SI21816A - Optical fibre elongation sensor - Google Patents

Optical fibre elongation sensor Download PDF

Info

Publication number
SI21816A
SI21816A SI200400159A SI200400159A SI21816A SI 21816 A SI21816 A SI 21816A SI 200400159 A SI200400159 A SI 200400159A SI 200400159 A SI200400159 A SI 200400159A SI 21816 A SI21816 A SI 21816A
Authority
SI
Slovenia
Prior art keywords
optical
optical fiber
air gap
fiber
segment
Prior art date
Application number
SI200400159A
Other languages
Slovenian (sl)
Inventor
Edvard Cibula
Denis Ńonlagic
Original Assignee
Feri Maribor
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 Feri Maribor filed Critical Feri Maribor
Priority to SI200400159A priority Critical patent/SI21816A/en
Priority to PCT/CA2005/000884 priority patent/WO2005121697A1/en
Publication of SI21816A publication Critical patent/SI21816A/en

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B11/00—Measuring arrangements characterised by the use of optical techniques
    • G01B11/16—Measuring arrangements characterised by the use of optical techniques for measuring the deformation in a solid, e.g. optical strain gauge
    • G01B11/18—Measuring arrangements characterised by the use of optical techniques for measuring the deformation in a solid, e.g. optical strain gauge using photoelastic elements

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Length Measuring Devices By Optical Means (AREA)
  • Optical Transform (AREA)

Abstract

The invention solves the problem of simple manufacturing and calibration of the optical fibre elongation sensor with a diameter of 125 micrometers or less, which is the diameter of a single-mode optical fibre (4). The operation of the sensor is based on the Fabry-Perot interferometer principle, where the optical resonator is made in the form of an air gap within the optical fibre. The manufacturing process includes the etching of the optical fibre core with the purpose of generating a recess (7) on top of the fibre, so that an air gap (9) is created after connecting this fibre to another optical fibre (8) at the welding point. The calibration of the length of the air gap is performed by controlled elongation of the optical fibre segment in the interface area, heated to the yield point of the optical fibre. The sensor features a small diameter, high elongation sensibility, small temperature sensibility and possibility of linking into a point distributed sensor network.

Description

OPTIČNI VLAKENSKI SENZOR RAZTEZKAOPTICAL FIBER EXTENSION SENSOR

Predmet izuma je postopek izdelave in kalibracije senzorja raztezka na osnovi optičnega vlakna, namenjenega za merjenje statičnih in dinamičnih raztezkov in deformacij različnih materialov in konstrukcij.The object of the invention is a method of manufacturing and calibrating an optical fiber-based elongation sensor for measuring static and dynamic elongation and deformation of various materials and structures.

Tehnična problema, ki ju rešuje izum, sta kot prvo izdelava senzorja raztezka, katerega zunanji premer ne presega premera standardnega optičnega vlakna t.j. 125 pm in kot drugo kalibracija oziroma nastavitev poljubne delovne točke senzorja. Senzor je izdelan izključno iz optičnega vlakna (kompozitna struktura SiO2+GeO2) in kot tak prenese razmeroma široko temperaturno območje (-270°C do 650°C). Delovanje senzorja temelji na principu Fabry-Perot interferometra z zračno režo, kar omogoča doseganje visoke občutljivosti na raztezek ob minimalni temperaturni občutljivosti. Zaradi uporabe standardnih optičnih vlaken in komercialno dosegljivih orodij izum obenem rešuje problem visoke cene izdelave tovrstnih senzorjev.The technical problems to be solved by the invention are, first, the fabrication of an elongation sensor whose outer diameter does not exceed the diameter of a standard optical fiber, ie 125 pm, and, second, the calibration or adjustment of any sensor operating point. The sensor is made exclusively of optical fiber (SiO 2 + GeO 2 composite structure) and as such transmits a relatively wide temperature range (-270 ° C to 650 ° C). The operation of the sensor is based on the principle of a Fabry-Perot interferometer with an air gap, which allows to achieve high elongation sensitivity at minimum temperature sensitivity. Due to the use of standard optical fibers and commercially available tools, the invention also solves the problem of the high cost of manufacturing such sensors.

