CN104215605A - Method for fast dynamic-calibration of fiber bragg grating (FBG) demodulation system - Google Patents
Method for fast dynamic-calibration of fiber bragg grating (FBG) demodulation system Download PDFInfo
- Publication number
- CN104215605A CN104215605A CN201410049033.5A CN201410049033A CN104215605A CN 104215605 A CN104215605 A CN 104215605A CN 201410049033 A CN201410049033 A CN 201410049033A CN 104215605 A CN104215605 A CN 104215605A
- Authority
- CN
- China
- Prior art keywords
- tunable
- fbg
- filter
- grating
- optical filter
- 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.)
- Pending
Links
Landscapes
- Investigating Or Analysing Materials By Optical Means (AREA)
Abstract
The invention discloses a method of tunable F-P optical filter-based dynamic-calibration of a fiber bragg grating (FBG) demodulation system and belongs to the technical field of FBG demodulation. The method utilizes devices of an adjustable laser source, a circulator, a FBG, a photoelectric detector, a comb filter, an acetylene gas unit and a digital signal processing unit. The method utilizes the combined comb filter and an absorption spectrum of acetylene gas to realize dynamic-calibration of a tunable F-P optical filter, eliminates the influence produced by PZT nonlinearity and instability on measurement and avoids the demodulation precision limit produced by the reference grating number of the traditional demodulation system. The method satisfies low-cost, high-rate and high-precision measurement requirements on the FBG demodulation system.
Description
Technical field
The present invention relates to fiber grating demodulation temperature and strain calibrating method, especially a kind of FBG demodulating system dynamic scaling method based on tunable F-P optical filter, belongs to technical field of optical fiber sensing.
Background technology
Distributed optical fiber sensing system can realize the long-term monitoring of the parameter such as strain, temperature to the large-scale pipeline such as oil pipeline, rail, roadbed, is with a wide range of applications in the monitoring structural health conditions of infrastructure.But, distributed optical fiber sensing system generally adopts the method for Brillouin scattering or Rayleigh scattering light in detection fiber, complete once effectively measure for up to tens seconds ~ a few minutes, therefore distributed optical fiber sensing system is not suitable for the higher monitoring occasion of requirement of real-time; In addition, for distributed optical fiber sensing system, need construct time by optical fibre pre-buried in object under test, limit systematic difference scope.By the multiplex mode such as time-division, wavelength-division, fiber grating (FBG) can form quasi-distributed sensor-based system, can realize monitoring of fixing a point on a large scale; Tested parameter only depends on the reflection wavelength of FBG, obtains corresponding tested parameter, do not need multiple averaging by wavelength interrogation technique, effectively can improve the accuracy and runtime of detection; By the technology of various encapsulation, realize FBG and the effective physical contact of various object under test, expand the range of application of FBG.
A complete FBG sensor-based system is made up of FBG sensor, transmission light path and demodulated equipment.FBG demodulated equipment adopts Wavelength demodulation method, and demodulation method not only affects measuring accuracy, the measuring speed of sensor-based system, and determines the topological structure of the multiplex mode of FBG in sensor-based system, multiplexing quantity and sensing network.
Utilize the scheme of carrying out demodulation with reference to grating pair sensing grating, higher wavelength resolution and higher speed can be obtained, but this scheme is unfavorable for that FBG's is multiplexing; Use the demodulation scheme of array waveguide grating (AWG), the demodulation to multiple FBG sensor can be realized simultaneously, can the signal frequency of demodulation more than 100kHz, but, in the program, a grating needs an AWG passage and a light receiving unit, improves system complexity; Use interferometric spectrometry to realize fast demodulation to FBG, can the frequency of restituted signal up to 48.6MHz, but, the limited amount of multiplexing FBG in the program; Use wideband light source and tunable Fabry Perot (F-P) wave filter to carry out demodulation to FBG, the quantity of multiplexing grating increases to some extent, and demodulation speed reaches 1,000 time/second, wavelength resolution reaches 2pm, but, multiplexing FBG quantity and wavelength detecting precision deficiency.
