CN104819737A - Optical fiber sensing system and method for acquiring polarization-related measurement data - Google Patents
Optical fiber sensing system and method for acquiring polarization-related measurement data Download PDFInfo
- Publication number
- CN104819737A CN104819737A CN201510180694.6A CN201510180694A CN104819737A CN 104819737 A CN104819737 A CN 104819737A CN 201510180694 A CN201510180694 A CN 201510180694A CN 104819737 A CN104819737 A CN 104819737A
- Authority
- CN
- China
- Prior art keywords
- cos
- light
- sin
- modulation
- optical fiber
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000013307 optical fiber Substances 0.000 title claims abstract description 89
- 230000010287 polarization Effects 0.000 title claims abstract description 35
- 238000005259 measurement Methods 0.000 title claims abstract description 25
- 238000000034 method Methods 0.000 title claims abstract description 24
- 101150118300 cos gene Proteins 0.000 claims description 103
- 238000002955 isolation Methods 0.000 claims description 58
- 230000003287 optical effect Effects 0.000 claims description 39
- 101100234408 Danio rerio kif7 gene Proteins 0.000 claims description 38
- 101100221620 Drosophila melanogaster cos gene Proteins 0.000 claims description 38
- 101100398237 Xenopus tropicalis kif11 gene Proteins 0.000 claims description 38
- 230000000694 effects Effects 0.000 claims description 28
- 230000005540 biological transmission Effects 0.000 claims description 25
- 239000000835 fiber Substances 0.000 claims description 17
- 238000012546 transfer Methods 0.000 claims description 9
- 230000008676 import Effects 0.000 claims description 6
- 238000005070 sampling Methods 0.000 claims description 6
- 230000008569 process Effects 0.000 claims description 4
- 230000000737 periodic effect Effects 0.000 claims description 3
- 230000008859 change Effects 0.000 description 5
- 230000035882 stress Effects 0.000 description 4
- 230000005684 electric field Effects 0.000 description 3
- 230000005693 optoelectronics Effects 0.000 description 3
- 230000000644 propagated effect Effects 0.000 description 3
- 239000000758 substrate Substances 0.000 description 3
- 230000032683 aging Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 230000002596 correlated effect Effects 0.000 description 1
- 230000000875 corresponding effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
Landscapes
- Investigating Or Analysing Materials By Optical Means (AREA)
Abstract
The invention provides an optical fiber sensing system which comprises the components of a light source, a modulating module, an isolated optical fiber, a sensing module and a modulating voltage generator. The light source, the modulating module, the isolated optical fiber and the sensing module are successively connected. The output voltage of the modulating voltage generator is applied on the modulating module. The invention further provides a method for acquiring polarization-related measurement data. The optical fiber sensing system makes an optical fiber polarimeter effectively eliminate the influence of various outer time-varying characteristics such as mechanical vibration and ambient temperature, so that higher accuracy of the data which are acquired in measurement is realized.
Description
Technical field
The present invention relates to a kind of technical field of optical fiber sensing, particularly relate to a kind of optical fiber sensing system and obtain the method for the measurement data relevant to polarization.
Background technology
The measurement that polarization is correlated with is a branch very important in optical measurement.Light is as an electromagnetic part, and in the process that space wave is propagated, its electric field component is vector field, and its polarization state conventional describes, and namely describes with the polaried orientation of this vector and phase differential.When phase differential is zero, this polarization state is called linear polarization; When phase differential is non-vanishing, this polarization is called elliptic polarization or circular polarization.
When light is propagated in sensing unit, surveyed physical quantity with (treating) and interact, change the polarization state of optical electric field, thus the information of measurand is loaded on light wave.In order to be extracted by the physical quantity information that light wave loads, optical system is generally made up of a pair polarizer of mutual orthogonal and the sensing unit that clips between them; Such optical system is called polarimeter.
The unit of optical polarization can be changed, be called birefringent elements.Polarizer between accompany a birefringent elements system be called first-order polarization meter; Polarizer between accompany two, or the system of N number of birefringent elements is called second order, or N rank polarimeter.Polarizer between birefringent elements, have plenty of and have a mind to add, the imperfection had plenty of due to optical element causes, and is can not be unheeded.Because polarizer and birefringent elements are all vector devices, the mathematical analysis of system optics intensity must be described by trigonometric function.The increase of polarimeter exponent number, will make mathematical analysis become exponentially level numerous and diverse, greatly hinder the development of polarimeter.
Optical fiber, as the wave director of light wave, is the basic device of optical fiber sensing system.Because its bendable breaks, propagation distance is far away, easy to use; Again because it is insulator, not by the impact of electromagnetic interference (EMI), optical fiber sensing system has lot of superiority.But, due to the effect of photoelasticity physical influence, any point on fiber optic conduction path, when being subject to the affecting of mechanical vibration or variation of ambient temperature, all will there is uncontrollable change in the polarization state at this some place in the light wave conducted in optical fiber, make optical fiber have time-varying characteristics as birefringent elements.
Usually, fiber polarimeter respectively has an optical fiber in the front and back that polarizer is right; Incident light is sent into polarimeter by optical fiber above, and polarimeter emergent light is sent back to by optical fiber below.Because polarimeter is very responsive to the polarization state of incident light, incident optical makes fiber polarimeter inevitably have time-varying characteristics as the time-varying characteristics that birefringent elements has.The optically-coupled of the light source temperature characterisitic of aging, photoelectric detector, light source and optical fiber, optical fiber and photoelectric detector, light (light beam) and optical fiber collimator etc. in time makes optical fiber sensing system can not be practical with the time-varying characteristics that the change etc. of ectocine produces.
Because each components and parts in optical fiber sensing system all have time-varying characteristics, have impact on the measurement result of the data relevant to polarization widely.Prior art does not recognize the time-varying characteristics of optical system, in order to improve the precision of measurement data, although also use photoelastic effect or bubble Ke Ersi (Pockels) electrooptical effect to improve polarimeter measuring accuracy as optical phase modulator, but still there is larger error in the data measured, and sinusoidal wave as basic modulation waveform owing to adopting, very complicated mathematical analysis originally becomes more numerous and diverse.The present invention adopts stepped square wave as the basic waveform of phase-modulation, with the analysis of easy data.The physical influence that sensing element in the present invention can have has: bubble Ke Ersi (Pockels) electrooptical effect, faraday's (Faraday) magneto-optic effect and light unisexuality effect etc., correspondingly measured physical quantity can comprise, but be not limited to voltage, (or electric field intensity), electric current (or magnetic field intensity), pressure (or stress).
