CN100554901C - Work in the method for making of the high-sensitivity optical fibre grating temperature sensor of high and low temperature - Google Patents

Work in the method for making of the high-sensitivity optical fibre grating temperature sensor of high and low temperature Download PDF

Info

Publication number
CN100554901C
CN100554901C CN 200810105788 CN200810105788A CN100554901C CN 100554901 C CN100554901 C CN 100554901C CN 200810105788 CN200810105788 CN 200810105788 CN 200810105788 A CN200810105788 A CN 200810105788A CN 100554901 C CN100554901 C CN 100554901C
Authority
CN
China
Prior art keywords
temperature
sensor
fiber grating
making
grating
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.)
Expired - Fee Related
Application number
CN 200810105788
Other languages
Chinese (zh)
Other versions
CN101298999A (en
Inventor
李阔
周振安
叶晓平
刘爱春
王永根
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Beijing Jing'ao Optronics Sci & Tech Co Ltd
Institute of Crustal Dynamics of China Earthquake Administration
Original Assignee
Beijing Jing'ao Optronics Sci & Tech Co Ltd
Institute of Crustal Dynamics of China Earthquake Administration
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Beijing Jing'ao Optronics Sci & Tech Co Ltd, Institute of Crustal Dynamics of China Earthquake Administration filed Critical Beijing Jing'ao Optronics Sci & Tech Co Ltd
Priority to CN 200810105788 priority Critical patent/CN100554901C/en
Publication of CN101298999A publication Critical patent/CN101298999A/en
Application granted granted Critical
Publication of CN100554901C publication Critical patent/CN100554901C/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01KMEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
    • G01K11/00Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00
    • G01K11/32Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00 using changes in transmittance, scattering or luminescence in optical fibres
    • G01K11/3206Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00 using changes in transmittance, scattering or luminescence in optical fibres at discrete locations in the fibre, e.g. using Bragg scattering
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01DMEASURING 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
    • G01D5/00Mechanical 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
    • G01D5/26Mechanical 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 infra-red, visible, or ultra-violet light
    • G01D5/32Mechanical 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 infra-red, visible, or ultra-violet light with attenuation or whole or partial obturation of beams of light
    • G01D5/34Mechanical 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 infra-red, visible, or ultra-violet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
    • G01D5/353Mechanical 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 infra-red, visible, or ultra-violet 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
    • G01D5/35306Mechanical 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 infra-red, visible, or ultra-violet 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 an interferometer arrangement
    • G01D5/35309Mechanical 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 infra-red, visible, or ultra-violet 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 an interferometer arrangement using multiple waves interferometer
    • G01D5/35316Mechanical 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 infra-red, visible, or ultra-violet 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 an interferometer arrangement using multiple waves interferometer using a Bragg gratings
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS, OR APPARATUS
    • G02B6/00Light guides
    • G02B6/02Optical fibre with cladding with or without a coating
    • G02B6/02057Optical fibre with cladding with or without a coating comprising gratings
    • G02B6/02076Refractive index modulation gratings, e.g. Bragg gratings
    • G02B6/02195Refractive index modulation gratings, e.g. Bragg gratings characterised by means for tuning the grating
    • G02B6/02204Refractive index modulation gratings, e.g. Bragg gratings characterised by means for tuning the grating using thermal effects, e.g. heating or cooling of a temperature sensitive mounting body

Abstract

The present invention is to provide a kind of method for making that works in the high-sensitivity optical fibre grating temperature sensor of high and low temperature.This sensor adopts bimetal structure, by regulating the pre-loose length of fiber grating, the temperature of starting working of regulating sensor.This method has solved the difficult problem that high-sensitivity optical fibre grating temperature sensor can't be worked under high and low temperature.To have wide application prospects in the temperature survey field.

