CN102589585B - Fiber bragg grating array sensing system in cavity - Google Patents
Fiber bragg grating array sensing system in cavity Download PDFInfo
- Publication number
- CN102589585B CN102589585B CN201210008636.1A CN201210008636A CN102589585B CN 102589585 B CN102589585 B CN 102589585B CN 201210008636 A CN201210008636 A CN 201210008636A CN 102589585 B CN102589585 B CN 102589585B
- Authority
- CN
- China
- Prior art keywords
- bragg grating
- fiber bragg
- grating fbg
- fiber
- array
- 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
Links
Abstract
The invention relates to a fiber bragg grating array sensing system in a cavity. Four FBGs are introduced in a laser resonance cavity; a laser is adopted as a sensing system. Compared with higher signal-to-noise ratio in the traditional scheme, the signal-to-noise ratio higher than that in the traditional scheme is obtained, and the temperature sensing accuracy and the stress sensing accuracy are better. Besides, the system is simple and feasible; the sensing scheme can sense and measure a plurality of gratings simultaneously, and is beneficial to repeated use of the fiber gratings.
Description
Technical field
The present invention relates to a kind of sensor-based system, particularly relate to a kind of fiber bragg grating array sensing system in cavity.
Background technology
Fiber-optic grating sensor is not by electromagnetic interference (EMI), signal transmission safety, non-cpntact measurement can be realized, the sensor miscellaneous of Fiber Optical Transmission Type and sensing type can be made, it has high sensitivity, high precision, high speed, high density, adapts to use under various rugged surroundings and noncontact, non-demolition and the feature such as easy to use.
In the middle of the research of traditional F BG sensor-based system, usually adopt wide spectrum light source or Wavelength tunable fiber laser to provide light signal for whole system, but wide spectrum light source exists more defect, such as output power is lower.Because the lower FBG of causing of the power signal to noise ratio (S/N ratio) when carrying out remote recording exported is lower, detectable power is not high, thus causes high power consumption; When scanning FBG with adjustable wavelength laser, again because of FBG reflectance spectrum broader bandwidth, top is more smooth, and is not easy to precisely determine the position residing for FBG centre wavelength.At present, based on above-described defect, sight is turned to fiber laser by people gradually.But existing this kind of sensor-based system research all concentrates on the sensing of single grating, cannot realize the array sensing to FBG multiple in chamber.And these scenario-frames and principle complexity, the feature that FBG is quasi-distributed can not be embodied, be unfavorable for the design of distributed sensing.The factor of temperature compensation is not taken into account by single grating sensing, and sensing accuracy is had a strong impact on.
For the research of the sensor-based system based on fiber laser of two or more FBG, do not obtain higher signal to noise ratio (S/N ratio), each wavelength output signal-to-noise ratio is only 25dB, sensor-based system less stable.
Summary of the invention
The technical matters that the present invention solves is: build a kind of fiber bragg grating array sensing system in cavity, overcome the technical matters of prior art sensor-based system poor stability.
Technical scheme of the present invention is: build a kind of chamber inner fiber bragg grating array sensor-based system, comprise: be connected in series by multiple Fiber Bragg Grating FBG the Fiber Bragg Grating FBG array formed, wavelength division multiplexer, pumping source, erbium-doped fiber, Polarization Controller, coupling mechanism, single-mode fiber, quarter wave plate, Wavelength demodulation device, described pumping source connects the port a of described wavelength division multiplexer, described Fiber Bragg Grating FBG array connects the port b of described wavelength division multiplexer, the port c of described wavelength division multiplexer is connected with one end of described erbium-doped fiber, one end of Polarization Controller described in described erbium-doped fiber other end downlink connection, the other end of described Polarization Controller connects the port c of described coupling mechanism, the port a of described coupling mechanism is connected described single-mode fiber and described quarter wave plate to form non-linear annular environment with port b, the port d of described coupling mechanism receives on described Wavelength demodulation device, when the Fiber Bragg Grating FBG of described Fiber Bragg Grating FBG array is subject to the effect of stress or temperature, described Wavelength demodulation device demodulates the change of described Fiber Bragg Grating FBG array reflection kernel wavelength.