Summary of the invention
The technical problem to be solved in the present invention, be to provide a kind of method obtaining the measurement data relevant to polarization, obtain the measurement data relevant to polarization by optical fiber sensing system, traditional polarimeter polarizer between, not only add phase modulation component, but also adding isolation optical fiber, the polarizer (first polarizer) is spatially separated with analyzer (second polarizer), and they are contained on two substrates respectively; Meanwhile, have employed the basic waveform of stepped square wave as phase-modulation, the mathematical analysis of optical fiber sensing system can be simplified and accurately carry out.
The present invention is achieved in that
A kind of optical fiber sensing system, comprise light source, modulation module, isolation optical fiber, sensing module, modulation voltage generator, described light source, described modulation module, described isolation optical fiber, described sensing module connect successively, and the output voltage of described modulation voltage generator puts on described modulation module.
Further, described modulation module comprises the polarizer, phase modulation component, and the light sent by described light source transfers to the described polarizer, described phase modulation component successively, and then imports described isolation optical fiber into.
Further, described sensing module comprises sensing element, analyzer, by the light that described isolation optical fiber transmits, transfers to described sensing element, described analyzer successively, and then imports the outgoing optical fiber of described isolation optical cable into.
Obtain a method for the measurement data relevant to polarization, described method needs the optical fiber sensing system providing foregoing invention, and described method specifically comprises the steps:
Step 1, start described modulation voltage generator power after, the laser sent by described light source is entered in the described polarizer, described phase modulation component successively by optical fiber, and then imports in the incident optical of described isolation optical cable;
Step 2, described modulation voltage generator is by generation one constant amplitude and have periodic stepwise voltage, then the signal of this voltage is put on described phase modulation component and modulates, modulated voltage signal is loaded on light wave and forms light modulated;
Step 3, this light modulated transfer in described sensing element by the incident optical of described isolation optical cable, now in described sensing element with the information of measured physical quantity, then this light modulated is imported in described analyzer, then this light modulated is imported in the outgoing optical fiber of described isolation optical cable;
Step 4, the light intensity signal of light modulated is converted to electric signal after, the intensity signal exported is sampled, one group of intensity signal is obtained by sampling, then carry out process to this group intensity signal to calculate, system function, intrinsic function can be calculated, then build intrinsic function group by described intrinsic function;
Step 5, by this intrinsic function group, calculate the measurement data proportional with measured physical quantity.
Further, described step 4 is specific as follows:
Step 41, the light intensity general expression sent by the outgoing optical fiber of described isolation optical cable are:
I(t)＝(1/2)γ(t)I
o(t){2α+cos2(ψ
P-ψ
M)β+sin2(ψ
P-ψ
M)η·cos[θ
M(t)]+sin2(ψ
P-ψ
M)ζ·sin[θ
M(t)]}，
And α={ [cos
2(ψ
p-ψ
m) cos
2(ψ
m-ψ
s)+sin
2(ψ
p-ψ
m) sin
2(ψ
m-ψ
s)] cos
2(ψ
s-ψ
v)+[cos
2(ψ
p-ψ
m) sin
2(ψ
m-ψ
s)+sin
2(ψ
p-ψ
m) cos
2(ψ
m-ψ
s)] sin
2(ψ
s-ψ
v)] cos
2(ψ
v-ψ
a)+{ [cos
2(ψ
p-ψ
m) cos
2(ψ
m-ψ
s)+sin
2(ψ
p-ψ
m) sin
2(ψ
m-ψ
s)] sin
2(ψ
s-ψ
v)+[cos
2(ψ
p-ψ
m) sin
2(ψ
m-ψ
s)+sin
2(ψ
p-ψ
m) cos
2(ψ
m-ψ
s)] cos
2(ψ
s-ψ
v)] sin
2(ψ
v-ψ
a)
Wherein, γ (t) is the total effect of the transmissivity of each unit to light, I
ot () is the light intensity that light source sends, ψ
pthe light transmission shaft orientation representing the polarizer, ψ
mthe fast axis orientation representing phase modulation component, θ
mt () is the phase differential or phase delay that represent that phase modulation component produces, ψ
sthe fast axis orientation representing isolation optical fiber entrance port, ψ
vthe fast axis orientation representing sensing element, ψ
abe the light transmission shaft orientation representing analyzer, β, η, ζ all represent intrinsic function;
The angle in the light transmission shaft orientation of the polarizer and the fast axis orientation of phase modulation component is set to 45 degree, i.e. (ψ
p-ψ
m)=45 °, then light intensity general expression can be changed further and is kept to:
I(t)＝(1/2)γ(t)I
o(t){1+η·cos[θ
M(t)]+ζ·sin[θ
M(t)]}，
Wherein, γ (t) is the total effect of the transmissivity of each unit to light, I
ot () is the light intensity that light source sends, θ
mt () is the phase differential or phase delay that represent that phase modulation component produces, η, ζ all represent intrinsic function;
All there are three kinds of modulation conditions each modulation period, are respectively θ
m(t)=+ θ
m, θ
m(t)=0, θ
m(t)=-θ
m, then its one group of intensity signal { I obtained that samples
+, I
0, I
-be respectively:
I
+(t)=(1/2) γ (t) I
o(t) { 1+ η cos [θ
m]+ζ sin [θ
m], wherein, γ (t) is the total effect of the transmissivity of each unit to light, I
ot () is the light intensity that light source sends, θ
mbe the modulation numerical value represented under phase modulation component modulation condition, η, ζ all represent intrinsic function;
I
0(t)=(1/2) γ (t) I
ot () { 1+ η }, wherein, γ (t) is the total effect of the transmissivity of each unit to light, I
ot () is the light intensity that light source sends, η represents intrinsic function;
I
-(t)=(1/2) γ (t) I
o(t) { 1+ η cos [θ
m]-ζ sin [θ
m], wherein, γ (t) is the total effect of the transmissivity of each unit to light, I
ot () is the light intensity that light source sends, θ
mbe the modulation numerical value represented under phase modulation component modulation condition, η, ζ all represent intrinsic function;
Step 42, the light intensity signal { I obtained by sampling
+, I
0, I
-, the system function I calculated
m, intrinsic function ζ and η be respectively:
I
m=[I
+(t)+I
-(t)-2I
0(t) cos (θ
m)]/tan (θ
m/ 2), in formula, I
+t () represents that modulation condition is θ
m(t)=+ θ
munder intensity signal, I
-t () represents that modulation condition is θ
m(t)=-θ
munder intensity signal, I
0t () represents that modulation condition is θ
mintensity signal under (t)=0, θ
mthe modulation numerical value represented under phase modulation component modulation condition;
ζ=[I
+(t) – I
-(t)]/I
m(t), in formula, I
+t () represents that modulation condition is θ
m(t)=+ θ
munder intensity signal, I
-t () represents that modulation condition is θ
m(t)=-θ
munder intensity signal, I
mt () represents system function;
η={ 2I
0(t)-[I
+(t)+I
-(t)] }/{ I
m(t) tan [θ
m/ 2] }, in formula, I
+t () represents that modulation condition is θ
m(t)=+ θ
munder intensity signal, I
-t () represents that modulation condition is θ
m(t)=-θ
munder intensity signal, I
0t () represents that modulation condition is θ
mintensity signal under (t)=0, θ
mthe modulation numerical value represented under phase modulation component modulation condition, I
mt () represents system function;
Wherein, system function I
mt () is defined by following formula: I
m(t)=γ (t) I
o(t) sin [θ
m];
Intrinsic function ζ and η is having based on during described sensing module:
ζ=ζ
tcos2 (ψ
v-ψ
a)+ζ
rsin2 (ψ
v-ψ
a), wherein, have when polarization counts three rank:
ζ
t=sin2 (ψ
s2-ψ
v) sin (θ
s), ζ
r=cos2 (ψ
s2-ψ
v) sin (θ
s) cos (θ
v)+cos (θ
s) sin (θ
v), in formula, ψ
vthe fast axis orientation representing sensing element, ψ
athe light transmission shaft orientation representing analyzer, ψ
s2the fast axis orientation representing isolation fiber exit mouth, θ
vthe phase differential or phase delay that represent that sensing element produces, θ
srepresent that isolation optical fiber gross phase postpones;
η=η
tcos2 (ψ
v-ψ
a)+η
rsin2 (ψ
v-ψ
a), wherein, have when polarization counts three rank:
η
T＝-sin2(ψ
M-ψ
S1)cos2(ψ
S2-ψ
V)-cos2(ψ
M-ψ
S1)sin2(ψ
S2-ψ
V)·cos(θ
S)，
η
R＝+sin2(ψ
M-ψ
S1)sin2(ψ
S2-ψ
V)·cos(θ
V)-cos2(ψ
M-ψ
S1)cos2(ψ
S2-ψ
V)
·cos(θ
V)cos(θ
S)+cos2(ψ
M-ψ
S1)·1·sin(θ
V)sin(θ
S)，
In formula, ψ
vthe fast axis orientation representing sensing element, ψ
athe light transmission shaft orientation representing analyzer, ψ
mthe fast axis orientation representing phase modulation component, ψ
s1the fast axis orientation representing isolation optical fiber entrance port, ψ
s2the fast axis orientation representing isolation fiber exit mouth, θ
vthe phase differential or phase delay that represent that sensing element produces, θ
srepresent that isolation optical fiber gross phase postpones;
Step 43, arrange between the fast axis direction of sensing element and the light transmission shaft direction of analyzer angle after, construct intrinsic function group.
Further, the measured physical quantity in described step 2 comprises voltage, electric current, pressure.
Tool of the present invention has the following advantages: the invention enables fiber polarimeter effectively can eliminate the various outside time-varying characteristics such as exterior mechanical vibration and environment temperature to the impact of measurement result, make to measure the data obtained more accurate.
Accompanying drawing explanation
The present invention is further illustrated in conjunction with the embodiments with reference to the accompanying drawings.
Fig. 1 is the structural representation of three rank polarimeters.
Fig. 2 is the basic index path of optical fiber sensing system.
Fig. 3 is the relation that the light intensity of optical fiber sensing system and stepped square wave phase differential are modulated.
Fig. 4 is the inventive method flowchart.
Embodiment
As shown in Figure 1, this three rank polarimeter comprises polarizer P, the first birefringence element M, the second birefringence element S, the 3rd birefringence element V, analyzer A; Polarizer P is by its light transmission shaft orientation ψ
pdescribe, the first birefringence element M is by its fast axis orientation ψ
mwith produced phase differential or phase delay θ
mdescribe, the second birefringence element S is by its fast axis orientation ψ
swith produced phase differential or phase delay θ
sdescribe, the 3rd birefringence element V is by its fast axis orientation ψ
vwith produced phase differential or phase delay θ
vdescribe, analyzer A is by its light transmission shaft orientation ψ
adescribe.
The light intensity expression (1) of the emergent light of this three rank polarimeter is:
I(t)＝γ(t)I
o(t){α-(1/2)sin2(ψ
P-ψ
M)sin2(ψ
M-ψ
S)cos2(ψ
S-ψ
V)cos2(ψ
V-ψ
A)·cos(θ
M)-(1/2)cos2(ψ
P-ψ
M)sin2(ψ
M-ψ
S)sin2(ψ
S-ψ
V)cos2(ψ
V-ψ
A)·cos(θ
S)-(1/2)sin2(ψ
P-ψ
M)cos2(ψ
M-ψ
S)sin2(ψ
S-ψ
V)cos2(ψ
V-ψ
A)·cos(θ
S)cos(θ
M)+(1/2)sin2(ψ
P-ψ
M)·1·sin2(ψ
S-ψ
V)cos2(ψ
V-ψ
A)·sin(θ
S)sin(θ
M)-(1/2)cos2(ψ
P-ψ
M)cos2(ψ
M-ψ
S)sin2(ψ
S-ψ
V)sin2(ψ
V-ψ
A)·cos(θ
V)+(1/2)sin2(ψ
P-ψ
M)sin2(ψ
M-ψ
S)sin2(ψ
S-ψ
V)sin2(ψ
V-ψ
A)·cos(θ
V)cos(θ
M)-(1/2)cos2(ψ
P-ψ
M)sin2(ψ
M-ψ
S)cos2(ψ
S-ψ
V)sin2(ψ
V-ψ
A)·cos(θ
V)cos(θ
S)+(1/2)cos2(ψ
P-ψ
M)sin2(ψ
M-ψ
S)·1·sin2(ψ
V-ψ
A)·sin(θ
V)sin(θ
S)-(1/2)sin2(ψ
P-ψ
M)cos2(ψ
M-ψ
S)cos2(ψ
S-ψ
V)sin2(ψ
V-ψ
A)·cos(θ
V)cos(θ
S)cos(θ
M)+(1/2)sin2(ψ
P-ψ
M)cos2(ψ
M-ψ
S)·1·sin2(ψ
V-ψ
A)·sin(θ
V)sin(θ
S)cos(θ
M)+(1/2)sin2(ψ
P-ψ
M)·1·1·sin2(ψ
V-ψ
A)·sin(θ
V)cos(θ
S)sin(θ
M)+(1/2)sin2(ψ
P-ψ
M)·1·cos2(ψ
S-ψ
V)sin2(ψ
V-ψ
A)·cos(θ
V)sin(θ
S)sin(θ
M)}
Wherein the formula (2) of α is:
α＝{[cos
2(ψ
P-ψ
M)cos
2(ψ
M-ψ
S)+sin
2(ψ
P-ψ
M)sin
2(ψ
M-ψ
S)]cos
2(ψ
S-ψ
V)+[cos
2(ψ
P-ψ
M)sin
2(ψ
M-ψ
S)+sin
2(ψ
P-ψ
M)cos
2(ψ
M-ψ
S)]sin
2(ψ
S-ψ
V)]}cos
2(ψ
V-ψ
A)+{[cos
2(ψ
P-ψ
M)cos
2(ψ
M-ψ
S)+sin
2(ψ
P-ψ
M)sin
2(ψ
M-ψ
S)]sin
2(ψ
S-ψ
V)+[cos
2(ψ
P-ψ
M)sin
2(ψ
M-ψ
S)+sin
2(ψ
P-ψ
M)cos
2(ψ
M-ψ
S)]cos
2(ψ
S-ψ
V)]}sin
2(ψ
V-ψ
A)
In formula (1), I
ot () is the light intensity that light source sends, γ (t) is the total effect of the transmissivity of each unit to light.
The basic light path of traditional fiber polarimeter, be respectively have an optical fiber in the front and back that polarizer is right, last is incident optical, and latter one is reception optical fiber, due to polarizer between distance less, therefore by polarizer to and birefringent elements between them all install on the same substrate.In order to be different from traditional fiber polarimeter, the basic light path of optical fiber sensing system of the present invention as shown in Figure 2, the basic light path of this optical fiber sensing system comprises light source, polarizer P, phase modulation component M, isolation optical fiber S, sensing element V, analyzer A, optical fiber sensing system is separated into two pieces of substrates by isolation optical fiber S, one piece of modulation module be made up of polarizer P, phase modulation component M, the sensing module that another block is made up of sensing element V, analyzer A, modulation module, sensing module can be carried out the isolation of remote space by isolation optical fiber S; Polarizer P is by its light transmission shaft orientation ψ
pdescribe, phase modulation component M is by its fast axis orientation ψ
mwith produced phase differential or phase delay θ
mdescribe, isolation optical fiber S is by the fast axis orientation ψ of its entrance port
s1, isolation optical fiber gross phase postpones θ
sand the fast axis orientation ψ of exit portal
s2describe, sensing element V is by its fast axis orientation ψ
vwith produced phase differential or phase delay θ
vdescribe, analyzer A is by its light transmission shaft orientation ψ
adescribe.
Based on modulation module, the output intensity general expression of this fiber polarimeter is:
I(t)＝(1/2)γ(t)I
o(t){2α+cos2(ψ
P-ψ
M)β+sin2(ψ
P-ψ
M)η·cos[θ
M(t)]+sin2(ψ
P-ψ
M)ζ·sin[θ
M(t)]} (3)
In formula (3), I
ot () is the light intensity that light source sends, γ (t) is the total effect of the transmissivity of each unit to light, and α is the value of formula (2), and β, η, ζ are intrinsic function.
Based on sensing module, for intrinsic function η and ζ in formula (3), can refine and be:
η＝η
T·cos2(ψ
V-ψ
A)+η
R·sin2(ψ
V-ψ
A) (4a)
ζ＝ζ
T·cos2(ψ
V-ψ
A)+ζ
R·sin2(ψ
V-ψ
A) (4b)
In formula (4a)-(4b), ψ
vthe fast axis orientation representing sensing element, ψ
ait is the light transmission shaft orientation representing analyzer.
For optical fiber sensing system as shown in Figure 2, the η in formula (4a)
t, η
rwith the ζ in formula (4b)
t, ζ
rexpression is:
η
T＝-sin2(ψ
M-ψ
S1)cos2(ψ
S2-ψ
V)-cos2(ψ
M-ψ
S1)sin2(ψ
S2-ψ
V)·cos(θ
S) (5a)
η
R＝+sin2(ψ
M-ψ
S1)sin2(ψ
S2-ψ
V)·cos(θ
V)-cos2(ψ
M-ψ
S1)cos2(ψ
S2-ψ
V)·cos(θ
V)cos(θ
S)+cos2(ψ
M-ψ
S1)·1·sin(θ
V)sin(θ
S) (5b)
ζ
T＝sin2(ψ
S2-ψ
V)·sin(θ
S) (5c)
ζ
R＝cos2(ψ
S2-ψ
V)·sin(θ
S)cos(θ
V)+cos(θ
S)sin(θ
V) (5d)
In formula (5a)-(5d), ψ
vthe fast axis orientation representing sensing element, ψ
athe light transmission shaft orientation representing analyzer, ψ
mthe fast axis orientation representing phase modulation component, ψ
s1the fast axis orientation representing isolation optical fiber entrance port, ψ
s2the fast axis orientation representing isolation fiber exit mouth, θ
vthe phase differential or phase delay that represent that sensing element produces, θ
srepresent that isolation optical fiber gross phase postpones;
Formula (5a)-(5d) is intrinsic function η and ζ separated with system function from actual measurement intensity signal, and they have departed from the impact of measuring system time-varying characteristics, containing isolation optical fiber [ψ
s1, θ
s], [ψ
s2] and measured physical quantity [ψ
v, θ
v] information.Through the combination arrangement of multi-pass, can from the intrinsic function corresponding to each light path system, by measured physical quantity [ψ
v, θ
v] information extraction out.
Simplify to make mathematical analysis, adopt periodic stepped square wave as basic modulation waveform, the relation that its light intensity and stepped square wave phase differential are modulated as shown in Figure 3, the angle in the M fast axis orientation of the light transmission shaft orientation of the polarizer P in Fig. 2 and phase modulation component is set to 45 degree, i.e. (ψ
p-ψ
m)=45 °, now formula (3) can abbreviation be further:
I(t)＝(1/2)γ(t)I
o(t){1+η·cos[θ
M(t)]+ζ·sin[θ
M(t)]} (6)
In formula, γ (t) is the total effect of the transmissivity of each unit to light, I
ot () is the light intensity that light source sends, θ
mt () is the phase differential or phase delay that represent that phase modulation component produces, η, ζ all represent intrinsic function;
All there are three kinds of modulation conditions each modulation period, are respectively θ
m(t)=+ θ
m, θ
m(t)=0, θ
m(t)=-θ
m, then the light intensity I of its correspondence
+(t), I
0t (), I-(t) are respectively:
I
+(t)＝(1/2)γ(t)I
o(t){1+η·cos[θ
M]+ζ·sin[θ
M]} (7a)
I
0(t)＝(1/2)γ(t)I
o(t){1+η} (7b)
I
-(t)＝(1/2)γ(t)I
o(t){1+η·cos[θ
M]-ζ·sin[θ
M]} (7c)
In formula (7a)-(7c), γ (t) is the total effect of the transmissivity of each unit to light, I
ot () is the light intensity that light source sends, θ
mbe the modulation amplitude of phase modulation component, η, ζ all represent intrinsic function.
Light intensity difference during positive and negative modulation condition is Δ I (t)=I
+(t) – I
-(t)=I
m(t) ζ (8)
I in formula (8)
mt () is called system function, ζ represents intrinsic function, I
mt () is defined by following formula:
I
M(t)＝γ(t)I
o(t)·sin[θ
M] (9)
From formula (9), I
ot () is the light intensity that light source sends; θ
mit is the modulation amplitude of phase modulation component; γ (t) is the total effect of the transmissivity of each unit to light, and these factors have time-varying characteristics to a certain extent.Therefore, system function I
mthe change of polarization state of incident optical before the age instability of what t () reflected is light source, analyzer, total effect of the hard ware measure condition such as transmissivity variation, the transmissivity of light path, the conversion characteristic of photoelectric commutator of fiber optic conduction light.
System function I
mt () and intrinsic function ζ and η, can by the light intensity I surveyed
+(t), I
0t (), I-(t) dynamically calculate by following formula:
I
M(t)＝[I
+(t)+I
-(t)-2I
0(t)cos(θ
M)]/tan(θ
M/2) (10a)
ζ＝[I
+(t)–I
-(t)]/I
M(t) (10b)
η＝{2I
0(t)-[I
+(t)+I
-(t)]}/{I
M(t)·tan[θ
M/2]} (10c)
In formula (10a)-(10c), I
+t () represents that modulation condition is θ
m(t)=+ θ
munder intensity signal, I
-t () represents that modulation condition is θ
m(t)=-θ
munder intensity signal, I
0t () represents that modulation condition is θ
mintensity signal under (t)=0, θ
mthe modulation amplitude of phase modulation component, I
mt () represents system function.
From actual measurement intensity signal, system function and intrinsic function are separated, just the impact of the time-varying characteristics of whole system on measurement result can be eliminated, thus eliminate mechanical vibration and variation of ambient temperature to the impact of measurement result.
Embodiment one: as shown in Figure 4, a kind of method obtaining the measurement data relevant to polarization, described method needs the optical fiber sensing system providing the invention described above, and described method specifically comprises the steps:
After step 1, startup modulation voltage generator power, the laser sent by described light source is entered in the described polarizer, described phase modulation component successively by optical fiber, and then enters in the incident optical of described isolation optical cable;
Step 2, the voltage signal that modulation voltage generator produces is transferred to described phase modulation component and modulates, make the signal loading of modulation voltage to light wave forms light modulated;
Step 3, this light modulated transfer in described sensing element by the incident optical of described isolation optical cable, now described sensing element is because having bubble Ke Ersi (Pockels) electrooptical effect, with the information of voltage in the light wave wherein passed through, then this light modulated is transferred in described analyzer, then this light modulated is transferred in the outgoing optical fiber of described isolation optical cable;
Step 4, the light intensity signal of light modulated is converted to electric signal after, the intensity signal exported is sampled, one group of intensity signal is obtained by sampling, then carry out process to this group intensity signal to calculate, system function, intrinsic function can be calculated, then build intrinsic function group by described intrinsic function; Specific as follows:
Step 41, the light intensity general expression sent by the outgoing optical fiber of described isolation optical cable are:
I(t)＝(1/2)γ(t)I
o(t){2α+cos2(ψ
P-ψ
M)β+sin2(ψ
P-ψ
M)η·cos[θ
M(t)]+sin2(ψ
P-ψ
M)ζ·sin[θ
M(t)]}，
And α={ [cos
2(ψ
p-ψ
m) cos
2(ψ
m-ψ
s)+sin
2(ψ
p-ψ
m) sin
2(ψ
m-ψ
s)] cos
2(ψ
s-ψ
v)+[cos
2(ψ
p-ψ
m) sin
2(ψ
m-ψ
s)+sin
2(ψ
p-ψ
m) cos
2(ψ
m-ψ
s)] sin
2(ψ
s-ψ
v)] cos
2(ψ
v-ψ
a)+{ [cos
2(ψ
p-ψ
m) cos
2(ψ
m-ψ
s)+sin
2(ψ
p-ψ
m) sin
2(ψ
m-ψ
s)] sin
2(ψ
s-ψ
v)+[cos
2(ψ
p-ψ
m) sin
2(ψ
m-ψ
s)+sin
2(ψ
p-ψ
m) cos
2(ψ
m-ψ
s)] cos
2(ψ
s-ψ
v)] sin
2(ψ
v-ψ
a)
Wherein, γ (t) is the total effect of the transmissivity of each unit to light, I
ot () is the light intensity that light source sends, ψ
pthe light transmission shaft orientation representing the polarizer, ψ
mthe fast axis orientation representing phase modulation component, θ
mt () is the phase differential or phase delay that represent that phase modulation component produces, ψ
sthe fast axis orientation representing isolation optical fiber entrance port, ψ
vthe fast axis orientation representing sensing element, ψ
abe the light transmission shaft orientation representing analyzer, η, ζ all represent intrinsic function;
The angle in the light transmission shaft orientation of the polarizer and the fast axis orientation of phase modulation component is set to 45 degree, i.e. (ψ
p-ψ
m)=45 °, then light intensity general expression can be changed further and is kept to:
I(t)＝(1/2)γ(t)I
o(t){1+η·cos[θ
M(t)]+ζ·sin[θ
M(t)]}，
Wherein, γ (t) is the total effect of the transmissivity of each unit to light, I
ot () is the light intensity that light source sends, θ
mt () is the phase differential or phase delay that represent that phase modulation component produces, η, ζ all represent intrinsic function;
All there are three kinds of modulation conditions each modulation period, are respectively θ
m(t)=+ θ
m, θ
m(t)=0, θ
m(t)=-θ
m, then its one group of intensity signal { I obtained that samples
+, I
0, I
-be respectively:
I
+(t)=(1/2) γ (t) I
o(t) { 1+ η cos [θ
m]+ζ sin [θ
m], wherein, γ (t) is the total effect of the transmissivity of each unit to light, I
ot () is the light intensity that light source sends, θ
mbe the modulation amplitude of phase-modulator, η, ζ all represent intrinsic function;
I
0(t)=(1/2) γ (t) I
ot () { 1+ η }, wherein, γ (t) is the total effect of the transmissivity of each unit to light, I
ot () is the light intensity that light source sends, η represents intrinsic function;
I
-(t)=(1/2) γ (t) I
o(t) { 1+ η cos [θ
m]-ζ sin [θ
m], wherein, γ (t) is the total effect of the transmissivity of each unit to light, I
ot () is the light intensity that light source sends, θ
mbe the modulation amplitude of phase modulation component, η, ζ all represent intrinsic function;
Step 42, the light intensity signal { I obtained by sampling
+, I
0, I
-, the system function I calculated
m, intrinsic function ζ and η be respectively:
I
m=[I
+(t)+I
-(t)-2I
0(t) cos (θ
m)]/tan (θ
m/ 2), in formula, I
+t () represents that modulation condition is θ
m(t)=+ θ
munder intensity signal, I
-t () represents that modulation condition is θ
m(t)=-θ
munder intensity signal, I
0t () represents that modulation condition is θ
mintensity signal under (t)=0, θ
mit is the modulation amplitude of phase modulation component;
ζ=[I
+(t) – I
-(t)]/I
m(t), in formula, I
+t () represents that modulation condition is θ
m(t)=+ θ
munder intensity signal, I
-t () represents that modulation condition is θ
m(t)=-θ
munder intensity signal, I
mt () represents system function;
η={ 2I
0(t)-[I
+(t)+I
-(t)] }/{ I
m(t) tan [θ
m/ 2] }, in formula, I
+t () represents that modulation condition is θ
m(t)=+ θ
munder intensity signal, I
-t () represents that modulation condition is θ
m(t)=-θ
munder intensity signal, I
0t () represents that modulation condition is θ
mintensity signal under (t)=0, θ
mthe modulation amplitude of phase modulation component, I
mt () represents system function;
Wherein, system function I
mt () is defined by following formula: I
m(t)=γ (t) I
o(t) sin [θ
m], wherein, γ (t) is the total effect of the transmissivity of each unit to light, I
ot () is the light intensity that light source sends, θ
mit is the modulation amplitude of phase modulation component.
Intrinsic function ζ and η is having based on during described sensing module:
ζ=ζ
tcos2 (ψ
v-ψ
a)+ζ
rsin2 (ψ
v-ψ
a), wherein, have when polarization counts three rank:
ζ
t=sin2 (ψ
s2-ψ
v) sin (θ
s), ζ
r=cos2 (ψ
s2-ψ
v) sin (θ
s) cos (θ
v)+cos (θ
s) sin (θ
v), in formula, ψ
vthe fast axis orientation representing sensing element, ψ
athe light transmission shaft orientation representing analyzer, ψ
s2the fast axis orientation representing isolation fiber exit mouth, θ
vthe phase differential or phase delay that represent that sensing element produces, θ
srepresent that isolation optical fiber gross phase postpones;
η=η
tcos2 (ψ
v-ψ
a)+η
rsin2 (ψ
v-ψ
a), wherein, have when polarization counts three rank:
η
T＝-sin2(ψ
M-ψ
S1)cos2(ψ
S2-ψ
V)-cos2(ψ
M-ψ
S1)sin2(ψ
S2-ψ
V)·cos(θ
S)，
η
R＝+sin2(ψ
M-ψ
S1)sin2(ψ
S2-ψ
V)·cos(θ
V)-cos2(ψ
M-ψ
S1)cos2(ψ
S2-ψ
V)·cos(θ
V)cos(θ
S)+cos2(ψ
M-ψ
S1)·1·sin(θ
V)sin(θ
S)，
In formula, ψ
vthe fast axis orientation representing sensing element, ψ
athe light transmission shaft orientation representing analyzer, ψ
mthe fast axis orientation representing phase modulation component, ψ
s1the fast axis orientation representing isolation optical fiber entrance port, ψ
s2the fast axis orientation representing isolation fiber exit mouth, θ
vthe phase differential or phase delay that represent that sensing element produces, θ
srepresent that isolation optical fiber gross phase postpones;
Step 43, arrange between the fast axis direction of sensing element and the light transmission shaft direction of analyzer angle after, construct intrinsic function group.
Step 5, by this intrinsic function group, calculate the measurement data with voltage in proportion.
Embodiment two: measured physical quantity is electric current or magnetic field intensity, its method is similar to the method in embodiment one, difference is: step 3 is: this light modulated transfers in described sensing element by the incident optical of described isolation optical cable, now described sensing element is because having faraday (Faraday) magneto-optic effect, the information of electric current or magnetic field intensity is loaded with in the light wave wherein passed through, then this light modulated is transferred in described analyzer, then this light modulated is transferred in the outgoing optical fiber of described isolation optical cable; Step 5 is by this intrinsic function group, calculates and electric current or the proportional measurement data of magnetic field intensity; Other steps are the same.
Embodiment three: measured physical quantity is pressure or stress, its method is similar to the method in embodiment one, difference is: step 3 is: this light modulated transfers in described sensing element by the incident optical of described isolation optical cable, now described sensing element is because having photoelastic effect, the information of pressure or stress is loaded with in the light wave wherein passed through, then this light modulated is transferred in described analyzer, then this light modulated is transferred in the outgoing optical fiber of described isolation optical cable; Step 5 is by this intrinsic function group, calculates and pressure or the proportional measurement data of stress; Other steps are the same.
Here the optical fiber referred to, as isolation optical fiber, refer to the single-mode fiber of general communication, its birefringence has time-varying characteristics.Some Fibre Optical Sensor, as Optical fibre interferometric etc., adopts polarization maintaining optical fibre or high birefringence optical fiber as isolation optical fiber, is to alleviate or ignoring isolation optical fiber to the impact of light conducting polarization state.Here the phase-modulator referred to, is actually orthogonal polarization phase-modulator, be to the polarized light component of mutual orthogonal between phase differential modulate.Phase-modulator conventional in Optical fibre interferometric, as Y type phase-modulator, is actually polarization phase modulator in the same way, is that the phase differential of the two bundle polarized lights formation after different optical paths is propagated utilizing polarization direction identical is to carry out phase-modulation.
Although the foregoing describe the specific embodiment of the present invention; but be familiar with those skilled in the art to be to be understood that; specific embodiment described by us is illustrative; instead of for the restriction to scope of the present invention; those of ordinary skill in the art, in the modification of the equivalence done according to spirit of the present invention and change, should be encompassed in scope that claim of the present invention protects.
Claims (5)
1. an optical fiber sensing system, it is characterized in that: comprise light source, modulation module, isolation optical fiber, sensing module, modulation voltage generator, described light source, described modulation module, described isolation optical fiber, described sensing module connect successively, and the output voltage of described modulation voltage generator puts on described modulation module.
2. a kind of optical fiber sensing system as claimed in claim 1, it is characterized in that: described modulation module comprises the polarizer, phase modulation component, the light sent by described light source transfers to the described polarizer, described phase modulation component successively, and then imports described isolation optical fiber into.
3. a kind of optical fiber sensing system as claimed in claim 1, it is characterized in that: described sensing module comprises sensing element, analyzer, by the light that described isolation optical fiber transmits, transfer to described sensing element, described analyzer successively, and then import the outgoing optical fiber of described isolation optical cable into.
4. obtain a method for the measurement data relevant to polarization, it is characterized in that: described method needs to provide optical fiber sensing system as claimed in claim 1, and described method specifically comprises the steps:
Step 1, start described modulation voltage generator power after, the laser sent by described light source is entered in the described polarizer, described phase modulation component successively by optical fiber, and then imports in the incident optical of described isolation optical cable;
Step 2, described modulation voltage generator is by generation one constant amplitude and have periodic stepwise voltage, then the signal of this voltage is put on described phase modulation component and modulates, modulated voltage signal is loaded on light wave and forms light modulated;
Step 3, this light modulated transfer in described sensing element by the incident optical of described isolation optical cable, now in described sensing element with the information of measured physical quantity, then this light modulated is imported in described analyzer, then this light modulated is imported in the outgoing optical fiber of described isolation optical cable;
Step 4, the light intensity signal of light modulated is converted to electric signal after, the intensity signal exported is sampled, one group of intensity signal is obtained by sampling, then carry out process to this group intensity signal to calculate, system function, intrinsic function can be calculated, then build intrinsic function group by described intrinsic function;
Step 5, by this intrinsic function group, calculate the measurement data proportional with measured physical quantity.
5. a kind of method obtaining the measurement data relevant to polarization as claimed in claim 4, is characterized in that: described step 4 specific as follows:
Step 41, the light intensity general expression sent by the outgoing optical fiber of described isolation optical cable are:
I(t)＝(1/2)γ(t)I
o(t){2α+cos2(ψ
P-ψ
M)β+sin2(ψ
P-ψ
M)η·cos[θ
M(t)]+sin2(ψ
P-ψ
M)ζ·sin[θ
M(t)]}，
And α={ [cos
2(ψ
p-ψ
m) cos
2(ψ
m-ψ
s)+sin
2(ψ
p-ψ
m) sin
2(ψ
m-ψ
s)] cos
2(ψ
s-ψ
v)+[cos
2(ψ
p-ψ
m) sin
2(ψ
m-ψ
s)+sin
2(ψ
p-ψ
m) cos
2(ψ
m-ψ
s)] sin
2(ψ
s-ψ
v)] cos
2(ψ
v-ψ
a)+{ [cos
2(ψ
p-ψ
m) cos
2(ψ
m-ψ
s)+sin
2(ψ
p-ψ
m) sin
2(ψ
m-ψ
s)] sin
2(ψ
s-ψ
v)+[cos
2(ψ
p-ψ
m) sin
2(ψ
m-ψ
s)+sin
2(ψ
p-ψ
m) cos
2(ψ
m-ψ
s)] cos
2(ψ
s-ψ
v)] sin
2(ψ
v-ψ
a)
Wherein, γ (t) is the total effect of the transmissivity of each unit to light, I
ot () is the light intensity that light source sends, ψ
pthe light transmission shaft orientation representing the polarizer, ψ
mthe fast axis orientation representing phase modulation component, θ
mt () is the phase differential or phase delay that represent that phase modulation component produces, ψ
sthe fast axis orientation representing isolation optical fiber entrance port, ψ
vthe fast axis orientation representing sensing element, ψ
abe the light transmission shaft orientation representing analyzer, β, η, ζ all represent intrinsic function;
The angle in the light transmission shaft orientation of the polarizer and the fast axis orientation of phase-modulator is set to 45 degree, i.e. (ψ
p-ψ
m)=45 °, then light intensity general expression can be changed further and is kept to:
I(t)＝(1/2)γ(t)I
o(t){1+η·cos[θ
M(t)]+ζ·sin[θ
M(t)]}，
Wherein, γ (t) is the total effect of the transmissivity of each unit to light, I
ot () is the light intensity that light source sends, θ
mt () is the phase differential or phase delay that represent that phase modulation component produces, η, ζ all represent intrinsic function;
All there are three kinds of modulation conditions each modulation period, are respectively θ
m(t)=+ θ
m, θ
m(t)=0, θ
m(t)=-θ
m, then its one group of intensity signal { I obtained that samples
+, I
0, I
-be respectively:
I
+(t)=(1/2) γ (t) I
o(t) { 1+ η cos [θ
m]+ζ sin [θ
m], wherein, γ (t) is the total effect of the transmissivity of each unit to light, I
ot () is the light intensity that light source sends, θ
mbe the modulation numerical value represented under phase modulation component modulation condition, η, ζ all represent intrinsic function;
I
0(t)=(1/2) γ (t) I
ot () { 1+ η }, wherein, γ (t) is the total effect of the transmissivity of each unit to light, I
ot () is the light intensity that light source sends, η represents intrinsic function;
I
-(t)=(1/2) γ (t) I
o(t) { 1+ η cos [θ
m]-ζ sin [θ
m], wherein, γ (t) is the total effect of the transmissivity of each unit to light, I
ot () is the light intensity that light source sends, θ
mbe the modulation numerical value represented under phase modulation component modulation condition, η, ζ all represent intrinsic function;
Step 42, the light intensity signal { I obtained by sampling
+, I
0, I
-, the system function I calculated
m, intrinsic function ζ and η be respectively:
I
m=[I
+(t)+I
-(t)-2I
0(t) cos (θ
m)]/tan (θ
m/ 2), in formula, I
+t () represents that modulation condition is θ
m(t)=+ θ
munder intensity signal, I
-t () represents that modulation condition is θ
m(t)=-θ
munder intensity signal, I
0t () represents that modulation condition is θ
mintensity signal under (t)=0, θ
mthe modulation numerical value represented under phase modulation component modulation condition;
ζ=[I
+(t) – I
-(t)]/I
m(t), in formula, I
+t () represents that modulation condition is θ
m(t)=+ θ
munder intensity signal, I
-t () represents that modulation condition is θ
m(t)=-θ
munder intensity signal, I
mt () represents system function;
η={ 2I
0(t)-[I
+(t)+I
-(t)] }/{ I
m(t) tan [θ
m/ 2] }, in formula, I
+t () represents that modulation condition is θ
m(t)=+ θ
munder intensity signal, I
-t () represents that modulation condition is θ
m(t)=-θ
munder intensity signal, I
0t () represents that modulation condition is θ
mintensity signal under (t)=0, θ
mthe modulation numerical value represented under phase modulation component modulation condition, I
mt () represents system function;
Wherein, system function I
mt () is defined by following formula: I
m(t)=γ (t) I
o(t) sin [θ
m];
Intrinsic function ζ and η is having based on during described sensing module:
ζ=ζ
tcos2 (ψ
v-ψ
a)+ζ
rsin2 (ψ
v-ψ
a), wherein, have when polarization counts three rank:
ζ
t=sin2 (ψ
s2-ψ
v) sin (θ
s), ζ
r=cos2 (ψ
s2-ψ
v) sin (θ
s) cos (θ
v)+cos (θ
s) sin (θ
v), in formula, ψ
vthe fast axis orientation representing sensing element, ψ
athe light transmission shaft orientation representing analyzer, ψ
s2the fast axis orientation representing isolation fiber exit mouth, θ
vthe phase differential or phase delay that represent that sensing element produces, θ
srepresent that isolation optical fiber gross phase postpones;
η=η
tcos2 (ψ
v-ψ
a)+η
rsin2 (ψ
v-ψ
a), wherein, have when polarization counts three rank:
η
T＝-sin2(ψ
M-ψ
S1)cos2(ψ
S2-ψ
V)-cos2(ψ
M-ψ
S1)sin2(ψ
S2-ψ
V)·cos(θ
S)，
η
R＝+sin2(ψ
M-ψ
S1)sin2(ψ
S2-ψ
V)·cos(θ
V)-cos2(ψ
M-ψ
S1)cos2(ψ
S2-ψ
V)·cos(θ
V)cos(θ
S)+cos2(ψ
M-ψ
S1)·1·sin(θ
V)sin(θ
S)，
In formula, ψ
vthe fast axis orientation representing sensing element, ψ
athe light transmission shaft orientation representing analyzer, ψ
mthe fast axis orientation representing phase modulation component, ψ
s1the fast axis orientation representing isolation optical fiber entrance port, ψ
s2the fast axis orientation representing isolation fiber exit mouth, θ
vthe phase differential or phase delay that represent that sensing element produces, θ
srepresent that isolation optical fiber gross phase postpones;
Step 43, arrange between the fast axis direction of sensing element and the light transmission shaft direction of analyzer angle after, construct intrinsic function group.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510180694.6A CN104819737B (en) | 2015-04-16 | 2015-04-16 | A kind of method for obtaining the measurement data related to polarization |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510180694.6A CN104819737B (en) | 2015-04-16 | 2015-04-16 | A kind of method for obtaining the measurement data related to polarization |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104819737A true CN104819737A (en) | 2015-08-05 |
| CN104819737B CN104819737B (en) | 2017-06-27 |
Family
ID=53730103
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510180694.6A Active CN104819737B (en) | 2015-04-16 | 2015-04-16 | A kind of method for obtaining the measurement data related to polarization |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104819737B (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1108760A (en) * | 1994-08-31 | 1995-09-20 | 清华大学 | High-precision polarization-modulating type optical fiber sensor compensating method |
| CN1215152A (en) * | 1998-11-13 | 1999-04-28 | 清华大学 | High-resolution surface plasma wave angle/refractive index sensor |
| US20050238066A1 (en) * | 2004-04-12 | 2005-10-27 | Jian Liu | Nonlinear polarization pulse shaping mode locked fiber laser |
| CN201331599Y (en) * | 2008-12-29 | 2009-10-21 | 飞康技术(深圳)有限公司 | Optical fiber connecting device |
| CN102402025A (en) * | 2011-12-19 | 2012-04-04 | 桂林市光隆光电科技有限公司 | Isolator core and optoisolator manufactured by using isolator core |
| CN203224647U (en) * | 2012-11-12 | 2013-10-02 | 光越科技(深圳)有限公司 | Novel polarization-maintaining optical isolator structure |
-
2015
- 2015-04-16 CN CN201510180694.6A patent/CN104819737B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1108760A (en) * | 1994-08-31 | 1995-09-20 | 清华大学 | High-precision polarization-modulating type optical fiber sensor compensating method |
| CN1215152A (en) * | 1998-11-13 | 1999-04-28 | 清华大学 | High-resolution surface plasma wave angle/refractive index sensor |
| US20050238066A1 (en) * | 2004-04-12 | 2005-10-27 | Jian Liu | Nonlinear polarization pulse shaping mode locked fiber laser |
| CN201331599Y (en) * | 2008-12-29 | 2009-10-21 | 飞康技术(深圳)有限公司 | Optical fiber connecting device |
| CN102402025A (en) * | 2011-12-19 | 2012-04-04 | 桂林市光隆光电科技有限公司 | Isolator core and optoisolator manufactured by using isolator core |
| CN203224647U (en) * | 2012-11-12 | 2013-10-02 | 光越科技(深圳)有限公司 | Novel polarization-maintaining optical isolator structure |
Non-Patent Citations (1)
| Title |
|---|
| 柳树 等: "磁光调制法测量高双折射光纤拍长的灵敏度分析", 《上海大学学报》 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104819737B (en) | 2017-06-27 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102135554B (en) | Sagnac interferometer-type fiber-optic current sensor | |
| CN101839698B (en) | BOTDR (Brillouin Optical Time Domain Reflectometer) for calibrating optical power of reference light and calibrating method thereof | |
| CN103591895B (en) | A kind of optical fiber length measuring system and measuring method | |
| CN108827601A (en) | A kind of measuring device of fibre optic interferometer arm length difference | |
| CN101592551B (en) | Sagnac interferometer-based method and Sagnac interferometer-based device for testing beat length of polarization maintaining optical fiber | |
| CN104279959A (en) | New method for precisely measuring optical fiber length by adoption of vector network analyzer | |
| CN103645371A (en) | Device and method for measuring half-wave voltage of electro-optic phase modulator | |
| CN101427142A (en) | Fiber-optic current sensor with polarimetric detection scheme | |
| CN110132330B (en) | Double refraction distributed measuring system and method based on CP-phi OTDR | |
| CN106768867B (en) | LiNbO 3 Performance detection system for phase modulator | |
| CN104049099A (en) | Rotation rate sensor with fiber-optic Sagnac interferometer and control method thereof | |
| CN103292976A (en) | Interferometry-based optical fiber Verdet constant measuring system | |
| CN106989904A (en) | A kind of measuring method of polarization maintaining optical fibre extinction ratio | |
| CN101639387B (en) | Optical fiber temperature sensor for detection based on wavelength corresponding to extreme value and temperature sensing method | |
| CN103605005B (en) | A kind of photoelectric integration electric-field measuring system based on two Y waveguides | |
| CN106501601A (en) | A kind of photodetector frequency response measurement method and measuring system | |
| CN102164003A (en) | Dispersion measurement device | |
| CN207133364U (en) | Field measurement device and system | |
| Temkina et al. | Fiber optic current meter for IIoT in power grid | |
| CN103308175B (en) | Linear double refraction measuring device and measuring method | |
| CN212300381U (en) | Fiber grating sensing demodulation device based on frequency shift interference fiber ring-down | |
| CN206556842U (en) | LiNbO3 phase-modulator performance detecting systems | |
| CN206497197U (en) | Optical fiber sensing ring performance detecting system | |
| CN104819737A (en) | Optical fiber sensing system and method for acquiring polarization-related measurement data | |
| CN115931105A (en) | Single-ended distributed optical fiber vibration sensor system and signal processing method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| EXSB | Decision made by sipo to initiate substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20171205 Address after: 710000 Shaanxi province Xi'an Beilin District No. thirty-one Xianning West Road staff collective households Patentee after: Zhu Yongchang Address before: 361000 North Tower, No. 88, A District, No. 88, Huli Road, Huli District, Xiamen, Fujian Province, 309-310, 325, 326 Patentee before: Xiamen Shi Bian optical fiber sensing technology company limited |