For the application scenario of general FBG sensor-based system, require that sensor-based system has larger coverage, namely require the multiplexing quantity of more FBG; System has response speed faster, and the demodulation speed of 1,000 time/second can meet the needs of great majority monitoring in real time; The wavelength resolution precision of system is less than 1pm, and corresponding that temperature detecting precision is less than 0.1 DEG C, microstrain accuracy of detection is less than 1 μ ε.
The present invention uses the light source of ring laser as FBG sensor-based system of based semiconductor image intensifer (SOA), tunable TEA CO2 laser is used to carry out length scanning, the absorption spectra of conbined usage comb filter and acetylene gas carries out Kinematic Positioning to wavelength, effectively improve available spectral width, multiplexing way, multiplexing FBG quantity, and sweep frequency and spectrally resolved precision.
Summary of the invention:
The object of the invention is to eliminate the non-linear of PZT with instability to measuring the impact brought, to solve in traditional demodulation system with reference to raster count the restriction of demodulation accuracy.The method makes optical fiber grating regulating system reach quick, high-precision measurement requirement.
For solving the problems of the technologies described above, technical solution of the present invention is:
Based on the FBG demodulating system of tunable F-P optical filter, it is characterized in that the tunable TEA CO2 laser that LASER Light Source adopts piezoelectric ceramics (PZT) to regulate and SOA are to realize the output of tunable wavelength; LASER Light Source output terminal is through multicoupler, 30 output terminals of multicoupler are optical fiber grating sensing passage, all be connected to the first port of circulator, second port of circulator connects several different wave length fiber-optic grating sensors of series connection, and the 3rd port of circulator connects photo-detector; Wherein another 2 the 31st, 32 output terminals of multicoupler connect two calibrated channels respectively; A passage demarcates device by Fiber connection to acetylene gas, then is connected to photo-detector; Another passage to optical comb filter, then is connected to photo-detector by Fiber connection; Photo-detectors the most all is sent into signal processing unit and is processed.
Preferably, the peak-to-peak 0.8nm being spaced apart standard of described comb filter two, is divided into 100 districts by the free spectrum zone of F-P wave filter, the voltage in each district can think linear relationship to the change of wavelength.
Preferably, in order to correct the error that told comb filter is brought, the air chamber injecting acetylene gas is introduced into described scheme.
Preferably, described acetylene gas has 6 larger absorption spectra peaks: 1528.12nm, 1530.37nm, 1531.59nm, 1532.84nm, 1534.12nm and 1535.40nm, and they are used to correct described comb filter.
Preferably, in the ring cavity of described system ring laser, introduce a spectrum width be about 75nm broadband filter, make the output wavelength of actual ring laser be limited to the scope of 1525 ~ 1600nm.
Accompanying drawing explanation
Fig. 1 is the FBG demodulating system dynamic scaling method realization figure based on tunable F-P optical filter.
Embodiment
The invention provides a kind of FBG demodulating system dynamic scaling method based on tunable F-P optical filter, its method realizes system and device and is characterised in that LASER Light Source adopts piezoelectric ceramics (PZT) tunable TEA CO2 laser 1 that regulates to realize the output of tunable wavelength; LASER Light Source output terminal is connected to multicoupler 2,30 output terminals of multicoupler are optical fiber grating sensing passage, be connected to the first port 31 of 30 circulators 3 respectively, second port 32 of circulator connects several different wave length fiber-optic grating sensors 4 of series connection, and the 3rd port 33 of circulator connects photo-detector 5; Wherein another 2 output terminals of multicoupler connect two calibrated channels respectively; A passage 231 demarcates device 7 by Fiber connection to acetylene gas, then is connected to photo-detector; Another passage 232 to optical comb filter 6, then is connected to photo-detector by Fiber connection; Photo-detectors the most all is sent into signal processing unit and is processed.
