CN109323750A - Distributed optical fiber vibration sensing system and phase demodulating method - Google Patents
Distributed optical fiber vibration sensing system and phase demodulating method Download PDFInfo
- Publication number
- CN109323750A CN109323750A CN201811353736.1A CN201811353736A CN109323750A CN 109323750 A CN109323750 A CN 109323750A CN 201811353736 A CN201811353736 A CN 201811353736A CN 109323750 A CN109323750 A CN 109323750A
- Authority
- CN
- China
- Prior art keywords
- coupler
- light
- output
- signal
- connect
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- 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
- G01H9/006—Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means using fibre optic sensors the vibrations causing a variation in the relative position of the end of a fibre and another element
Abstract
The invention discloses a kind of distributed optical fiber vibration sensing system and phase demodulating methods, belong to technical field of optical fiber sensing.The present invention is based onOptical fiber vibration sensing principle, devise phase demodulating light path system and demodulating algorithm.Distributed optical fiber vibration sensing system of the invention includes: narrow linewidth laser, the first coupler, acousto-optic modulator, second coupler, electrooptic modulator, the first EDFA Erbium-Doped Fiber Amplifier, circulator, third coupler, the first variable optical attenuator, 4th coupler, the 5th coupler, the second variable optical attenuator, 6th coupler, the second EDFA Erbium-Doped Fiber Amplifier, photodetector, filter, digital collection processor.The present invention introduces two kinds of difference frequencies from same source in traditional Φ-OTDR system, and the vibration signal of a certain position of optical fiber is modulated in the first heterodyne frequency, then eliminates the first outer difference frequency by another outer difference frequency.This method avoids the influence of low frequency noise simultaneously, while also avoiding using information such as complicated lower frequency changer circuit demodulation phases.
Description
Technical field
The present invention relates to distributed fiber Rayleigh scattering vibration sensing system technical field more particularly to a kind of phase demodulatings
System and method.
Background technique
Distributed optical fiber vibration sensor is that the one kind developed in recent decades is divided for real-time measurement space oscillations information
The optical fiber sensing system of cloth.φ-OTDR distributed optical fiber vibration sensing system utilizes Rayleigh scattering signal, which generallys use
Optical heterodyne improves sensitivity.Heterodyne method is a kind of method of interferometry, it is made by the frequency of change reference signal
It generates a difference on the frequency between measuring signal and contains in interference signal phase after reference signal and measuring signal are interfered
Measured phase can be obtained by carrying out demodulation to interference signal in phase-modulation item (carrier wave) and tested quantifier.It is this
The method that carrier wave is introduced in interference signal phase is known as heterodyne method.
Heterodyne method demodulates phase and amplitude, it is thus necessary to determine that outer frequency difference △ f, such as patent: CN 207036249 U, CN
102628698 A of 107976248 A, CN etc..The outer frequency difference that device due to generating outer frequency difference generates absolutely not is a fixation
80MHZ ± 0.1% is indicated in value, such as Britain's acousto-optic modulator index gathering of calligraphers.Even if outer frequency difference error only has one thousandth, still
Influence to result is fatal, so there is many technologies, to determine outer frequency difference △ f, (namely Δ w (t) differs one often
Number), detailed method is shown in correlative theses, such as: the acquisition of heterodyne laser interference signal and demodulation method summarize [J] laser
Magazine, 2018 (1): 20-24.It can be seen that determining that outer frequency difference △ f process is more complicated, while there is also certain mistakes
Difference.
Summary of the invention
For existing distributed vibration sensing system and phase demodulating method deficiency or Improvement requirement, the present invention provides one
The distributed vibration sensing system and phase demodulating method of the new coherent reception of kind, its object is to simpler, according to accurate
Demodulate the relevant information of the vibration signal phase along testing fiber.
