CN105588674A - Intensity modulated type optical fiber stress sensor - Google Patents
Intensity modulated type optical fiber stress sensor Download PDFInfo
- Publication number
- CN105588674A CN105588674A CN201610160864.9A CN201610160864A CN105588674A CN 105588674 A CN105588674 A CN 105588674A CN 201610160864 A CN201610160864 A CN 201610160864A CN 105588674 A CN105588674 A CN 105588674A
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- optical fiber
- stress sensor
- stress
- lpfg
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- 239000013307 optical fiber Substances 0.000 title claims abstract description 44
- 238000001228 spectrum Methods 0.000 claims abstract description 6
- 239000000835 fiber Substances 0.000 claims description 36
- 230000003287 optical effect Effects 0.000 claims description 9
- 230000003321 amplification Effects 0.000 abstract description 7
- 238000003199 nucleic acid amplification method Methods 0.000 abstract description 7
- 230000005489 elastic deformation Effects 0.000 abstract description 2
- 238000005253 cladding Methods 0.000 description 6
- 230000035945 sensitivity Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 3
- 238000012544 monitoring process Methods 0.000 description 2
- 230000001902 propagating effect Effects 0.000 description 2
- 238000003466 welding Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 238000005305 interferometry Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000000644 propagated effect Effects 0.000 description 1
- 230000001953 sensory effect Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000000411 transmission spectrum Methods 0.000 description 1
Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L1/00—Measuring force or stress, in general
- G01L1/24—Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis using infrared, visible light, ultraviolet
- G01L1/242—Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis using infrared, visible light, ultraviolet the material being an optical fibre
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optical Transform (AREA)
Abstract
The invention provides an intensity modulated type optical fiber stress sensor which is characterized in that the intensity modulated type optical fiber stress sensor is composed of a broadband light source (1), a waist cone amplification optical fiber (2), a long-period optical fiber grating (3), and a spectrum analyzer (4), wherein the waist cone amplification optical fiber (2) and the long-period optical fiber grating (3) form a optical fiber sensing head with the length of 10-50mm; the left end of the waist cone amplification optical fiber (2) is connected to the broadband light source (1), and the right end of the waist cone amplification optical fiber (2) is connected to the long-period optical fiber grating (3); and the right end of the long-period optical fiber grating (3) is connected to the spectrum analyzer (4). According to the invention, a Mach-zehnder interferometer formed by the waist cone amplification optical fiber (2) and the long-period optical fiber grating (3) is employed as a sensing part. When the stress is applied to the sensing optical fiber, the elastic deformation of the waist cone amplification optical fiber (2) will cause the variation of the interference intensity, and finally the variation of the stress applied to the sensing optical fiber is converted to the variation of the output light intensity.
Description
Technical field
The present invention proposes a kind of intensity modulation type optical fiber stress sensor, this strain gauge has been introduced optical fiber expansion with a tight waistLarge and LPFG (Long-periodfibergrating, LPG) technology, belongs to technical field of optical fiber sensing.
Background technology
Optical fiber stress sensor is widely used in monitoring the health condition of the facilities such as building, bridge and dam. OrderBefore the optical fiber stress sensor of the marketization be mainly based on bragg grating (FiberBragggrating, FBG)Strain gauge, but this class sensing system needs the drift value of spectroanalysis instrument or modem demonstration wavelength, thisWill increase the cost of whole sensor-based system. The Fibre Optical Sensor of intensity modulation type can rely on power meter by tested stress completelyVariable quantity is converted into the signal of telecommunication that can show in real time, simple and convenient and with low cost. It is dry based on M-Z that the present invention proposesThe intensity modulation type optical fiber stress sensor relating to, completely can by detect output intensity variation with realize counter stress changeMonitoring.
LPFG is mainly to have benefited from its lower insertion loss, tight being widely used of sensory field of optic fibreThe structure of gathering and to good characteristics such as surrounding environment are responsive. In Fibre Optical Sensor, introduce after LPFG, formantSpectrum width is narrower, makes the certainty of measurement of transmission spectrum significantly improve, and result also will be more accurate.
Mach Zehnder interference type Fibre Optical Sensor is by adopting interferometry to produce phase-modulation to obtain higherSensitivity and resolution ratio, this principle is also widely used in monitoring in various Fibre Optical Sensors all kinds of to be measured, its developmentProspect is quite wide.