Long by the chamber changing the voltage change F-P wave filter be applied on PZT, when voltage changes to 18v from 0v, the free spectrum zone of the inswept F-P wave filter of output wavelength of ring laser, the voltage determined correspond to ring laser output wavelength determined.Ring laser scans the FBG in each shunt in wavelength domain, the reflectance spectrum of the FBG collected is the distribution relation of luminous power and voltage, can be demarcated the reflectance spectrum wavelength of FBG with the relation curve being applied to voltage on PZT by the centre wavelength of F-P wave filter, obtain the reflectance spectrum of real FBG.
Comb filter also can be subject to the impact of temperature, therefore calibrates device and also can bring measuring error.Because the absorption line of gas does not vary with temperature, in order to correct the error that comb filter is brought, the air chamber injecting acetylene gas is introduced into described scheme.
Near 1530nm, acetylene gas has 6 larger absorption spectra peaks: 1528.12nm, 1530.37nm, 1531.59nm, 1532.84nm, 1534.12nm and 1535.40nm, and they are used to correct comb filter.In addition, due near 1518nm, acetylene gas also has 6 larger absorption spectra peaks, in the ring cavity of system ring laser, therefore introduces a spectrum width be about 75nm broadband filter, make the output wavelength of actual ring laser be limited to the scope of 1525 ~ 1600nm.
Need to carry out dynamic calibration to tunable TEA CO2 laser in each scanning process in real system, form a closed loop control process simultaneously, by by the wavelength demarcated, the initial value of dynamic adjustment PZT scanning voltage, makes F-P wave filter be operated in a controlled steady state (SS).
Can be demarcated absorption peak by comb filter after carrying out single pass, the measuring error of difference namely for being caused by temperature of the result obtained and the absorption line of standard, correct with the reflectance spectrum of this error to FBG, just can obtain real reflectance spectrum.
Above-described embodiment is only illustrative rather than definitive thereof technical scheme of the present invention.Any technical scheme not departing from spirit and scope of the invention all should be encompassed in the middle of patent claim of the present invention.
Claims (1)
1. based on a FBG demodulating system for tunable F-P optical filter, this system and device comprises tunable laser sources, multicoupler, circulator, fiber grating, photodetector, comb filter, acetylene gas sensing primitive and digital signal processing unit.It is characterized in that LASER Light Source adopts piezoelectric ceramics (PZT) tunable TEA CO2 laser that regulates to realize the output of tunable wavelength; LASER Light Source output terminal is through multicoupler, 30 output terminals of multicoupler are optical fiber grating sensing passage, all be connected to the first port of circulator, second port of circulator connects several different wave length fiber-optic grating sensors of series connection, and the 3rd port of circulator connects photo-detector; Wherein 31,32 output terminals of multicoupler connect two calibrated channels respectively; A passage demarcates device by Fiber connection to acetylene gas, then is connected to photo-detector; Another passage to optical comb filter, then is connected to photo-detector by Fiber connection; Photo-detectors the most all is sent into signal processing unit and is processed.
As described in claim 1 based on the FBG demodulating system device of tunable F-P optical filter, it is characterized in that in optical fiber grating sensing passage, the reflectivity of grating is 0.9, and Transmission Fibers length is 10km.
As described in claim 1 based on the FBG demodulating system device of tunable F-P optical filter, it is characterized in that described photo-detector PIN, detection sensitivity is less than 1 μ w.
As described in claim 1 based on the FBG demodulating system device of tunable F-P optical filter, it is characterized in that the number of whole 30 sensing passage temperature sensing gratings is about 1000, or the number of strain sensing grating is about 240; Photodetector number is corresponding with grating channel number, is 30.
As described in claim 1 based on the FBG demodulating system device of tunable F-P optical filter, it is characterized in that the peak-to-peak 0.8nm being spaced apart standard of described comb filter two, the free spectrum zone of F-P wave filter is divided into 100 districts, the voltage in each district can think linear relationship to the change of wavelength.
