CN107990996A - A kind of temperature sensor based on interference spectrum cursor effect and annular Research on Cavity Ring Down Spectroscopy - Google Patents

A kind of temperature sensor based on interference spectrum cursor effect and annular Research on Cavity Ring Down Spectroscopy Download PDF

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CN107990996A
CN107990996A CN201711070395.2A CN201711070395A CN107990996A CN 107990996 A CN107990996 A CN 107990996A CN 201711070395 A CN201711070395 A CN 201711070395A CN 107990996 A CN107990996 A CN 107990996A
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mrow
sagnac
msub
optical fiber
fsr
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CN107990996B (en
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李林军
杨玉强
杨曦凝
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Heilongjiang Institute of Technology
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Heilongjiang Institute of Technology
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    • GPHYSICS
    • G01MEASURING; TESTING
    • G01KMEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
    • G01K11/00Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00
    • G01K11/32Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00 using changes in transmittance, scattering or luminescence in optical fibres

Abstract

The present invention relates to a kind of temperature sensor based on interference spectrum cursor effect and annular Research on Cavity Ring Down Spectroscopy, include successively along optical path direction:DFB optical fiber lasers, polarizer, electrooptic modulator, isolator, FP chambers, decline and swing loop, photodetector;Described decline is swung loop and is included successively along optical path direction:First coupler, the second coupler, Sagnac interference rings, circulator, flat-top grating, EDFA amplifiers, the 3rd coupler;The continuous light that light source is sent is changed into pulsed light after the polarizer and the electrooptic modulator, the pulsed light is after the FP cavity reflections, decline as described in entering 10% input terminal of first coupler and swing loop, the pulsed light it is described decline to swing often circulated in loop one week, its portion of energy is exported by the 1% of the 3rd coupler, the photodetector is translated into voltage signal, by oscilloscope display.Temperature sensor sensitivity based on interference spectrum cursor effect and annular Research on Cavity Ring Down Spectroscopy improves tens times.

Description

A kind of temperature based on interference spectrum cursor effect and annular Research on Cavity Ring Down Spectroscopy passes Sensor
Technical field
The present invention relates to a kind of oscillograph to detect temperature sensor, more particularly to a kind of to be based on interference spectrum cursor effect and ring The temperature sensor of shape Research on Cavity Ring Down Spectroscopy.
Background technology
It is too low to be currently based on the temperature sensor sensitivity of fiber grating, only about 10pm/ DEG C, based on long-period gratings Temperature sensor sensitivity is of a relatively high, but there is the problem of to bending and exterior material cross sensitivity, based on optical fiber mach-once The temperature sensor of Deccan interferometer or Optical Fiber Michelson Interferometer is to extraneous vibration cross sensitivity, although compared to temperatures above Sensor, ability of the temperature sensor with stronger anti-external interference based on the interference of single Sagnac rings, but usual feelings Its sensitivity only has about 1nm/ DEG C under condition.Therefore, a kind of fibre optical sensor in higher sensitivity is developed urgently to solve as this area Technical problem certainly.
The content of the invention
The purpose of the present invention is to solve the not high technical problem of current fibre optical sensor sensitivity, a kind of base is developed In interference spectrum cursor effect and the temperature sensor of annular Research on Cavity Ring Down Spectroscopy.
Specifically, the present invention relates to a kind of temperature sensing based on interference spectrum cursor effect and annular Research on Cavity Ring Down Spectroscopy Device, includes successively along optical path direction:DFB optical fiber lasers, polarizer, electrooptic modulator, isolator, FP chambers, decline and swing loop, light Electric explorer;The DFB optical fiber lasers, polarizer, electrooptic modulator, isolator, FP chambers, decline and swing loop, photodetector Connected by single mode optical fiber;
Described decline is swung loop and is included successively along optical path direction:First coupler, the second coupler, Sagnac interference rings, ring Shape device, flat-top grating, EDFA amplifiers, the 3rd coupler;First coupler, the second coupler, Sagnac interference rings, ring Shape device, flat-top grating, EDFA amplifiers, the 3rd coupler are connected by single mode optical fiber;
The continuous light that light source is sent is changed into pulsed light, the pulsed light warp after the polarizer and the electrooptic modulator After the FP cavity reflections, decline as described in entering 10% input terminal of first coupler and swing loop, the pulsed light is in institute State to decline to swing and often circulated in loop one week, its portion of energy by the 3rd coupler 1% output, the photodetector by its Voltage signal is converted into, by oscilloscope display.
Further, the diplopore optical fiber that a segment length is 0.1-2 meters, the diplopore optical fiber two are included in the Sagnac rings End and the single mode optical fiber welding;The diplopore optical fiber is comprising fibre core and two relative to the symmetrical air of the fibre core Hole, the interior filling alcohol of two airports.
Further, the diameter of the diplopore optical fiber and single mode optical fiber are 110-140 microns, and the two of the diplopore optical fiber The diameter of a airport is 10-30 microns, 40-60 microns of holes interval.