The technical solution adopted by the present invention to solve the technical problems is:
A kind of distributed optical fiber vibration sensing system is provided, including sequentially connected narrow linewidth laser, the first coupler,
Acousto-optic modulator, the second coupler, electrooptic modulator, the first EDFA Erbium-Doped Fiber Amplifier and circulator, a port of circulator
It is connect with sensing optic cable；
Narrow linewidth laser is connect with the first coupler input, and first the first output end of coupler and acousto-optic modulator are defeated
Enter end connection, the output end of acousto-optic modulator connect with the input terminal of the second coupler, the first output end of the second coupler and
The input terminal of electrooptic modulator connects, and the output end of electrooptic modulator is connect with the input terminal of the first EDFA Erbium-Doped Fiber Amplifier, the
The output end of one EDFA Erbium-Doped Fiber Amplifier and the first port of circulator connect, and the second port and sensing optic cable of circulator connect
It connects；
The sensor-based system further include third coupler, the first variable optical attenuator, the 4th coupler, the 5th coupler,
Second variable optical attenuator, the 6th coupler；
The second output terminal of first coupler is connect with the input terminal of third coupler, the first output end of third coupler
It is connect with the input terminal of the first variable optical attenuator, the second output of the second output terminal of third coupler, the second coupler
End is connect with two input terminals of the 4th coupler respectively；The third port of the output end of first variable optical attenuator, circulator
It is connect respectively with two input terminals of the 5th coupler, the input of the output end and the second variable optical attenuator of the 4th coupler
End connection, output end, the output end of the second variable optical attenuator of the 5th coupler are defeated with two of the 6th coupler respectively
Enter end connection；
The sensor-based system further includes sequentially connected second EDFA Erbium-Doped Fiber Amplifier, photodetector, filter and signal
Acquisition Processor；The input terminal of second EDFA Erbium-Doped Fiber Amplifier is connect with the output end of the 6th coupler.
Connect above-mentioned technical proposal, third coupler, the 4th coupler, the 5th coupler, the 6th coupler are respectively coupling
Clutch.
Above-mentioned technical proposal is connect, the laser of narrow linewidth laser output is divided into two-way, including first by the first coupler
Main road light and first via reference light, main road light enter acousto-optic modulator, generate a frequency shift amount, and output light is continuous light；Acousto-optic
The output light of modulator enters the second coupler and is divided into two-way, including the second main road light and the second road reference light, the second main road light
Into electro-optical demodulator, the second road reference light enters the 4th coupler.
The present invention also provides a kind of phase demodulatings based on distributed optical fiber vibration sensing optical fiber described in claim 1
Method, comprising the following steps:
The laser of narrow linewidth laser output is divided into two-way, including the first main road light and first via ginseng by the first coupler
Light is examined, main road light enters acousto-optic modulator, generates a frequency shift amount, and output light is continuous light；The output light of acousto-optic modulator into
Enter the second coupler and be divided into two-way, including the second main road light and the second road reference light, the second main road light enter electro-optical demodulator, the
Two road reference lights enter the 4th coupler；
Second main road light enters electrooptic modulator and generates pulsed light, and pulsed light is put using the first EDFA Erbium-Doped Fiber Amplifier
Greatly, it is entered in sensor fibre by circulator；
The signal E10*exp [- iwt] of the first via reference light of the second output terminal light of first coupler, by third coupling
Clutch light splitting, the first via light splitting of first via reference light enter the first variable optical attenuator and carry out power regulation, optical signal vibration
Width changes, phase invariant；
The signal that the second output terminal of second coupler exports the second road reference light is
E20*exp{-i[w+Δw(t)]t}；
The second tunnel light splitting of first via reference light and the second road reference light pass through the 4th coupler, the 4th coupler output light
Signal are as follows: E14*exp [- iwt]+E21*exp {-i [w+ Δ w (t)] t }；
The optical signal of 4th coupler output enters the second variable optical attenuator and carries out power regulation, and optical signal amplitude changes
Become, phase invariant；
Extraneous optical cable vibration information is carried from the reflected signal light of the third port of circulator, optical signal is
First via light splitting and the reflected signal of third port from circulator of first via reference light after decaying
Light is coupled in the 5th coupler, the 5th coupler output optical signal are as follows:
First via reference light, the second road reference light and reflected signal light after decaying is at the 6th coupler
It is mixed, the optical signal of the 6th coupler output are as follows:
The optical signal of 6th coupler output amplifies by the second EDFA Erbium-Doped Fiber Amplifier, phase invariant；
Amplified optical signal carries out photoelectric conversion through photodetector, exports as electric signal are as follows:
Wherein, A is DC quantity, Δ w (t) frequency
In MHz magnitude,Frequency is in KHz magnitude or lower；
Electric signal filters DC quantity and high frequency content after bandpass filter, and signal is
Filtered signal enters data collection processor and is handled, output phase relevant information；
In above formula, E10, E13, E14, E16, E20, E21, E23, E30, E31, E32 are amplitude, and w is light frequency,
Δ w (t) is the heterodyne frequency shift amount of modulator, and heterodyne frequency shift amount changes at random at any time,The change of phase caused by invade
Changing, D is amplitude,For the phase of signal.
