection module be filtered detection after,
The output signal of acquisition module acquisition filtering detection module.
5. single-ended dynamic distributed Brillouin's reflection unit based on frequency agility technology, which is characterized in that including laser, the 5th
Electrooptic modulator, pulse module, EDFA Erbium-Doped Fiber Amplifier (1), circulator (2), the 6th electrooptic modulator, microwave source, the 3rd filtering
Device (6), balanced detector, frequency mixer, agile frequency module, low-pass filter and acquisition module；
The laser of laser output is divided into 2 tunnels, and light is used to generate the pump light of pulse all the way, and another way light is for generating under fixation
The reference light of frequency displacement；
The light all the way is modulated to pulsed light through the 5th electrooptic modulator, and pulsed light is after EDFA Erbium-Doped Fiber Amplifier (1) power amplification
As pump light, inputted then in turn through the 1 and 2 port of circulator (2), then by one end of testing fiber (4)；5th
The pulse signal of electrooptic modulator is provided by pulse module；
The another way light is modulated to the signal light of the lower sideband of fixing frequency displacement through the 6th electrooptic modulator, through the 3rd filter
(6) lower sideband is filtered out as reference light, and the fixing frequency displacement microwave signal of the 6th electrooptic modulator is provided by microwave source；
Spontaneous brillouin scattering occurs in testing fiber (4), the spontaneous Brillouin signal of back scattering is by the one of testing fiber (4)
2 ports of end input circulator (2), then exported by 3 ports of circulator (2), the spontaneous Brillouin signal and reference light of output
Beat frequency, balanced detector detection beat signal simultaneously carry out photoelectric conversion, and the output signal of balanced detector is defeated as microwave signal
Enter frequency mixer, the output signal of agile frequency module is as local oscillation signal input mixer, and the output signal of frequency mixer is through low pass filtered
After wave device is filtered, acquisition module acquires the output signal of low-pass filter.
6. single-ended dynamic distributed Brillouin's reflection according to above-mentioned any one claim based on frequency agility technology
Device, which is characterized in that agile frequency module and/or pulse module are replaced using arbitrary waveform generator.
7. single-ended dynamic distributed Brillouin's method for reflection based on frequency agility technology, which is characterized in that by the frequency of required scanning
Agile frequency module, and primary all output is written in rate, while exporting pumping light pulse sequence, each pump light pulse pair answers one
The microwave frequency of a agile frequency module；
Using one of following three kinds of modes when frequency agility is modulated:
Frequency agility module drive electrooptic modulator, electrooptic modulator modulate reference light；
Frequency agility module drive electrooptic modulator, electrooptic modulator modulated pumping light；
Electric signal after spontaneous Brillouin signal and reference light beat frequency as microwave signal input mixer, agile frequency module it is defeated
Signal is as local oscillation signal input mixer out.
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