Further, the length of the diplopore optical fiber is 1 meter, and diameter and single mode optical fiber are 125 microns, the diplopore light The diameter of two fine airports is 20 microns, 50 microns of holes interval.
Further, the FP chambers are single mode optical fiber described in the welding of quartz ampoule both ends, and the quartz length of tube is 100-500 Micron, the quartz pipe outside diameter and the single mode fiber diameters are 110-140 microns, and the quartz bore is micro- for 20-80 Rice.
Further, the quartzy length of tube is 300 microns, and the quartz pipe outside diameter is with the single mode fiber diameters 125 microns, the quartz bore is 60 microns.
Further, the FP chambers interference spectrum is:
Wherein, IFPFor FP chamber interference spectrum light intensity, I1And I2The respectively reflective light intensity of FP cavity reflections face 1 and reflecting surface 2, d For the length of FP chambers, n is FP chamber air refractive index, and λ is the wavelength of incident light, the Free Spectral Range FSR of FP chambersFPFor
FSRFP2/2nd (2)
The transmission spectrum of the Sagnac rings is:
Wherein, IsagnacFor Sagnac ring interference spectrum light intensity, B and L are respectively the double refractive inde and length of diplopore optical fiber, λ For the wavelength of incident light, the Free Spectral Range FSR of Sagnac ringsSagnacFor
FSRSagnac2/BL (4)
Interfere the Free Spectral Range FSR of spectrum envelopeEnvelopeWith FP chamber Free Spectral Ranges FSRFPIt is free with Sagnac rings Spectral region FSRSagnacRelation be
When Sagnac rings are in frequency displacement under the action of temperature, interfere spectrum envelope frequency displacement therewith, and frequency shift amount is Sagnac rings M times of frequency shift amount, M are sensitivity enhancement factor, are expressed as
The value range of the M is 10-50.
Further, the value of the M is 20.
Further, the transmission spectrum of Sagnac rings interference is represented by:
Wherein, IsagnacFor Sagnac ring interference spectrum light intensity, B and L are respectively the double refractive inde and length of diplopore optical fiber, λ For lambda1-wavelength, its Free Spectral Range FSRSagacIt is represented by
FSRSagnac2/BL (2)
When diplopore fiber optic temperature change Delta T, Sagnac rings will produce frequency displacement, frequency shift amount Δ λSagnacFor
Wherein, the variable quantity of the double refractive inde of diplopore optical fiber when Δ B is change in temperature Δ T;
When the wavelength X of Distributed Feedback Laser is located on the sideband of Sagnac ring transmission spectrums, pass through the flashlights of Sagnac rings Strength Changes Δ I is with Sagnac ring transmission spectrum frequency displacement Δs λSagnacVariation relation be
Δ I=k Δs λSagnac (4)
In formula, Δ I is signal light intensity, and k is the sideband slope of Sagnac ring transmission spectrums;
(3) formula is brought into (4) formula to obtain:
Signal light intensity is converted into voltage signal by the photodetector, and the relation of its voltage variety and temperature change is
In formula, Δ V is voltage variety, and α is the transformation efficiency of photodetector;
The change of temperature can be obtained by the change for the output voltage for detecting photodetector.
Beneficial effects of the present invention:The present invention proposes a kind of based on interference spectrum cursor effect and annular cavity ring-down spectroscopy skill The temperature sensor of art.When Sagnac rings and FP chambers cascade, since their Free Spectral Range approaches, interference spectrum wraps Network, produces cursor effect.When the temperature is changed, the frequency displacement for interfering spectrum envelope is tens times of Sagnac ring interference spectrum frequency displacements.Phase Than making temperature measurement sensitivity improve tens times in single Sagnac rings, interference spectrum cursor effect.However, spectrographic detection needs Expensive equipment, for lowering apparatus cost, interference spectrum cursor effect is combined by the present invention with annular Research on Cavity Ring Down Spectroscopy, Temperature survey is realized by the way of intensity demodulation.Since annular Research on Cavity Ring Down Spectroscopy is intensity demodulation enhanced sensitivity technology, The invention is low-cost and high-precision temperature sensing temperature sensor.Improved fibre optic temperature sensor, temperature survey are sensitive Degree can improve the 1-2 order of magnitude.
Brief description of the drawings
To describe the technical solutions in the embodiments of the present invention more clearly, make required in being described below to embodiment Attached drawing is briefly introduced, it should be apparent that, drawings in the following description are only some embodiments of the present invention, for this For the those of ordinary skill in field, without having to pay creative labor, it can also be obtained according to these attached drawings His attached drawing.
Fig. 1 is the principle schematic diagram of temperature sensor of the embodiment of the present invention;
Fig. 2 is diplopore fiber cross-sections figure of the embodiment of the present invention;
Fig. 3 is FP cavity configuration principle schematics of the embodiment of the present invention;
Fig. 4 (a) is general for independent FP chambers and the interference of Sagnac rings;
Fig. 4 (b) is general for FP chambers and the interference in parallel of Sagnac rings;
Fig. 5 (a) is the interference spectrum of single Sagnac rings interferometer and single FP chambers interferometer;
Fig. 5 (b) is general for FP chambers and the interference in parallel of Sagnac rings;
The interference spectrum of single Sagnac rings and single FP chambers when Fig. 6 (a) is 42.2 DEG C and 43.0 DEG C;
FP chambers and Sagnac ring parallel connection interference spectrums when Fig. 6 (b) is 42.2 DEG C and 43.0 DEG C;
Fig. 7 is single Sagnac rings and cascaded structure interference spectrum frequency displacement variation with temperature.