The beneficial effect comprise that: present invention employs the method for two-way reference light, eliminates and solve outer frequency difference
Influence of the precision to phase demodulating result, avoid the outer frequency difference process of complicated determination, so that it may obtain phase, the letter such as amplitude
Breath.
Detailed description of the invention
Present invention will be further explained below with reference to the attached drawings and examples, in attached drawing:
Fig. 1 is a kind of distributed optical fiber vibration sensing system schematic diagram of the embodiment of the present invention；
Fig. 2 is coherent reception schematic illustration of the embodiment of the present invention.
Specific embodiment
In order to make the objectives, technical solutions, and advantages of the present invention clearer, with reference to the accompanying drawings and embodiments, right
The present invention is further elaborated.It should be appreciated that described herein, specific examples are only used to explain the present invention, not
For limiting the present invention.
Distributed optical fiber vibration sensing system of the invention includes narrow linewidth laser 1, the first coupler 2, acousto-optic modulation
Device 3, the second coupler 4, electrooptic modulator 5, the first EDFA Erbium-Doped Fiber Amplifier 6 and circulator 7 further include third coupler 8,
One variable optical attenuator 9, the 4th coupler 11, the 5th coupler 10, the second variable optical attenuator 12, the 6th coupler
13, the second EDFA Erbium-Doped Fiber Amplifier 14, photodetector 15, filter 16 and signal acquisition process device 17.
Narrow linewidth laser 1 is connect with 2 input terminal of the first coupler, first the first output end of coupler and acousto-optic modulator
(AOM) 3 input terminals connect, and the output end of acousto-optic modulator (AOM) 3 is connect with the input terminal of the second coupler 4, the second coupler
4 the first output end is connect with the input terminal of electrooptic modulator (EOM) 5, and 5 output end of electrooptic modulator (EOM) and first mixes bait
The connection of 6 input terminal of fiber amplifier (EDFA), the first EDFA Erbium-Doped Fiber Amplifier (EDFA) 6 are connect with 7 first port of circulator, ring
7 second port of shape device is connect with sensing optic cable.First coupler, 2 second output terminal is connect with 8 input terminal of third coupler, third
8 first output end of coupler and the input of the first variable optical attenuator (VOA) 9 connect, 8 second output terminal of third coupler and the
Two couplers, 4 second output terminal is connect with 11 two input terminals of the 4th coupler respectively.First variable optical attenuator (VOA) 9
7 third port of output end and circulator, connect with 10 two input terminals of the 5th coupler respectively, 11 output end of the 4th coupler with
Second variable optical attenuator (VOA) 12 connects, and 10 output end of the 5th coupler and the second variable optical attenuator (VOA) 12 are defeated
Outlet is connect with two output ends of the 6th coupler 13 respectively.6th coupler, 13 output end respectively with the second erbium-doped fiber
Amplifier (EDFA) 14, photodetector (PD) 15, filter 16, digital collection processor 17 connect.Third coupler is to
Six couplers are equal branch/coupler.
