CN201993558U - FBG (Fiber Bragg Grating) wavelength demodulation device - Google Patents
FBG (Fiber Bragg Grating) wavelength demodulation device Download PDFInfo
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- CN201993558U CN201993558U CN2011201001003U CN201120100100U CN201993558U CN 201993558 U CN201993558 U CN 201993558U CN 2011201001003 U CN2011201001003 U CN 2011201001003U CN 201120100100 U CN201120100100 U CN 201120100100U CN 201993558 U CN201993558 U CN 201993558U
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Abstract
The utility model relates to an FBG (Fiber Bragg Grating) wavelength demodulation device and belongs to the technical field of FBG wavelength demodulation. The device comprises an ASE (Amplified Spontaneous Emission) light source, a 3db coupler, an FBG, a linear beveled edge filter, a wavelength demultiplexer, light intensity detection arrays and an A/D (Analog to Digital) converter and is characterized in that the ASE light source is positioned in front of the 3db coupler; the FBG is placed at the rear of the 3db coupler; the 3db coupler is respectively connected with the linear beveled edge filter and the FBG through optical fibers; the front end of the wavelength demultiplexer is connected with the linear beveled edge filter; the rear end of the wavelength demultiplexer is connected with different light intensity detection arrays; and the light intensity detection arrays are respectively and electrically connected to a computer system through leads so as to realize wavelength demodulation by a computer. The device has low cost. A method for monitoring by the FBG wavelength demodulation device is simple and practical. The FBG wavelength demodulation device can be widely applied to various fields in production and life, such as temperature and stress monitoring.
Description
(1) technical field
The utility model relates to a kind of optic fiber grating wavelength demodulating equipment, belongs to optic fiber grating wavelength demodulation techniques field.
(2) technical background
When wide range light incides in the fiber grating, the light of the pairing centre wavelength of fiber grating can be reflected back, and the pairing centre wavelength of fiber grating can be along with external environments such as the suffered temperature of fiber grating, stress and is changed, and this character of utilizing fiber grating has been widely used in numerous areas in the productive life to fiber grating as sensor-based systems such as the temperature of sensor, strains.In optical fiber sensing system, the value of the wavelength of fiber grating reflected back need be passed through the certain method demodulation, and at present common demodulation method has matched filtering method, tunable Fabry-Perot chamber method etc., and that realizes the marketization has products such as spectrometer, wavemeter.According to the present market price, be applicable to that spectrometer, wavemeter, the price of optical fiber sensing system do not wait to hundreds of thousands unit at several ten thousand yuan.The high price of optical fiber sensing system, the range of application and the place of optical fiber sensing system have been limited to a certain extent, having influenced the marketing of optical fiber sensing system and further develop, is that CN200710038145.0, denomination of invention promptly belong to these row for the patent of " high temperature fiber grating sensing system " as the number of applying for a patent.And simple hypotenuse filters demodulate method, though the cost performance height, the grating capacity of demodulation is little, promptly belongs to these row as the patent that application number is 200920172889.6, the utility model name is called " based on the sensing wavelength demodulation device of triangular Bragg grating ".
(3) summary of the invention
In order to overcome the shortcoming that prior art exists, the utility model proposes a kind of optic fiber grating wavelength demodulating equipment.
The technical solution of the utility model is as follows:
A kind of optic fiber grating wavelength demodulating equipment, comprise ASE light source, isolator, three-dB coupler, FBG series, linear hypotenuse wave filter, wavelength demultiplexer, photodetector array, A/D converter, computing machine and light transmitting fiber, it is characterized in that the ASE light source is positioned at before the isolator, place the 3db coupling mechanism after the isolator; The front end of 3db coupling mechanism links to each other by the input end of optical fiber with linear hypotenuse wave filter, its rear end links to each other with the wavelength demultiplexer by optical fiber by the output terminal of optical fiber with the serial linear hypotenuse wave filter that links to each other of a FBG, the wavelength demultiplexer is connected with each photodetector in the photodetector array respectively through optical fiber, makes the light of the different wave length that the wavelength demultiplexer is told pass to and carries out opto-electronic conversion on the photodetector corresponding with it; The output terminal of each photodetector is connected on the input end of an A/D converter, and the analog electrical signal that photodetector is exported converts digital electric signal to; The output terminal of each A/D converter is connected on the computing machine, and each way word electric signal of exporting is carried out demodulation process by computing machine.
The FBG number is 6-10 in the described FBG series; Photodetector number in the photodetector array is 6-10, respectively with FBG series in the FBG correspondence.
Described ASE light source is the amplified spontaneous emission light source, is that a kind of wavelength coverage is at the wide range light of 1525nm to 1565nm.
Described FBG is the abbreviation of Fiber Bragg Grating, i.e. Fiber Bragg Grating FBG.
The wavelength coverage broad of ASE light source, spectral shape, power are comparatively stable, and price is lower, can be as the light source of optical fiber sensing system.The light intensity of the output light of linear hypotenuse wave filter can change and change along with the input light wavelength, therefore can utilize this feature to measure the wavelength change amount.
Specifically, the light that ASE sends incides among a series of FBG through coupling mechanism, and the light that each FBG reflects is divided into two-way through behind the coupling mechanism.Wherein one the tunnel incide and decayed by isolator in the isolator, another road is incided in the linear hypotenuse wave filter by linear hypotenuse wave filter modulation.A series of FBG reflected light wavelength differences, light intensity difference after linear hypotenuse wave filter modulation are assigned on the different light intensity sensors through the wavelength demultiplexer.Light intensity sensor is converted to electric signal with light signal, and is connected to computing machine by A/D converter.For one of them light intensity sensor, the size of electric signal becomes corresponding relation with the wavelength of corresponding FBG, therefore can realize the demodulation of wavelength by the size of computing machine demodulation electric signal.
When coming the demodulation wavelength, before device is installed, under predetermined temperature, select the FBG of specific wavelength, and write down the wavelength value of these a series of specific FBG by the utility model demodulating equipment demodulation temperature information.Each FBG and corresponding with it photodetector are mapped one by one the electric signal size of the wavelength value of record each FBG at this moment and the corresponding photodetector of this FBG.According to the inclined linear of the used linear hypotenuse wave filter of device, when through the emergent light wavelength of linear hypotenuse wave filter not simultaneously, corresponding outgoing light intensity also can be along with variation.The light of different wave length can be from different output terminal output through the wavelength demultiplexer, and the photodetector that links to each other with each output terminal can detect the light intensity of output light, and is converted into the power of electric signal.With a certain road output light wherein is example, if the record electrical signal intensity is I during the initial alignment wavelength
Demarcate, according to the effect of hypotenuse wave filter, then
(I
In real timeThe time be the electric signal size of measuring in real time, I
DemarcateThe electric signal size of measuring when being decided to be Wavelength calibration, λ
In real timeThe reflection wavelength of this FBG during for measurement in real time, λ
DemarcateBe the reflection wavelength of this FBG of timing signal, K is the slope coefficient of linear hypotenuse wave filter).Therefore after system building is finished,, can measure I by photodetector for a certain specific FBG
In real timeSize, the I during known initial alignment
Demarcate, λ
Demarcate, K size, therefore can draw
So just can realize the demodulation of FBG reflection wavelength according to the size of electric signal and the size of demarcating wavelength, demarcating electric signal
Use the utility model, utilize linear hypotenuse wave filter to carry out the effect of optic fiber grating wavelength demodulation method energy instead of optical spectrometer, wavemeter, thereby reduced the cost of optical fiber sensing system.This method can remedy the little problem of edge filter method power system capacity, realizes jumbo grating demodulation in the scope that the light source spectrum width allows.This demodulation method is applicable to temperature, the strain monitoring of fiber grating, and development along with ASE light source, linear hypotenuse wave filter, Wavelength branching device, photodetector, demodulation accuracy can be more and more higher, thereby replace traditional wavelength demodulation device, will promote the development of fiber grating sensing technology with the demodulation capacity of super large, accurate demodulation accuracy and cheap cost.Because the spectral shape power of ASE light source has certain stability, so this kind method can be used for detected temperatures, strain etc. widely.
The beneficial effects of the utility model can be learnt according to the concrete narration to above-mentioned technology, the optical fiber sensing system price that comprises demodulation modules such as spectrometer, wavemeter does not wait to hundreds of thousands unit at several ten thousand yuan, and the higher market of optical fiber sensing system that makes of price is subjected to certain restriction.And adopted the novel optical fiber sensor-based system that utilizes linear hypotenuse wave filter and wavelength demultiplexer that the price of sensor-based system is significantly descended.This system can be widely used in the numerous areas of productive life, and for example temperature detection, strain detecting etc. play an important role for ensureing industrial safety production, daily life safety.And along with further developing of optics optical device manufacture craft, the capacity of this system can further improve, and is with a wide range of applications.
(4) description of drawings
Fig. 1 is the structural representation of the utility model device.
Wherein: 1, ASE light source, 2, isolator, 3, three-dB coupler, 4, FBG, 5, linear hypotenuse wave filter, 6, wavelength demultiplexer, 7, photodetector, 8, computing machine, 9, light transmitting fiber, 10, A/D converter.
(5) embodiment
Below in conjunction with drawings and Examples the utility model is further specified, but be not limited thereto.
Embodiment 1:
The utility model embodiment 1 as shown in Figure 1, comprise ASE light source 1, isolator 2, three-dB coupler 3, FBG series 4, linear hypotenuse wave filter 5, wavelength demultiplexer 6, photodetector array 7, A/D converter 10, computing machine 8 and light transmitting fiber 9, it is characterized in that ASE light source 1 is positioned at before the isolator 2, place 3db coupling mechanism 3 after the isolator 2; The front end of 3db coupling mechanism 3 links to each other by the input end of optical fiber with linear hypotenuse wave filter 5, and its rear end links to each other with FBG series 4 by optical fiber; The output terminal of linear hypotenuse wave filter 5 links to each other with wavelength demultiplexer 6 by optical fiber, wavelength demultiplexer 6 is connected with each photodetector 7 in the photodetector array respectively through optical fiber, makes the light of the different wave length that wavelength demultiplexer 6 is told pass to and carries out opto-electronic conversion on the photodetector corresponding with it 7; The output terminal of each photodetector 7 is connected on the input end of an A/D converter 10, and the analog electrical signal that photodetector 7 is exported converts digital electric signal to; The output terminal of each A/D converter 10 is connected on the computing machine 8, and each way word electric signal of exporting is carried out demodulation process by computing machine 8.
The FBG number is 10 in the described FBG series 4; Photodetector 7 numbers in the photodetector array are 10, respectively with FBG series 4 in the FBG correspondence.
Embodiment 2:
Identical with embodiment 1, the number that is FBG in the described FBG series 4 is 8, is respectively 1528nm, 1531nm, 1534nm, 1537nm, 1540nm, 1543nm, 1546nm, 1549nm; Photodetector 7 numbers in the photodetector array are 8, respectively with FBG series 4 in the FBG correspondence.
Embodiment 3:
Identical with embodiment 1, the number that is FBG in the described FBG series 4 is 6, is respectively 1528nm, 1534nm, 1540nm, 1543nm, 1546nm, 1549nm; Photodetector 7 numbers in the photodetector array are 6, respectively with FBG series 4 in the FBG correspondence.
Claims (2)
1. optic fiber grating wavelength demodulating equipment, comprise ASE light source, isolator, three-dB coupler, FBG series, linear hypotenuse wave filter, wavelength demultiplexer, photodetector array, A/D converter, computing machine and light transmitting fiber, it is characterized in that the ASE light source is positioned at before the isolator, place the 3db coupling mechanism after the isolator; The front end of 3db coupling mechanism links to each other by the input end of optical fiber with linear hypotenuse wave filter, and its rear end links to each other with FBG series by optical fiber; The output terminal of linear hypotenuse wave filter links to each other with the wavelength demultiplexer by optical fiber, the wavelength demultiplexer is connected with each photodetector in the photodetector array respectively through optical fiber, makes the light of the different wave length that the wavelength demultiplexer is told pass to and carries out opto-electronic conversion on the photodetector corresponding with it; The output terminal of each photodetector is connected on the input end of an A/D converter, and the analog electrical signal that photodetector is exported converts digital electric signal to; The output terminal of each A/D converter is connected on the computing machine, and each way word electric signal of exporting is carried out demodulation process by computing machine.
2. a kind of optic fiber grating wavelength demodulating equipment as claimed in claim 1 is characterized in that the FBG number is 6-10 in the described FBG series; Photodetector number in the photodetector array is 6-10, respectively with FBG series in the FBG correspondence.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011201001003U CN201993558U (en) | 2011-04-08 | 2011-04-08 | FBG (Fiber Bragg Grating) wavelength demodulation device |
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| Application Number | Priority Date | Filing Date | Title |
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| CN2011201001003U CN201993558U (en) | 2011-04-08 | 2011-04-08 | FBG (Fiber Bragg Grating) wavelength demodulation device |
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| CN201993558U true CN201993558U (en) | 2011-09-28 |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102169272A (en) * | 2011-04-08 | 2011-08-31 | 山东大学 | Method for demodulating wavelength of fiber grating by utilizing linear tilt filter |
| CN103776475A (en) * | 2014-01-28 | 2014-05-07 | 浙江大学 | Optical fiber sensor and sensing method based on linear filter and photoelectric detector |
| CN104764471A (en) * | 2014-01-02 | 2015-07-08 | 国网江西省电力公司信息通信分公司 | Wavelength demodulation method and system |
| CN106289166A (en) * | 2016-07-18 | 2017-01-04 | 武汉理工大学 | A kind of optical fiber obliquity sensor and wavelength-division multiplex method thereof |
| CN109506687A (en) * | 2018-12-26 | 2019-03-22 | 中国工程物理研究院流体物理研究所 | A kind of measuring system and measurement method for dynamic test |
-
2011
- 2011-04-08 CN CN2011201001003U patent/CN201993558U/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102169272A (en) * | 2011-04-08 | 2011-08-31 | 山东大学 | Method for demodulating wavelength of fiber grating by utilizing linear tilt filter |
| CN104764471A (en) * | 2014-01-02 | 2015-07-08 | 国网江西省电力公司信息通信分公司 | Wavelength demodulation method and system |
| CN104764471B (en) * | 2014-01-02 | 2017-05-31 | 国网江西省电力公司信息通信分公司 | A kind of Wavelength demodulation method and system |
| CN103776475A (en) * | 2014-01-28 | 2014-05-07 | 浙江大学 | Optical fiber sensor and sensing method based on linear filter and photoelectric detector |
| CN106289166A (en) * | 2016-07-18 | 2017-01-04 | 武汉理工大学 | A kind of optical fiber obliquity sensor and wavelength-division multiplex method thereof |
| CN109506687A (en) * | 2018-12-26 | 2019-03-22 | 中国工程物理研究院流体物理研究所 | A kind of measuring system and measurement method for dynamic test |
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| C14 | Grant of patent or utility model | ||
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| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20110928 Termination date: 20140408 |