Further technical scheme of the present invention is: described Fiber Bragg Grating FBG array comprises multipair Fiber Bragg Grating FBG, and one of them of often pair of Fiber Bragg Grating FBG is for stress sensing.
Further technical scheme of the present invention is: described Fiber Bragg Grating FBG array comprises multipair Fiber Bragg Grating FBG, and one of them of often pair of Fiber Bragg Grating FBG is for carrying out temperature compensation to sensing grating.
Further technical scheme of the present invention is: the Fiber Bragg Grating FBG increasing series connection in described Fiber Bragg Grating FBG array.
Further technical scheme of the present invention is: described coupling mechanism is the coupling mechanism of Energy for Symmetrical.
Technique effect of the present invention is: provide a kind of fiber bragg grating array sensing system in cavity, multiple FBG is introduced in laserresonator, laser instrument itself is applied as sensor-based system, obtain the signal to noise ratio (S/N ratio) higher compared with traditional scheme, temperature sensing precision and stress sensing precision are all better, in addition, system architecture simple possible, this sensing solutions can carry out sensing measurement to multiple grating simultaneously, can realize remote recording, is conducive to the multiplexing of fiber grating.
Accompanying drawing explanation
Fig. 1 is structural representation of the present invention.
Fig. 2 is four-wavelength laser output spectrum of the present invention.
Fig. 3 is that laser instrument of the present invention output spectral line changes with temperature survey.
Fig. 4 is that Laser output of the present invention is with temperature linearity change curve.
Fig. 5 is that laser instrument of the present invention exports spectral line with measurement STRESS VARIATION.
Fig. 6 is that laser output wavelength of the present invention is with stress changing curve.
Embodiment
Below in conjunction with specific embodiment, technical solution of the present invention is further illustrated.
As shown in Figure 1, the specific embodiment of the invention is: build a kind of chamber inner fiber bragg grating array sensor-based system, comprise: be connected in series by multiple Fiber Bragg Grating FBG the Fiber Bragg Grating FBG array 15 formed, wavelength division multiplexer 5, pumping source 6, erbium-doped fiber 7, Polarization Controller 8, coupling mechanism 9, single-mode fiber 10, quarter wave plate 11, Wavelength demodulation device 12, computing machine 13, described pumping source 6 connects the port a of described wavelength division multiplexer 5, described Fiber Bragg Grating FBG array 15 connects the port b of described wavelength division multiplexer 5, the port c of described wavelength division multiplexer 5 is connected with one end of described erbium-doped fiber 7, one end of Polarization Controller 8 described in described erbium-doped fiber 7 other end downlink connection, the other end of described Polarization Controller 8 connects the port c of described coupling mechanism 9, the port a of described coupling mechanism 9 is connected described single-mode fiber 10 and described quarter wave plate 11 to form non-linear annular environment with port b, the port d of described coupling mechanism 9 receives on described Wavelength demodulation device 12, when the Fiber Bragg Grating FBG of described Fiber Bragg Grating FBG array 15 is subject to the effect of stress or temperature, described Wavelength demodulation device 12 demodulates the change of described Fiber Bragg Grating FBG array reflection kernel wavelength.
In the preferred embodiment for the present invention, described Fiber Bragg Grating FBG array 1 comprises multipair Fiber Bragg Grating FBG, in Fig. 1, comprise two pairs of Fiber Bragg Grating FBGs (2,3), one of them of often pair of Fiber Bragg Grating FBG is for stress sensing, and another of often pair of Fiber Bragg Grating FBG is for carrying out temperature compensation to sensing grating.
As shown in Figure 1, in the specific embodiment of the invention, fiber laser is linear cavity structure, and wherein adopt the pumping (Amonics:ALD1480-400-B-FA) of unidirectional 1480nm as driving source, gain media 7 adopts 11 meters of long doping contents to be 4.0*10
-4cm
-3highly doped Er-doped fiber (Nufern:EDFL-980-HP), nonlinear fiber loop mirror comprises single-mode fiber 10, quarter-wave plate 11 of one section 10 kilometers long, and the directional coupler 9 of 2 × 2 ports 50/50 forms.Single-mode fiber is according to certain twisting rate around getting up, and the twisting of 10 kilometers of single-mode fibers is 3 turns/meter.Wavelength demodulation device 12 is spectrometer.