When system is run, 1 outputting high quality laser of narrow linewidth laser is divided into two-way (main road light by the first coupler 2
With first via reference light), main road light enters acousto-optic modulator (AOM) 3, generates a frequency shift amount, and output light is continuous light.From sound
3 output light of optical modulator (AOM) enters the second coupler 4 and is divided into two-way (main road light and the second road reference light), electrooptic modulator
(EOM) 5 effect is to generate pulse.Again into the amplification of the first EDFA Erbium-Doped Fiber Amplifier (EDFA) 6 is crossed, entered by circulator 7
In sensor fibre.Signal light and the first via, the second tunnel are reflected back with reference to photomixing, demodulation from 7 third port of circulator.
First coupler, 2 second output terminal optical signal is that E10*exp [- iwt] is divided by third coupler 8, and first can
It tunes optical attenuator (VOA) 9 and carries out power regulation, optical signal amplitude changes, phase invariant.
Second coupler, 4 second output terminal optical signal is (note that outer frequency difference Δ w (t) is not one quantitative, strictly speaking
It is as the time changes at random): E20*exp {-i [w+ Δ w (t)] t }.
It is divided by the 4th coupler 11, the second variable optical attenuator (VOA) 12 carries out power regulation, optical signal amplitude
Change, phase invariant.
7 third port of circulator carries extraneous optical cable vibration information, and optical signal is
The output optical signal of 7 third port of circulator is coupled with the output signal light of the first tunable attenuator 9 the 5th
It is coupled at device 10, output optical signal are as follows:
The light splitting all the way of third coupler 8 couples at the 4th coupler 11 with the second road reference light, output optical signal are as follows:
E14*exp[-iwt]+E21*exp{-i[w+Δw(t)]t}
First via reference light, the second road reference light and reflected signal light after decaying is in the 6th coupler 13
Place is mixed, 13 output optical signal of the 6th coupler are as follows:
By the second EDFA Erbium-Doped Fiber Amplifier (EDFA) 14, optical signal is amplified, phase invariant.
The output of photodetector (PD) 15 is electric signal are as follows:
Wherein, A is DC quantity, Δ w (t) frequency generally in MHz magnitude,Frequency is generally in KHz or lower.
After bandpass filter 16, DC quantity and high frequency content, signal can be removed are as follows:Wherein D is
Amplitude,For the phase of signal.
Filtered signal enters data collection processor 17 and is simply handled, the relevant information of output phase.
The method of the present invention is compared with traditional coherent demodulation method, and the light and laser for adding additional frequency displacement issue signal light
Mixing, extracts the heterodyne frequency shift amount changed at random at any time.The heterodyne changed at random at any time is contained in traditional coherent
Shift frequency amount is eliminated solved outer frequency difference in this way with changing at random at any time of extracting of the method " subtracting " of secondary mixing
Influence of the precision to phase demodulating result, avoid the outer frequency difference process of complicated determination
It can be seen that 1) heterodyne approach avoids the influence of low frequency noise from the above process；2) two-way heterodyne signal is again
Heterodyne, avoids the process of the real-time outer difference frequency of complicated solution, and precision is higher；It 3) can be with demodulation phase, the information such as amplitude.
It should be understood that for those of ordinary skills, it can be modified or changed according to the above description,
And all these modifications and variations should all belong to the protection domain of appended claims of the present invention.
