CN200955961Y - Coherence multiplexing device for optical fiber Bragg grating sensor - Google Patents
Coherence multiplexing device for optical fiber Bragg grating sensor Download PDFInfo
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- CN200955961Y CN200955961Y CN 200620106570 CN200620106570U CN200955961Y CN 200955961 Y CN200955961 Y CN 200955961Y CN 200620106570 CN200620106570 CN 200620106570 CN 200620106570 U CN200620106570 U CN 200620106570U CN 200955961 Y CN200955961 Y CN 200955961Y
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- 239000013307 optical fiber Substances 0.000 title claims abstract description 19
- 239000000835 fiber Substances 0.000 claims description 13
- 230000001427 coherent effect Effects 0.000 claims description 7
- 230000003287 optical effect Effects 0.000 abstract description 13
- 238000013480 data collection Methods 0.000 abstract 1
- 238000004519 manufacturing process Methods 0.000 abstract 1
- 238000005259 measurement Methods 0.000 abstract 1
- 238000005516 engineering process Methods 0.000 description 5
- 230000008878 coupling Effects 0.000 description 3
- 238000010168 coupling process Methods 0.000 description 3
- 238000005859 coupling reaction Methods 0.000 description 3
- 230000007246 mechanism Effects 0.000 description 3
- 238000012544 monitoring process Methods 0.000 description 3
- 230000007812 deficiency Effects 0.000 description 2
- 239000011551 heat transfer agent Substances 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 238000000985 reflectance spectrum Methods 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- 230000006855 networking Effects 0.000 description 1
- 238000002310 reflectometry Methods 0.000 description 1
- 230000002463 transducing effect Effects 0.000 description 1
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Abstract
The utility model relates to a coherence reused device of an optical fiber Bragg grating sensor. An output terminal of a common light source of the utility model is connected with a circulator(1) port optical signal; a circulator(2) port is connected with a FBG sensor array optical signal; a circulator(3) port and an input terminal of a photodiode are respectively connected with a one side optical signal of a 2 multiplied by 2 optical fiber coupler; an output terminal of the photodiode is electrically connected with a data collection card and the other side of the 2 multiplied by 2 optical fiber coupler is respectively connected with two optical fiber collimator optical signals. Two reflectors are mounted on the place corresponding to the two optical fiber collimators and the position shift of one reflector is controlled by a step motor. The utility model has the advantages of high measurement precision, low manufacturing complexity and system cost saving.
Description
Technical field
The utility model belongs to technical field of optical fiber sensing, particularly a kind of coherent multiplexing device of fiber Bragg grating sensor.
Background technology
Fiber Bragg Grating FBG (FBG) owing to its distinctive inside of optical fibre sensitivity, Wavelength-encoding, be easy to a kind of important devices that advantages such as networking become Fibre Optical Sensor.Based on wavelength-division multiplex that has grown up (WDM) and Time Division Multiplexing technology, optical fiber optical grating array is widely used in the quasi-distributed sensing of optical fiber, as: the real-time health monitoring of building, bridge, dam etc., the monitoring temperature that the trunk power transmission line is along the line.Wherein, WDM requires each FBG working sensor at different reflection wavelengths, need a wideband light source (bandwidth is often greater than 40nm) as the input light source, also need the wavelength sensitive system of a cover relative complex to carry out the demultiplexing of multiplexed signals, as: adjustable Fabry Perot wave filter, Fourier spectrometer, wavelength sensitive coupling mechanism etc.And in TDM, generally adopt the input of burst pulse light source, the reflected light signal of each FBG sensor to utilize different time-delays to realize signal multiplexing, and by the high-speed door treatment circuit demultiplexing of demodulating end.This two covers multiplex technique all needs higher light source of cost and complicated demodulating system, has directly caused the cost of FBG sensing network high, has limited its a lot of practical applications.
The coherent multiplexing technology is the another kind of sensor multiplexing technology that is different from WDM and TDM, its principle is: the different optical path differences that each sensor is introduced, compensated respectively by the scanned michelson interferometer of demodulating end, obtain comprising heat transfer agent coherent interference striped, thereby realize the multiplexing of a plurality of sensors.At the deficiency that WDM and TDM exist on FBG sensor multiplexing problem, the coherent multiplexing technology is hopeful to realize a kind of FBG sensor multiplexing demodulation scheme of Cheap highly effective.