Znana je množica različnih izvedb optičnih vlakenskih senzorjev raztezka. Najstarejša znana rešitev je po patentu US4295738 s posebnim dvojedrnim optičnim vlaknom, pri katerem zaznavanje raztezka temelji na prenosu svetlobe med posameznima jedroma. Sledijo rešitve po patentih WO8901614, US5694497 in US6003340, kjer gre za različne izvedbe senzorjev na principu ukrivljanja vlakna pod vplivom raztezka in s tem povečevanja izgub svetlobnega signala. Za vse izvedbe je značilno razmeroma enostavno zaznavanje merjenega raztezka, toda z nizko občutljivostjo. Rešitev z Braggovo strukturo znotraj optičnega vlakna po patentu US5319435 je predstavljena kot senzor z visoko občutljivostjo, ki pa zahteva nekoliko kompleksnejši sistem za procesiranje optičnih signalov. Poleg tega je za tak senzor značilna precejšnja temperaturna občutljivost, zaradi česar je potrebno zagotoviti ustrezno temperaturno kompenzacijo.A variety of different versions of fiber optic stretch sensors are known. The oldest known solution is patent US4295738 with a special dual-core optical fiber, in which elongation detection is based on the transmission of light between individual nuclei. The following are patent solutions WO8901614, US5694497 and US6003340, where different versions of sensors based on the principle of curvature of the fiber under the influence of elongation, thereby increasing the loss of light signal, are involved. All designs are characterized by relatively easy detection of measured elongation, but with low sensitivity. The Bragg structure solution inside the optical fiber according to US5319435 is presented as a high sensitivity sensor, which in turn requires a somewhat more complex system for processing optical signals. In addition, such a sensor is characterized by a considerable temperature sensitivity, which makes it necessary to provide adequate temperature compensation.

Uporaba principa Fabry-Perot interferometra za merjenje raztezka je predstavljena v patentu US5301001. Dva ravno odrezana vrha optičnih vlaken sta postavljena in pritrjena v tanko kapilaro tako, da je med njima kratka zračna reža, ki ima vlogo optičnega resonatorja. Slabost takšne rešitve je odvisnost dolžine aktivnega dela senzorja od točke pritrditve vlaken na kapilaro, ki je posledica naključne globine polzenja lepila v prostor med njima. Poleg tega je zunanji premer senzorja zaradi uporabe kapilare večji od premera optičnega vlakna.The use of the Fabry-Perot interferometer principle for measuring elongation is disclosed in US5301001. Two straight-cut optical fiber tips are positioned and secured in a thin capillary such that there is a short air gap between them, which acts as an optical resonator. The disadvantage of such a solution is the dependence of the length of the active part of the sensor on the point of attachment of the fibers to the capillary, which is due to the random depth of the adhesive creep into the space between them. In addition, the outside diameter of the sensor is greater than the diameter of the optical fiber due to the use of the capillary.

Pri rešitvi po patentu US 6056436 je uporabljeno optično vlakno z votlim jedrom, ki služi kot distančnik med dvema ravno odrezanima koncema optičnih vlaken. Senzor ne presega premera optičnega vlakna, vendar zahteva predhodno izdelavo optičnega vlakna z votlim jedrom, kar podraži celoten postopek izdelave.The solution of US 6056436 uses a hollow-core optical fiber to serve as a spacer between two straight-cut optical fiber ends. The sensor does not exceed the diameter of the optical fiber, but requires the pre-fabrication of the hollow core optical fiber, which makes the whole fabrication process more expensive.

Preostale rešitve realizacije optičnih vlakenskih senzorjev raztezka temeljijo na vplivu raztezka na polarizacijo svetlobe v optičnem vlaknu (patent JP62085805) in merjenjem časa potovanja svetlobnega pulza skozi optično vlakno, izpostavljeno raztezku (patenta US5649035 in US4928004).Other solutions for the realization of optical fiber sensors of elongation are based on the effect of elongation on the polarization of light in the optical fiber (patent JP62085805) and on measuring the travel time of the light pulse through the optical fiber exposed to the elongation (patents US5649035 and US4928004).