Fig. 8 is sideband demodulation principle schematic diagram of the embodiment of the present invention;
Fig. 9 declines for present invention implementation pulse and swings signal graph.
Embodiment
In order to make the object, technical solutions and advantages of the present invention clearer, the present invention is made below in conjunction with attached drawing into One step it is described in detail, it is clear that described embodiment only part of the embodiment of the present invention, rather than whole implementation Example.Based on the embodiments of the present invention, those of ordinary skill in the art are obtained without making creative work All other embodiment, belongs to the scope of protection of the invention.
The preferred embodiment that the invention will now be described in detail with reference to the accompanying drawings.
As shown in Figure 1, specifically, the present invention relates to one kind based on interference spectrum cursor effect and annular Research on Cavity Ring Down Spectroscopy Temperature sensor, include successively along optical path direction:DFB optical fiber lasers, polarizer, electrooptic modulator, isolator, FP chambers, Decline and swing loop, photodetector;The DFB optical fiber lasers, polarizer, electrooptic modulator, isolator, FP chambers, decline swing loop, Photodetector is connected by single mode optical fiber;
Described decline is swung loop and is included successively along optical path direction:First coupler, the second coupler, Sagnac interference rings, ring Shape device, flat-top grating, EDFA amplifiers, the 3rd coupler;First coupler, the second coupler, Sagnac interference rings, ring Shape device, flat-top grating, EDFA amplifiers, the 3rd coupler are connected by single mode optical fiber;
The continuous light that light source is sent is changed into pulsed light, the pulsed light warp after the polarizer and the electrooptic modulator After the FP cavity reflections, decline as described in entering 10% input terminal of first coupler and swing loop, the pulsed light is in institute State to decline to swing and often circulated in loop one week, its portion of energy by the 3rd coupler 1% output, the photodetector by its Voltage signal is converted into, by oscilloscope display.
Detection light (usually taking C-band to the ASE light sources of L-band) is changed into pulsed light after polarizer and electrooptic modulator, Pulsed light enters FP chambers, and optical signal forms interference fringe (as schemed after the front-back reflection of FP chambers, due to there is position difference Shown in 4 (a)), then decline as described in entering 10% input terminal of first coupler and swing loop, into Sagnac rings, warp Diplopore optical fibre time division in Sagnac rings is the two-beam transmitted respectively along fast and slow axis, since fast and slow axis refractive index is different, when this When two-beam meets through the 3rd coupler again, Sagnac interference fringes will be formed, (shown in such as Fig. 4 (a)), two parts interference Signal optical superposition, forms the envelope after superposition (shown in such as Fig. 4 (b)), the light is after flat-top grating, its portion of energy is by institute State the 3rd coupler 1% output, the pulsed light it is described decline to swing often circulated in loop one week, have 1% output, the photoelectricity Detector is translated into voltage signal, by oscilloscope display.
As shown in Fig. 2, wherein, the diplopore optical fiber that a segment length is 0.1-2 meters, the diplopore are included in the Sagnac rings Optical fiber both ends and the single mode optical fiber welding;The diplopore optical fiber includes fibre core and two symmetrical relative to the fibre core Airport, filling alcohol in two airports, can also fill other thermo-responsive liquid such as kerosene, pass through sensitive liquids Change of the material to environment temperature, causes the change of optical fibre refractivity, so that the Free Spectral Range of Sagnac rings occurs Change, incident light interfere, are finally reflected the amplification variable signal of the Free Spectral Range of integral sensors, pass through oscillography Device is detected.
Wherein, the diameter of the diplopore optical fiber and single mode optical fiber are 110-140 microns, two skies of the diplopore optical fiber The diameter of stomata is 10-30 microns, 40-60 microns of holes interval, and the size is the energy derived according to above-mentioned formula The preferred dimensions of temperature change are enough accurately measured, there is excellent detectability also by experimental simulation, can obtain optimal Temperature detecting precision.
Wherein, the length of the diplopore optical fiber is 1 meter, and diameter and single mode optical fiber are 125 microns, the diplopore optical fiber The diameter of two airports is 20 microns, 50 microns of holes interval, and the size is the energy derived according to above-mentioned formula The preferred dimensions of temperature change are enough accurately measured, there is excellent detectability also by experimental simulation, can obtain optimal Temperature detecting precision.
Wherein, as shown in figure 3, FP chambers are single mode optical fiber described in the welding of quartz ampoule both ends, the quartz length of tube is 100- 500 microns, the quartz pipe outside diameter and the single mode fiber diameters are 110-140 microns, and the quartz bore is 20-80 Micron, the size is the preferred dimensions that can accurately measure temperature change derived according to above-mentioned formula, also by reality Testing simulation has excellent detectability, can obtain optimal temperature detecting precision.
Incoming signal light part is reflected in reflecting surface 1, is partly transmitted in reflecting surface 1, is reflected in reflecting surface 2, in reflecting surface 1 With the flashlight that reflecting surface 2 reflects there are phase difference, interference signal is produced after superposition (shown in such as Fig. 4 (a)).
Wherein, the quartzy length of tube is 300 microns, and the quartz pipe outside diameter and the single mode fiber diameters are 125 Micron, the quartz bore is 60 microns, and the size is that can accurately measure temperature according to what above-mentioned formula was derived The preferred dimensions of change, have excellent detectability also by experimental simulation, can obtain optimal temperature detecting precision.
Wherein, when detection light incides FP chambers, the FP chambers interference spectrum is:
Wherein, IFPFor FP chamber interference spectrum light intensity, I1And I2The respectively reflective light intensity of FP cavity reflections face 1 and reflecting surface 2, d For the length of FP chambers, n is FP chamber air refractive index, and λ is the wavelength of incident light, the Free Spectral Range FSR of FP chambersFPFor (such as Shown in Fig. 4 (a))
FSRFP2/2nd (2)
When detection light incides Sagnac rings, the transmission spectrum of the Sagnac rings is:
Wherein, IsagnacFor Sagnac ring interference spectrum light intensity, B and L are respectively the double refractive inde and length of diplopore optical fiber, λ For the wavelength of incident light, the Free Spectral Range FSR of Sagnac ringsSagnacFor (shown in such as Fig. 4 (a))
FSRSagnac2/BL (4)
Interfere the Free Spectral Range FSR of spectrum envelopeEnvelopeWith FP chamber Free Spectral Ranges FSRFPIt is free with Sagnac rings Spectral region FSRSagnacRelation be (such as Fig. 4 (b) shown in)
When Sagnac rings are in frequency displacement under the action of temperature, interfere spectrum envelope frequency displacement therewith, and frequency shift amount is Sagnac rings M times of frequency shift amount, M are sensitivity enhancement factor, are expressed as
In principle, the value of M is bigger, illustrates that amplified signal is bigger, and temperature sensing sensitivity is higher, can from above-mentioned formula (6) To find out, work as FSRFPWith FSREnvelopeWhen close, the value of M is infinity, but spectral region FSR in parallel at this timeEnvelopeAlso it is nothing Poor big, oscillograph can not measure the Free Spectral Range at this time, also can not just measure the change of temperature, therefore, by experiment Prove, the value range of the M is preferable for 10-50.It is preferred that the value of the M is 20.
As change in temperature Δ T, Sagnac rings will produce frequency displacement, frequency shift amount Δ λSagnacFor
Wherein, the variable quantity of the double refractive inde of diplopore optical fiber when Δ B is change in temperature Δ T.
FP chambers are extremely insensitive to temperature, and as the fixed ruler of " vernier caliper ", Sagnac rings are temperature sensitive, as " trip The slip ruler of mark slide calliper rule ".When Sagnac rings are in frequency displacement under the action of temperature, interfere spectrum envelope frequency displacement therewith, and frequency shift amount is M times of Sagnac ring frequency shift amounts.
Therefore, frequency displacement Δ λ of the spectrum envelope with temperature is interferedEnvelopeIt is represented by
That is Δ λEnvelope=Δ λSagnac·M (9)
The frequency shift amount varied with temperature by detecting interference spectrum envelope can obtain FP chambers in parallel and Sagnac circumstance temperatures degree passes The sensitivity of sensor, its sensitivity are M times of single Sagnac rings sensitivity degree, and usual M values are in 10-50.Therefore, the parallel connection temperature Degree sensor improves the 1-2 order of magnitude relative to single Sagnac circumstance temperatures degree transducer sensitivity.
Light source needed for the above-mentioned temperature sensor based on Sagnac rings and FP chamber parallel-connection structures, wave-length coverage preferably cover About 80-100nm, such as the ASE light sources including C-band and L-band, or wideband light source.
As illustrated in figs. 5-7, Fig. 5 (a) is the interference of single Sagnac rings interferometer and single FP chambers interferometer to experimental data Spectrum;Experiment measures, its cycle is respectively 3.21nm and 3.38nm, is calculated with reference to formula (5) and understands that M amplification factors are 19.9, Fig. 5 (b) measured for series connection interference spectrum, experiment, its cycle is 48nm.
The interference spectrum of single Sagnac rings when Fig. 6 (a) is 42.2 DEG C and 43.0 DEG C, when temperature is increased to 43.0 by 42.2 DEG C DEG C when, single Sagnac rings and single when the interference spectrum blue shift 0.8nm of single Sagnac rings, Fig. 6 (b) are 42.2 DEG C and 43.0 DEG C Interference spectrum after the cascade of FP chambers, when temperature is increased to 43.0 DEG C by 42.2 DEG C, its interference spectrum blue shift 23nm.
Fig. 7 is single Sagnac rings and cascade structure interference spectrum frequency displacement variation with temperature, it is known that cascaded structure sensitivity For 20.7 times of single Sagnac rings, this experimental result is coincide substantially with notional result (19.9).
Wherein, the transmission spectrum of Sagnac rings interference is represented by:
Wherein, IsagnacFor Sagnac ring interference spectrum light intensity, B and L are respectively the double refractive inde and length of diplopore optical fiber, λ For lambda1-wavelength, its Free Spectral Range FSRSagacIt is represented by
FSRSagnac2/BL (2)
When diplopore fiber optic temperature change Delta T, Sagnac rings will produce frequency displacement, frequency shift amount Δ λSagnacFor
Wherein, the variable quantity of the double refractive inde of diplopore optical fiber when Δ B is change in temperature Δ T;
When the wavelength X of Distributed Feedback Laser is located on the sideband of Sagnac ring transmission spectrums, pass through the flashlights of Sagnac rings Strength Changes Δ I is with Sagnac ring transmission spectrum frequency displacement Δs λSagnacVariation relation be
Δ I=k Δs λSagnac (4)
In formula, Δ I is signal light intensity, and k is the sideband slope of Sagnac ring transmission spectrums;As shown in Figure 8.
(3) formula is brought into (4) formula to obtain:
Signal light intensity is converted into voltage signal by the photodetector, and the relation of its voltage variety and temperature change is
In formula, Δ V is voltage variety, and α is the transformation efficiency of photodetector;
The change of temperature can be obtained by the change for the output voltage for detecting photodetector.
Further, fiber annular cavity ring-down spectroscopy technical principle:
As shown in figure 9, the continuous light that ASE light sources are sent is changed into pulse light, pulse letter after being modulated by electrooptic modulator Number light decline into annular swing intracavitary and in it circulation it is multiple, until loss disappears.In each circulation, only sub-fraction arteries and veins Rush flashlight to export by 1% end of coupler 3, and detected by photodetector, remainder continues to decline in annular chamber to swing Loss.Exponential damping change is presented with the time by the pulse light that photodetector detects, can be represented with following formula:
In formula, I represent t moment light intensity (namely from second the second output terminal of coupler output light intensity), L, c, n and The annular that δ represents respectively declines the total length of the optical fiber for swinging chamber chamber, the spread speed of light in a fiber, the refractive index of fiber core and Total losses of the light in annular chamber.Real-time pulse signal light intensity I can be expressed as:
I0Represent initial beam intensity (namely pulsed light enters the initial beam intensity of annular chamber), trIt is light pulse signal in annular chamber The middle circle of transmission one time used, when photodetector detects that light intensity decays to initial beam intensity I in annular chamber01/e when, The ring-down time τ of ring-down spectroscopy declines with annular and swings cavity loss (δ0It is that annular decline swings the fixed loss value of chamber, δtIt is external physical quantity The loss that the lower pulsed optical signals of effect produce in sensing unit) between relation be:
Carrying out differential to formula (8) both sides can obtain:
As change in temperature Δ T, Sagnac ring transmission spectrum frequency displacement Δ λ Sagnac, cause flashlight produce loss be
Formula (10) is substituted into formula (9) to obtain:
Formula (11) shows:Pulsed light becomes in the variable quantity d τ variation with temperature of the annular ring-down time for swinging intracavitary that declines Change, swing the ring-down time of intracavitary by measuring pulsed light and declining in annular and can obtain temperature change.
The length of the pulsewidth of pulse light and cycle and the annular chamber is configured to:The pulse light is set to exist One week required time t of the annular cavity circulationrIn the range of 2-10 times of the pulsewidth of the pulse light and described In the range of the 1/50-1/20 in the cycle of pulse light.
Beneficial effects of the present invention:The present invention proposes a kind of based on interference spectrum cursor effect and annular cavity ring-down spectroscopy skill The temperature sensor of art.When Sagnac rings and FP chambers cascade, since their Free Spectral Range approaches, interference spectrum wraps Network, produces cursor effect.When the temperature is changed, the frequency displacement for interfering spectrum envelope is tens times of Sagnac ring interference spectrum frequency displacements.Phase Than making temperature measurement sensitivity improve tens times in single Sagnac rings, interference spectrum cursor effect.However, spectrographic detection needs Expensive equipment, for lowering apparatus cost, interference spectrum cursor effect is combined by the present invention with annular Research on Cavity Ring Down Spectroscopy, Temperature survey is realized by the way of intensity demodulation.Since annular Research on Cavity Ring Down Spectroscopy is intensity demodulation enhanced sensitivity technology, The invention is low-cost and high-precision temperature sensing temperature sensor.Improved fibre optic temperature sensor, temperature survey are sensitive Degree can improve the 1-2 order of magnitude.
Device embodiment described above is only schematical, wherein the unit illustrated as separating component can To be or may not be physically separate, physics list is may or may not be as the component that unit is shown Member, you can with positioned at a place, or can also be distributed in multiple network unit.It can be selected according to the actual needs In some or all of module realize the purpose of this embodiment scheme.
Through the above description of the embodiments, those skilled in the art can be understood that each embodiment can Realized by the mode of software plus required general hardware platform, naturally it is also possible to pass through hardware.Based on such understanding, on The part that technical solution substantially in other words contributes to the prior art is stated to embody in the form of software product, should Computer software product can store in a computer-readable storage medium, such as ROM/RAM, magnetic disc, CD, including some fingers Order is used so that a computer equipment (can be personal computer, server, or network equipment etc.) performs each implementation Method described in some parts of example or embodiment.
Finally it should be noted that:The above embodiments are merely illustrative of the technical solutions of the present invention, rather than its limitations;Although The present invention is described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that:It still may be used To modify to the technical solution described in foregoing embodiments, or equivalent substitution is carried out to which part technical characteristic; And these modification or replace, do not make appropriate technical solution essence depart from various embodiments of the present invention technical solution spirit and Scope.

Claims (9)

1. a kind of temperature sensor based on interference spectrum cursor effect and annular Research on Cavity Ring Down Spectroscopy, it is characterised in that along light Road direction includes successively:DFB optical fiber lasers, polarizer, electrooptic modulator, isolator, FP chambers, decline and swing loop, photodetection Device;The DFB optical fiber lasers, polarizer, electrooptic modulator, isolator, FP chambers, decline swing loop, photodetector passes through list Mode fiber connects;
Described decline is swung loop and is included successively along optical path direction:First coupler, the second coupler, Sagnac interference rings, circulator, Flat-top grating, EDFA amplifiers, the 3rd coupler;First coupler, the second coupler, Sagnac interference rings, circulator, Flat-top grating, EDFA amplifiers, the 3rd coupler are connected by single mode optical fiber;
The continuous light that light source is sent is changed into pulsed light after the polarizer and the electrooptic modulator, described in the pulsed light warp After FP cavity reflections, decline as described in entering 10% input terminal of first coupler and swing loop, the pulsed light declines described Swing and often circulated in loop one week, its portion of energy is exported by the 1% of the 3rd coupler, and the photodetector is converted For voltage signal, by oscilloscope display.
2. temperature sensor according to claim 1, it is characterised in that
The diplopore optical fiber that a segment length is 0.1-2 meters, the diplopore optical fiber both ends and the single mode are included in the Sagnac rings Fused fiber splice;The diplopore optical fiber is comprising fibre core and two relative to the symmetrical airport of the fibre core, two skies Filling alcohol in stomata.
3. temperature sensor according to claim 2, it is characterised in that
The diameter of the diplopore optical fiber and single mode optical fiber are 110-140 microns, two airports of the diplopore optical fiber it is straight Footpath is 10-30 microns, 40-60 microns of holes interval.
4. temperature sensor according to claim 3, it is characterised in that
The length of the diplopore optical fiber is 1 meter, and diameter and single mode optical fiber are 125 microns, two air of the diplopore optical fiber The diameter in hole is 20 microns, 50 microns of holes interval.
5. temperature sensor according to claim 1, it is characterised in that
The FP chambers are single mode optical fiber described in the welding of quartz ampoule both ends, and the quartz length of tube is 100-500 microns, the quartz Pipe outside diameter and the single mode fiber diameters are 110-140 microns, and the quartz bore is 20-80 microns.
6. temperature sensor according to claim 5, it is characterised in that
The quartz length of tube is 300 microns, and the quartz pipe outside diameter and the single mode fiber diameters are 125 microns, described Quartzy bore is 60 microns.
7. temperature sensor according to claim 1, it is characterised in that
The FP chambers interference spectrum is:
<mrow> <msub> <mi>I</mi> <mrow> <mi>F</mi> <mi>P</mi> </mrow> </msub> <mrow> <mo>(</mo> <mi>&amp;lambda;</mi> <mo>)</mo> </mrow> <mo>=</mo> <msub> <mi>I</mi> <mn>1</mn> </msub> <mo>+</mo> <msub> <mi>I</mi> <mn>2</mn> </msub> <mo>+</mo> <mn>2</mn> <msqrt> <mrow> <msub> <mi>I</mi> <mn>1</mn> </msub> <msub> <mi>I</mi> <mn>2</mn> </msub> </mrow> </msqrt> <mi>c</mi> <mi>o</mi> <mi>s</mi> <mrow> <mo>(</mo> <mfrac> <mrow> <mn>4</mn> <mi>&amp;pi;</mi> <mi>n</mi> <mi>d</mi> </mrow> <mi>&amp;lambda;</mi> </mfrac> <mo>)</mo> </mrow> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>1</mn> <mo>)</mo> </mrow> </mrow>
Wherein, IFPFor FP chamber interference spectrum light intensity, I1And I2The respectively reflective light intensity of FP cavity reflections face 1 and reflecting surface 2, d are FP chambers Length, n is FP chamber air refractive index, and λ is the wavelength of incident light, the Free Spectral Range FSR of FP chambersFPFor
FSRFP2/2nd (2)
The transmission spectrum of the Sagnac rings is:
<mrow> <msub> <mi>I</mi> <mrow> <mi>s</mi> <mi>a</mi> <mi>g</mi> <mi>n</mi> <mi>a</mi> <mi>c</mi> </mrow> </msub> <mo>=</mo> <mo>&amp;lsqb;</mo> <mn>1</mn> <mo>-</mo> <mi>c</mi> <mi>o</mi> <mi>s</mi> <mrow> <mo>(</mo> <mfrac> <mrow> <mn>2</mn> <mi>&amp;pi;</mi> <mi>B</mi> <mi>L</mi> </mrow> <mi>&amp;lambda;</mi> </mfrac> <mo>)</mo> </mrow> <mo>&amp;rsqb;</mo> <mo>/</mo> <mn>2</mn> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>3</mn> <mo>)</mo> </mrow> </mrow>
Wherein, IsagnacFor Sagnac ring interference spectrum light intensity, B and L are respectively the double refractive inde and length of diplopore optical fiber, λ be into Penetrate the wavelength of light, the Free Spectral Range FSR of Sagnac ringsSagnacFor
FSRSagnac2/BL (4)
Interfere the Free Spectral Range FSR of spectrum envelopeEnvelopeWith FP chamber Free Spectral Ranges FSRFPWith Sagnac ring free spectrums Scope FSRSagnacRelation be
<mrow> <msub> <mi>FSR</mi> <mrow> <mi>E</mi> <mi>n</mi> <mi>v</mi> <mi>e</mi> <mi>l</mi> <mi>o</mi> <mi>p</mi> <mi>e</mi> </mrow> </msub> <mo>=</mo> <mfrac> <mrow> <msub> <mi>FSR</mi> <mrow> <mi>F</mi> <mi>P</mi> </mrow> </msub> <mo>&amp;CenterDot;</mo> <msub> <mi>FSR</mi> <mrow> <mi>S</mi> <mi>a</mi> <mi>g</mi> <mi>n</mi> <mi>a</mi> <mi>c</mi> </mrow> </msub> </mrow> <mrow> <mo>|</mo> <mrow> <msub> <mi>FSR</mi> <mrow> <mi>F</mi> <mi>P</mi> </mrow> </msub> <mo>-</mo> <msub> <mi>FSR</mi> <mrow> <mi>S</mi> <mi>a</mi> <mi>g</mi> <mi>n</mi> <mi>a</mi> <mi>c</mi> </mrow> </msub> </mrow> <mo>|</mo> </mrow> </mfrac> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>5</mn> <mo>)</mo> </mrow> </mrow>
When Sagnac rings are in frequency displacement under the action of temperature, interfere spectrum envelope frequency displacement therewith, and frequency shift amount is Sagnac ring frequency displacements M times of amount, M are sensitivity enhancement factor, are expressed as
<mrow> <mi>M</mi> <mo>=</mo> <mfrac> <mrow> <msub> <mi>FSR</mi> <mrow> <mi>F</mi> <mi>P</mi> </mrow> </msub> </mrow> <mrow> <mo>|</mo> <mrow> <msub> <mi>FSR</mi> <mrow> <mi>F</mi> <mi>P</mi> </mrow> </msub> <mo>-</mo> <msub> <mi>FSR</mi> <mrow> <mi>S</mi> <mi>a</mi> <mi>g</mi> <mi>n</mi> <mi>a</mi> <mi>c</mi> </mrow> </msub> </mrow> <mo>|</mo> </mrow> </mfrac> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>6</mn> <mo>)</mo> </mrow> </mrow>
The value range of the M is 10-50.
8. temperature sensor according to claim 7, it is characterised in that the value of the M is 20.
9. temperature sensor according to claim 1, it is characterised in that
The transmission spectrum of Sagnac rings interference is represented by:
<mrow> <msub> <mi>I</mi> <mrow> <mi>s</mi> <mi>a</mi> <mi>g</mi> <mi>n</mi> <mi>a</mi> <mi>c</mi> </mrow> </msub> <mo>=</mo> <mo>&amp;lsqb;</mo> <mn>1</mn> <mo>-</mo> <mi>c</mi> <mi>o</mi> <mi>s</mi> <mrow> <mo>(</mo> <mfrac> <mrow> <mn>2</mn> <mi>&amp;pi;</mi> <mi>B</mi> <mi>L</mi> </mrow> <mi>&amp;lambda;</mi> </mfrac> <mo>)</mo> </mrow> <mo>&amp;rsqb;</mo> <mo>/</mo> <mn>2</mn> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>1</mn> <mo>)</mo> </mrow> </mrow>
Wherein, IsagnacFor Sagnac ring interference spectrum light intensity, B and L are respectively the double refractive inde and length of diplopore optical fiber, λ be into Optical wavelength is penetrated, its Free Spectral Range FSRSagnacIt is represented by
FSRSagnac2/BL (2)
When diplopore fiber optic temperature change Delta T, Sagnac rings will produce frequency displacement, frequency shift amount Δ λSagnacFor
<mrow> <msub> <mi>&amp;Delta;&amp;lambda;</mi> <mrow> <mi>S</mi> <mi>a</mi> <mi>g</mi> <mi>n</mi> <mi>a</mi> <mi>c</mi> </mrow> </msub> <mo>=</mo> <mi>&amp;lambda;</mi> <mfrac> <mrow> <mi>&amp;Delta;</mi> <mi>B</mi> <mrow> <mo>(</mo> <mi>&amp;Delta;</mi> <mi>T</mi> <mo>)</mo> </mrow> </mrow> <mi>B</mi> </mfrac> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>3</mn> <mo>)</mo> </mrow> </mrow>
Wherein, the variable quantity of the double refractive inde of diplopore optical fiber when Δ B is change in temperature Δ T;
When the wavelength X of Distributed Feedback Laser is located on the sideband of Sagnac ring transmission spectrums, pass through the intensity of the flashlight of Sagnac rings Changes delta I is with Sagnac ring transmission spectrum frequency displacement Δs λSagnacVariation relation be
Δ I=k Δs λSagnac (4)
In formula, Δ I is signal light intensity, and k is the sideband slope of Sagnac ring transmission spectrums;
(3) formula is brought into (4) formula to obtain:
<mrow> <mi>&amp;Delta;</mi> <mi>I</mi> <mo>=</mo> <mi>k</mi> <mo>&amp;CenterDot;</mo> <mi>&amp;lambda;</mi> <mfrac> <mrow> <mi>&amp;Delta;</mi> <mi>B</mi> <mrow> <mo>(</mo> <mi>&amp;Delta;</mi> <mi>T</mi> <mo>)</mo> </mrow> </mrow> <mi>B</mi> </mfrac> </mrow>
Signal light intensity is converted into voltage signal by the photodetector, and the relation of its voltage variety and temperature change is
<mrow> <mi>&amp;Delta;</mi> <mi>V</mi> <mo>=</mo> <mi>k</mi> <mi>&amp;alpha;</mi> <mi>&amp;lambda;</mi> <mfrac> <mrow> <mi>&amp;Delta;</mi> <mi>B</mi> <mrow> <mo>(</mo> <mi>&amp;Delta;</mi> <mi>T</mi> <mo>)</mo> </mrow> </mrow> <mi>B</mi> </mfrac> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>5</mn> <mo>)</mo> </mrow> </mrow>
In formula, Δ V is voltage variety, and α is the transformation efficiency of photodetector;
The change of temperature can be obtained by the change for the output voltage for detecting photodetector.
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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109459598A (en) * 2018-11-14 2019-03-12 国网黑龙江省电力有限公司信息通信公司 A kind of voltage value detection device and method based on FBG
CN109490235A (en) * 2019-01-17 2019-03-19 哈尔滨理工大学 Spectrographic detection type gas sensor based on optical fiber Sagnac ring and optical fiber FP chamber cascade enhanced sensitivity
CN109507132A (en) * 2019-01-17 2019-03-22 哈尔滨理工大学 Spectrographic detection type gas sensor based on double optical fiber FP interferometer parallel-connection structures
CN112432724A (en) * 2020-12-01 2021-03-02 东北林业大学 Stress sensor based on vernier effect of optical fiber resonant cavity and stress measurement method

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070258087A1 (en) * 2006-05-02 2007-11-08 Hitachi Cable Ltd. Optical fiber temperature sensor
CN104950162A (en) * 2015-07-18 2015-09-30 中国人民解放军国防科学技术大学 Optical fiber current sensor based on ring cavity ring-down spectroscopy technology
CN106091973A (en) * 2016-07-05 2016-11-09 哈尔滨理工大学 Based on annular Research on Cavity Ring Down Spectroscopy strain transducer and strain detecting method

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070258087A1 (en) * 2006-05-02 2007-11-08 Hitachi Cable Ltd. Optical fiber temperature sensor
CN104950162A (en) * 2015-07-18 2015-09-30 中国人民解放军国防科学技术大学 Optical fiber current sensor based on ring cavity ring-down spectroscopy technology
CN106091973A (en) * 2016-07-05 2016-11-09 哈尔滨理工大学 Based on annular Research on Cavity Ring Down Spectroscopy strain transducer and strain detecting method

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109459598A (en) * 2018-11-14 2019-03-12 国网黑龙江省电力有限公司信息通信公司 A kind of voltage value detection device and method based on FBG
CN109459598B (en) * 2018-11-14 2021-02-09 国网黑龙江省电力有限公司信息通信公司 Voltage value detection device and method based on FBG (fiber Bragg Grating)
CN109490235A (en) * 2019-01-17 2019-03-19 哈尔滨理工大学 Spectrographic detection type gas sensor based on optical fiber Sagnac ring and optical fiber FP chamber cascade enhanced sensitivity
CN109507132A (en) * 2019-01-17 2019-03-22 哈尔滨理工大学 Spectrographic detection type gas sensor based on double optical fiber FP interferometer parallel-connection structures
CN112432724A (en) * 2020-12-01 2021-03-02 东北林业大学 Stress sensor based on vernier effect of optical fiber resonant cavity and stress measurement method

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