Claims (4)
1. a kind of distributed optical fiber vibration sensing system, which is characterized in that including sequentially connected narrow linewidth laser, the first coupling
Clutch, acousto-optic modulator, the second coupler, electrooptic modulator, the first EDFA Erbium-Doped Fiber Amplifier and circulator, one of circulator
Port is connect with sensing optic cable；
Narrow linewidth laser is connect with the first coupler input, first the first output end of coupler and acousto-optic modulator input terminal
Connection, the output end of acousto-optic modulator are connect with the input terminal of the second coupler, the first output end and electric light of the second coupler
The input terminal of modulator connects, and the output end of electrooptic modulator is connect with the input terminal of the first EDFA Erbium-Doped Fiber Amplifier, and first mixes
The output end of bait fiber amplifier and the first port of circulator connect, and the second port of circulator is connect with sensing optic cable；
The sensor-based system further includes third coupler, the first variable optical attenuator, the 4th coupler, the 5th coupler, second
Variable optical attenuator, the 6th coupler；
The second output terminal of first coupler is connect with the input terminal of third coupler, the first output end of third coupler and
The input terminal of one variable optical attenuator connects, the second output terminal of third coupler, the second output terminal of the second coupler point
It is not connect with two input terminals of the 4th coupler；The output end of first variable optical attenuator, the third port of circulator are distinguished
It is connect with two input terminals of the 5th coupler, the output end of the 4th coupler and the input terminal of the second variable optical attenuator connect
Connect, the output end of the 5th coupler, the second variable optical attenuator output end respectively with two input terminals of the 6th coupler
Connection；
The sensor-based system further includes sequentially connected second EDFA Erbium-Doped Fiber Amplifier, photodetector, filter and signal acquisition
Processor；The input terminal of second EDFA Erbium-Doped Fiber Amplifier is connect with the output end of the 6th coupler.
2. distributed optical fiber vibration sensing system according to claim 1, which is characterized in that third coupler, the 4th coupling
Clutch, the 5th coupler, the 6th coupler are equal branch/coupler.
3. distributed optical fiber vibration sensing system according to claim 1, which is characterized in that narrow linewidth laser output
Laser is divided into two-way by the first coupler, including the first main road light and first via reference light, main road light enter acousto-optic modulator,
A frequency shift amount is generated, output light is continuous light；The output light of acousto-optic modulator enters the second coupler and is divided into two-way, including the
Two main road light and the second road reference light, the second main road light enter electro-optical demodulator, and the second road reference light enters the 4th coupler.
4. a kind of phase demodulating method based on distributed optical fiber vibration sensing optical fiber described in claim 1, which is characterized in that
The following steps are included:
The laser of narrow linewidth laser output is divided into two-way, including the first main road light and first via reference by the first coupler
Light, main road light enter acousto-optic modulator, generate a frequency shift amount, and output light is continuous light；The output light of acousto-optic modulator enters
Second coupler is divided into two-way, including the second main road light and the second road reference light, and the second main road light enters electro-optical demodulator, and second
Road reference light enters the 4th coupler；
Second main road light enters electrooptic modulator and generates pulsed light, and pulsed light amplifies using the first EDFA Erbium-Doped Fiber Amplifier, leads to
Circulator is crossed to enter in sensor fibre；
The signal E10*exp [- iwt] of the first via reference light of the second output terminal light of first coupler, by third coupler
Light splitting, the first via light splitting of first via reference light enter the first variable optical attenuator and carry out power regulation, and optical signal amplitude changes
Become, phase invariant；