As described in claim 1 based on the FBG demodulating system device of tunable F-P optical filter, it is characterized in that described acetylene gas unit is near 1530nm, there is the absorption spectra peak that 6 larger: 1528.12nm, 1530.37nm, 1531.59nm, 1532.84nm, 1534.12nm and 1535.40nm, they are used to correct described comb filter.
As described in claim 1 based on the FBG demodulating system device of tunable F-P optical filter, it is characterized in that: need to carry out dynamic calibration to tunable TEA CO2 laser in each scanning process in real system, form a closed loop control process simultaneously, by by the wavelength demarcated, the initial value of dynamic adjustment PZT scanning voltage, makes F-P wave filter be operated in a controlled steady state (SS).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410049033.5A CN104215605A (en) | 2014-02-12 | 2014-02-12 | Method for fast dynamic-calibration of fiber bragg grating (FBG) demodulation system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410049033.5A CN104215605A (en) | 2014-02-12 | 2014-02-12 | Method for fast dynamic-calibration of fiber bragg grating (FBG) demodulation system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN104215605A true CN104215605A (en) | 2014-12-17 |
Family
ID=52097325
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410049033.5A Pending CN104215605A (en) | 2014-02-12 | 2014-02-12 | Method for fast dynamic-calibration of fiber bragg grating (FBG) demodulation system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104215605A (en) |
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104931081A (en) * | 2015-06-10 | 2015-09-23 | 天津大学 | Composite wavelength reference-based fiber bragg grating sensing demodulation device and method |
| CN105021310A (en) * | 2015-07-28 | 2015-11-04 | 上海交通大学 | High precision fiber grating temperature sensing system |
| CN105066898A (en) * | 2015-08-16 | 2015-11-18 | 北京航空航天大学 | Method for calibrating surface-mounted fiber grating strain sensor |
| CN106595862A (en) * | 2016-12-28 | 2017-04-26 | 华中科技大学 | Device employing raster to carry out spectral analysis on adjustable FP temperature and non-linear compensation |
| CN107328737A (en) * | 2017-06-20 | 2017-11-07 | 山西大学 | A kind of device and method for measuring gas absorption spectra |
| CN107655504A (en) * | 2017-08-29 | 2018-02-02 | 北京航空航天大学 | The method for filtering out impulse disturbances in optical fibre interrogation system based on adaptive threshold |
| CN108226094A (en) * | 2018-01-23 | 2018-06-29 | 山东省科学院激光研究所 | gas concentration monitoring system, method and device |
| CN108279209A (en) * | 2018-04-11 | 2018-07-13 | 中国石油大学(华东) | A kind of more gas detecting systems of wave-length coverage and wavelength continuously adjustable |
| CN108303124A (en) * | 2018-02-05 | 2018-07-20 | 江南大学 | A kind of optical fiber grating regulating system and method based on static tunable optical source |
| CN109990813A (en) * | 2019-03-19 | 2019-07-09 | 北京航天时代光电科技有限公司 | A kind of optical fiber grating wavelength demodulating equipment based on wideband adjustable light source |
| CN113607209A (en) * | 2021-06-25 | 2021-11-05 | 重庆大学 | Temperature strain double-parameter measurement system based on FBG pair |
| CN114964323A (en) * | 2022-07-12 | 2022-08-30 | 中国航空工业集团公司北京长城计量测试技术研究所 | Multi-wavelength optical signal generating device and method |
| CN117387673A (en) * | 2023-12-08 | 2024-01-12 | 山东星冉信息科技有限公司 | Fiber bragg grating demodulation method and device based on reference air chamber |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101059433A (en) * | 2007-06-05 | 2007-10-24 | 天津大学 | Quasi-distribution type hybrid gas sensing system based on internal chamber optical fiber laser |