Summary of the invention
The utility model is exactly at the deficiencies in the prior art, has proposed a kind of technical scheme of coherent multiplexing device of fiber Bragg grating sensor.
The utility model is achieved in that ordinary light source (the about 1nm of bandwidth, CW) output terminal and circulator 1. the port light signal be connected, circulator 2. port is connected the sensor array light signal with the FBG of series, parallel, cascade or Y-connection, the circulator 3. input end of port and photodiode is connected with one side light signal of 2 * 2 fiber couplers respectively, and photodiode output is electrically connected with data collecting card.The another side of 2 * 2 fiber couplers is connected with two optical fiber collimator light signals respectively, and corresponding two optical fiber collimator positions are provided with two catoptrons, and one of them catoptron moves by its position of step motor control.
A FBG centering, a FBG is shielded as a reference, another is used for sensing determinand (temperature, stress etc.), determinand causes that sensing FBG reflection wavelength moves, thereby and the reflectance spectrum mismatch has taken place between the reference FBG that remains unchanged of reflection wavelength, cause that this FBG weakens pairing interference strength.By monitoring, can realize sensing to determinand to interference strength.
The utility model mainly is applicable to the demodulation of multiplexed FBG to sensor signal, and the maximum demodulation number of channel surpasses 100.Because FBG reflection peak smaller bandwidth, the measuring method of utilizing this wavelength mismatch to cause that interference strength weakens can reach very high precision and resolution.In utility model, used light source is less expensive narrow bandwidth continuous light, and all used gratings all are identical (antiradar reflectivity, identical reflection wavelengths), have reduced the making complexity to a great extent, have saved system cost.
Description of drawings
Fig. 1 is the FBG that connects in the utility model one-piece construction synoptic diagram to sensor array;
Fig. 2 is that in parallel FBG is to the sensor array structural representation;
Fig. 3 is the FBG sensor array structural representation of cascade;
Fig. 4 is the FBG sensor array structural representation of Y-connection.
Embodiment
As shown in Figure 1, in the mode of being connected in series is example, the FBG of a plurality of different grating centre distances is to connecting by optical fiber 6 between the sensor 5 (being made up of reference FBG 3 and sensing FBG 4), the 2. port of its input end by circulator 2 is connected with light source 1 light signal with 1. port, the input end of the 3. port photodiode 7 of circulator 2 is connected with one side light signal of 2 * 2 fiber couplers 12 respectively, and the output terminal of photodiode 7 is electrically connected with data collecting card 8.The another side of 2 * 2 fiber couplers 12 is connected with two optical fiber collimator 11 light signals respectively, and corresponding two optical fiber collimator 11 positions are provided with two catoptrons 10, and one of them catoptron moves by stepper motor 9 its positions of control.Above-mentioned a plurality of FBG are embedded in the environment to be measured sensor 5, and light source 1 and signal demodulation part are all in monitoring center.
Select for use wavelength coverage to cover the common continuous light source of FBG reflection peak bandwidth (about 1nm), the FBG that light intensity is injected a plurality of series connection by circulator is to sensor, the FBG of each different grating centre distance to sensor to the different optical path difference of light signal introducing:
OPD＝2n
effl
c-c， (1)
Carry each FBG the reflected signal light of heat transfer agent is entered one 2 * 2 fiber coupler through circulator, 2 * 2 fiber couplers are divided into aplanatic two bundles with light signal; The aplanatic flashlight of two bundles incides on the catoptron by optical fiber collimator respectively and reflects coupled back into optical fibers; Control the position of one of them catoptron and move, make between the two paths of signals light and to introduce another and go into optical path difference, and produce scanning, thereby compensate the optical path difference that the FBG of different grating centre distances introduces sensor respectively.Two ways of optical signals after the compensation is converged interference in 2 * 2 coupling mechanisms, interference signal is converted into electric signal through an arm of 2 * 2 coupling mechanisms by photodiode, by the data collecting card collection, finishes demodulation.