Description

Work in the method for making of the high-sensitivity optical fibre grating temperature sensor of high and low temperature
One, technical field
The present invention relates to Fibre Optical Sensor, especially thermometal optical fiber grating temperature sensitizing sensor method for designing and manufacture craft.
Two, technical background
Fiber grating has the incomparable advantage of many other sensors: full photo measure at the on-the-spot no electrical equipment of monitoring, is not disturbed by electromagnetism and nuclear radiation; There is not drift zero point, long-term stability; Measured with catoptrical centre wavelength sign, be not subjected to the influence of factors such as light source power fluctuation, optical fiber micro-bending effect and coupling loss; Absolute magnitude is measured, and need not calibration in system's installation and the long-term use; Long service life or the like.
Fiber grating is a photosensitivity of utilizing fiber optic materials, be that extraneous incident photon and fibre core interact and cause the permanent change of latter's refractive index, with the space phase grating that the Ultra-Violet Laser method of writing direct forms, its essence is the light filter or the catoptron that in fibre core, form an arrowband in the fibre core of single-mode fiber.Fiber grating belongs to the reflection-type device work, when the continuous wide band light that sends when light source is injected by Transmission Fibers, and it and grating generation coupling, this broadband light of grating pair is the corresponding narrow band light of reflected back selectively, and returns along former Transmission Fibers; The then direct transmissive of all the other broadband light.The centre wavelength value of the narrow band light of reflected back (also being the Bragg wavelength) is:
λ B=2n effΛ
In the following formula, n EffBe the effective reflection coefficient of FBG, Λ is the geometric distance between adjacent two barriers of FBG.When temperature variation, cause that the sensitivity of returning wavelength variable quantity relative temperature variable quantity is:
Δλ B/ΔT=[(1-P e)ε+ζ]λ B (1)
Wherein, P eValid round light constant for FBG; ε is that unit temperature changes the dependent variable of FBG down; ζ is the thermo-optical coeffecient of FBG.
The intrinsic temperature resolution of FBG is very low, about 0.1 ℃/pm.This all can't meet the demands in a lot of applications.Therefore, a lot of researchists just improve its temperature control and have done a lot of work.The principle of FBG temperature sensor enhanced sensitivity is to utilize FBG to temperature and the responsive simultaneously characteristic of strain, by reasonable structural design, FBG is in the same place with the high thermal expansion coefficient material package.When dut temperature changed, the deformation by the high thermal expansion coefficient material applied a dependent variable to FBG, made the wavelength variable quantity of returning of FBG strengthen.At first, the researchist is by directly sticking on FBG the enterprising trip temperature enhanced sensitivity of big expansion coefficient material.The effect of enhanced sensitivity that this method obtains is limited, is subjected to the restriction of material coefficient of thermal expansion coefficient.In March, 1999, people such as Jeahooh Hung have proposed to realize temperature sensitizing by thermometal that effect is obvious on Applied Optics periodical.Bi-metal temperature enhanced sensitivity principle: during temperature variation, the difference of the different metal length variable quantity of two kinds of thermal expansivity is changed into the variable quantity of grating length, make the variable quantity that returns centre wavelength of fiber grating increase, thereby improve the temperature control of fiber grating.
The structure principle chart of bimetallic temperature sensitizing method as shown in Figure 1.The variable quantity apart from d under unit temperature changes between two affixed points of fiber grating is:
Δd=α 1L-α 2(L-d)
L is the length between two point of fixity on the base 3, α 1Be 3 thermal expansivity, α 2It is 2 thermal expansivity.
After fiber grating was stretched, its strain variation was two strain variation between affixed points.Therefore have the strain variation of fiber grating under unit temperature variation this moment to be:
ε=[α 1L-α 2(L-d)]/d (2)
(2) formula substitution (1), the temperature control coefficient that obtains fiber grating is:
Δλ B/ΔT={(1-P e)[α 1L-α 2(L-d)]/d+ζ}λ B (3)
For high-sensitivity optical fibre grating temperature sensor, the fiber grating thermo-optical coeffecient changes the contribution that produces to the contribution of sensor temperature sensitivity much smaller than fiber grating strain.The thermometric range of sensor approximates the maximum strain amount that fiber grating can bear and the merchant of transducer sensitivity.Limited because of the strain that fiber grating can bear, cause the range of high-sensitivity optical fibre grating temperature sensor limited.For example, when the sensitivity of high-sensitivity optical fibre grating temperature sensor is 1000pm/ ℃, because the maximum strain amount that fiber grating can bear is about 4000ustrain, corresponding wavelength variations is about 4800pm, so the range of fiber-optical grating temperature sensor is about 4.8 ℃ (1000pm/ ℃ of 4800pm ÷) at this moment.
High-sensitivity optical fibre grating temperature sensor can be worked under high temperature and low temperature, just seem particularly important.
Three, summary of the invention
For addressing this problem, we propose to change the temperature that it begins to be tightened up, thereby make working sensor in different temperature by regulating the pre-loose length of fiber grating.
Temperature when sensor is made in making and settlement is Tr, and the initial working temperature that requires sensor is Ts.The environment temperature of living sensor is changed to by Tr in the process of Ts, and just to increase to, the length variations amount of base 3 is α 1L (Ts-Tr), rectangular 2 length variations amount is α 2(L-d) (Ts-Tr).Therefore, the length variations amount between two of fiber grating affixed points should be:
Δd=α 1L(Ts-Tr)-α 2(L-d)(Ts-Tr)
=[α 1L-α 2(L-d)](Ts-Tr)
Just in order to make fiber grating begin to be tightened up at temperature T s, when making sensor under temperature T r, the length of fiber grating between its two affixed points should be than the distance Δ d between two affixed points, promptly the pre-loose length of fiber grating is Δ d.
Δ d>0 o'clock, sensor is under temperature T r, and its fiber grating is a relaxed state.And, having at fiber grating under the situation of certain length, its slack can be very big, Δ d can be very big (work as d=40mm, Δ d>4mm).Δ d<0 o'clock, sensor is under temperature T r, and its fiber grating is a tension.Because the strain that fiber grating can bear is limited, works as d=40mm, Δ d<-0.2mm.Do not broken under temperature T s for the fiber grating that makes the high sensitivity temperature sensor, should be got Δ d>0.
In order to make Δ d>0, the temperature control Δ λ of while sensor B/ Δ T is higher, when Ts>Tr (working sensor is in high temperature), should make α when making sensor 1>>α 2When Ts<Tr (working sensor is in low temperature), should make α when making sensor 1<<α 2
In order better to control the pre-loose length of fiber grating, we have designed a sensor, structural representation such as Figure of description Fig. 2 and shown in Figure 3.By adjusting rectangular 2 position, can change the distance between two affixed points of fiber grating.Adjust earlier rectangular 2 position, be used wavelength demodulation device, make fiber grating just begin to be tightened up, write down between two affixed points this moment apart from d.Then, adjust rectangular 2 position again to shorten d, the amount of shortening is pre-loose length Δ d.By changing Δ d, just can make sensor can be operated in different temperature ranges.
Four, description of drawings
Accompanying drawing 1 is a bi-metal temperature enhanced sensitivity schematic diagram; Accompanying drawing 2 is structural representation of the present invention (front elevations); Accompanying drawing 3 is structural representation of the present invention (vertical views).
Wherein, 1 is fiber grating, and 4 is point of fixity, and 5 is cylindrical void, and 6 is gib screw, and 7 is nut; When making was operated in the high sensitivity temperature sensor of high temperature, 2 was little expansion coefficient material, and 3 is big expansion coefficient material; When making was operated in the sensor of low temperature, 2 was big expansion coefficient material, and 3 is little expansion coefficient material.
Five, specific embodiments
Below in conjunction with for example the present invention being done more detailed description:
Example 1: under 20 ℃ environment, make initial working temperature and be 120 ℃ sensor.This sensing plays it will be by forming with the lower part: a fiber grating, big thermal expansivity aluminium (α=22*10 -6/ K) base, little thermal expansivity invar (α=0.5*10 -6/ K) rectangular, wherein invar has made a strip hole, a gib screw and a nut on rectangular.According to Fig. 2 and mode shown in Figure 3, earlier aluminium backing with invar is rectangular is fixed together by screw and nut.And then the two ends of fiber grating are pasted aluminium backing and the rectangular end points of invar respectively with epoxide-resin glue.Then, just can be rectangular by mobile invar, determine d, and, selected different Δ d according to different Ts.
Might as well establish L=500mm, d=15mm.At this moment, the pre-loose length of fiber grating should be:
Δd=[α 2L-α 1(L-d)](Ts-Tr)≈1.05mm
The temperature control of sensor is:
Δλ B/ΔT={(1-0.22)[22*500-0.5*(500-15)]/15+6.7}*1.55=877pm/℃
Δλ B/ΔT={(1-0.22)[22*500-0.5*(500-15)]/15+6.7}*1.55=877pm/℃
Example 2: under 20 ℃ environment, make initial working temperature and be-80 ℃ sensor.This sensing rises mainly by forming with the lower part: a fiber grating, and little thermal expansivity invar base, big thermal expansivity aluminium is rectangular, and wherein aluminium has been made a strip hole, a gib screw and a nut on rectangular.According to Fig. 2 and mode shown in Figure 3, earlier the invar base with aluminium is rectangular is fixed together by screw and nut.And then the two ends of fiber grating are pasted invar base and the rectangular end points of aluminium respectively with epoxide-resin glue.Then, just can be rectangular by mobile aluminium, determine d, and, selected different Δ d according to different Ts.
Might as well establish L=500mm, d=15mm.At this moment, the pre-loose length of fiber grating should be:
Δd=[α 2L-α 1(L-d)](Ts-Tr)≈1.04mm,
The temperature control of sensor is:
Δλ B/ΔT={(1-0.22)[22*500-0.5*(500-15)]/15+6.7}*1.55=-829pm/℃

Claims (1)

1, a kind of method for making that works in the high-sensitivity optical fibre grating temperature sensor of high and low temperature, it is characterized in that: for making high-sensitivity optical fibre grating temperature sensor in the thermometal mode, described sensor is mainly by forming with the lower part: fiber grating, to have thermal expansivity be α 1Metab, to have thermal expansivity be α 2Metal rectangular, described metab and described metal is rectangular is fixed together, the two ends of fiber grating paste described metab and the rectangular end points of described metal respectively, distance between two affixed points is d, and L is the length between two point of fixity on the described metab, and the temperature when making sensor is Tr, requiring the initial working temperature of sensor is Ts, when Ts>Tr, promptly working sensor should make α when making sensor when high temperature 1>>α 2When Ts<Tr, promptly working sensor should make α when making sensor when low temperature 1<<α 2Just in order to make fiber grating begin to be tightened up at described temperature T s, when under described temperature T r, making sensor, the length of fiber grating between its two affixed points should than between two affixed points apart from the long Δ d of d, be the pre-loose length Δ d of fiber grating, in order to change the temperature that it is started working, the pre-loose length Δ d=[α of described fiber grating 1L-α 2(L-d)] (Ts-Tr).
CN 200810105788 2008-05-05 2008-05-05 Work in the method for making of the high-sensitivity optical fibre grating temperature sensor of high and low temperature Expired - Fee Related CN100554901C (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN 200810105788 CN100554901C (en) 2008-05-05 2008-05-05 Work in the method for making of the high-sensitivity optical fibre grating temperature sensor of high and low temperature

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN 200810105788 CN100554901C (en) 2008-05-05 2008-05-05 Work in the method for making of the high-sensitivity optical fibre grating temperature sensor of high and low temperature
PCT/IB2009/051802 WO2009136339A1 (en) 2008-05-05 2009-05-04 A method to make high sensitive fiber bragg grating temperature sensors

Publications (2)

Publication Number Publication Date
CN101298999A CN101298999A (en) 2008-11-05
CN100554901C true CN100554901C (en) 2009-10-28

Family

ID=40078893

Family Applications (1)

Application Number Title Priority Date Filing Date
CN 200810105788 Expired - Fee Related CN100554901C (en) 2008-05-05 2008-05-05 Work in the method for making of the high-sensitivity optical fibre grating temperature sensor of high and low temperature

Country Status (2)

Country Link
CN (1) CN100554901C (en)
WO (1) WO2009136339A1 (en)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN100554901C (en) * 2008-05-05 2009-10-28 中国地震局地壳应力研究所 Work in the method for making of the high-sensitivity optical fibre grating temperature sensor of high and low temperature
CN101893492A (en) * 2010-04-06 2010-11-24 中国地震局地壳应力研究所 Mutually-clamped optical fiber grating temperature sensor
CN101943614A (en) * 2010-08-27 2011-01-12 广东电网公司佛山供电局 Device and method for improving sensitivity of optical fiber grating temperature sensor
CN103134609A (en) * 2011-11-23 2013-06-05 成都酷玩网络科技有限公司 High-sensitivity fiber bragg grating temperature sensor with adjustable sensitivity coefficient
CN102798484B (en) * 2012-08-14 2014-06-25 广东电网公司佛山供电局 Low-hysteresis fiber bragg grating temperature sensor
CN103776568A (en) * 2012-10-18 2014-05-07 无锡华润上华半导体有限公司 Pressure sensor
CN105241572B (en) * 2015-10-13 2017-10-13 西安石油大学 Monometallic dual sensitivity wide scope fiber-optical grating temperature sensor and its method for packing

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6243527B1 (en) * 1998-01-16 2001-06-05 Corning Incorporated Athermalization techniques for fiber gratings and temperature sensitive components
US6147341A (en) * 1998-02-13 2000-11-14 Lucent Technologies Inc. Temperature compensating device for fiber gratings
JP4193357B2 (en) * 2000-12-08 2008-12-10 住友電気工業株式会社 Optical device having optical fiber diffraction grating
US6907164B2 (en) * 2001-02-22 2005-06-14 Teraxion, Inc. Adjustable athermal package for optical fiber devices
JP4403674B2 (en) * 2001-06-28 2010-01-27 日立電線株式会社 Optical fiber sensor
CN1145049C (en) * 2001-07-25 2004-04-07 华为技术有限公司 Fiber grating with passive temperature compensation and its making process
JP2003247899A (en) * 2002-02-27 2003-09-05 Toyoko Elmes Co Ltd Optical fiber tensile detector
CN2572422Y (en) * 2002-10-11 2003-09-10 东南大学 Optical fibre raster single end temp compensation package device
CN100554901C (en) * 2008-05-05 2009-10-28 中国地震局地壳应力研究所 Work in the method for making of the high-sensitivity optical fibre grating temperature sensor of high and low temperature

Non-Patent Citations (6)

* Cited by examiner, † Cited by third party
Title
光纤光栅温度补偿桥式结构. 黄山等.半导体光电,第24卷第6期. 2003
光纤光栅温度补偿桥式结构. 黄山等.半导体光电,第24卷第6期. 2003 *
光纤光栅温敏特性研究. 罗映祥等.重庆三峡学院学报,第22卷第3期. 2006
光纤光栅温敏特性研究. 罗映祥等.重庆三峡学院学报,第22卷第3期. 2006 *
双金属结构对布拉格光栅的温度补偿研究. 胡纪平等.电子测试,第3期. 2008
双金属结构对布拉格光栅的温度补偿研究. 胡纪平等.电子测试,第3期. 2008 *

Also Published As

Publication number Publication date
WO2009136339A1 (en) 2009-11-12
CN101298999A (en) 2008-11-05

Similar Documents

Publication Publication Date Title
CN100554901C (en) Work in the method for making of the high-sensitivity optical fibre grating temperature sensor of high and low temperature
Guo et al. Temperature-insensitive fiber Bragg grating liquid-level sensor based on bending cantilever beam
Shi et al. Environmentally stable Fabry–Pérot-type strain sensor based on hollow-core photonic bandgap fiber
Díaz et al. A cost-effective edge-filter based FBG interrogator using catastrophic fuse effect micro-cavity interferometers
Zhao et al. A cheap and practical FBG temperature sensor utilizing a long-period grating in a photonic crystal fiber
Pang et al. Temperature-insensitivity bending sensor based on cladding-mode resonance of special optical fiber
Li et al. Integration of miniature Fabry–Perot fiber optic sensor with FBG for the measurement of temperature and strain
CN103852191B (en) The fibre optic temperature sensor that a kind of refractive index is insensitive
Zhao et al. High sensitive modal interferometer for temperature and refractive index measurement
Rajan et al. All-fibre temperature sensor based on macro-bend singlemode fibre loop
CN101298980A (en) Design method and manufacturing technique of high-sensitivity temperature self-compensation optical fiber grating strain sensor
Miao et al. Dynamic temperature compensating interrogation technique for strain sensors with tilted fiber Bragg gratings
CN102829893A (en) Method for simultaneously measuring temperature and stress of fiber bragg gratings (obtained by corrosion) with different diameters
Chen et al. Multiplexed oil level meter using a thin core fiber cladding mode exciter
Zheng et al. Temperature-insensitive optical tilt sensor based on a single eccentric-core fiber Bragg grating
CN201203488Y (en) Sensitivity adjustable optical fiber grating temperature sensor
CN201488837U (en) Fiber grating sensor measuring temperature and strain simultaneously
CN201464078U (en) Single sleeve pipe etch-type fiber Bragg grating temperature and enhanced sensibility sensor
Gao et al. In-fiber double-layered resonator for high-sensitive strain sensing
Xia et al. Half-size metal-packaged fiber Bragg grating for simultaneous measurement of strain and temperature
Meng et al. A novel liquid level monitoring sensor system using a fiber Bragg grating
CN201476902U (en) Sandwich type fiber bragg gratting temperature sensor with high sensitivity
CN201476903U (en) Serial-connection FBG (fiber Bragg grating) high sensitiveness temperature sensor
CN201476904U (en) Parallel fiber Bragg grating high-sensitivity temperature sensor
CN201852650U (en) Narrow slit type bimetal fiber grating temperature sensor

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant
C17 Cessation of patent right
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20091028

Termination date: 20140505