Summary of the invention
The object of the present invention is to provide a kind of intensity modulation type optical fiber stress sensor, adopt the optical fiber amplifying with a tight waist andThe Mach Zehnder interference instrument (Mach-zehnderinterferometer, MZI) that LPFG forms is as passingSense position, this device can be converted into the corresponding transmission of detectable signal by the axial stress variable quantity acting on Fibre Optical SensorThe change amount of luminous intensity. There is compact conformation, simple, the advantage such as easy and simple to handle, sensitivity is high.
The present invention is achieved through the following technical solutions:
The invention provides a kind of intensity modulation type optical fiber stress sensor, it is characterized in that: by wideband light source (1), waistVertebra amplifying fiber (2), LPFG (3) and spectroanalysis instrument (4) composition, wherein lumbar vertebrae amplifying fiber (2) and long weekPhase fiber grating (3) has formed optical fiber sensor head, and this optical fiber sensor head length is 10～50mm; Lumbar vertebrae amplifying fiber (2) left endBe connected with wideband light source (1), lumbar vertebrae amplifying fiber (2) right-hand member is connected with LPFG (3), LPFG(3) right-hand member is connected with spectroanalysis instrument (4).
Described a kind of intensity modulation type optical fiber stress sensor, is characterized in that: optical fiber (2) length with a tight waist of amplification is120～150 μ m, diameter is 150～180 μ m.
Described a kind of intensity modulation type optical fiber stress sensor, is characterized in that: the length of LPFG (3)Be 20～25mm, the cycle is 600 μ m.
Operation principle of the present invention is:
Incident light is when through lumbar vertebrae amplifying fiber (2), and the light that part is propagated in fiber core can be coupled to optical fiberIn covering, inspire the cladding mode of propagating in covering, remaining light will continue to propagate forward along fibre core as core mode; LPGThe cladding mode of propagating in covering can be coupled in fibre core again, thereby form MZI with core mode. Two of MZI interfere armPhysical length is identical, but because the effective refractive index of covering and fibre core is different, thereby form optical path difference. Core mode and cladding modeSatisfied phase-matching condition expression formula is:
WhereinWithRepresent respectively the effective refractive index of fibre core effective refractive index and i cladding mode, λ is for enteringPenetrate optical wavelength, d is the distance between lumbar vertebrae amplifying fiber (2) and LPFG (3),Expression fibre core is effectively rolled overPenetrate the difference of the effective refractive index of rate and i cladding mode.
The expression formula that MZI interference fringe contrast changes can be expressed as:
K represents fringe contrast, IcoreRepresent core mode energy, IcladRepresent cladding mode energy. When effect of stress is in sensingOn device time, will there is elastic deformation in lumbar vertebrae amplifying fiber (2), and its diameter will diminish, and lumbar vertebrae amplifying fiber (2) is by incident optocouplerClose into the ability of covering and will reduce, thus IcladTo reduce IcoreTo increase, K will diminish, thereby interference strength will reduce, thisTo be applied to STRESS VARIATION on sensor fibre and be converted into the variation of output intensity with regard to having realized.
The invention has the beneficial effects as follows: in the time that stress is applied on sensor fibre, due to the elasticity of lumbar vertebrae amplifying fiber (2)Deformation, causes the variation of interference strength, has finally realized the STRESS VARIATION being applied on sensor fibre is converted into output intensityVariation. This sensor, in the time of test stress, can replace spectroanalysis instrument (4) with power meter, and this just greatly reduces sensingThe cost of system, and more simply light, and sensitivity is also higher.
Brief description of the drawings
Fig. 1 is a kind of intensity modulation type optical fiber stress sensor feature device schematic diagram of the present invention;
Fig. 2 is that the interference spectrum of different stress of the present invention while being applied on sensor fibre changes lab diagram;
Fig. 3 is stress sensitivity curve map of the present invention.
Detailed description of the invention
Below in conjunction with accompanying drawing and embodiment, the invention will be further described:
Referring to accompanying drawing 1, a kind of intensity modulation type optical fiber stress sensor, is characterized in that: by wideband light source (1), lumbar vertebraeAmplifying fiber (2), LPFG (3) and spectroanalysis instrument (4) composition, wherein lumbar vertebrae amplifying fiber (2) and long periodFiber grating (3) has formed optical fiber sensor head, and this optical fiber sensor head length is 10～50mm; Lumbar vertebrae amplifying fiber (2) left end withWideband light source (1) connects, and lumbar vertebrae amplifying fiber (2) right-hand member is connected with LPFG (3), LPFG (3)Right-hand member is connected with spectroanalysis instrument (4).
