CN102183318B - Two-in-parallel high birefringence optical fiber sagnac interference ring multi-parameter sensor - Google Patents
Two-in-parallel high birefringence optical fiber sagnac interference ring multi-parameter sensor Download PDFInfo
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- CN102183318B CN102183318B CN201110054072.0A CN201110054072A CN102183318B CN 102183318 B CN102183318 B CN 102183318B CN 201110054072 A CN201110054072 A CN 201110054072A CN 102183318 B CN102183318 B CN 102183318B
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Abstract
The invention relates to a two-in-parallel high birefringence optical fiber sagnac interference ring multi-parameter sensor in the technical field of optical fiber communication, comprising a broadband light source, a wavelength selection switch, a high birefringence optical fiber sagnac interference ring, an optical fiber multiplexer and a spectrum analyzer which are connected in series, wherein the birefringence optical fiber sagnac interference ring consists of two couplings and two polarization controllers. According to the technical scheme, two high birefringence optical fiber sagnac interference rings are connected in parallel to be used as the optical fiber sensor through the wavelength selection switch, so that temperature and strain measurement can be simultaneously realized; and the two-in-parallel high birefringence optical fiber sagnac interference ring multi-parameter sensor has the advantages of simple structure, low cost and high measurement precision.
Description
Technical field
What the present invention relates to is a kind of system and transmission method thereof of technical field of optical fiber communication, specifically a kind of two-in-parallel high birefringence optical fiber sagnac interference ring multi-parameter sensor.
Background technology
In recent years, Fibre Optical Sensor thereby has obtained paying close attention to widely because its relative traditional sensors has that volume is little, measuring accuracy is high, cost is low and can be applicable to the advantage such as strong electromagnetic interference environment.And in the optical fiber sensing monitoring system of reality, the cross sensitivity of each parameter is a unavoidable key issue, impact when namely measurement result easily is subject in the external environment condition a plurality of parameter.For example in the common fiber-optic grating sensor, the variation of wavelength signals is subjected to the impact of temperature and stress simultaneously.Therefore how to realize that it is the important research direction of following Fibre Optical Sensor that a plurality of parameters are measured simultaneously.
The application of optical fiber sagnac interference ring aspect sensing more and more causes people's attention.In the optical fiber sagnac interference ring sensing scheme, high birefringence optical fiber sagnac ring (High birefringent sagnac loop, Hi-Bi sagnac loop) has huge application prospect at sensory field of optic fibre.Hi-Bi sagnac interference ring is one section hi bi birefringence fiber of series connection in basic sagnac ring, output spectrum presents periodic filtering characteristic, double refractive inde and the length of Hi-Bi optical fiber during the cycle of output spectrum is decided by to encircle, and irrelevant with the length of ring.As pickup arm, when the changes such as external environment parameters such as temperature, strain, refractive index acted on pickup arm, the length of Hi-Bi optical fiber and double refractive inde all changed, and cause output spectrum generation wave length shift with this section high birefringence optical fiber.The sensing sensitivity of Hi-Bi sagnac interference ring is higher, and (for example the sensitivity coefficient of common fiber grating pair temperature is only had an appointment 0.01nm/ ℃, the susceptibility of long-period grating pair temperature can reach 0.1nm/ ℃, and the susceptibility that Hi-Bi sagnac encircles temperature can reach 1nm/ ℃); Hi-Bi sagnac ring also has advantages such as input polarisation of light independence, simple in structure and cost are lower in addition.
Through existing literature search is found, 2007, O.Frazao, J.L.Santos, the people such as J.M.Baptista have delivered the article that is entitled as " Strain and temperaturediscrimination using concatenated high-birefringence fiber loop mirrors (strain and temperature based on Cascade H i-Bi fiber loop mirror are distinguished) " at " IEEEPhotonics Technology Letter (IEEE fibreoptics wall bulletin) ", the Hi-Bi fiber optic loop of two cascades that adopted this article realizes the differentiation to temperature and strain, a Hi-Bi ring is as pickup arm in this technology, and another Hi-Bi ring is as the temperature reference arm, utilize two rings to the different temperature that solve of sensitivity of strain and temperature to the cross sensitivity problem of strain.But this technical size is larger, is unfavorable for actual measurement.
Find through retrieval again, 2008, Frazao, O., the people such as D.Egypto have delivered " Strain and temperature discrimination usinghigh-birefringence erbium-doped fiber loop mirror with high pump power laser (stress of the high birefringence Er-doped fiber ring mirror of high power pump and temperature are distinguished) " at " IEEE Photonics Technology Letter (IEEE fibreoptics wall bulletin) ", this technology is taked one section special er-doped high birefringence optical fiber of series connection in the sagnac interference ring, adding wavelength in the sagnac ring is the pumping source of 980nm, utilization adds the to external world sensitivity difference of parameter of pump light front and back Hi-Bi EDF, realizes distinguishing the purpose of temperature and strain.But the stability of pump light also can affect greatly measurement result after the interior adding of this technology ring pump light source, so that the measurement result accuracy rate is low.
Also find through retrieval, 2009, hun-Liu, Z., the people such as Z.Jiarong are at " Optics Communication, (optical communication) " on delivered the article that is entitled as " Simultaneous strain and temperature measurement using a highlybirefringence fiber loop mirror and a long-period grating written ina photonic crystal fiber (based on strain and the temperature simultaneously measuring of etching long period fiber grating on high birefringence ring mirror and the photonic crystal fiber) ", this technology adopts one section special photonic crystal fiber long-period gratings (Long-period Grating written ina PhotonicCrystal Fiber, PCF LPG) as temperature compensation, Hi-Bi sagnac interference ring is as pickup arm, PCF LPG then plays the effect of wave filter, as long as the output spectra of ring and the two window selection of transmission spectrum of PCF LPG are proper, then can monitor certain crest and change with wave length shift and the power that external parameter changes.Can measure simultaneously the variation of temperature and strain by the monitoring of wavelength and power.But the PCF LPG that this technology adopts preparation needs expensive equipment, the high and system complex of cost.
Summary of the invention
The present invention is directed to the prior art above shortcomings, a kind of two-in-parallel high birefringence optical fiber sagnac interference ring multi-parameter sensor is provided, by wavelength-selective switches two high birefringence sagnac interference rings are together in parallel as Fibre Optical Sensor, can realize simultaneously temperature and strain measurement, have advantages of simple in structure, cost is low and measuring accuracy is high.
The present invention is achieved by the following technical solutions, the present invention includes: wide spectrum light source, wavelength-selective switches, birefringence fiber sagnac interference ring, optical fiber wave multiplexer and the spectroanalysis instrument of connecting successively, wherein: birefringence fiber sagnac interference ring is comprised of two coupling mechanisms and two Polarization Controllers.
One end of described the first coupling mechanism links to each other by the first high birefringence optical fiber with the first Polarization Controller and consists of first refractive optical fiber sagnac interference ring, and the other end links to each other by the first high birefringence optical fiber with the optical fiber wave multiplexer with wavelength-selective switches.
Described the second coupling mechanism with an end and the second Polarization Controller link to each other by the second high birefringence optical fiber and consist of the second refraction optical fiber sagnac interference ring, the other end and wavelength-selective switches link to each other by the second high birefringence optical fiber with the optical fiber wave multiplexer.
Described the first high birefringence optical fiber is fixedly installed on the four-dimensional adjusting bracket of optical precision.
The bandwidth range of described wide spectrum light source is: 1525nm-1570nm.
Described wavelength-selective switches adopts 1 * 2 wavelength-selective switches based on liquid crystal polarized control.
Described coupling mechanism is three-dB coupler
The cladding diameter of described the first high birefringence optical fiber is 125 μ m, and this first high birefringence optical fiber places temperature field and strain field as pickup arm simultaneously.
The cladding diameter of described the second high birefringence optical fiber is that 80 μ m and this second high birefringence optical fiber only place the temperature field.
Described optical fiber wave multiplexer converges the input spectrum instrument with the output spectrum of two interference rings.
Described spectroanalysis instrument is used for surveying the output spectrum signal.
Compared with prior art, the present invention has following beneficial effect: by wavelength-selective switches two different high birefringence sagnac interference rings are together in parallel as Fibre Optical Sensor, measure problem when can effectively solve temperature and strain; Because high birefringence sagnac interference ring is high to temperature and strain sensitivity, so being combined with of the two help give full play to the two highly sensitive advantage, makes the high sensitivity optical fiber sensor; The device that adopts among the present invention comprises that three-dB coupler, Polarization Controller, high birefringence optical fiber etc. all belong to conventional device, and the connection of each device all belongs to conventional welding, so the present invention has the low and simple characteristics of preparation technology of cost.
Description of drawings
Fig. 1 is structural representation of the present invention.
Embodiment
The below elaborates to embodiments of the invention, and the present embodiment is implemented under take technical solution of the present invention as prerequisite, provided detailed embodiment and concrete operating process, but protection scope of the present invention is not limited to following embodiment.
As shown in Figure 1, the present embodiment comprises: successively wide spectrum light source 1, wavelength-selective switches 2, birefringence fiber sagnac interference ring 3,4, optical fiber wave multiplexer 5 and the spectroanalysis instrument 6 of series connection, wherein: birefringence fiber sagnac interference ring is comprised of two coupling mechanisms 7,10 and two Polarization Controllers 8,11.
One end of described the first coupling mechanism 7 links to each other by the first high birefringence optical fiber 9 with the first Polarization Controller 8 and consists of first refractive optical fiber sagnac interference ring 3, and the other end links to each other by the first high birefringence optical fiber 9 with optical fiber wave multiplexer 5 with wavelength-selective switches 2.
Described the second coupling mechanism 10 with an end and the second Polarization Controller 11 link to each other by the second high birefringence optical fiber 12 and consist of the second refraction optical fiber sagnac interference ring 4, the other end and wavelength-selective switches 2 link to each other by the second high birefringence optical fiber 12 with optical fiber wave multiplexer 5.
Described the first high birefringence optical fiber 9 is fixedly installed on the four-dimensional adjusting bracket 13 of optical precision.
The bandwidth range of described wide spectrum light source 1 is: 1525nm-1570nm.
1 * 2 wavelength-selective switches 2 that described wavelength-selective switches 2 adopts based on liquid crystal polarized control.
Described coupling mechanism is three-dB coupler
Described the first high birefringence optical fiber 9 cladding diameters are 125 μ m, and this first high birefringence optical fiber places temperature field and strain field as pickup arm simultaneously.
Described the second high birefringence optical fiber 12 cladding diameters are that 80 μ m and this second high birefringence optical fiber only place the temperature field.
Described optical fiber wave multiplexer 5 converges the input spectrum instrument with the output spectrum of two interference rings.
Described spectroanalysis instrument 6 adopts Anristu Ms9710B type, and its wavelength resolution is 0.07nm.
The course of work of the present embodiment:
1) by adjusting wavelength-selective switches 2, be that two high birefringence sagnac interference rings distribute suitable wavelength coverage.
2) by adjusting the Polarization Controller in the high birefringence sagnac interference ring, select suitable resonance wavelength, be the wavelength coverage of its distribution so that the resonance wavelength of two rings is positioned at wavelength-selective switches 2 separately, namely can clearly observe the resonance wavelength of the two at spectrometer 6 places.
3) make that strain variation is zero, temperature value changes, obtain respectively the temperature variant wavelength shift of resonance wavelength of the first high birefringence sagnac interference ring and the second high birefringence sagnac interference ring, and then obtain high birefringence sagnac interference ring to the sensitivity coefficient of temperature, specifically:
Δλ
1＝K
1TΔT+K
εΔε
Δλ
2＝K
2TΔT
Wherein: Δ λ
1The resonance wavelength of the first high birefringence optical fiber 9; Δ λ
2Be the resonance wavelength of the second high birefringence optical fiber 128; Δ ε is the variation of strain; Δ T is the variation of temperature; K
1TAnd K
εRespectively Δ λ
1Sensitivity coefficient to temperature and strain; K
2TΔ λ
2Sensitivity coefficient to temperature.
4) make that temperature variation is zero, strain value changes, and obtains high birefringence sagnac interference ring resonance wavelength to the drift value of strain value, and then obtains high birefringence sagnac interference ring to the sensitivity coefficient of strain variation, specifically:
Δλ
1＝K
1TΔT+K
εΔε
Δλ
2＝K
2TΔT
Wherein: Δ λ
1The resonance wavelength of the first high birefringence optical fiber 9; Δ λ
2Be the resonance wavelength of the second high birefringence optical fiber 12; Δ ε is the variation of strain; Δ T is the variation of temperature; K
1TAnd K
εRespectively Δ λ
1Sensitivity coefficient to temperature and strain; K
2TΔ λ
2Sensitivity coefficient to temperature.
5) obtain the calibration formula of temperature and strain, specifically:
ΔT＝Δλ
2/K
2T
Δε＝(Δλ
1-K
1TΔT)/K
ε
The present embodiment is respectively 0.90nm/ ℃ and 0.014nm/ μ ε to the sensitivity of temperature and strain, has improved an order of magnitude than traditional fiber-optic grating sensor sensitivity.
Claims (7)
1. two-in-parallel high birefringence optical fiber sagnac interference ring multi-parameter sensor, comprise: wide spectrum light source, wavelength-selective switches, birefringence fiber sagnac interference ring, optical fiber wave multiplexer and the spectroanalysis instrument of connecting successively, it is characterized in that: birefringence fiber sagnac interference ring is comprised of two coupling mechanisms and two Polarization Controllers;
One end of the first coupling mechanism of described birefringence fiber sagnac interference ring links to each other by the first high birefringence optical fiber with the first Polarization Controller and consists of first refractive optical fiber sagnac interference ring, and the other end links to each other by the first high birefringence optical fiber with the optical fiber wave multiplexer with wavelength-selective switches;
One end of the second coupling mechanism of described birefringence fiber sagnac interference ring links to each other by the second high birefringence optical fiber with the second Polarization Controller and consists of the second refraction optical fiber sagnac interference ring, and the other end links to each other by the second high birefringence optical fiber with the optical fiber wave multiplexer with wavelength-selective switches.
2. two-in-parallel high birefringence optical fiber sagnac interference ring multi-parameter sensor according to claim 1 is characterized in that, described the first high birefringence optical fiber is fixedly installed on the four-dimensional adjusting bracket of optical precision.
3. two-in-parallel high birefringence optical fiber sagnac interference ring multi-parameter sensor according to claim 1 is characterized in that, the bandwidth range of described wide spectrum light source is: 1525nm-1570nm.
4. two-in-parallel high birefringence optical fiber sagnac interference ring multi-parameter sensor according to claim 1 is characterized in that, described wavelength-selective switches adopts 1 * 2 wavelength-selective switches based on liquid crystal polarized control.
5. two-in-parallel high birefringence optical fiber sagnac interference ring multi-parameter sensor according to claim 1 is characterized in that, described coupling mechanism is three-dB coupler.
6. two-in-parallel high birefringence optical fiber sagnac interference ring multi-parameter sensor according to claim 1 and 2, it is characterized in that, the cladding diameter of described the first high birefringence optical fiber is 125 μ m, and this first high birefringence optical fiber places temperature field and strain field as pickup arm simultaneously.
7. two-in-parallel high birefringence optical fiber sagnac interference ring multi-parameter sensor according to claim 1 is characterized in that, the cladding diameter of described the second high birefringence optical fiber is that 80 μ m and this second high birefringence optical fiber only place the temperature field.
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| CN103616046A (en) * | 2013-11-26 | 2014-03-05 | 沈阳工程学院 | Method for detecting temperature and magnetic field simultaneously based on magnetofluid-filled crystal fiber loop mirror |
| CN105716755B (en) * | 2016-01-25 | 2018-09-21 | 西南交通大学 | A kind of sensitivity enhanced sensor based on Loyt-Sagnac interferometers |
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| CN109507130B (en) * | 2019-01-17 | 2021-01-26 | 哈尔滨理工大学 | Strength detection type gas sensor based on Sagnac double-ring parallel structure and photo-thermal technology |
| CN112857610A (en) * | 2021-01-13 | 2021-05-28 | 贵州大学 | High-sensitivity temperature sensing system based on laser oscillation loop |
| CN114739436A (en) * | 2022-04-12 | 2022-07-12 | 南京航空航天大学 | Multi-parameter optical fiber sensing method and device based on photoelectric oscillation loop |
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2011
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| EP0729012B1 (en) * | 1995-02-21 | 2000-09-06 | Commissariat A L'energie Atomique | Photo-induced Bragg-grating sensor with good signal to noise ratio |
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Non-Patent Citations (1)
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