CN106796125A - Interference determination sensor with differential modulated phase-detection - Google Patents
Interference determination sensor with differential modulated phase-detection Download PDFInfo
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Abstract
A kind of sensor is provided, it has：Sensing element (8), thus measurand cause the relative phase shift between two ripples；Phase-modulator (5), relative phase shift is added to by modulation；At least two detectors (10 1,10 2), wherein the first detector (10 1) does not include in response to relative phase shift and interference signal is detected such as the relative phase shift as caused by measurand, and wherein the second detector (10 2) includes detecting interference signal such as the relative phase shift as caused by measurand in response to relative phase shift；And also including signal processing unit (11), its suitable analysis two detects interference signal, and draws measurand value therefrom.
Description
Technical field
The present invention relates to the interference determination sensor using phase modulation detection scheme.
Background technology
US 3707329 describes a kind of equipment for analyzing the light beam modulated by amount to be measured.It includes machinery
Chopper, its amplitude that light beam was modulated before light beam enters electro-optical sensor.
DE 19544778 describes a kind of current sensor, and wherein the two of the sensing optical fiber of different length section twine around conductor
Around（would）.
It is known by the sensor of the interference between two ripples, typically two orthogonal polarization modes of ripple, and
(referring to bibliography [1]-[7]) in for large-scale technical field.The detector signal of these sensors and two ripples it
Between relative phase shiftCosine it is related.Phase shift can be detected using such as polarimetry scheme.This sensor typically will
Seek multiple detector channels (such as two cross-polarizations determine the reference channel of passage and measurement total optical power).In order to meet one
High accuracy requirement in a little applications, such as DC Electro-optical voltages sensing, it is necessary to extremely good relatively steady between the multiple passages of holding
Qualitative (protection precision ~ 1-5% opposing channels stability), this is serious practical challenge.
Interference determination sensor also can detect (MPD) skill using the phase modulation as described in such as bibliography [8]
Art, builds according to open loop and closed loop configurations.MPD technologies are general to be realized in " nonreciprocal phase-modulation " scheme, and is led to
It is usually used in fibre optic gyroscope (FOG) and fibre optic current sensor (FOCS) ([9,10]).Jointly owned patent US
7911196 [11] descriptions it is a kind of according to combine Voltage sensing element (or some this class components), 45 ° of Faraday rotators with
And the voltage sensor of the reflection configuration of MPD modulation and detection electronic device.Similar system with landscape configuration voltage cell
Can see [12].
But polarimetry optical phase measurement usually requires that the comparing of the luminous power measured by multiple detectors,
In MPD, fast phase modulation is added in phase shift to be measured, and only need a detector come measure response wave shape and from
Wherein calculate phase shift.MPD phase shifts calculate unrelated with the absolute level of measurement power, and therefore to resulting from low-frequency vibration and ring
(it can change the optical power fluctuation of border disturbance between different detectors, but can not change the shape of the waveform of detectors measure
Shape (as long as disturbance is much smaller than modulating frequency)) it is inherently immune（immune）.
So far, the design of actual MPD sensors uses " nonreciprocal phase-modulation " principle.This kind of sensor can mainly be drawn
It is divided into two classes：Sagnac interferometer configuration and reflection configuration.Optical design is interactive, it is meant that must be offset in circuit
Propagation during all intrinsic phase shift accumulated.But, the measurand in sensing element causes phase shift and by modulator institute
The phase-modulation forced is noninteractive and is added up to.Therefore, interference ripple before it reaches the detectors must be in phase negative side
Upwards twice by phase-modulator and any interconnection fabric.Single mode (polarization keep (PM)) optical fiber is needed to be to and from determining
The optical phase modulator transmission ripple of adopted phase shift (and polarization).For signal transacting, closed loop and open loop policy are developed, with from
Measured waveform extracts measurand and causes phase shift, see, for example, [8].
The principle of interaction design has been essential in all actual MPD sensors, because phase-modulator and PM
Intrinsic phase shift in both optical fiber is extremely sensitive to temperature or stress disturbance.Therefore, in the feelings without interaction optics circuit system
Under condition, simple MPD equipment will not reliably work in real world environments, because measurement phase shift will be held by environmental perturbation
Continuous disturbance.On the other hand, using interaction design, MPD sensors are verified to obtain the outstanding phase with notable DC stability
Measurement accuracy.
Realize that the interactive optical design of all -fiber device, such as FOG or FOCS is relatively simple, because in this kind of device,
Optical fiber is in itself that high coupling efficiency of the sensing between medium, and various optical fiber components can be spliced by standard（splicing）
It is reliably achieved.But, it is not optical fiber but the sensor of such as block elements for wherein sensing element, with optical fiber coupling
The interactive optical design for closing optical phase modulator is quite difficult to.That because, by bulk optical sensing element it
Afterwards, light must be coupled back in single-mode fiber (same fibre in reflection configuration before sensing element), and for
It is alone sizable technological challenge that high efficiency and reliability is done like that.
According to above, it will thus provide one kind need not be from sensing element, (it has using differential modulated Phase Detecting Device
Body can be bulk optical sensing element) regard the present invention as optically coupling to the interference determination sensor in single-mode fiber or waveguide
Purpose.
The content of the invention
Therefore, according to the first aspect of the present invention, there is provided one kind interference determination sensor, it has：Sensing element, thus
Measurand causes the relative phase shift between two ripples；Phase-modulator, relative phase shift is added to by modulation；At least two detections
Device, wherein the first detector response does not cause relative phase shift and detects interference signal in relative phase shift comprising measurand, and
And wherein the second detector response causes relative phase shift and detects interference signal in relative phase shift comprising measurand.Can compare
Two signals, to draw measurand value therefrom.
The physical significance by verbatim means to be included in all of room and time propagation term " ripple " herein
The vibration of type.Ripple can have narrow or wide range content, can be permanent or be restricted in duration, Yi Jike
By the generation of source or from multiple source synthesis.The property of ripple generally can be mechanical (sound), electromagnetism (light), or have
Any other type.In being described below, the present invention described as an example using light wave.Two interference wave energy are enough such as light
Two orthogonal linears or circular polarisation mode of ripple.
In preferred embodiment in this aspect of the invention, after being modulated by phase-modulator, light wave is entering
By beam splitter before sensing element, and two groups of polarizers and detector respectively respectively measurement sensing element before and after do
Disturb signal.Phase shift is independently retrieved with two measured waveforms, and their difference produces the phase shift inside sensing medium, and it is then
It is converted into measurand value.
Therefore, using the present invention, sensor can be with the reduction to the phase shift variations in the wave path outside sensing element
Sensitivity builds, while do not require that ripple returns to phase-modulator along same paths.
In order to keep the appropriate coherence high between interference ripple at detector, group postpones biasing element and is preferably able to
It is introduced into wave path, so that the intrinsic relative group before and after at least part of compensation sensing element between two ripples postpones.
Group delay compensation can determine that interference contrast value or any related or equivalent metric enter by from interference signal
One step strengthens.Interference contrast additionally be able to for provide cycle information (its help from measurement phase shift in remove cycle ambiguousness,
And thus extend clear and definite measurement range), or as surround sensor birefringence element at least some of control environment
Monitoring signals.
Advantageously, the modulation as caused by phase-modulator is unrelated with measurand.In addition, signal processing unit be adapted to from
Modulate to determine the relative phase shift between two ripples as caused by phase-modulator.Specifically, modulation has and is not present in
At least one spectral component with given frequency in measurand, and signal processing unit is adapted to determine using given frequency
Relative phase shift.
For according to voltage of the invention or electric field measurement, sensing element can include electro-optic crystal, crystallization electric light fibre, pole
Change optical fiber or be attached to the optical fiber or Bulk optical material of piezoelectric element.For according to power of the invention or strain measurement, sense
Surveying element can include optical fiber or Bulk optical material.For according to optical magnetic field sensors of the invention or current sensor,
Sensing element can include optical fiber or waveguide, and it includes professional low birefringent fiber, flint glass optical fiber or spin high birefringence
Optical fiber, block magneto-optic memory technique (such as yttrium iron garnet crystal or fused silica glass block) are attached to magnetostriction element
Optical fiber, waveguide or Bulk optical material or its combination.
Sensor is special as the sensor for DC signals and more particularly for D/C voltage or electric field measurement
Preferably, especially for medium-pressure or high pressure application.But, it can also be potentially applied to fibre optic current sensor, rotation
Sensor or other MPD sensors.
It is particularly suitable for the sensor with block sensing element.
Be described below be described in more detail in accompanying drawing it is of the invention above and other aspect have in addition together with of the invention
Sharp embodiment and application.
Brief description of the drawings
Fig. 1 is illustrated according to the first example of the invention；
Fig. 2A and Fig. 2 B are shown with the example of the invention of relative group delay compensation；And
Fig. 3 is illustrated according to the example of the invention of reflection configuration.
Specific embodiment
According to Basic Differential MPD sensors example of the invention figure 1 illustrates.Light source 1 generates light wave, and it is via single mode
Optical fiber is directed to fibre optic polarizer 2.By 45 ° of fibre-optical splices（splice）4 and in two axles of PM optical fiber 3 carry
Polarization light output passes to optical fiber collimator 6 by optical phase modulator 5, and wherein light is coupled from PM optical fiber 3.It is free of birefringence
Beam splitter 7 is located between collimator and sensing element 8.By a branch of the separated light output of beam splitter 7 by first piece
Shape linear polarization 9-1, and detected by the first photoelectric detector 10-1.Another branch of light output by sensing element 8,
Second block linear polarization 9-2, and detected by the second photoelectric detector 10-2.Two detectors 10-1,10-2's is defeated
Go out signal and be imported into signal processing unit 11.The optical axis for sensing medium 8 abreast aligns, and block linear polarization 9-1,
The axle that the axle of 9-2 snaps to PM optical fiber 3 (it is connected to phase-modulator 5) with 45 °.Optical phase modulator can be Integrated Light
Learn LiNbO3Birefringent phase modulator [8,10] has 90 ° of PM light in one of branch as described in bibliography [9]
The Y type modulators of fine joint.The phase that another part is made up of the PZT (piezoelectric transducer) with the optical fiber attached with it
Modulator [9].
Be added to phase-modulation on the relative phase shift between two interference ripples by phase-modulator 5, and signal transacting list
Unit performs independent MPD signal transactings using measured waveform at two photoelectric detectors 10-1 and 10-2, and divides
Ji Suan not two phase shifts.Measured waveform produces the first phase shift between joint 4 and polarizer 9-1 at detector 10-1, and measured waveform at the detector 10-2 produces the second phase shift between joint 4 and polarizer 9-2。
Therefore, two differences of measurement phase shiftCorresponding to the phase shift inside sensing medium 8.The differential phase is surveyed
AmountDo not influenceed by any phase shift variations between polarizer 2 and beam splitter 7, as long as MPD modulating frequencies are far above disturbance frequency
Rate so that disturbance passes throughWithMeasure simultaneously and comparably track, and be therefore subtracted completely.
For voltage measurement, electro-optic crystal can act as sensing medium 8, so as to by voltage conversion to be measured into crystal
Phase shift between orthogonal polarization mode.There is no electro-optic crystal (such as Bi of natural birefringence4Ge3O12, BGO) be preferred.Electricity
Fiber waveguide or optical fiber can also act as voltage sensing medium.The end face (being cut along [001] direction) of BGO crystal is electrically connected to electricity
Pole, it provides voltage drop V.
As mentioned, there is two kinds of MPD signal transactings configuration (and referring to bibliography [8])：Open loop and closed loop.
In general, closed loop configurations are than open loop homologue（counterpart）Be more difficult to realize, but sensor output stability and
Linearity aspect is excellent.
In open-loop configuration, phase-modulator applies self-excitation modulation, and phase shift by signal processing unit 11 from measurement ripple
Shape is calculated.A kind of typical case realizes described in patent US 6429939 (bibliography [13]), wherein being adjusted using sinusoidal phase
β (t) processed, and phase shift is calculated from the relative ratios of the various harmonic powers in measured waveform.
In Open-loop sensors, the feedback to modulation waveform is not carried out from the phase shift for being calculated, except modulation amplitude
Outside license energy (but not being forcibly) is stablized using the output calculated from measured waveform.
By contrast, in closed loop configurations [8], the skew of phase-modulation waveform (or equivalent 2 π amplitude zig-zags
Phase) pass through to calculate the opposite continuous adjustment of phase shift via feedback control loop so that the phase shift operating point of sensor remains
Fixing point (such as zero).Detector and phase-modulator are linked in the feedback loop via signal processing unit 11, wherein institute
The phase shift of retrieval is fed back to control phase-modulation waveform.
In differential MPD schemes of the invention, there are at least two detectors, but there is normally only a phase-modulation
Device.Therefore, it is not possible to two kinds of detector output operation closed loop detections.Can realize to two kinds of open loop signals of detector output
Treatment；Or it is alternatively possible to realize to detector output one of them (such as detector 10-1) closed signal treatment,
And process from another detection signal (such as detector 10-2) to extract phase shift using open loop signal.
If the closed signal treatment to detector 10-1 is realized in selection, will to the phase shift of polarizer 9-1 from tap points 4
Remain at and value (such as zero) is fixedly installed.In this case, the phase shift of sensing medium 8 is in detector 10-2 places
The phase shift of measurement subtracts arranges value, and does not need further subtracting between institute's detection signal generally.
The second aspect of the present invention is related to the coherence of the light generated by light source 1.Although MPD phase measurement principles will
Worked together with high-coherence light source, such as laser of narrowband diode, but in fact, broad band source, example with short coherence time
If superluminescent LED (SLED) is often preferred, so as to location interference ripple, and avoid being coupled from various optical fiber
Point（junction）The cross-linked parasitic disturbances at place.Using this low-coherence light source, can only be observed in relatively short scope
To interference signal, relative group of delay between two of which polarization was completely within the coherence time of source, and outside it, it is right to disturb
Rapid decrease and zero will be finally dropped to than degree, and MPD Phase Detecting Devices will be stopped.
Therefore, if using low-coherence light source, various birefringence components, such as PM optical fiber and modulator in system must
Design and balance its intrinsic relative group must be adjusted to postpone so that the total phase between tap points 4 and output polarizer 9-1 and 9-2
Postpone to remain minimum and fall completely within the coherence time of light source to group.For this purpose, additional group of delay is mended
It can be preferred to repay during element inserts wave path.
However, with changes in environmental conditions, the temperature and stress sensitive of component and possible non-homogeneous environment in system
Degree remains able to make total relative group delay slow drift leave minimal design value.Therefore, environmental perturbation is excessive wherein and/or light
In coherence time in source too short sensing system, may certify that it is advantageous that active stabilization always relative group postpones or equivalent
Stabilization interference contrast, successfully to realize differential MPD schemes.This is it is naturally required that measurement and the interference of control MPD signals are right
Than the ability of degree.
Although MPD schemes are routinely only used for measuring phase shift, it is possible that extension signal processing algorithm, and also from survey
Signal is measured to draw interference contrast.Many to realize existing, this depends on the factor of such as modulation waveform and feedback control configuration.
Below, the example procedure for being calculated come description disturbance contrast using the Sine Modulated waveform of open-loop configuration, it is patent US
The extension of the algorithm described in 6429939 (bibliography [13]).
Phase-modulator 5 is connected with sensing medium 8, is added to phase shift to be measured so as to additional phase shift is modulated into β (t)。
Modulation luminous power after detector, detector 10-2 measurements linear polarization, such as polarizer 9-2 of such as Fig. 1.Modulation inspection
Surveying device signal can write
[1]。
Wherein I0The power output of light source is represented,Be in the phase shift to be measured of the central wavelength of ripple, and A be interference
Contrast.
Using Sine Modulated, the detector signal of equation [1] can write according to fourier expansion
It is a series of harmonic of the different rank k in modulating frequency Ω, i.e.
[1']
Wherein first three harmonic amplitude BkAnd phaseFor
Use the first species JkThe Bessel function of (β).The symbol of harmonic component can by by the phase of harmonic component with swash
The phase for encouraging waveform is compared to determine.
Vector or plural number can be formed from above-mentioned expression, and it allows to draw phase shift main value from institute's detection signalWith it is dry
Disturb contrast A.
[2]
Phase shift main valueThe independent variable of Y can be calculated as, and interference contrast A is equal to its absolute value divided by I0.Total optical power
I0Can be calculated as
。
It is preferred that modulation amplitude is β=1.84 rad, wherein J1(β) has its first maximum number；Another preferred amplitude is
β=2.63 rad, wherein J1(β) and J2(β) is equal.But, generally, for the MPD methods for work, phase-modulation width
Degree β can be arbitrarily small.Additionally, for example for the purpose of stable amplitude, it is known that modulation amplitude β also can be from measurement harmonic wave
Amplitude is calculated.The other details of open loop MPD signal transactings can see bibliography [8,13].
In the example of fig. 1, the additional measurement of interference contrast or any parameter associated therewith or equivalent is expressed as
IC。
Simultaneously as the interference contrast of MPD signals can be by environmental perturbation, so it also can be by controlling environment bar
Part is controlled.As indicated by the arrow IC in Fig. 1, institute's determination value of interference contrast or any coherent signal can be used for controlling
At least some parameters of sensor processed.
A kind of possibility is the temperature of the phase-modulator in heater to be controlled or peltier unit.As temperature becomes
Change, the birefringence of modulator crystal and relative group postpone also to change.Similarly, it is also possible to control the temperature of the section of PM optical fiber
Or strain.Realize that the other method of this interference contrast control also can be easily designed.
Using measurement and controlling mechanism, then feedback control loop can be set up, to stablize MPD interference contrasts, to prevent it
It is drifted away from coherent ranges.But, feedback had both been needed not be accurately also without being quick, because the coherent ranges of light source
It is usually moderate, and possible group of delay drift is actually also slow.
Next, proposing several examples of relative group delay compensation in the design of sensor.
In the example of Fig. 2A, two substantially the same birefringent phase modulators 5 and 5' are spelled with 90 ° of relative axle alignment
It is connected together, therefore its intrinsic birefringence is cancelled.The length of the PM optical fiber 3 between 45 ° of tap points and 90 ° of tap points 4' should be with
PM fiber lengths between 90 ° of tap points 4' and collimator 6 are identical so that its birefringence is also cancelled.Phase-modulator 5' and
PM optical fiber between tap points 4' and collimator 6 collectively forms group delay compensation component 20.At least some energy of birefringence component
Enough it is maintained in housing 21, to keep the uniform environment among them and shield（shield against）Stress and temperature wave
It is dynamic.The PM fiber segments 3 stayed in outside housing 21 are preferably held as short as possible.Meanwhile, MPD phase-modulations can be distributed in two
Between individual phase-modulator 5 and 5', so as to allow each modulator may to be operated in more small range with the more preferable linearity.
The example of Fig. 2 B is similar with Fig. 2A, and wherein difference is, using only a phase-modulator 5, and phase-modulation
The intrinsic birefringence of device crystal 5 is (signified by ring in Fig. 2 B by serving as one of section of PM optical fiber 3 of group delay compensation component 20
Show) in extra length compensate.Housing 21 can similarly include at least some of birefringence component.Because phase-modulator
The temperature characterisitic of crystal 5 and PM optical fiber 3 can be different, so with the temperature change of sensor, this design can be subjected to
Postpone drift than designing many groups shown in Fig. 2A.
If low-coherence light source is used as source 1, the measurement of IC is with the another of ambiguousness removal and measurement range extension relatively
Outer benefit, if being described as follows：
The phase-shift measurement of sensor is disturbed typically inherently in terms of 2 π cycles（periodwise）It is ambiguity.But, low phase
The auto-correlation function (being defined as disturbing contrast herein) in dry source is narrow function, and its value is within its coherence time from a phase
Bit period is to another phase cycling significant changes.Therefore, if simultaneously measurement phase shift main value ((- π ,+π] within phase shift it is exhausted
To value（mod）2 π) and interference contrast, then auto-correlation function has the model of the strongly monotone correlation postponed to relative group wherein
In enclosing, interference contrast can be used for phase shift main value measured by correct period allocated, and thus clearly determine relative phase
The value completely moved.
Thus, for example according to equation [2] to relative phase shift and IC (or any relevant parameter) while measurement can be
Outside being used for for phase-shift measurement scope expanding to 2 π in sensor of the invention, effectively extend to by the auto-correlation letter of light source
The slope and scope determined by form of number (or cross-correlation function, if ripple passes through two not homologous generations).
Such as can be also employed in conjunction with using any other cycle clear one's mind of doubt method of two different wave lengths, so as to
Outside clear and definite phase-shift measurement scope expanded into 2 π.In patent application WO 9805975A1 [6] and EP 1179735A1 [7]
The example of this kind of method is described.The third aspect of the present invention is related to the geometry designs of sensor.Fig. 1 shows transmission configuration sensor
Example, wherein light source 1 (and many other components) and detector 10-2 be located at sensing crystal two opposite ends.For voltage
The example of sensor, this causes some components, particularly one of detector 10-1 or 10-2 to be located at high-voltage.Fig. 3
Illustrate the example of reflection configuration voltage sensor.In reflection configuration, reflective optical device 30 is placed on one end of sensing element 8
(one end preferably at high-voltage), and every other optics is located at the other end (preferably at ground potential
End).Reflective optical device 30 can be flat/curved reflectors, roof type speculum, corner cube retrodirective reflector or only
It is deposited on the reflective film coating on crystal end-face.Reflection at reflective optical device 30 should ideally preserve the polarization shape of light
State, without rotating or polarizing dependent phase shift.Element 20 represent again described in during as discussed above concerning Fig. 2A and Fig. 2 B (one or
It is multiple) optional group of delay compensation component.
The electric light axle of crystal should abreast align with the axle of PM optical fiber 3.Preferably, the beam splitter 7 before sensing medium 8
Should be alignd with its axle with 45 ° relative to PM fiber axis, so as to any possible phase for making two interference ripples to be experienced from beam splitter
Phase shift etc..Any remaining system of the remaining natural birefringence for example from beam splitter, retrodirective reflector or from BGO crystal
Phase shift can be characterized and removed by calibrating.The residual birefringence of BGO can also be dropped by two BGO crystal of tandem compound
Low, wherein antiparallel [001] axle and x/y axles are rotated relatively to each other 90 °.In this arrangement, electric light phase shift is added up to, and this
Birefringence cancellation is levied, so as to cause more preferable zero stability.Detector 10-1 or 10-2 can be directly attached to its of sensor
Remaining part point, or alternatively, they can be connected to sensor via single mode or multimode fibre.
Although some currently preferred embodiments of the present invention is illustrated and described herein, it is to be appreciated that the invention is not limited in
This, but can implement and embody by different way in addition within the scope of claims below.
Cited bibliography
List of reference characters
Light source 1
Linear polarizer 2
Polarization keeps (PM) optical fiber 3
Fibre-optical splice 4,4'
Optical phase modulator 5,5'
Collimator 6
Beam splitter 7
Sensing element 8
Linear polarization 9-1,9-2
Fluorescence detector 10-1,10-2
Signal processing unit 11
Group postpones biasing element 20
Control housing 21
Reflective optical device 30.
Claims (15)
1. one kind interferes determination sensor, including
Sensing element (8), thus measurand add two ripples between relative phase shift,
At least the first and second detectors (10-1,10-2),
Separator element (7), wherein the first output branch of the separator element goes to first detector (10-1), and
And the second output branch of the separator element is by the sensing element (8) and goes to second detector (10-2)
On,
Characterized in that, the sensor also includes phase-modulator (5), it causes the modulation to the relative phase shift,
Wherein described separator element is located between the phase-modulator (5) and the sensing element (8),
Wherein described first detector (10-1) is not included described in as caused by the measurand in response to relative phase shift
Relative phase shift and detect interference signal, and wherein described second detector (10-2) in response to relative phase shift include by the quilt
Survey the relative phase shift caused by object and detect interference signal,
The sensor also includes signal processing unit (11), and it is adapted to determine described two from detected interference signal each
Relative phase shift between individual ripple, and determine measurand value using the amount for representing their difference.
2. sensor as claimed in claim 1, also postpones biasing element (20), to control in first detector including group
Described relative group between the ripple of (10-1) place and the detection of second detector (10-2) place postpones.
3. sensor as claimed in claim 2, wherein, described group of delay biasing element (20) including with birefringence axis (4')
90 ° of change the polarization-maintaining fiber (3) for being connected to other sections at least one sections.
4. sensor as claimed in claim 2, wherein, described group of delay biasing element (20) including with the phase-modulator
(5) substantially the same at least second phase modulator (5'), wherein described two modulators with the birefringence axis (4')
90 ° of transformations are connected to each other.
5. the sensor as any one of claim 2 to 4, wherein, described group of delay biasing element (20) and the phase
Position modulator (5) is in common housing (21) or temperature controlled.
6. such as sensor in any one of the preceding claims wherein, wherein, the separator element (7) is bulk optical beam splitting
Device or multiple-limb fiber coupler.
7. such as sensor in any one of the preceding claims wherein, wherein, the signal processing unit (11) is adapted to from described
Any value and the relative phase shift that interference contrast (IC) is represented to draw of interference signal.
8. such as sensor in any one of the preceding claims wherein, wherein, the phase-modulator (5) is electric light phase-modulation
Device, integrated optic phase modulator, specifically birefringence modulator, Y type modulators or piezoelectric fibers modulator.
9. such as sensor in any one of the preceding claims wherein, wherein, the phase-modulator is in closed feedback loop
One of interference signal is detected using two to control, and wherein described measurand is from another detected interference signal
To draw, changed by the arranges value of the closed feedback loop.
10. such as sensor in any one of the preceding claims wherein, wherein, the ripple is light wave, specifically cross line
Property polarized lightwave or left and right circular polarization light wave.
11. such as sensor in any one of the preceding claims wherein, wherein, the measurand is voltage or electric-field intensity,
And the relative phase shift inside the sensing element is in response to the voltage that is applied between its two faces.
12. such as sensor in any one of the preceding claims wherein, wherein, the sensing element includes electro-optic crystal or electric light
Fibre, specifically crystallizes electric light fibre or polarization electric light fibre or optical fiber and piezoelectric.
13. sensor as described in claim 11 or 12, as reflection configuration sensor, wherein reflective optical device (30) edge
Same paths return to the ripple by the sensing element.
14. such as sensor in any one of the preceding claims wherein, wherein, the sensing element includes magneto-optic memory technique or light
It is fine.
15. such as sensor in any one of the preceding claims wherein,
Wherein, the modulation as caused by the phase-modulator (5) is unrelated with the measurand, and
Wherein described signal processing unit (11) is adapted to from the modulation as caused by the phase-modulator (5) to determine
State the relative phase shift between two ripples.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP14156092.0 | 2014-02-21 | ||
| EP14156092 | 2014-02-21 | ||
| PCT/EP2015/053516 WO2015124678A1 (en) | 2014-02-21 | 2015-02-19 | Interferometric sensor with differential modulated phase detection |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106796125A true CN106796125A (en) | 2017-05-31 |
| CN106796125B CN106796125B (en) | 2019-06-18 |
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ID=50137559
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201580009312.1A Active CN106796125B (en) | 2014-02-21 | 2015-02-19 | Interference determination sensor with differential modulated phase-detection |
Country Status (3)
| Country | Link |
|---|---|
| CN (1) | CN106796125B (en) |
| DE (1) | DE112015000886T5 (en) |
| WO (1) | WO2015124678A1 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3290870B1 (en) | 2016-09-02 | 2019-03-13 | ABB Schweiz AG | Closed-loop interferometric sensor using loop gain for determining interference contrast |
| EP3290931B1 (en) * | 2016-09-02 | 2019-05-15 | ABB Schweiz AG | Interferometric voltage sensor with error compensation |
| CN114325030B (en) * | 2021-09-30 | 2024-05-03 | 南京曦光信息科技研究院有限公司 | Double-square-wave modulation open-loop demodulation method based on optical current transformer |
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|---|---|---|---|---|
| US3707329A (en) * | 1970-02-25 | 1972-12-26 | Bbc Brown Boveri & Cie | Apparatus for electronically analyzing modulated light beams |
| US5308973A (en) * | 1990-11-22 | 1994-05-03 | Hilti Aktiengesellschaft | Method and device for the measurement of force by a fiber optics system by evaluating phase shift of light waves |
| DE19544778A1 (en) * | 1995-11-30 | 1997-06-05 | Siemens Ag | Method and arrangement for measuring a measured variable, in particular an electrical current, with high measurement resolution |
| CN101155162A (en) * | 2006-09-28 | 2008-04-02 | 冲电气工业株式会社 | Otdm-dpsk signal generator capable of detecting an optical carrier phase difference between optical pulses |
| CN101334427A (en) * | 2008-07-16 | 2008-12-31 | 上海大学 | Reflecting type full-optical fiber current sensor |
| CN101568842A (en) * | 2006-12-22 | 2009-10-28 | Abb研究有限公司 | Optical high voltage sensor |
| CN101600968A (en) * | 2006-12-22 | 2009-12-09 | Abb研究有限公司 | Optical voltage sensor |
| CN102109414A (en) * | 2010-12-15 | 2011-06-29 | 深圳大学 | Method and device for calibrating phase modulation of spatial light modulators by utilizing heterodyne interference |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5402234A (en) * | 1992-08-31 | 1995-03-28 | Zygo Corporation | Method and apparatus for the rapid acquisition of data in coherence scanning interferometry |
-
2015
- 2015-02-19 CN CN201580009312.1A patent/CN106796125B/en active Active
- 2015-02-19 DE DE112015000886.1T patent/DE112015000886T5/en not_active Withdrawn
- 2015-02-19 WO PCT/EP2015/053516 patent/WO2015124678A1/en active Application Filing
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3707329A (en) * | 1970-02-25 | 1972-12-26 | Bbc Brown Boveri & Cie | Apparatus for electronically analyzing modulated light beams |
| US5308973A (en) * | 1990-11-22 | 1994-05-03 | Hilti Aktiengesellschaft | Method and device for the measurement of force by a fiber optics system by evaluating phase shift of light waves |
| DE19544778A1 (en) * | 1995-11-30 | 1997-06-05 | Siemens Ag | Method and arrangement for measuring a measured variable, in particular an electrical current, with high measurement resolution |
| CN101155162A (en) * | 2006-09-28 | 2008-04-02 | 冲电气工业株式会社 | Otdm-dpsk signal generator capable of detecting an optical carrier phase difference between optical pulses |
| CN101568842A (en) * | 2006-12-22 | 2009-10-28 | Abb研究有限公司 | Optical high voltage sensor |
| CN101600968A (en) * | 2006-12-22 | 2009-12-09 | Abb研究有限公司 | Optical voltage sensor |
| CN101334427A (en) * | 2008-07-16 | 2008-12-31 | 上海大学 | Reflecting type full-optical fiber current sensor |
| CN102109414A (en) * | 2010-12-15 | 2011-06-29 | 深圳大学 | Method and device for calibrating phase modulation of spatial light modulators by utilizing heterodyne interference |
Also Published As
| Publication number | Publication date |
|---|---|
| CN106796125B (en) | 2019-06-18 |
| WO2015124678A1 (en) | 2015-08-27 |
| DE112015000886T5 (en) | 2016-11-10 |
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