Po izumu je problem rešen z varjenjem dveh optičnih vlaken, pri katerem ima vsaj eno vlakno na vrhu vdolbino. Ozka zračna reža, ki pri tem nastane med obema vlaknoma, deluje ob vstopu svetlobe kot optični resonator z dvema delno-odbojnima površinama, katerega spektralne lastnosti so odvisne od njune medsebojne razdalje. Raztezek, ki povzroči spremembo dolžine resonatorja je mogoče ovrednotiti z visoko ločljivostjo na dva načina. Prvi način temelji na primerjavi spektralne porazdelitve moči vstopne in reflektirane svetlobe, drugi pa na uporabi laserskega svetlobnega vira z dovolj ozko spektralno širino in merjenjem deleža od resonatorja reflektirane svetlobe.According to the invention, the problem is solved by welding two optical fibers in which at least one fiber has a recess at the top. The narrow air gap created between the two fibers acts as an optical resonator with two partially reflective surfaces upon the entry of light, whose spectral properties depend on their distance from each other. The elongation that causes the resonator length to change can be evaluated in high resolution in two ways. The first method is based on the comparison of the spectral distribution of the power of the incoming and reflected light, and the second method is on the use of a laser light source with a sufficiently narrow spectral width and measuring the fraction from the resonator of the reflected light.

Kalibracija oz. nastavitev poljubne delovne točke senzorja je rešena s kontroliranim raztegovanjem senzorja, t.j. spoja z zračno režo pri temperaturi, ki omogoča plastično deformacijo uporabljenih optičnih vlaken. Kalibracija dolžine optičnega resonatorja je namreč potrebna v primeru uporabe enostavnega merilnega sistema na osnovi merjenja odbojnosti resonatorja ob uporabi laserskega vira, kakor tudi v primeru izgradnje mreže zaporedno povezanih senzorjev z OTDR (Optical Time Domain Reflectometry) metodo ovrednotenja raztezka posameznega senzorja.Calibration or. the setting of any sensor operating point is solved by controlled stretching of the sensor, i.e. joint with an air gap at a temperature that permits plastic deformation of the optical fibers used. The calibration of the optical resonator length is necessary when using a simple measuring system based on measuring the resonator reflectance using a laser source, as well as when constructing a network of sequentially coupled sensors with OTDR (Optical Time Domain Reflectometry) method of evaluating the elongation of a single sensor.

Izum bo podrobneje opisan na izvedbenem primeru in slikah, ki prikazujejo:The invention will be described in more detail in the embodiment and in the drawings showing:

sl. 1 standardno enorodovno optično vlakno s privarjenim segmentom mnogorodovnega optičnega vlakna sl. 2 izjedkan vrh optičnega vlakna sl. 3 optično vlakno z vdolbino, privarjeno na drugo enorodovno optično vlakno sl. 4 kalibracijo oz. fino nastavitev dolžine senzorja s segrevanjem in raztegovanjemFIG. 1 shows a standard single-layer optical fiber with a welded segment of a multiple-layer optical fiber; 2 shows the etched tip of the optical fiber; 3 shows a recessed optical fiber welded to another single-layer optical fiber; 4 calibration or fine adjustment of sensor length by heating and stretching

Na sliki 1 je prikazano enorodovno optično vlakno 1 (v nadaljevanju EOV), na katero je privarjeno mnogorodovno optično vlakno 2 (v nadaljevanju MOV) in odrezano na želeni razdalji 3 od spoja, ki lahko znaša od 0 do 200 μίτι. Varjenje je izvedeno z uporabo standardnega varilnika za optična vlakna in odrezano z rezalnikom za optična vlakna. Zunanji premer 4 uporabljenih optičnih vlaken znaša 125 μίτι. Premer jedra EOV je ca. 9 μηη 5. MOV ima stopnični ali gradientni lomni lik s premerom jedra okoli 60 μίτι 6.Figure 1 shows a single-mode optical fiber 1 (hereinafter referred to as EOV) to which a multi-fiber optical fiber 2 (hereinafter MOV) is welded and cut off at a desired distance 3 from a joint that can range from 0 to 200 μίτι. Welding is performed using a standard optical fiber welder and cut with an optical fiber cutter. The outer diameter of the 4 optical fibers used is 125 μίτι. The core diameter of the EOV is approx. 9 μηη 5. The MOV has a step or gradient fracture character with a core diameter of about 60 μίτι 6.