The signal that the second output terminal of second coupler exports the second road reference light is
E20*exp{-i[w+Δw(t)]t}；
The second tunnel light splitting of first via reference light and the second road reference light pass through the 4th coupler, the 4th coupler output optical signal
Are as follows: E14*exp [- iwt]+E21*exp {-i [w+ Δ w (t)] t }；
The optical signal of 4th coupler output enters the second variable optical attenuator and carries out power regulation, and optical signal amplitude changes,
Phase invariant；
Extraneous optical cable vibration information is carried from the reflected signal light of the third port of circulator, optical signal is
First via light splitting and the reflected signal light of third port from circulator of first via reference light after decaying exist
The coupling of 5th coupler, the 5th coupler output optical signal are as follows:
First via reference light, the second road reference light and reflected signal light after decaying carry out at the 6th coupler
Mixing, the optical signal of the 6th coupler output are as follows:
The optical signal of 6th coupler output amplifies by the second EDFA Erbium-Doped Fiber Amplifier, phase invariant；
Amplified optical signal carries out photoelectric conversion through photodetector, exports as electric signal are as follows:Wherein, A is DC quantity, and Δ w (t) frequency is in MHz amount
Grade,Frequency is in KHz magnitude or lower；
Electric signal filters DC quantity and high frequency content after bandpass filter, and signal is
Filtered signal enters data collection processor and is handled, output phase relevant information；
In above formula, E10, E13, E14, E16, E20, E21, E23, E30, E31, E32 are amplitude, and w is light frequency, Δ w
It (t) is the heterodyne frequency shift amount of modulator, heterodyne frequency shift amount changes at random at any time,The variation of phase caused by invade, D
For amplitude,For the phase of signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811353736.1A CN109323750B (en) | 2018-11-14 | 2018-11-14 | Distributed optical fiber vibration sensing system and phase demodulation method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811353736.1A CN109323750B (en) | 2018-11-14 | 2018-11-14 | Distributed optical fiber vibration sensing system and phase demodulation method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109323750A true CN109323750A (en) | 2019-02-12 |
| CN109323750B CN109323750B (en) | 2021-08-06 |
Family
ID=65257641
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811353736.1A Active CN109323750B (en) | 2018-11-14 | 2018-11-14 | Distributed optical fiber vibration sensing system and phase demodulation method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109323750B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111289089A (en) * | 2020-03-20 | 2020-06-16 | 吉林大学 | Distributed optical fiber sensing system based on heterodyne detection technology |
| CN115102626A (en) * | 2022-07-15 | 2022-09-23 | 长沙军民先进技术研究有限公司 | Device and method for realizing space multi-polarization coding |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5857040A (en) * | 1995-12-21 | 1999-01-05 | Alcatel Submarine Networks | Adjustable optical amplitude and phase modulator, and a soliton regenerator including such a modulator |
| CN102506912A (en) * | 2011-09-29 | 2012-06-20 | 北京航空航天大学 | Optical fiber distributed disturbance sensor |
| CN102645268A (en) * | 2012-04-26 | 2012-08-22 | 中国科学院上海光学精密机械研究所 | Optical frequency division multiplexing phase-sensitive optical time domain reflectometer |
| CN104266742A (en) * | 2014-10-22 | 2015-01-07 | 威海北洋光电信息技术股份公司 | High-target distribution type optical fiber vibration sensor |
| CN104819770A (en) * | 2015-05-14 | 2015-08-05 | 中国人民解放军国防科学技术大学 | Phase-light time domain reflection device and method based on heterodyne detection phase demodulation |
| CN106197904A (en) * | 2016-06-16 | 2016-12-07 | 威海北洋光电信息技术股份公司 | Distributed optical fiber pipeline safety monitoring assembly |
| CN107664541A (en) * | 2017-09-18 | 2018-02-06 | 南京大学 | A kind of distributed optical fiber vibration and Temperature fusion sensor-based system and method |
| CN107917738A (en) * | 2017-12-26 | 2018-04-17 | 南京大学（苏州）高新技术研究院 | A kind of while measurement temperature, strain and the distributed optical fiber sensing system of vibration |
-
2018
- 2018-11-14 CN CN201811353736.1A patent/CN109323750B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5857040A (en) * | 1995-12-21 | 1999-01-05 | Alcatel Submarine Networks | Adjustable optical amplitude and phase modulator, and a soliton regenerator including such a modulator |