Lumbar vertebrae amplifying fiber (2) adopts model to be: the optical fiber splicer of FujikuraFSM-60s is made, two weldingsFiber stack length is set to 130 μ m, and other programming is all the standard configuration of optical fiber splicer. LPFG(3) adopt high-frequency CO2Laser fabrication, the cycle is 600 μ m, length is set to 24mm. Cutting optical fibre end face, welding lumbar vertebraeWhen amplifying fiber (2) and LPFG (3), adopt the standard welding procedure of single mode-single mode, the distance between two structuresFrom keeping 15mm.
Fig. 2 is that under room temperature condition, the interference spectrum in different stress situations changes lab diagram, and stress is at the model of 0～590 ε μWhile enclosing interior variation, the interference strength of corresponding interference spectrum changes, and interference strength reduces gradually. Fig. 3 is of the present invention answeringForce sensitivity curve map, the sensitivity of this sensor is 0.026dB/ μ ε.
Claims (3)
1. an intensity modulation type optical fiber stress sensor, is characterized in that: by wideband light source (1), waist cone amplifying fiber (2),LPFG (3) and spectroanalysis instrument (4) composition, its middle part of the side cone amplifying fiber (2) and LPFG (3) groupBecome optical fiber sensor head, this optical fiber sensor head length is 10～50mm; Waist cone amplifying fiber (2) left end and wideband light source (1) connectConnect, waist cone amplifying fiber (2) right-hand member is connected with LPFG (3), LPFG (3) right-hand member and spectrum analysisInstrument (4) connects.
2. a kind of intensity modulation type optical fiber stress sensor according to claim 1, is characterized in that: waist cone amplifying fiber(2) length is 120～150 μ m, and diameter is 150～180 μ m.
3. a kind of intensity modulation type optical fiber stress sensor according to claim 1, is characterized in that: long period optical fiberThe length of grid (3) is 20～25mm, and the cycle is 600 μ m.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610160864.9A CN105588674A (en) | 2016-03-18 | 2016-03-18 | Intensity modulated type optical fiber stress sensor |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610160864.9A CN105588674A (en) | 2016-03-18 | 2016-03-18 | Intensity modulated type optical fiber stress sensor |
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| CN105588674A true CN105588674A (en) | 2016-05-18 |
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| CN201610160864.9A Pending CN105588674A (en) | 2016-03-18 | 2016-03-18 | Intensity modulated type optical fiber stress sensor |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107655600A (en) * | 2017-11-17 | 2018-02-02 | 广东海洋大学 | A kind of tension measuring device based on fibre optic interferometer |
| CN111487000A (en) * | 2020-04-21 | 2020-08-04 | 东北大学 | Vector stress meter based on micro-nano multi-core special optical fiber |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102109395A (en) * | 2010-04-27 | 2011-06-29 | 南京航空航天大学 | Monitoring method for LPFG (Long Period Fiber Grating) transverse load direction characteristic and pavement pressure sensor |
-
2016
- 2016-03-18 CN CN201610160864.9A patent/CN105588674A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102109395A (en) * | 2010-04-27 | 2011-06-29 | 南京航空航天大学 | Monitoring method for LPFG (Long Period Fiber Grating) transverse load direction characteristic and pavement pressure sensor |
Non-Patent Citations (7)
| Title |
|---|
| 付兴虎 等: "单模与多模光纤级联型压力传感器", 《光子学报》 * |
| 宋海峰 等: "基于保偏光纤模式干涉的应变传感器研究", 《光电子.激光》 * |
| 宋海峰: "基于波长与强度双解调的光纤温度传感器", 《光电子.激光》 * |
| 康泽新 等: "基于包层腐蚀的单模光纤型声光滤波器及其轴向应力特性的研究", 《光学学报》 * |
| 张琪 等: "基于Ｂｉｔａｐｅｒ－ＬＰＦＧ－Ｂｉｔａｐｅｒ结构的全光纤", 《光子学报》 * |
| 徐贲 等: "自映像多模干涉仪的应力传感研究", 《光电子.激光》 * |
| 杨先辉 等: "可调谐F-P 腔进行锥形光栅", 《光学 精密工程》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107655600A (en) * | 2017-11-17 | 2018-02-02 | 广东海洋大学 | A kind of tension measuring device based on fibre optic interferometer |
| CN107655600B (en) * | 2017-11-17 | 2024-01-30 | 广东海洋大学 | Tension measuring device based on optical fiber interferometer |
| CN111487000A (en) * | 2020-04-21 | 2020-08-04 | 东北大学 | Vector stress meter based on micro-nano multi-core special optical fiber |
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