Tako pripravljen konec optičnega vlakna je potopljen v HF kislino, ki povzroči razgradnjo oz. jedkanje jedra MOV. Jedkanje poteka vse do spoja obeh optičnih vlaken, kjer znaša reflektivnost na meji vlakno/zrak ca. 2%. Tolikšna reflektivnost je nujna za delovanje senzorja. Pomembno je, da se jedkanje prekine v trenutku, ko je dosežen spoj obeh vlaken, sicer pride do poškodbe površine EOV na spoju in s tem do naglega padca reflektivnosti. V ta namen se med procesom jedkanja meri moč odbite svetlobe in ko ta doseže maksimum, se jedkanje prekine. Neposredno po jedkanju se vrh vlakna očisti, npr. v ultrazvočnem čistilniku, da se odstranijo ostanki HF kisline in druge nečistoče. Na sliki 2 je prikazana izjedkana vdolbina 7 na vrhu vlakna.The optical fiber end thus prepared is immersed in HF acid, which causes degradation or etching of the MOV core. The etching extends to the junction of both optical fibers, where the reflectivity at the fiber / air interface is approx. 2%. Such reflectivity is essential for the operation of the sensor. It is important that the etching is stopped at the moment when the joint of the two fibers is reached, otherwise the surface of the EOV at the joint is damaged and thus a sudden drop in reflectivity occurs. To this end, the power of reflected light is measured during the etching process and when it reaches its maximum, the etching is interrupted. Immediately after etching, the fiber tip is cleaned, e.g. in an ultrasonic cleaner to remove residues of HF acid and other impurities. Figure 2 shows the etched recess 7 at the top of the fiber.

Na sliki 3 je prikazan zvarjeni spoj pojedkanega optičnega vlakna 1 z drugim, prednostno ravno odrezanim EOV 8 skupaj z zračno režo 9 na mestu njunega spoja. V primerih, ko je potrebna daljša zračna reža, je mogoče zvariti dve pojedkani vlakni. Postopek varjenja zahteva ustrezno prilagoditev varilnih parametrov, t.j. temperature in časa segrevanja optičnih vlaken. Zrak, ki po stiku obeh vlaken ostane ujet v reži, je namreč podvržen ekspanziji zaradi porasta temperature, ki praviloma znaša okoli 1800°C. Posledica je deformacija notranjih sten varjenih vlaken kar pomeni zmanjšanje odbojnosti sten tako nastalega optičnega resonatorja ali celo uničenje varjenih vlaken. Izum rešuje problem s segrevanjem vlaken v dveh korakih in sicer s segrevanjem pred stikanjem varjenih vlaken in segrevanjem po njunem stiku. V prvem koraku gre za segrevanje vlakna na varilno temperaturo za kratek čas, nato pa se v drugem koraku neposredno po stiku vrhov obeh vlaken temperatura rahlo zniža, kar prepreči omenjeno deformacijo vlaken.Figure 3 shows the welded joint of the chopped fiber 1 with another, preferably flat-cut EOV 8 together with an air gap 9 at the junction thereof. In cases where a longer air gap is required, two chopped fibers can be welded. The welding process requires appropriate adjustment of the welding parameters, i.e. temperature and heating time of optical fibers. The air, which remains trapped in the gap after contact of both fibers, is subject to expansion due to the temperature rise, which is generally around 1800 ° C. The result is a deformation of the inner walls of the welded fibers, which means a decrease in the reflectance of the walls of the resulting optical resonator or even the destruction of the welded fibers. The invention solves the problem of heating fibers in two steps by heating them before contacting welded fibers and heating them after contact. The first step involves heating the fiber to a welding temperature for a short time, and then in the second step, the temperature drops slightly after contacting the tops of the two fibers, which prevents said deformation of the fibers.

Slika 4 prikazuje princip kalibracije dolžine zračne reže s segrevanjem s pomočjo navitja iz grelne žice 10 ter sočasnim raztegovanjem segrevanega segmenta. Vlakno je pritrjeno v eni fiksni točki 11 in drugi premični 12, ki se nahaja na precizijskem linearnem translatorju 13. Temperatura, ki omogoča plastični (trajni) raztezek optičnega vlakna znaša za standardno SiO2 vlakno okoli 850-1000 °C. Postopek kalibracije zahteva sprotno merjenje dolžine reže, npr. z uporabo široko-spektralnega svetlobnega vira in spektralnega analizatorja.Figure 4 shows the principle of calibrating the length of the air gap by heating it with the help of winding from the heating wire 10 and simultaneously stretching the heated segment. The fiber is fixed at one fixed point 11 and the other movable 12, which is located on the precision linear translator 13. The temperature allowing the plastic (permanent) elongation of the optical fiber is about 850-1000 ° C for a standard SiO 2 fiber. The calibration process requires a continuous measurement of the slot length, e.g. using a wide-spectrum light source and a spectrum analyzer.

Na sliki 5 je prikazan tipičen odziv senzorja raztezka kot odvisnost reflektivnosti optičnega resonatorja od raztezka. Senzor je kalibriran tako, da deluje v okolici kvadraturne točke v območju raztezkov ±5000 pm/m s približno linearno odvisnostjo.Figure 5 shows a typical response of the elongation sensor as a dependence of the reflectivity of the optical resonator on the elongation. The sensor is calibrated to operate around the quadrature point in the range of ± 5000 pm / m with approximately linear dependence.

Claims (7)

PATENTNI ZAHTEVKIPATENT APPLICATIONS 1. Optični vlakenski senzor raztezka, značilen po tem, da ga sestavljata dve enorodovni vlakni, med katerima se nahaja segment optičnega vlakna z vdolbino stopnične ali konkavne oblike, ki ima vlogo optičnega resonatorja.CLAIMS 1. An optical fiber stretch sensor characterized by two homogeneous fibers, between which is a segment of optical fiber with a recessed step or concave shape, which acts as an optical resonator. 2. Postopek za izdelavo optičnega senzorja raztezka po zahtevku 1, značilen po tem, da se izvede varjenje segmenta mnogorodovnega optičnega vlakna (2) na enorodovno optično vlakno (1), kateremu sledi jedkanje v HF kislini.A method for manufacturing an optical stretch sensor according to claim 1, characterized in that the segment of the multipart optical fiber (2) is welded to a single-optical fiber (1) followed by etching in HF acid. 3. Postopek za izdelavo optičnega senzorja raztezka po zahtevku 1, značilen po tem, da se pojedkano vlakno zvari z ravno odrezanim enorodovnim optičnim vlaknom ali drugim pojedkanim vlaknom (8).3. A method for manufacturing an optical stretch sensor according to claim 1, characterized in that the chopped fiber is welded with a straight cut single-ended optical fiber or other chopped fiber (8). 4. Optični vlakenski senzor raztezka, značilen po tem, da ga sestavljajo dovodno enorodovno vlakno (1), na katerega je pritrjen distančnik. Vlakni se nadaljujeta v drugo enorodovno optično vlakno (8), tako, da se med obema enorodovnima vlaknoma tvori optični resonator (9).Optical fiber stretch sensor, characterized in that it consists of a single feed fiber (1) to which a spacer is attached. The fibers continue into another single-stranded optical fiber (8) so as to form an optical resonator (9) between the two single-stranded fibers. 5. Postopek za izdelavo optičnega senzorja raztezka po zahtevku 4, značilen po tem, da se distančnik izdela s procesom jedkanja.A method for manufacturing an optical stretch sensor according to claim 4, characterized in that the spacer is made by an etching process. 6. Kalibracija dolžine zračne reže senzorja raztezka, značilna po tem, da se krajši segment vlakna v okolici zračne reže, ki je ustvarjena med dvema optičnima vlaknoma, ločenima s segmentom optičnega vlakna z vdolbino stopnične ali konkavne oblike (7), segreje do temperature, ki omogoča plastično deformacijo segretega segmenta in s tem fino nastavitev želene dolžine zračne reže.6. Calibration of the air gap length of the elongation sensor, characterized in that the shorter fiber segment surrounding the air gap created between two optical fibers separated by an optical fiber segment with a recessed step or concave shape (7) is heated to temperature, which allows plastic deformation of the heated segment and thus fine-tuning of the desired air gap length. 7. Kalibracija dolžine zračne reže senzorja raztezka, značilna po tem, da se krajši segment vlakna v okolici zračne reže, ki je ustvarjena med dvema optičnima vlaknoma, ločenima z distnčnikom, segreje do temperature, ki omogoča plastično deformacijo segretega segmenta in s tem fino nastavitev želene dolžine zračne reže.7. Calibration of the air gap length of the elongation sensor, characterized in that the shorter fiber segment in the vicinity of the air gap created between the two optical fibers separated by a spacer is heated to a temperature that permits plastic deformation of the heated segment and thereby fine-tuning the desired air gap lengths.
SI200400159A 2004-06-07 2004-06-07 Optical fibre elongation sensor SI21816A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
SI200400159A SI21816A (en) 2004-06-07 2004-06-07 Optical fibre elongation sensor
PCT/CA2005/000884 WO2005121697A1 (en) 2004-06-07 2005-06-07 Optical fiber strain sensor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SI200400159A SI21816A (en) 2004-06-07 2004-06-07 Optical fibre elongation sensor

Publications (1)

Publication Number Publication Date
SI21816A true SI21816A (en) 2005-12-31

Family

ID=35503177

Family Applications (1)

Application Number Title Priority Date Filing Date
SI200400159A SI21816A (en) 2004-06-07 2004-06-07 Optical fibre elongation sensor

Country Status (2)

Country Link
SI (1) SI21816A (en)
WO (1) WO2005121697A1 (en)

Families Citing this family (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA2618685C (en) * 2005-08-12 2015-02-03 Fiso Technologies Inc. Single piece fabry-perot optical sensor and method of manufacturing the same
CN101034007A (en) * 2007-01-24 2007-09-12 冉曾令 Optical fiber Fabry-Perot sensor and manufacture method therefore
US8655117B2 (en) 2011-03-11 2014-02-18 University of Maribor Optical fiber sensors having long active lengths, systems, and methods
US8655123B2 (en) 2011-03-11 2014-02-18 University of Maribor In-line optical fiber devices, optical systems, and methods
CN102494702B (en) * 2011-12-05 2013-09-18 重庆大学 Long period fiber grating sensor and remote-sensing demodulating system
CN102645175A (en) * 2012-03-31 2012-08-22 无锡成电光纤传感科技有限公司 Optical fiber Fabry-Perot strain sensor structure
CN103676142A (en) * 2012-09-13 2014-03-26 福州高意通讯有限公司 Scanning etalon
EP2720020A1 (en) 2012-10-15 2014-04-16 HIDRIA AET Druzba za proizvodnjo vzignih sistemov in elektronike d.o.o. Pressure sensing plug with integrated optical pressure sensor
CN103697921B (en) * 2013-12-30 2016-01-20 哈尔滨工业大学 A kind of optical fiber sensor head and based on the optical fiber sensing system of the monitor strain of this sensing head, stress and pressure and method
CN103940355A (en) * 2014-02-26 2014-07-23 深圳大学 Intensity-modulating-type optical-fiber Michelson strain sensor and manufacturing method thereof
CN104596435B (en) * 2014-12-04 2017-09-19 中国科学院上海微系统与信息技术研究所 A kind of long adjustable optic fibre F P strain gauges of chamber based on MEMS technology and forming method
CN105607188B (en) * 2016-03-09 2019-03-22 南京吉隆光纤通信股份有限公司 A kind of bipolar electrode fiber Fabry-Pérot cavity fusion splicing devices
CN107621274B (en) * 2016-07-13 2020-01-07 上海交通大学 Optical fiber sensor and sound wave detection application method thereof
CN108572047B (en) * 2017-03-10 2024-04-05 中国计量大学 Optical fiber air pressure sensing device based on multiple Fabry-Perot microcavities
CN107817043B (en) * 2017-09-22 2019-09-17 暨南大学 A kind of air micro chamber fibre optic hydrophone and production method and signal detecting method
CN110044288A (en) * 2019-04-03 2019-07-23 西北工业大学 High temperature resistant strain transducer based on FBG
CN110174068A (en) * 2019-05-23 2019-08-27 西安工业大学 A kind of sensitizing type Fabry-perot optical fiber microcavity strain transducer and preparation method thereof
CN110470328B (en) * 2019-07-29 2021-07-09 东北大学 Optical fiber FP sensor with low temperature drift and filling function and preparation method thereof
CN110726374B (en) * 2019-09-17 2021-12-07 天津大学 Optical fiber Fabry-Perot strain sensor based on single-mode optical fiber, manufacturing method and measuring method
CN110823359B (en) * 2019-11-14 2021-08-10 北京遥测技术研究所 Low-temperature optical fiber sound sensing system