| JP2012177612A (en) * | 2011-02-25 | 2012-09-13 | Mitsubishi Heavy Ind Ltd | Signal processing apparatus and laser measurement instrument |
| CN103487402A (en) * | 2013-10-14 | 2014-01-01 | 北京信息科技大学 | Ring cavity inner-cavity optical fiber laser gas detection system with saturated absorption optical fibers |
| CN103487403A (en) * | 2013-10-14 | 2014-01-01 | 北京信息科技大学 | Fiber bragg grating combined optical fiber laser gas detection system with reference cavity compensation |
-
2014
- 2014-02-12 CN CN201410049033.5A patent/CN104215605A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101059433A (en) * | 2007-06-05 | 2007-10-24 | 天津大学 | Quasi-distribution type hybrid gas sensing system based on internal chamber optical fiber laser |
| JP2012177612A (en) * | 2011-02-25 | 2012-09-13 | Mitsubishi Heavy Ind Ltd | Signal processing apparatus and laser measurement instrument |
| CN103487402A (en) * | 2013-10-14 | 2014-01-01 | 北京信息科技大学 | Ring cavity inner-cavity optical fiber laser gas detection system with saturated absorption optical fibers |
| CN103487403A (en) * | 2013-10-14 | 2014-01-01 | 北京信息科技大学 | Fiber bragg grating combined optical fiber laser gas detection system with reference cavity compensation |
Non-Patent Citations (2)
| Title |
|---|
| WANG YONGJUN: "High multiplexing capability and ultrahigh resolution interrogation for optical fiber bragg grating sensing system", 《INTERNATIONAL SOCIETY FOR OPTICS AND PHOTONICS》 * |
| 乔学光: "可调谐法布里-珀罗滤波器的高精度大范围实时定标", 《光学学报》 * |
Cited By (21)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104931081A (en) * | 2015-06-10 | 2015-09-23 | 天津大学 | Composite wavelength reference-based fiber bragg grating sensing demodulation device and method |
| CN105021310A (en) * | 2015-07-28 | 2015-11-04 | 上海交通大学 | High precision fiber grating temperature sensing system |
| CN105021310B (en) * | 2015-07-28 | 2017-07-18 | 上海交通大学 | High precision optical fiber grating temperature-sensing system |
| CN105066898A (en) * | 2015-08-16 | 2015-11-18 | 北京航空航天大学 | Method for calibrating surface-mounted fiber grating strain sensor |
| CN105066898B (en) * | 2015-08-16 | 2017-08-22 | 北京航空航天大学 | A kind of scaling method of surface-mount type fiber Bragg grating strain sensor |
| CN106595862B (en) * | 2016-12-28 | 2018-02-27 | 华中科技大学 | A kind of spectral analysis device using grating to adjustable FP temperature and nonlinear compensation |
| CN106595862A (en) * | 2016-12-28 | 2017-04-26 | 华中科技大学 | Device employing raster to carry out spectral analysis on adjustable FP temperature and non-linear compensation |
| CN107328737A (en) * | 2017-06-20 | 2017-11-07 | 山西大学 | A kind of device and method for measuring gas absorption spectra |
| CN107655504A (en) * | 2017-08-29 | 2018-02-02 | 北京航空航天大学 | The method for filtering out impulse disturbances in optical fibre interrogation system based on adaptive threshold |
| CN107655504B (en) * | 2017-08-29 | 2020-10-27 | 北京航空航天大学 | Method for filtering pulse interference in optical fiber demodulation system based on self-adaptive threshold |
| CN108226094A (en) * | 2018-01-23 | 2018-06-29 | 山东省科学院激光研究所 | gas concentration monitoring system, method and device |
| CN108226094B (en) * | 2018-01-23 | 2023-08-15 | 山东省科学院激光研究所 | Gas concentration monitoring system, method and device |
| CN108303124A (en) * | 2018-02-05 | 2018-07-20 | 江南大学 | A kind of optical fiber grating regulating system and method based on static tunable optical source |
| CN108303124B (en) * | 2018-02-05 | 2023-09-29 | 江南大学 | Fiber bragg grating demodulation system and method based on static tunable light source |