Each FBG is made up of two identical FBG sensor, and one of them and measured object shielding are and insensitive to measured object, and as reference FBG, another is to the measured object sensitivity, as sensing FBG.When whole FBG is placed in the measured object to sensor, a dislocation can take place with reference to the reflectance spectrum of FBG and sensing FBG, this dislocation will cause this FBG that pairing interference strength is weakened.By observing the right interference strength of each FBG, can monitor the variation of each point determinand physical quantity.
Can see from (1) formula, the phase differential difference that the FBG of different grating centre distances introduces sensor, scan a certain position so work as the Maxwell interferometer, certain FBG is compensated for as zero to the phase differential of sensor, and then this FBG occurs the optical interference signals of sensor correspondence.The FBG that arranges a series of different grating centre distances by series connection (perhaps as Fig. 2 parallel connection, as Fig. 3 cascade, as Fig. 4 Y-connection) can realize the multiplexing and demodulation of a plurality of FBG to sensor to sensor and the wherein arm that scans the Maxwell interferometer.
Utilization can scan the Maxwell interferometer and a plurality of FBG are compensated the optical path difference of introducing obtain to comprise the interference fringe of transducing signal, thereby has realized the multiplexing and demodulation to sensor to FBG.
Claims (1)
1, the coherent multiplexing device of fiber Bragg grating sensor, it is characterized in that in this device ordinary light source output terminal and circulator 1. the port light signal be connected, circulator 2. port with connect, in parallel, the FBG of cascade or Y-connection connects the sensor array light signal, the circulator 3. input end of port and photodiode is connected with one side light signal of 2 * 2 fiber couplers respectively, photodiode output is electrically connected with data collecting card, the another side of 2 * 2 fiber couplers is connected with two optical fiber collimator light signals respectively, corresponding two optical fiber collimator positions are provided with two catoptrons, and one of them catoptron moves by its position of step motor control.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN 200620106570 CN200955961Y (en) | 2006-08-10 | 2006-08-10 | Coherence multiplexing device for optical fiber Bragg grating sensor |
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| Application Number | Priority Date | Filing Date | Title |
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| CN 200620106570 CN200955961Y (en) | 2006-08-10 | 2006-08-10 | Coherence multiplexing device for optical fiber Bragg grating sensor |
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| CN200955961Y true CN200955961Y (en) | 2007-10-03 |
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| CN 200620106570 Expired - Fee Related CN200955961Y (en) | 2006-08-10 | 2006-08-10 | Coherence multiplexing device for optical fiber Bragg grating sensor |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101975594A (en) * | 2010-10-08 | 2011-02-16 | 武汉理工光科股份有限公司 | Distributed realtime fiber bragg grating wavelength demodulating system and method |
| CN104315347A (en) * | 2010-02-18 | 2015-01-28 | 美国地震系统有限公司 | Fiber optic pipeline monitoring systems and methods of using the same |
| CN107588860A (en) * | 2017-09-16 | 2018-01-16 | 国网电力科学研究院武汉南瑞有限责任公司 | A kind of fibre optical sensor fixing quality control method |
| CN107631739A (en) * | 2017-09-07 | 2018-01-26 | 西安交通大学 | Optical fiber raster vibration/stress compound sensor |
-
2006
- 2006-08-10 CN CN 200620106570 patent/CN200955961Y/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104315347A (en) * | 2010-02-18 | 2015-01-28 | 美国地震系统有限公司 | Fiber optic pipeline monitoring systems and methods of using the same |
| CN101975594A (en) * | 2010-10-08 | 2011-02-16 | 武汉理工光科股份有限公司 | Distributed realtime fiber bragg grating wavelength demodulating system and method |
| CN107631739A (en) * | 2017-09-07 | 2018-01-26 | 西安交通大学 | Optical fiber raster vibration/stress compound sensor |
| CN107588860A (en) * | 2017-09-16 | 2018-01-16 | 国网电力科学研究院武汉南瑞有限责任公司 | A kind of fibre optical sensor fixing quality control method |
| CN107588860B (en) * | 2017-09-16 | 2019-10-15 | 国网电力科学研究院武汉南瑞有限责任公司 | A kind of fibre optical sensor fixing quality control method |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
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Granted publication date: 20071003 Termination date: 20090910 |