As shown in Figure 1, specific implementation process of the present invention is as follows: adopt the pumping 6 of unidirectional 1480nm as driving source, then the coupling pump light of 1480nm enters in chamber to enter in erbium-doped fiber 7 by the wavelength division multiplexer 5 of 1480/1550nm, after power arrives certain threshold value, the generation particle beams reverses, erbium ion stimulated radiation transits to ground state by upper laser level, produce stimulated radiation, output wavelength is in the laser of about 1550nm, light signal is to the right by Polarization Controller 8, the degree of stability that control system exports is realized in the process of modulating polarization controller 8, light signal just enters nonlinear fiber loop mirror after by Polarization Controller 8, after light signal arrives the coupling mechanism 9 of 50: 50, inputted by the port c of Energy for Symmetrical coupling mechanism 9, coupling mechanism 9 is respectively by the Energy Coupling inlet side mouth a of 50% and port b, the incident light of entered by port a 50% is propagated along clockwise direction, the incident light of entered by port c 50% is propagated in the counterclockwise direction.The different two-way light in the direction of propagation is at nonlinear fiber loop mirror (10,11) the nonlinear polarization rotation effect accumulated after a week is propagated in different, the laser of 50% is exported respectively at the port c of Energy for Symmetrical type coupling mechanism 9 and port d, port a export 50% light be finally 0.01nm by resolution spectrometer carries out demodulation, and utilize virtual instrument technique to carry out the data on recording light spectrometer by computing machine 13, and further process is done to the data of record.Meanwhile, in addition by port c export 50% light, by Polarization Controller 8, the port c entering wavelength division multiplexer 5 is again amplified again through erbium-doped fiber 7, exported by the port b of wavelength division multiplexer 5, then reflect through the Fiber Bragg Grating FBG that multiple centre wavelength is different, now Fiber Bragg Grating FBG has carried out wavelength chooses as wavelength-selecting feedback element to light wave, reflected light is entered by the port b of wavelength division multiplexer 5, then together with pump light, exported by port c, be transmitted all processes, sustained oscillation.While in this process, Fiber Bragg Grating FBG plays the effect of filtering as the feedback original paper of fiber laser, also as responsive original paper, as shown in Figure 1, Fiber Bragg Grating FBG is to (2,3), a Fiber Bragg Grating FBG does temperature compensation, for eliminating environmental impact; Another both may be used for sensing temperature as sensing, may be used for again sensing stress, when it is subject to the effect of stress or temperature, there is meeting subtle change in its reflection kernel wavelength, is demodulated the subtle change of wavelength, thus realize temperature or stress sensing function by spectrometer.
In order to specifically test the performance of sensor-based system, introduce the experiment utilizing native system to complete below: four Fiber Bragg Grating FBGs that first have selected centre wavelength difference 1552nm 1550nm 1548nm 1546nm, then first in laboratory environments laser output spectrum is monitored.The spectrum of four more stable wavelength that accompanying drawing 2 exports for laser instrument.As seen from the figure, by the laser of four wavelength exported after four FBG filtering, centre wavelength is respectively 1545.97810nm, 1548.01425nm, 1549.87108nm and 1552.05601nm, corresponding Single wavelength gain is respectively-12.076dBm ,-5.448dBm ,-13.467dBm and-5.647dBm, the gain of visible four wavelength is not identical, main cause is that mode competition is comparatively violent, and light loss in chamber of the wavelength that gain is low is greater than the light of the high wavelength of gain.But the crest place of four wavelength is all rounder and more smooth, the intensity dependent loss that visible nonlinear fiber loop mirror is introduced and the intensity loss characteristic that has nothing to do effectively inhibits hole-burning effect under room temperature.In addition, the three dB bandwidth of four wavelength is also about 0.1nm, and this provides advantage to raising system sensing precision equally.
In Fig. 2, background-noise level is about-40dBm, then system signal noise ratio can be obtained by the gain subtracting background noise power that four wavelength are corresponding respectively.Known system signal noise ratio is about 30dB, and the method for carrying out sensing relative to traditional application wide spectrum light source and tunable laser light source is compared, and this chamber inner fiber bragg grating array sensor-based system signal to noise ratio (S/N ratio) tool in array sensing has great advantage.