| CN108279209A (en) * | 2018-04-11 | 2018-07-13 | 中国石油大学(华东) | A kind of more gas detecting systems of wave-length coverage and wavelength continuously adjustable |
| CN109990813B (en) * | 2019-03-19 | 2021-09-07 | 北京航天时代光电科技有限公司 | Fiber grating wavelength demodulating equipment based on broadband tunable light source |
| CN109990813A (en) * | 2019-03-19 | 2019-07-09 | 北京航天时代光电科技有限公司 | A kind of optical fiber grating wavelength demodulating equipment based on wideband adjustable light source |
| CN113607209A (en) * | 2021-06-25 | 2021-11-05 | 重庆大学 | Temperature strain double-parameter measurement system based on FBG pair |
| CN114964323A (en) * | 2022-07-12 | 2022-08-30 | 中国航空工业集团公司北京长城计量测试技术研究所 | Multi-wavelength optical signal generating device and method |
| CN117387673A (en) * | 2023-12-08 | 2024-01-12 | 山东星冉信息科技有限公司 | Fiber bragg grating demodulation method and device based on reference air chamber |
| CN117387673B (en) * | 2023-12-08 | 2024-02-23 | 山东星冉信息科技有限公司 | Fiber bragg grating demodulation method and device based on reference air chamber |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104215605A (en) | Method for fast dynamic-calibration of fiber bragg grating (FBG) demodulation system | |
| US8734011B2 (en) | Distributed optical fiber temperature sensor based on optical fiber delay | |
| CN102052930B (en) | Fiber bragg grating distributed strain sensor and strain monitoring method thereof | |
| CN103196473B (en) | Multi-channel high-accuracy fiber grating sensing demodulation device and demodulation method thereof | |
| US20060131488A1 (en) | Optical wavelength interrogator | |
| WO2008028138A3 (en) | Method and apparatus for high frequency optical sensor interrogation | |
| CN100507455C (en) | Intensity modulation type optical fiber sensor multiplexing method | |
| US10731969B2 (en) | In-line fiber sensing, noise cancellation and strain detection | |
| CA2899044C (en) | Multi-peak reference grating | |
| CN105021310B (en) | High precision optical fiber grating temperature-sensing system | |
| CN102818531A (en) | Dynamic strain measurement instrument based on multiple overlapped gratings | |
| CN103697922A (en) | High-speed demodulation system of optical fiber F-P cavity sensor | |
| CN106017533A (en) | Rapid tuning real-time calibration fiber grating demodulation device and work method | |
| CN111811554A (en) | Optical cavity ring-down-based large-range high-precision fiber grating sensing method and device | |
| Nureev et al. | Distributed Raman sensor system with point spots for downhole telemetry | |
| RU2608394C1 (en) | Device for measuring parameters of physical fields | |
| CN103196472A (en) | Demodulation instrument and demodulation method of fiber grating dynamic strain based on random unequal interval sampling | |
| Nunes et al. | FBG sensor multiplexing system based on the TDM and fixed filters approach | |
| Liu et al. | An integrated design of ultra-high-speed FBG interrogation system-based on FDML laser | |
| CN102735270B (en) | Wavelength-scanning-based active fiber Bragg grating time domain demodulating device | |
| CN100399083C (en) | Tunable double parallel matching fiber grating demodulation system | |
| CN201654405U (en) | FBG demodulating system | |
| RU161644U1 (en) | DEVICE FOR MEASURING PHYSICAL FIELD PARAMETERS | |
| CN2916581Y (en) | Optical fiber Bragg grating sensing device for eliminating cross sensitivity | |
| Ni et al. | A high efficient method for demodulation of FBG sensors |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20141217 |
|
| WD01 | Invention patent application deemed withdrawn after publication |