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5528367A (en) * 1994-09-09 1996-06-18 The United States Of America As Represented By The Secretary Of The Navy In-line fiber etalon strain sensor
CA2267976A1 (en) * 1996-10-09 1998-04-16 John H. Belk Strain sensor and system
JP4365979B2 (en) * 2000-03-29 2009-11-18 株式会社東京測器研究所 Optical fiber strain sensor and manufacturing method thereof

Also Published As

Publication number Publication date
WO2005121697A1 (en) 2005-12-22

Similar Documents

Publication Publication Date Title
SI21816A (en) Optical fibre elongation sensor
US11002594B2 (en) Method and apparatus for distributed sensing
Mathew et al. In-fiber Fabry–Perot cavity sensor for high-temperature applications
JP3496011B2 (en) Optical fiber structure deformation sensing system
Antunes et al. Optical fiber microcavity strain sensors produced by the catastrophic fuse effect
EP2498049B1 (en) Optical fiber sensors having long active lengths, systems, and methods
US9285273B2 (en) Optical fiber-based environmental detection system and the method thereof
Wolf et al. Advances in femtosecond laser direct writing of fiber Bragg gratings in multicore fibers: technology, sensor and laser applications
CN103196474B (en) A kind of optical fiber F-P sensor method for making and the pick-up unit be made up of it
CN112945284B (en) High-sensitivity high-temperature sensor based on suspension optical fiber dislocation welding
Zhao et al. Cascaded Mach–Zehnder interferometers with Vernier effect for gas pressure sensing
CN105180980A (en) Symmetrical all-fiber Fabry-Perot sensor and manufacturing method thereof
CN104266777A (en) All-fiber temperature sensor based on fiber core mismatch attenuators
CN108168584A (en) Full single mode optical fiber F-P sensors and preparation method thereof
CN113959606A (en) Hybrid transverse pressure sensor based on cascade enhancement vernier effect
CN108731841A (en) CW with frequency modulation laser interference optical fiber temperature sensor
CN110987228A (en) High-sensitivity optical fiber high-temperature sensor made of pure quartz material and preparation method thereof
Bao et al. Sensing characteristics for a fiber Bragg grating inscribed over a fiber core and cladding
CN102073104B (en) Tunable F-P (Fabry-Perot) filter based on hollow photonic band-gap fiber and micro fiber
CN109655176B (en) High-precision temperature probe based on cavity filling type microstructure optical fiber interferometer
Lee et al. Enhanced-backscattering and enhanced-backreflection fibers for distributed optical fiber sensors
CN111623729A (en) Novel optical fiber torsion sensor insensitive to temperature, stress and light source intensity
JP2011180133A (en) Optical fiber sensor and manufacturing method thereof
CN108279079B (en) Point type temperature sensing device based on radial large dislocation structure coating polydimethylsiloxane of coreless optical fiber
Monteiro et al. Fabry-Perot sensor based on two coupled microspheres for strain measurement

Legal Events

Date Code Title Description
OO00 Grant of patent

Effective date: 20050921

KO00 Lapse of patent

Effective date: 20080307