In laboratory environments the stability of Laser output is monitored, records the drift conditions of wavelength in half an hour as shown in table 1:
Wave length shift data statistics in table 1 one hour
| Grating | Wavelength average (nm) | Wave length shift standard deviation (nm) |
| FBG1 | 1545.96938 | 0.0034 |
| FBG2 | 1548.01487 | 0.00231 |
| FBG3 | 1549.88268 | 0.00223 |
| FBG4 | 1552.04308 | 0.004 |
The drift value of the wavelength shown in table is up to 0.004nm, and the output of this dual laser is comparatively stable.
Temperature sensing experimental analysis:
Utilization the system have been temperature sensing experiment, and the Fiber Bragg Grating FBG being first 1550nm to centre wavelength does the measurement of temperature sensing.Because centre wavelength is that the Fiber Bragg Grating FBG putting position of the Fiber Bragg Grating FBG putting position of 1552nm and 1550nm is nearest, therefore, for providing condition to the temperature compensation of stress sensing below, we have carried out the measurement of temperature sensing to the Fiber Bragg Grating FBG of 1552nm again.Fig. 3 is under different temperatures, and centre wavelength is the movement of the FBG Output of laser spectral line of 1552nm.In Fig. 3, the rising of FBG center wavelength with temperature and moving to right.When temperature is increased to 45.1 DEG C from 1.2 DEG C, wavelength about moves to 1552.24nm from 1551.8nm.Spectral line shape crest place regular shape in figure, and three dB bandwidth several remains on about 0.1nm.
Temperature is slowly increased to 100 DEG C from 1 DEG C, on average the data of every ten degree of record 20 subcenter wavelength, finally average and standard deviation is got to all data, obtain result as shown in table 2:
Table 2 1552nm fiber bragg grating temperature measures sensing data statistics
| Temperature (DEG C) | Wavelength average (nm) | Standard of wavelength difference (nm) |
| 1.2 | 1551.80989 | 0.00301 |
| 12.6 | 1551.91498 | 0.004899 |
| 22.1 | 1552.01978 | 0.00321 |
| 32.8 | 1552.11901 | 0.00501 |
| 45.1 | 1552.25088 | 0.00487 |
| 50.8 | 1552.30901 | 0.00341 |
| 60.8 | 1552.41798 | 0.00499 |
| 70.5 | 1552.51420 | 0.004885 |
| 80.6 | 1552.62110 | 0.003314 |
| 90.1 | 1552.71921 | 0.00301 |
| 101.5 | 1552.80601 | 0.00805 |
In measuring process, be increased to 101.5 DEG C with temperature from 1.2 DEG C, wavelength moves to 1552.80601nm by 1551.80989nm, and standard of wavelength difference is maximum reaches 0.00805nm, and namely sensing accuracy can reach 0.00805nm.Wavelength-temperature curve can be obtained as shown in Figure 4: figure hollow core round dot represents actual measured value, and straight line represents matched curve by table 2.Error bar on each round dot then represents duplicate measurements error range, i.e. sensing and demodulating precision, maximumly reaches 0.00805nm.Matching is carried out to experimental data, obtains Laser output and can be expressed as the function of temperature variation:
λ
B(nm)＝1551.79248+0.01015T(℃) (1)
Fitting result shows that laser instrument Output rusults becomes substantially linear relation with temperature variation, the right R ≈ 0.99972 of Linear Quasi, and visible experiment obtains the good linearity, and sensitivity is 10.15pm/ DEG C.Demodulation Systems precision can be obtained by formula (1) and be about 0.79 DEG C.
In the same way temperature sensing measurement is carried out to the FBG that centre wavelength is 1550nm in experiment, has obtained Laser output and can be expressed as the function of temperature variation:
λ
B(nm)＝1549.80337+0.01023T(℃) (2)
Fitting result shows that fiber laser Output rusults becomes substantially linear relation with temperature variation, the right R ≈ 0.99968 of Linear Quasi, and visible experiment obtains the good linearity.Sensitivity is 10.2pm/ DEG C.Experiment directly records the most I of demodulation accuracy and reaches 0.0075nm, can extrapolate temperature sensing precision be about 0.733 DEG C by formula (2).
Stress sensing interpretation
Utilize this sensor, the FBG that we are mainly 1550nm to centre wavelength has done the measurement of stress sensing, and all the other gratings are motionless.Fig. 5 is the situation of Laser output spectral line movement with the change of axial tension: as seen from the figure, increase to 0.5N with stress from 0.11N.Laser output spectral line moves to right, and moves to 1550.5nm by about 1550.0nm.Crest place regular shape, and three dB bandwidth several remains on about 0.1nm.Higher trend is gradually had along with stress increases gain coefficient, main because mode competition causes laser output power unstable.Table 3 gives centre wavelength average and the standard deviation of corresponding all stress in experiment after temperature compensation.
Table 3 1550nmFBG stress measurement sensing data is added up
In measuring process, be increased to 0.5N with stress from 0, wavelength moves to 1550.56960nm by 1549.877867nm, and the most I of standard of wavelength difference reaches 0.00794nm, and namely sensing accuracy is minimum reaches 0.00794nm.Wavelength-stress relation curve can be obtained as shown in Figure 6: figure orbicular spot represents actual measured value, and straight line represents matched curve by table 3.Error bar on each round dot then represents measuring error scope, i.e. sensing and demodulating precision, and most I reaches 0.00794nm.Matching is carried out to experimental data, obtains Laser output and can be expressed as the function of STRESS VARIATION:
λ
B(nm)＝1549.87632+1.38398F(N) (3)
Fitting result shows that laser instrument Output rusults becomes substantially linear relation with STRESS VARIATION, the right R ≈ 0.99878 of Linear Quasi, and visible experiment obtains the good linearity, and sensitivity is 1.38398nm/N.Demodulation Systems precision can be obtained by formula (3) and be about 6.568 μ ε.
Above content is in conjunction with concrete preferred implementation further description made for the present invention, can not assert that specific embodiment of the invention is confined to these explanations.For general technical staff of the technical field of the invention, without departing from the inventive concept of the premise, some simple deduction or replace can also be made, all should be considered as belonging to protection scope of the present invention.
Claims (5)
1. a fiber bragg grating array sensing system in cavity, its feature is, comprise: be connected in series by multiple Fiber Bragg Grating FBG the Fiber Bragg Grating FBG array formed, wavelength division multiplexer, pumping source, erbium-doped fiber, Polarization Controller, coupling mechanism, single-mode fiber, quarter wave plate, Wavelength demodulation device, described pumping source connects the port a of described wavelength division multiplexer, described Fiber Bragg Grating FBG array connects the port b of described wavelength division multiplexer, the port c of described wavelength division multiplexer is connected with one end of described erbium-doped fiber, the described erbium-doped fiber other end connects one end of described Polarization Controller, the other end of described Polarization Controller connects the port c of described coupling mechanism, the port a of described coupling mechanism is connected described single-mode fiber and described quarter wave plate to form non-linear annular environment with port b, the port d of described coupling mechanism receives on described Wavelength demodulation device, when the Fiber Bragg Grating FBG of described Fiber Bragg Grating FBG array is subject to the effect of stress or temperature, described Wavelength demodulation device demodulates the change of described Fiber Bragg Grating FBG array reflection kernel wavelength.
2. fiber bragg grating array sensing system in cavity according to claim 1, its feature is, described Fiber Bragg Grating FBG array comprises multipair Fiber Bragg Grating FBG, and one of them of often pair of Fiber Bragg Grating FBG is for stress sensing.
3. fiber bragg grating array sensing system in cavity according to claim 1, its feature is, described Fiber Bragg Grating FBG array comprises multipair Fiber Bragg Grating FBG, and one of them of often pair of Fiber Bragg Grating FBG is for carrying out temperature compensation to sensing grating.
4. fiber bragg grating array sensing system in cavity according to claim 1, its feature is, increases the Fiber Bragg Grating FBG of series connection in described Fiber Bragg Grating FBG array.
5. fiber bragg grating array sensing system in cavity according to claim 1, its feature is, described coupling mechanism is the coupling mechanism of Energy for Symmetrical.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210008636.1A CN102589585B (en) | 2012-01-11 | 2012-01-11 | Fiber bragg grating array sensing system in cavity |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210008636.1A CN102589585B (en) | 2012-01-11 | 2012-01-11 | Fiber bragg grating array sensing system in cavity |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102589585A CN102589585A (en) | 2012-07-18 |
| CN102589585B true CN102589585B (en) | 2014-12-17 |
Family
ID=46478560
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210008636.1A Expired - Fee Related CN102589585B (en) | 2012-01-11 | 2012-01-11 | Fiber bragg grating array sensing system in cavity |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102589585B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104768087B (en) * | 2014-01-07 | 2019-01-18 | 上海诺基亚贝尔股份有限公司 | The method and apparatus and central office transmission method and equipment of generation multi-wavelength light wave |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101561612A (en) * | 2009-05-15 | 2009-10-21 | 哈尔滨工业大学深圳研究生院 | Dynamic gain flattening device based on nonlinear fiber loop mirror and method thereof |
| CN101216326B (en) * | 2008-01-08 | 2010-07-21 | 西安石油大学 | Long distance optical fiber grating sensing and transmitting device |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6016702A (en) * | 1997-09-08 | 2000-01-25 | Cidra Corporation | High sensitivity fiber optic pressure sensor for use in harsh environments |
-
2012
- 2012-01-11 CN CN201210008636.1A patent/CN102589585B/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101216326B (en) * | 2008-01-08 | 2010-07-21 | 西安石油大学 | Long distance optical fiber grating sensing and transmitting device |
| CN101561612A (en) * | 2009-05-15 | 2009-10-21 | 哈尔滨工业大学深圳研究生院 | Dynamic gain flattening device based on nonlinear fiber loop mirror and method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102589585A (en) | 2012-07-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102183318B (en) | Two-in-parallel high birefringence optical fiber sagnac interference ring multi-parameter sensor | |
| CN102506906B (en) | Method and system for improving performance of distributed optical fiber sensing system based on phi-OTDR | |
| DE19807891A1 (en) | Fiber-laser sensor for measurement of elongation, temperature or especially isotropic pressure in oil well | |
| CN103575313B (en) | Many longitudinal modes annular chamber laser sensor frequency division multiplexing device based on beat frequency technology | |
| CN101813459A (en) | Temperature-compensated optical fiber sagnac interference ring strain sensor | |
| CN100582658C (en) | Bending radius measuring apparatus based on optical fibre laser | |
| CN103337783A (en) | Method for measuring temperature by utilizing output longitudinal mode of short-cavity optical fiber laser | |
| CN104617473A (en) | Brillouin three-loop narrow-linewidth fiber laser with low insertion loss | |
| CN107063317B (en) | Demodulation method of multi-core fiber Bragg grating curvature sensor | |
| CN101907495B (en) | Fiber bragg grating wavelength demodulation system with long-period fiber bragg grating Sagnac loop | |
| CN102707388B (en) | Micro and nano optical fiber filter, optical fiber laser, optical fiber sensing device and manufacturing method | |
| CN103852093A (en) | Fiber laser sensing system based on mode interference reflection structure | |
| CN102589585B (en) | Fiber bragg grating array sensing system in cavity | |
| CN104614062A (en) | Distributed ultrasonic sensor based on multi-wavelength Er-doped fiber laser | |
| CN110031097B (en) | All-fiber Gaussian SLED light source spectrum flattening device | |
| CN104019760A (en) | Sensitivity enhancement demodulation method and device of fiber optical Bragg grating strain sensor | |
| CN214702149U (en) | Optical fiber sensor capable of simultaneously monitoring temperature and strain | |
| CN202083512U (en) | Micro-pressure sensor | |
| CN103575309A (en) | Frequency division multiplexing device of single-grating optical fiber multi-longitudinal mode laser straight-cavity sensor | |
| CN112816096A (en) | Cascade interferometer optical fiber temperature sensor based on vernier effect | |
| CN220230751U (en) | SMF-NCF-FMF-TCF-FBG fiber laser temperature sensor based on dislocation structure | |
| CN217442582U (en) | Dual-parameter optical fiber laser sensor based on PM-FBG-SI structure | |
| CN219368977U (en) | PDMS sensitized optical fiber laser temperature sensor based on SMF-PMF-SMF-FBG structure | |
| CN102221425A (en) | Micro-pressure sensor based on short cavity fiber laser | |
| CN204064257U (en) | The sensitivity of bragg grating strain transducer strengthens demodulating equipment |
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 | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20141217 Termination date: 20160111 |