| CN102506912A (en) * | 2011-09-29 | 2012-06-20 | 北京航空航天大学 | Optical fiber distributed disturbance sensor |
| CN102645268A (en) * | 2012-04-26 | 2012-08-22 | 中国科学院上海光学精密机械研究所 | Optical frequency division multiplexing phase-sensitive optical time domain reflectometer |
| CN104266742A (en) * | 2014-10-22 | 2015-01-07 | 威海北洋光电信息技术股份公司 | High-target distribution type optical fiber vibration sensor |
| CN104819770A (en) * | 2015-05-14 | 2015-08-05 | 中国人民解放军国防科学技术大学 | Phase-light time domain reflection device and method based on heterodyne detection phase demodulation |
| CN106197904A (en) * | 2016-06-16 | 2016-12-07 | 威海北洋光电信息技术股份公司 | Distributed optical fiber pipeline safety monitoring assembly |
| CN107664541A (en) * | 2017-09-18 | 2018-02-06 | 南京大学 | A kind of distributed optical fiber vibration and Temperature fusion sensor-based system and method |
| CN107917738A (en) * | 2017-12-26 | 2018-04-17 | 南京大学（苏州）高新技术研究院 | A kind of while measurement temperature, strain and the distributed optical fiber sensing system of vibration |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111289089A (en) * | 2020-03-20 | 2020-06-16 | 吉林大学 | Distributed optical fiber sensing system based on heterodyne detection technology |
| CN115102626A (en) * | 2022-07-15 | 2022-09-23 | 长沙军民先进技术研究有限公司 | Device and method for realizing space multi-polarization coding |
| CN115102626B (en) * | 2022-07-15 | 2024-01-16 | 长沙军民先进技术研究有限公司 | Device and method for realizing space multi-polarization coding |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109323750B (en) | 2021-08-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111238551B (en) | Distributed phase-sensitive optical time domain reflectometer sensing system and phase extraction method | |
| CN105136175B (en) | A kind of phase sensitive optical time domain reflection system based on self-mixing technology | |
| Ghafoori-Shiraz et al. | Fault location in optical fibers using optical frequency domain reflectometry | |
| CN110132329B (en) | Stress, temperature and vibration composite detection optical fiber sensor and signal processing method | |
| CN110470327A (en) | A kind of optical time-domain analyzer and analysis method | |
| CN105203136B (en) | A kind of distributed sensing system based on differential amplification technology | |
| CN113447110B (en) | Distributed optical fiber vibration sensing system and phase carrier demodulation method thereof | |
| WO1987007014A2 (en) | Greatly enhanced spatial detection of optical backscatter for sensor applications | |
| CN109596205A (en) | A kind of dipulse optical fiber vibration sensing method based on time delay optical fiber | |
| CN113852416B (en) | Phase demodulation method and device with fading noise identification and elimination function | |
| CN113315573B (en) | Optical-assisted broadband microwave instantaneous frequency measurement method | |
| CN109141490A (en) | A kind of fibre-optical sensing device and demodulation method of disturbance waveform and position measurement simultaneously | |
| CN109323750A (en) | Distributed optical fiber vibration sensing system and phase demodulating method | |
| CN205120239U (en) | Vibration detection device based on optical frequency domain reflectometer | |
| CN112880711B (en) | Distributed optical fiber sensing method and system based on double pulse modulation | |
| CN109724529A (en) | Larger Dynamic range Brillouin's Fast measurement system based on more slopes auxiliary | |
| CN113390449A (en) | Optical fiber sensing device | |
| US4957365A (en) | Optical meter with dual functions avalanche photodiode | |
| CN115901043A (en) | Power cable external force monitoring system and method based on distributed optical fiber sensing | |
| JPH01276039A (en) | Optical fiber characteristic evaluating device | |
| JP3496878B2 (en) | Chromatic dispersion and loss wavelength dependence measuring device | |
| CN216717401U (en) | Brillouin optical time domain reflectometer | |
| CN116295782B (en) | Distributed optical fiber vibration sensing system based on phi-OTDR and phase demodulation method | |
| CN212752265U (en) | System for detecting Rayleigh scattering signal intensity by adopting EDFA (erbium doped fiber amplifier) | |
| CN212030564U (en) | Light source frequency shift calibration auxiliary channel structure and optical fiber vibration measuring device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |