CN110672239A - Method for selecting optimal incident polarization state in optical fiber pressure sensing based on Stokes parameters - Google Patents
Method for selecting optimal incident polarization state in optical fiber pressure sensing based on Stokes parameters Download PDFInfo
- Publication number
- CN110672239A CN110672239A CN201910636006.0A CN201910636006A CN110672239A CN 110672239 A CN110672239 A CN 110672239A CN 201910636006 A CN201910636006 A CN 201910636006A CN 110672239 A CN110672239 A CN 110672239A
- Authority
- CN
- China
- Prior art keywords
- polarization state
- optical fiber
- pressure
- sensing
- selecting
- 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
- 230000010287 polarization Effects 0.000 title claims abstract description 97
- 239000013307 optical fiber Substances 0.000 title claims abstract description 48
- 238000000034 method Methods 0.000 title claims abstract description 19
- 230000035945 sensitivity Effects 0.000 claims abstract description 12
- 239000011159 matrix material Substances 0.000 claims description 13
- 239000000835 fiber Substances 0.000 claims description 10
- 230000003287 optical effect Effects 0.000 claims description 2
- 238000009877 rendering Methods 0.000 claims 1
- 238000001514 detection method Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 241000962146 Alsophila tricolor Species 0.000 description 2
- 238000004088 simulation Methods 0.000 description 2
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L1/00—Measuring force or stress, in general
- G01L1/24—Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis using infrared, visible light, ultraviolet
- G01L1/242—Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis using infrared, visible light, ultraviolet the material being an optical fibre
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L11/00—Measuring steady or quasi-steady pressure of a fluid or a fluent solid material by means not provided for in group G01L7/00 or G01L9/00
- G01L11/02—Measuring steady or quasi-steady pressure of a fluid or a fluent solid material by means not provided for in group G01L7/00 or G01L9/00 by optical means
- G01L11/025—Measuring steady or quasi-steady pressure of a fluid or a fluent solid material by means not provided for in group G01L7/00 or G01L9/00 by optical means using a pressure-sensitive optical fibre
Abstract
A method for selecting the optimal incident polarization state in optical fiber pressure sensing based on Stokes parameters relates to the technical field of optical fiber sensing. The invention utilizes the linear birefringence generated by the optical fiber under the action of external pressure to cause the three Stokes parameters of the transmitted light to change and form a cosine curve relation with the pressure. Through the optimal selection of the polarization state of incident light, the sensitivity, the linearity and the dynamic range of a sensing capacity curve are accurately optimized, the sensing performance curve is prevented from falling into low sensitivity and nonlinear regionality, and the sensing performance is greatly improved.
Description
Technical Field
The invention relates to the technical field of optical fiber sensing, in particular to a performance optimization scheme for sensing by using Stokes parameters of optical fibers.
Background
When the optical fiber is affected by external environment (temperature, stress, magnetic field, pressure, etc.), parameters such as intensity, phase, frequency, polarization state, etc. of the transmitted light in the optical fiber will change correspondingly. The change of the corresponding physical quantity can be known by detecting these parameters of the transmitted light, and this technique is called optical fiber sensing technique.
Pressure sensing can be performed using the polarization properties of the optical fiber. The various possible polarization states of a light wave can be represented by a set of four real numbers (only three of which are independent of each other), called stokes parameters, in S0，S1，S2，S3Is a mark. Stokes parameter for fully polarized light
Handle S1，S2，S3Is divided by S0The normalized Stokes parameter s can be obtained1，s2，s3。
si＝Si/S0(i＝1,2,3)
Common normalized Stokes parameter s ═ s(s)1,s2,s3) To represent the polarization state of the light. The Stokes space introduces a sphere of radius 1 (Ponga sphere), and any polarization state of light can be represented by a point(s) on the Ponga sphere1,s2,s3) And (4) showing.
The pressure (or other parameter measured by pressure) sensing method based on the stokes parameter is shown in fig. 1: laser emitted by the laser passes through the polarization controller, the polarization controller can be adjusted to obtain light in a certain polarization state and enters the sensing optical fiber, the sensing optical fiber is under the action of pressure, the GP on-line polarization detection module collects the light transmitted from the sensing optical fiber, the signal output end of the on-line polarization detection module is connected with the signal input end of the signal processing module, and three normalized Stokes parameters s of the polarization state of the transmitted light are obtained1,s2,s3The signal processing module is connected with the signal input end of the display module and can display and record s in real time1,s2,s3The data of (1).
If the polarization state of the input light is sin＝(s1,s2,s3)inThen outputs the Stokes parameters s of the light after passing through the sensor headoutIs that
sout＝M×sin
Where M is the mueller matrix of the sensor head, the optical fiber generates linear birefringence under the action of pressure, resulting in changes in the three stokes parameters of the transmitted light, and the output polarization state will rotate around some intrinsic rotation axis, as shown in fig. 2. The trajectory of the polarization state depends on the position s of the initial polarization stateinAnd direction of intrinsic axis of rotation
So that there is a cosine-varying relationship between the stokes parameter and the external pressure, as illustrated in fig. 3. With the fiber press stationary, the eigen-axis of rotation is determined, at which time the incident polarization state sinBecomes an important factor in adjusting the relationship curve.
Disclosure of Invention
The invention aims to provide a method for determining the optimal incident polarization state to obtain the maximum sensitivity, the expected linearity and the dynamic range aiming at the problem of optimally selecting the incident polarization state.
The technical scheme of the invention is as follows:
the invention provides a method for selecting an optimal incident polarization state in optical fiber pressure sensing based on Stokes parameters, which comprises the following steps:
s1, acquiring the direction vector of the intrinsic rotating shaft of the optical fiber pressure sensor
Determining an actual Mueller matrix M of the optical fiber pressure sensor;
s2, plotting the maximum sensitivity output polarization state SoutCorresponding to input polarization state SinThe circumference is located;
s3, selecting one point on the circle as input polarization state SinObtaining the output polarization state SoutThe cosine relation curve of three Stokes parameters and pressure F is the peak-peakThe cosine relation curve with the maximum value is used as a sensing curve, and the expected linearity and linear range are selected on the sensing curve to obtain the optimal incident polarization state Sin。
Further, step S1 in the method specifically includes:
s1.1 at an arbitrary input polarization state SinContinuously increasing pressure, and measuring output polarization state S under corresponding pressure by using an online polarization analysis moduleout(s1, s2, s3) out; wherein s1, s2, s3 represent the first, second and third stokes parameters of the light, respectively;
s1.2, according to the output polarization state data under the corresponding pressure, obtaining a circular surface where an output polarization state point is located;
s1.3, acquiring normal vector of circular surface, namely direction vector of intrinsic rotating shaft of optical fiber pressure sensor
S1.4, acquiring an actual Mueller matrix M of the optical fiber pressure sensing by adopting the following formula;
wherein a, b and c respectively represent the direction vector of the intrinsic rotating shaft of the optical fiber pressure sensing,
K＝9.0431×10-12where λ represents the wavelength of light, D is the diameter of the fiber, F is the pressure applied by the fiber pressure sensor, and L is the length of the compressed fiber.
Further, step S2 in the method specifically includes: direction vector of eigen-rotation axis obtained in step 1
A circle with a radius of 1 is drawn on the poincare sphere as a normal vector, with the best input polarization state on this circle, when the output polarization state has the possibility to obtain the maximum sensitivity under pressure.
Further, step S3 in the method specifically includes:
s3.1, for the circle drawn in the step 2, optionally selecting a point on the circle as an input polarization state SinCombining the actual Mueller matrix M of the optical fiber pressure sensor obtained in the step 1, and respectively obtaining three cosine relation curves of the normalized Stokes parameters and the pressure F by adopting the following formula;
Sout＝M×Sin，
s3.2, taking the curve with the maximum peak value as a sensing curve in the cosine relation curves of the three normalized Steckes parameters and the pressure F;
s3.3, in a period on the cosine curve, determining expected linearity and a linear range;
s3.4, determining initial points according to expectation, and selecting one initial point as an optimal incident polarization state Sin。
A system adopted by a method for selecting the optimal incident polarization state in optical fiber pressure sensing based on Stokes parameters comprises a laser, a polarization controller, an optical fiber pressure sensor, an online polarization detection module and a signal processing module which are sequentially arranged, wherein the laser emits laser, the laser passes through the polarization controller to obtain light in a certain polarization state and enters the optical fiber pressure sensor, the online polarization detection module is used for receiving optical signals containing pressure information, and the signal output end of the online polarization detection module is connected with the signal input end of the signal processing module to demodulate the pressure information.
The invention has the beneficial effects that:
the invention utilizes the linear birefringence generated by the optical fiber under the action of external pressure to cause the three Stokes parameters of the transmitted light to change and form a cosine curve relation with the pressure. Through the optimal selection of the polarization state of incident light, the sensitivity, the linearity and the dynamic range of a sensing capacity curve are accurately optimized, the sensing performance curve is prevented from falling into low sensitivity and nonlinear regionality, and the sensing performance is greatly improved.
Additional features and advantages of the invention will be set forth in the detailed description which follows.
Drawings
The above and other objects, features and advantages of the present invention will become more apparent by describing in more detail exemplary embodiments thereof with reference to the attached drawings, in which like reference numerals generally represent like parts throughout.
Fig. 1 shows a schematic diagram of a pressure sensing system based on stokes parameters.
FIG. 2 shows a schematic diagram of the rotation of the output polarization state about some intrinsic axis of rotation under pressure.
Fig. 3 shows a schematic diagram of the cosine relationship between three normalized stokes parameters and pressure.
Fig. 4 shows a schematic view of a normal vector of a circular plane, i.e., a direction vector of the rotation axis.
FIG. 5 shows a schematic view of a circle on the Poincar sphere of radius 1 about the axis of rotation.
Fig. 6 shows a cosine curve of the maximum peak-to-peak value selected in the embodiment.
Fig. 7 shows a simulation of the performance curve obtained by selecting one of the best polarization states in the example.
Detailed Description
Preferred embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. While the preferred embodiments of the present invention are shown in the drawings, it should be understood that the present invention may be embodied in various forms and should not be limited to the embodiments set forth herein.
The invention provides a method for selecting an optimal incident polarization state in optical fiber pressure sensing based on Stokes parameters, which comprises the following steps:
s1, acquiring the direction vector of the intrinsic rotating shaft of the optical fiber pressure sensor
Determining an actual Mueller matrix M of the optical fiber pressure sensor, specifically:
s1.1 at an arbitrary input polarization state SinContinuously increasing pressure, on-lineThe polarization analysis module measures the output polarization state S under the corresponding pressureout；
S1.2, according to the output polarization state data under the corresponding pressure, obtaining a circular surface where an output polarization state point is located;
s1.3, acquiring normal vector of circular surface, namely direction vector of intrinsic rotating shaft of optical fiber pressure sensor
S1.4, acquiring an actual Mueller matrix M of the optical fiber pressure sensing by adopting the following formula;
wherein a, b and c respectively represent the direction vector of the intrinsic rotating shaft of the optical fiber pressure sensing,K＝9.0431×10-12where λ represents the wavelength of light, D is the diameter of the fiber, F is the pressure applied by the fiber pressure sensor, and L is the length of the compressed fiber.
S2, obtaining direction vector of eigen rotation axis in step 1
A circle with a radius of 1 is drawn on the poincare sphere as a normal vector, with the best input polarization state on this circle, when the output polarization state has the possibility to obtain the maximum sensitivity under pressure.
S3, selecting one point on the circle as input polarization state SinObtaining the output polarization state SoutThree cosine relation curves of the Stokes parameters and the pressure F, the cosine relation curve with the maximum peak value is taken as a sensing curve, and expected linearity and linear range are selected on the sensing curve to obtain the optimal incident polarization state SinSpecifically, the method comprises the following steps;
s3.1, for the circle drawn in the step 2, selecting a point on the circle as an inputInto the polarization state SinCombining the actual Mueller matrix M of the optical fiber pressure sensor obtained in the step 1, and respectively obtaining three cosine relation curves of the normalized Stokes parameters and the pressure F by adopting the following formula;
Sout＝M×Sin
s3.2, taking the curve with the maximum peak value as a sensing curve in the cosine relation curves of the three normalized Steckes parameters and the pressure F;
s3.3, in a period on the cosine curve, determining expected linearity and a linear range;
s3.4, determining initial points according to expectation, and selecting one initial point as an optimal incident polarization state Sin。
Example (b):
and obtaining a direction vector of the intrinsic rotating shaft of the optical fiber pressure sensor according to the experimental data, and determining the actual Mueller matrix of the optical fiber pressure sensor.
1.1 continuously increasing pressure under any input polarization state, and measuring an output polarization state;
1.2, according to the output polarization state data, obtaining a circular surface where the output polarization state point is located;
1.3 obtaining the normal vector of the circular surface, i.e. the vector in the direction of the rotating shaft
As shown in fig. 4;
1.4 utilization of
And substituting the M expression to obtain the Mueller matrix of the pressure sensing head.
Finding the input polarization state s corresponding to the maximum sensitivityinOn the circumference of the circle.
Intrinsic rotation axis obtained in step 1
A circle with a radius of 1 is drawn on the poincare sphere as a normal vector, as shown in fig. 5. The optimum input polarization state is on the circleWhen the output polarization state has the possibility of obtaining the maximum sensitivity under pressure.
Selecting a desired linearity and linear range, optionally one point on a circle with radius 1 in step 2 as the input polarization state sinAnd (3) combining the actual Mueller matrix M of the pressure sensing head obtained in the step (1), and simulating to obtain a relational graph (cosine curve) corresponding to the three normalized Stokes parameters and the pressure F.
Cosine curves(s) at three normalized Stokes parameters1,s2,s3) And determining the curve with the maximum peak value as a sensing curve.
On this cosine curve, the desired linearity and linear range are determined, as shown in FIG. 6, and two initial points are determined, one of which is optionally selected as the optimum incident polarization state s, as desiredin。
FIG. 4 is a direction vector of a rotating shaft of an extruder, which is obtained by obtaining points of Stokes parameters of output light on a Poincar sphere under the action of uniformly-changed pressure according to experimental data and calculating the direction vector according to the data points 
Fig. 5 is a circle of radius 1 around the axis of rotation drawn according to step 2.
FIG. 6 shows s obtained by simulation according to step 33Pressure F. On this cosine curve, a desired linearity (correlation coefficient ═ 0.9995) and linear range (quarter period) were selected. In one period of the cosine curve, two curves (such as a circle area of a graph) with the same performance exist. According to curve starting point s3Corresponding values, the polarization states are respectively sinEither (0.2649, 0.6767, -0.6870) or sin(-0.2378, -0.6407,0.7300), which is the best incident polarization state in this example.
FIG. 7 is a diagram of selecting one of the optimal polarization states: sinWhen the alloy is (-0.2378, -0.6407,0.7300), the obtained performance curve is similarTrue. High sensitivity and high linearity were obtained in the range of 0-5N (R ═ 99.95%).
Having described embodiments of the present invention, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.
Claims (5)
1. A method for selecting the optimal incident polarization state in optical fiber pressure sensing based on Stokes parameters is characterized by comprising the following steps:
s1, acquiring the direction vector of the intrinsic rotating shaft of the optical fiber pressure sensor
Determining an actual Mueller matrix M of the optical fiber pressure sensor;
s2, drawing the maximum sensitivity output polarization state S on the Poincar sphereoutCorresponding to input polarization state SinThe circumference is located;
s3, selecting one point on the circle as input polarization state SinObtaining the output polarization state SoutThree Stokes parameters sjout(j ═ 1,2,3) and pressure F, taking the cosine curve with the maximum peak-to-peak value as the sensing curve, selecting the desired linearity and linear range on the sensing curve, and obtaining the optimum incident polarization state Sin。
2. The method for selecting the optimal incident polarization state in the stokes parameter based optical fiber pressure sensing according to claim 1, wherein the step S1 is specifically as follows:
s1.1 at an arbitrary input polarization state SinContinuously increasing pressure, and measuring output polarization state S under corresponding pressure by using an online polarization analysis moduleout(s1, s2, s3) out; wherein s1, s2, s3 denote normalized first, second and third Stokes of light, respectivelyA Kers parameter;
s1.2, according to the output polarization state data under the corresponding pressure, obtaining a circular surface where an output polarization state point is located;
s1.3, acquiring normal vector of circular surface, namely direction vector of intrinsic rotating shaft of optical fiber pressure sensor
S1.4, acquiring an actual Mueller matrix M of the optical fiber pressure sensor by adopting the following formula;
wherein a, b and c respectively represent the direction vector of the intrinsic rotating shaft of the optical fiber pressure sensing,
K＝9.0431×10-12where λ represents the wavelength of light, D is the diameter of the fiber, F is the pressure applied by the fiber pressure sensor, and L is the length of the compressed fiber.
3. The method for selecting the optimal incident polarization state in the stokes parameter based optical fiber pressure sensing according to claim 1, wherein the step S2 is specifically as follows: direction vector of eigen-rotation axis obtained in step 1
A circle with a radius of 1 is drawn on the poincare sphere as a normal vector, with the best input polarization state on this circle, when the output polarization state has the possibility to obtain the maximum sensitivity under pressure.
4. The method for selecting the optimal incident polarization state in the stokes parameter based optical fiber pressure sensing according to claim 1, wherein the step S3 is specifically as follows:
s3.1, rendering for step 2Optionally a point on the circumference as the input polarization state SinCombining the actual Mueller matrix M of the optical fiber pressure sensor obtained in the step 1, and respectively obtaining three cosine relation curves of the normalized Stokes parameters and the pressure F by adopting the following formula;
Sout＝MSin,
namely, it is
S3.2, taking the curve with the maximum peak value as a sensing curve in the cosine relation curves of the three normalized Steckes parameters and the pressure F;
s3.3, in a period on the cosine curve, determining expected linearity and a linear range;
s3.4, determining initial points according to expectation, and selecting one initial point as an optimal incident polarization state Sin。
5. A system adopted by the method for selecting the optimal incident polarization state in the Stokes parameter-based optical fiber pressure sensor in claims 1-4 is characterized by comprising a laser, a polarization controller, an optical fiber pressure sensor, an online polarization analyzing module and a signal processing module which are sequentially arranged, wherein the laser emits laser light, the laser light passes through the polarization controller to obtain light in a certain polarization state and enters the optical fiber pressure sensor, the online polarization analyzing module is used for receiving an optical signal containing pressure information, and the signal output end of the online polarization analyzing module is connected with the signal input end of the signal processing module to demodulate the pressure information.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910636006.0A CN110672239B (en) | 2019-07-15 | 2019-07-15 | Method for selecting optimal incident polarization state in optical fiber pressure sensing based on Stokes parameters |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910636006.0A CN110672239B (en) | 2019-07-15 | 2019-07-15 | Method for selecting optimal incident polarization state in optical fiber pressure sensing based on Stokes parameters |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110672239A true CN110672239A (en) | 2020-01-10 |
| CN110672239B CN110672239B (en) | 2021-07-30 |
Family
ID=69068878
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910636006.0A Active CN110672239B (en) | 2019-07-15 | 2019-07-15 | Method for selecting optimal incident polarization state in optical fiber pressure sensing based on Stokes parameters |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110672239B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114739545A (en) * | 2022-04-12 | 2022-07-12 | 中国人民解放军陆军工程大学 | High-frequency polarization information demodulation system based on PBS and calibration and installation method |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1811359A (en) * | 2004-12-01 | 2006-08-02 | 通用光讯光电技术（北京）有限公司 | Measurements of polarization-dependent loss (pdl) and degree of polarization (dop) using optical polarization controllers and method thereof |
| CN102706494A (en) * | 2012-06-06 | 2012-10-03 | 中国人民解放军理工大学 | Real-time pressure sensing method based on fiber bragg grating reflected light polarization parameter |
| CN103196561A (en) * | 2013-04-01 | 2013-07-10 | 哈尔滨工业大学 | Device of measuring polarization characteristic of object at multiple angles and method of achieving measurement of polarization characteristic of object at multiple angles thereof |
| CN105698986A (en) * | 2016-03-17 | 2016-06-22 | 中国人民解放军理工大学 | Dynamic pressure detection system and method based on fiber grating Stokes parameters |
| CN106404243A (en) * | 2016-10-13 | 2017-02-15 | 中国人民解放军理工大学 | High-frequency dynamic information demodulation system and method based on optical fiber grating polarization information detection |
-
2019
- 2019-07-15 CN CN201910636006.0A patent/CN110672239B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1811359A (en) * | 2004-12-01 | 2006-08-02 | 通用光讯光电技术（北京）有限公司 | Measurements of polarization-dependent loss (pdl) and degree of polarization (dop) using optical polarization controllers and method thereof |
| CN102706494A (en) * | 2012-06-06 | 2012-10-03 | 中国人民解放军理工大学 | Real-time pressure sensing method based on fiber bragg grating reflected light polarization parameter |
| CN103196561A (en) * | 2013-04-01 | 2013-07-10 | 哈尔滨工业大学 | Device of measuring polarization characteristic of object at multiple angles and method of achieving measurement of polarization characteristic of object at multiple angles thereof |
| CN105698986A (en) * | 2016-03-17 | 2016-06-22 | 中国人民解放军理工大学 | Dynamic pressure detection system and method based on fiber grating Stokes parameters |
| CN106404243A (en) * | 2016-10-13 | 2017-02-15 | 中国人民解放军理工大学 | High-frequency dynamic information demodulation system and method based on optical fiber grating polarization information detection |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114739545A (en) * | 2022-04-12 | 2022-07-12 | 中国人民解放军陆军工程大学 | High-frequency polarization information demodulation system based on PBS and calibration and installation method |
| CN114739545B (en) * | 2022-04-12 | 2023-09-22 | 中国人民解放军陆军工程大学 | PBS-based high-frequency vibration information demodulation system and calibration method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110672239B (en) | 2021-07-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101339093B (en) | Optical fiber ring quality measurement method and its device for optical fibre gyroscope | |
| GB2414796A (en) | Optical wavelength determination using multiple measurable features | |
| CN111256827B (en) | Light wave polarization state detection method based on vector light field modulation and image processing | |
| CN104215368A (en) | F-P cavity optical fiber pressure sensing device and demodulation method thereof | |
| US20070280581A1 (en) | Optical pressure measuring apparatus | |
| CN109990975A (en) | Detection system, debugging system and sensor based on optical microcavity mechanical mode | |
| CN110672239B (en) | Method for selecting optimal incident polarization state in optical fiber pressure sensing based on Stokes parameters | |
| CN108195943A (en) | A kind of optical fiber acoustic emission system and its monitoring method for monitoring explosive damage and failure process | |
| CN111060711A (en) | Optical rotating speed measuring system and method based on Stokes vector | |
| CN111579075B (en) | Fast detection method for light wave polarization state based on Fourier analysis | |
| CN111025306A (en) | Vibration positioning method and system based on phase-sensitive OTDR | |
| CN208238813U (en) | Screw type optic fibre turning sensor | |
| CN110388995A (en) | High-accuracy optical temperature monitoring device and method based on the weak measure theory of quantum | |
| CN106989852A (en) | A kind of fibre optical sensor for measuring stress direction | |
| CN113820051B (en) | Complementary interference stress measuring device for material | |
| CN204101218U (en) | A kind of F-P cavity fiber pressure sensing device | |
| CN107764748B (en) | Device and method for measuring linear birefringence of glass material | |
| CN106441612B (en) | Friction pair three-point fusion temperature measurement system and temperature measurement method | |
| CN112432724B (en) | Stress sensor based on vernier effect of optical fiber resonant cavity and stress measurement method | |
| CN115014606A (en) | Fiber bragg grating dynamic torque measuring device and method based on off-axis interconnector | |
| Parkinson et al. | Correction of peak tracking ripple in solid state spectrometers | |
| CN113639769B (en) | Method for improving sensitivity of sensor based on speckle correlation | |
| CN110440951A (en) | A kind of temperature measuring device of plasma gas | |
| JP2007322437A (en) | Device and method for performing measurement processing of fiber bragg grating element reflection light wavelength | |
| Song et al. | The optimization of multimode fiber speckle sensor for microvibration |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |