CN108007603A - A kind of many reference amounts distribution measurement system based on Asymmetric Twin-Core Fiber - Google Patents
A kind of many reference amounts distribution measurement system based on Asymmetric Twin-Core Fiber Download PDFInfo
- Publication number
- CN108007603A CN108007603A CN201711361638.8A CN201711361638A CN108007603A CN 108007603 A CN108007603 A CN 108007603A CN 201711361638 A CN201711361638 A CN 201711361638A CN 108007603 A CN108007603 A CN 108007603A
- Authority
- CN
- China
- Prior art keywords
- core
- coupler
- circulator
- optical fiber
- dual
- 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
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K11/00—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00
- G01K11/32—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00 using changes in transmittance, scattering or luminescence in optical fibres
-
- 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
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optical Transform (AREA)
- Length Measuring Devices By Optical Means (AREA)
Abstract
本发明涉及多参量分布式测量系统技术领域，特指一种基于非对称双芯光纤的多参量分布式测量系统，包括宽带光源、脉冲调制器、第一耦合器、双芯光纤耦合器、双芯光纤、第一环形器、第二环形器、第二耦合器、光纤延迟线、第一陷波滤波片、第二陷波滤波片、第一光电二极管、第二光电二极管、第三光电二极管、信息采集单元与计算机。本发明通过非对称双芯光纤的轴上芯与表层芯对温度与应变的敏感系数不同的特点，利用双芯的瑞利散射信号构建温度和应变求解矩阵；利用弱光栅阵列对全光纤范围内的瑞利散射进行空间分段定位，以提高传感系统的空间分辨率和测量精度，实现对温度和应变的同时精确测量和其在区间内的精确定位。
The present invention relates to the technical field of multi-parameter distributed measurement systems, in particular to a multi-parameter distributed measurement system based on asymmetric dual-core optical fibers, including a broadband light source, a pulse modulator, a first coupler, a dual-core optical fiber coupler, a dual Core fiber, first circulator, second circulator, second coupler, fiber delay line, first notch filter, second notch filter, first photodiode, second photodiode, third photodiode , an information collection unit and a computer. The present invention utilizes the characteristic that the on-axis core and the surface core of the asymmetric dual-core optical fiber have different sensitivity coefficients to temperature and strain, and utilizes the Rayleigh scattering signal of the dual core to construct a solution matrix for temperature and strain; Rayleigh scattering is used for spatial segmentation positioning to improve the spatial resolution and measurement accuracy of the sensing system, and to achieve simultaneous accurate measurement of temperature and strain and precise positioning within the interval.
Description
Technical Field
The invention relates to the technical field of multi-parameter distributed measurement systems, in particular to a multi-parameter distributed measurement system based on asymmetric double-core optical fibers.
Background
With the development of scientific technology and the improvement of application requirements of the internet of things, an optical fiber sensing network is developing towards high-capacity and multi-parameter measurement, a distributed optical fiber sensing network based on Rayleigh scattering, Brillouin scattering and Raman scattering provides a feasible new means for measuring physical parameters such as temperature, strain and the like of various points continuously distributed in space in severe environments such as high voltage, strong magnetic field interference, large current, complex geometric space, flammability, explosiveness and the like, and the distributed optical fiber sensing technology is developed along with the generation of Optical Time Domain Reflectometry (OTDR), for example: measuring the intensity and polarization state of a backward Rayleigh scattering signal by using an optical time domain reflection technology to monitor temperature/strain; measuring the intensity of a backward Raman scattering signal by using an optical time domain reflection technology to monitor the temperature; temperature/strain is monitored by measuring the intensity and frequency shift of the brillouin signal using optical time domain reflectometry.
The distributed optical fiber sensor based on Brillouin scattering and the distributed optical fiber sensor based on Raman scattering have low response speed and spatial resolution, are not suitable for monitoring requirements of many application occasions on quick response of accidents, and the complex and expensive system also limits the engineering application of the two types of distributed measurement technologies. The distributed optical fiber sensor based on rayleigh scattering has a fast response speed and high sensitivity, and is beginning to be emphasized. However, the distributed optical fiber sensing system based on single-mode optical fiber rayleigh scattering uses weak backward rayleigh scattering signals as information carriers, the signal-to-noise ratio of the system is low, the measurement accuracy and the spatial resolution are low, the sensing function is single, quantitative detection of temperature and strain is difficult to realize, and the like, and the development of the distributed optical fiber sensing technology based on rayleigh scattering is restricted. Particularly, because the optical fiber is sensitive to the cross of temperature and strain, the optical fiber is difficult to be guaranteed not to be disturbed by stress by adding an additional temperature-sensing optical fiber, the measurement precision is difficult to be guaranteed due to the position deviation of the temperature compensation grating and the measurement grating, and the like, and the optical fiber is difficult to be applied in engineering. At present, no report that strain and temperature continuous distributed optical fiber sensing detection can be simultaneously carried out on all positions along an optical fiber by adopting a weak optical fiber grating array is available. If the strain, temperature and other measurements can be simultaneously and rapidly monitored in a distributed manner in a long distance, the monitoring cost can be greatly reduced, and the effectiveness and reliability of monitoring can be improved. Therefore, innovative sensing mechanisms and methods are needed to meet the requirements of practical applications.
Disclosure of Invention
Aiming at the problems, the invention provides a multi-parameter distributed measurement system based on asymmetric double-core optical fibers, which can realize high spatial resolution and high-precision distributed measurement of temperature and strain signals.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
the utility model provides a many parameter distributed measurement system based on asymmetric two-core optical fiber, includes broadband light source, pulse modulator, first coupler, two-core optical fiber, first circulator, second circulator, the second coupler, the optical fiber delay line, first notch filter, second notch filter, first photodiode, second photodiode, third photodiode, information acquisition unit and computer, two-core optical fiber include on-axis core and surface layer core, be equipped with weak grating array on-axis core and the surface layer core respectively.
Further, the broadband light source is connected to a pulse modulator, the pulse modulator is connected to an input end of a first coupler of the first coupler, a first output end of the first coupler is connected to a first port of a first circulator of the first circulator, a second port of the first circulator is connected to a first input end of a dual-core fiber coupler of the dual-core fiber coupler, a first output end of the dual-core fiber coupler is coupled to an on-axis core of the dual-core fiber, and a second output end of the dual-core fiber coupler is coupled to a surface core of the dual-core fiber.
Further, a third port of the first circulator is connected to a first input end of a second coupler of the second coupler, a first output end of the second coupler is connected to a first port of the information acquisition unit through a first photodiode, and a second output end of the second coupler is connected to a second port of the information acquisition unit through a first notch filter and a second photodiode.
Further, a second output end of the first coupler is connected to a first port of a second circulator of the second circulator, a second port of the second circulator is connected to a second input end of the dual-core fiber coupler, and a third port of the second circulator is connected to a third port of the information acquisition unit through the fiber delay line, the second notch filter and the third photodiode.
Further, the information acquisition unit is connected to a computer, and the computer is connected to the pulse modulator.
Furthermore, the dual-core optical fiber is a transmission type dual-chip optical fiber, the on-axis core and the surface layer core have different sensitivity coefficients to pressure and temperature, and no coupling effect exists between the on-axis core and the surface layer core.
Furthermore, the weak grating array is an identical weak fiber grating, is manufactured by adopting the same mask plate, and has consistent central wavelength.
The invention has the beneficial effects that:
1. the method comprises the steps of exciting Rayleigh scattering light by using a modulated pulse light source to perform distributed measurement, performing space segmentation positioning on Rayleigh scattering in an all-fiber range by using pulses and weak grating arrays to improve the spatial resolution and the measurement precision of a sensing system, and constructing a temperature and strain solving matrix by using Rayleigh scattering signals of every two adjacent weak grating regions of a double-core fiber to realize simultaneous accurate measurement of temperature and strain and accurate positioning of the temperature and strain in the regions;
2. the distributed measurement is carried out by combining Rayleigh scattering and weak grating arrays in the double-core optical fiber, the measurement precision is high, the spatial resolution is high, and the simultaneous measurement of temperature and strain is realized on one optical fiber;
3. the distributed optical fiber sensing device has the advantages of simple structure, high response speed and high spatial resolution, and can simultaneously realize high-precision distributed optical fiber sensing measurement of temperature and strain parameters.
Drawings
FIG. 1 is a block diagram of a measurement system of the present invention;
FIG. 2 is a graph of time versus fiber length;
FIG. 3 is a graph of temperature versus time;
FIG. 4 is a plot of strain versus time;
FIG. 5 is a temperature distribution curve in the spatial domain;
fig. 6 is a strain distribution curve in the spatial domain.
1. A broadband light source; 2. a pulse modulator; 3. a first coupler; 301. a first coupler input; 302. a first coupler first output; 303. a first coupler second output; 4. a dual-core fiber coupler; 401. a first input end of the double-core optical fiber coupler; 402. a second input end of the double-core optical fiber coupler; 403. a first output end of the dual-core optical fiber coupler; 404. a second output end of the dual-core optical fiber coupler; 5. a dual-core optical fiber; 501. an on-axis core; 502. a skin core; 6. a weak grating array; 7. a first circulator; 701. a first circulator first port; 702. a first circulator second port; 703. a first circulator third port; 8. a second circulator; 801. a second circulator first port; 802. a second circulator second port; 803. a second circulator third port; 9. a second coupler; 901. a second coupler first input; 902. a second coupler first output; 903. a second coupler second output; 10. a fiber delay line; 11. a first notch filter; 12. a second notch filter; 13. a first photodiode; 14. a second photodiode; 15. a third photodiode; 16. an information acquisition unit; 1601. a first port of an information acquisition unit; 1602. a second port of the information acquisition unit; 1603. a third port of the information acquisition unit; 17. and (4) a computer.
Detailed Description
The technical solution of the present invention is described below with reference to the accompanying drawings and examples.
As shown in fig. 1, the multiparameter distributed measurement system based on the asymmetric dual-core fiber of the present invention includes a broadband light source 1, a pulse modulator 2, a first coupler 3, a dual-core fiber coupler 4, a dual-core fiber 5, a first circulator 7, a second circulator 8, a second coupler 9, a fiber delay line 10, a first notch filter 11, a second notch filter 12, a first photodiode 13, a second photodiode 14, a third photodiode 15, an information acquisition unit 16, and a computer 17, where the dual-core fiber 5 includes an on-axis core 501 and a surface core 502, and the on-axis core 501 and the surface core 502 are respectively provided with a weak grating array 6.
More specifically, the broadband light source 1 is connected to the pulse modulator 2, the pulse modulator 2 is connected to the first coupler input end 301 of the first coupler 3, and the broadband light output by the broadband light source 1 is output as pulsed light through the pulse modulator 2, input to the first coupler 3, and divided into a first beam of probe light and a second beam of probe light.
More specifically, the first coupler first output end 302 of the first coupler 3 is connected to the first circulator first port 701 of the first circulator 7, the first circulator second port 702 of the first circulator 7 is connected to the dual-core fiber coupler first input end 401 of the dual-core fiber coupler 4, the dual-core fiber coupler first output end 403 of the dual-core fiber coupler 4 is coupled to the on-axis core 501 of the dual-core fiber 5, the third port 703 of the first circulator 7 is connected to the first input port 901 of the second coupler 9, the first output port 902 of the second coupler 9 of the second coupler is connected to the first port 1601 of the information acquisition unit 16 through the first photodiode 13, and the second output port 903 of the second coupler 9 of the second coupler is connected to the second port 1602 of the information acquisition unit 16 through the first notch filter 11 and the second photodiode 14. By adopting the structure, the working principle is as follows: the first beam of probe light is incident on the first circulator first port 701 of the first circulator 7, is emitted from the first circulator second port 702 of the first circulator 7, enters the dual-core optical fiber coupler first input end 401 of the dual-core optical fiber coupler 4, is coupled into the on-axis core 501 of the dual-core optical fiber 5 from the dual-core optical fiber coupler first output end 403 of the dual-core optical fiber coupler 4, is incident on the dual-core optical fiber coupler first output end 403 of the dual-core optical fiber coupler 4 from the weak grating array 6 on the on-axis core 501 and the first reflected light generated by the rayleigh scattering effect, is emitted from the dual-core optical fiber coupler first input end 401 of the dual-core optical fiber coupler 4, is incident on the first circulator second port 702 of the first circulator 7, is emitted from the third port 703 of the first circulator 7, is subsequently incident on the second coupler 9, and is divided into two beams of on-axis core reflected light and on-axis core reflected light, the reflected light of the on-axis core grating is incident to the first photodiode 13 and converted into a grating electric signal, and then transmitted to the first port 1601 of the information acquisition unit 16, and the rayleigh reflected light of the on-axis core grating passes through the first notch filter 11, is incident to the second photodiode 14 and converted into a rayleigh electric signal, and then transmitted to the second port 1602 of the information acquisition unit 16.
More specifically, the first coupler second output end 303 of the first coupler 3 is connected to the second circulator first port 801 of the second circulator 8, the second circulator second port 802 of the second circulator 8 is connected to the two-core optical fiber coupler second input end 402 of the two-core optical fiber coupler 4, the two-core optical fiber coupler second output end 404 of the two-core optical fiber coupler 4 is coupled to the sheath core 502 of the two-core optical fiber 5, and the second circulator third port 803 of the second circulator 8 is connected to the information acquisition unit third port 1603 of the information acquisition unit 16 through the optical fiber delay line 10 and the second notch filter 12. By adopting the structure, the working principle is as follows: the second beam of probe light is incident on the second circulator first port 801 of the second circulator 8, exits from the second circulator second port 802 of the second circulator 8, enters the dual-core fiber coupler second input end 402 of the dual-core fiber coupler 4, is coupled into the sheath core 502 of the dual-core fiber 5 from the dual-core fiber coupler second output end 404 of the dual-core fiber coupler 4, enters the dual-core fiber coupler second output end 404 of the dual-core fiber coupler 4 through the weak grating array 6 on the sheath core 502 and the rayleigh scattering effect, exits from the dual-core fiber coupler second input end 402 of the dual-core fiber coupler 4, enters the second circulator second port 802 of the second circulator 8, exits from the second circulator third port 803 of the second circulator 8, enters the third photodiode 15 through the fiber delay line 10 and the second notch filter 12, and is converted into a sheath electrical signal, and then to the information gathering unit third port 1603 of the information gathering unit 16.
More specifically, the information acquisition unit 16 is connected to a computer 17, and the computer 17 is connected to the pulse modulator 2. With such a configuration, the three electrical signals collected by the information collecting unit 16 are finally transmitted to the computer 17 for signal processing for image display.
More specifically, the two-core optical fiber 5 is a transmission type two-chip optical fiber, the on-axis core 501 and the surface core 502 have different sensitivity coefficients to pressure and temperature, and there is no coupling effect between the on-axis core 501 and the surface core 502.
More specifically, the weak grating array 6 is an identical weak fiber grating, and is made of the same mask plate, and the central wavelengths are identical.
The invention also provides a measuring method of the multi-parameter distributed measuring system based on the asymmetric double-core optical fiber, which comprises the following steps:
step one, setting the pulse interval tau of a pulse modulator to be required to be longer than the time of transmitting a pulse in a double-core optical fiber, namely:
τ＞2nL/c
wherein n is the refractive index of the fiber core of the dual-core fiber, L is the length of the dual-core fiber, and c is the speed of light;
step two, the position of the weak fiber bragg grating (wFBG) can be calculated by using the pulse signal in the first grating electrical signal as follows:
d＝(t-t0)c/2n
where t is the time of receiving the corresponding pulse signal in the reference electrical signal, t0For the sending time of the square wave driving signal sent by the computer 17 to the pulse modulator, the relation between the time and the weak grating distance can be obtained by a formulaA system curve, i.e. a time versus fiber length curve, as shown in fig. 2, so that each grating in the array of weak gratings can be located;
and step three, after the pulse enters the double-core optical fiber, Rayleigh scattering light with certain intensity is reflected back after passing through one point, so that Rayleigh scattering signals received by the optical detector are continuous and variable, and the light intensity received at a certain moment is related to the stress and the temperature at a certain position on the double-core optical fiber.
Step four, through simultaneous first Rayleigh electric signal I12And a second electrical signal I2Solving the matrix of (1):
wherein,the temperature sensitive coefficients of the on-axis core and the surface layer core of the double-core optical fiber are respectively,strain sensitive coefficients of an on-axis core and a surface layer core of the dual-core optical fiber are respectively, and a relation curve of temperature and time can be obtained through a formula, as shown in fig. 3; strain versus time, as shown in fig. 4;
and step five, combining the obtained relation curve of time and optical fiber length, the obtained relation curve of temperature and time and the obtained relation curve of strain and time to obtain the respective distribution conditions of temperature and strain on the spatial domain, as shown in fig. 5 and 6.
While the present invention has been described with reference to the embodiments shown in the drawings, the present invention is not limited to the embodiments, which are illustrative and not restrictive, and those skilled in the art can make various modifications without departing from the spirit and scope of the present invention.
Claims (3)
1. A multi-parameter distributed measurement system based on asymmetric double-core optical fibers is characterized in that: the broadband optical fiber (1), a pulse modulator (2), a first coupler (3), a double-core optical fiber coupler (4), a double-core optical fiber (5), a first circulator (7), a second circulator (8), a second coupler (9), an optical fiber delay line (10), a first notch filter (11), a second notch filter (12), a first photodiode (13), a second photodiode (14), a third photodiode (15), an information acquisition unit (16) and a computer (17), wherein the double-core optical fiber (5) comprises an on-axis core (501) and a surface core (502), and weak grating arrays (6) are respectively arranged on the on-axis core (501) and the surface core (502),
the broadband light source (1) is connected with the pulse modulator (2), the pulse modulator (2) is connected with the first coupler input end (301) of the first coupler (3),
the first output end (302) of the first coupler (3) is connected to the first circulator first port (701) of the first circulator (7), the first circulator second port (702) of the first circulator (7) is connected to the first input end (401) of the dual-core fiber coupler (4), the first output end (403) of the dual-core fiber coupler (4) is coupled to the on-axis core (501) of the dual-core fiber (5), the second output end (404) of the dual-core fiber coupler (4) is coupled to the surface layer core (502) of the dual-core fiber (5),
a third port (703) of the first circulator (7) is connected to a first input end (901) of a second coupler of the second coupler (9), a first output end (902) of the second coupler (9) is connected to a first port (1601) of an information acquisition unit of the information acquisition unit (16) through a first photodiode (13), a second output end (903) of the second coupler (9) is connected to a second port (1602) of the information acquisition unit (16) through a first notch filter (11) and a second photodiode (14),
a second output end (303) of the first coupler (3) is connected with a first port (801) of a second circulator of the second circulator (8), a second port (802) of the second circulator (8) is connected with a second input end (402) of the double-core optical fiber coupler (4), a third port (803) of the second circulator (8) is connected with a third port (1603) of an information acquisition unit (16) through an optical fiber delay line (10), a second notch filter (12) and a third photodiode (15),
the information acquisition unit (16) is connected to a computer (17), and the computer (17) is connected to the pulse modulator (2).
2. The asymmetric two-core fiber-based multi-parameter distributed measurement system according to claim 1, wherein: the double-core optical fiber (5) is a transmission type double-chip optical fiber, the sensitivity coefficients of the on-axis core (501) and the surface layer core (502) to pressure and temperature are different, and no coupling effect exists between the on-axis core (501) and the surface layer core (502).
3. The asymmetric two-core fiber-based multi-parameter distributed measurement system according to claim 1, wherein: the weak grating array (6) is identical weak fiber grating, is made of the same mask plate, and has consistent central wavelength.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711361638.8A CN108007603B (en) | 2017-12-18 | 2017-12-18 | Multi-parameter distribution measuring system based on asymmetric double-core optical fiber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711361638.8A CN108007603B (en) | 2017-12-18 | 2017-12-18 | Multi-parameter distribution measuring system based on asymmetric double-core optical fiber |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108007603A true CN108007603A (en) | 2018-05-08 |
| CN108007603B CN108007603B (en) | 2020-05-05 |
Family
ID=62059711
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201711361638.8A Active CN108007603B (en) | 2017-12-18 | 2017-12-18 | Multi-parameter distribution measuring system based on asymmetric double-core optical fiber |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108007603B (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108801304A (en) * | 2018-06-13 | 2018-11-13 | 武汉理工大学 | A method of improving Rayleigh scattering many reference amounts distributed measurement precision |
| CN113984126A (en) * | 2021-11-04 | 2022-01-28 | 日照武汉理工大生物医药暨新材料研究院 | Temperature strain monitoring system and method based on different-doped double-core weak reflection FBG array |
| CN114354974A (en) * | 2021-12-30 | 2022-04-15 | 广东工业大学 | Distributed wind speed sensor based on double-core optical fiber, measuring device and method |
| CN116989832A (en) * | 2023-09-26 | 2023-11-03 | 北京大学 | A variable multi-spatial sensing scale seismic exploration method and system |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1828229A (en) * | 2006-04-19 | 2006-09-06 | 黑龙江大学 | CPLD-based Time Division Multiplexing Fiber Bragg Grating Sensing Test System |
| CN105181111A (en) * | 2015-09-21 | 2015-12-23 | 电子科技大学 | Ultraweak fiber bragg grating array and Phi-OTDR combined optical fiber vibration sensing system |
| CN105698831A (en) * | 2016-01-26 | 2016-06-22 | 武汉理工大学 | Double-core FBG (fiber bragg grating) array sensing network and distributed sensing information obtaining method |
| CN107036733A (en) * | 2017-04-21 | 2017-08-11 | 武汉理工大学 | The many reference amounts Distributed Measurement System and measuring method of twin-core dim light grid array based on dark pulse light source |
-
2017
- 2017-12-18 CN CN201711361638.8A patent/CN108007603B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1828229A (en) * | 2006-04-19 | 2006-09-06 | 黑龙江大学 | CPLD-based Time Division Multiplexing Fiber Bragg Grating Sensing Test System |
| CN105181111A (en) * | 2015-09-21 | 2015-12-23 | 电子科技大学 | Ultraweak fiber bragg grating array and Phi-OTDR combined optical fiber vibration sensing system |
| CN105698831A (en) * | 2016-01-26 | 2016-06-22 | 武汉理工大学 | Double-core FBG (fiber bragg grating) array sensing network and distributed sensing information obtaining method |
| CN107036733A (en) * | 2017-04-21 | 2017-08-11 | 武汉理工大学 | The many reference amounts Distributed Measurement System and measuring method of twin-core dim light grid array based on dark pulse light source |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108801304A (en) * | 2018-06-13 | 2018-11-13 | 武汉理工大学 | A method of improving Rayleigh scattering many reference amounts distributed measurement precision |
| CN108801304B (en) * | 2018-06-13 | 2019-11-26 | 武汉理工大学 | A method of improving Rayleigh scattering many reference amounts distributed measurement precision |
| CN113984126A (en) * | 2021-11-04 | 2022-01-28 | 日照武汉理工大生物医药暨新材料研究院 | Temperature strain monitoring system and method based on different-doped double-core weak reflection FBG array |
| CN113984126B (en) * | 2021-11-04 | 2024-05-14 | 武汉理工大学威海研究院 | Temperature strain monitoring system and method based on differently doped double-core weak reflection FBG array |
| CN114354974A (en) * | 2021-12-30 | 2022-04-15 | 广东工业大学 | Distributed wind speed sensor based on double-core optical fiber, measuring device and method |
| CN114354974B (en) * | 2021-12-30 | 2023-06-16 | 广东工业大学 | Distributed wind speed sensor based on double-core optical fiber, measuring device and method |
| CN116989832A (en) * | 2023-09-26 | 2023-11-03 | 北京大学 | A variable multi-spatial sensing scale seismic exploration method and system |
| CN116989832B (en) * | 2023-09-26 | 2023-12-26 | 北京大学 | Variable multi-space sensing scale seismic exploration method and system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108007603B (en) | 2020-05-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107036733B (en) | Multi-parameter distributed measurement system and measurement method of double-core weak grating array based on dark pulse light source | |
| CN109238355B (en) | Device and method for simultaneously sensing and measuring distributed dynamic and static parameters of optical fiber | |
| CN103674086B (en) | Measure entirely with method and the device of weak optical fiber Bragg grating temperature and strain based on Brillouin scattering simultaneously | |
| US6285446B1 (en) | Distributed sensing system | |
| CN107238412B (en) | A kind of while monitoring vibration, stress, temperature distributed fiberoptic sensor | |
| CN106248247B (en) | A kind of sensing device based on the brillouin distributed temperature of Raman-, the double Parametric Detections of stress | |
| CN103674117B (en) | Measure entirely method and device with weak optical fiber Bragg grating temperature and strain based on Raman scattering simultaneously | |
| CN103591971B (en) | A kind of localization method of fiber grating | |
| CN106643832A (en) | Phase-sensitive optical time-domain reflectometer based on linear frequency-modulation pulse and measurement method of phase-sensitive optical time-domain reflectometer | |
| CN109959403B (en) | Multi-parameter large-capacity sensing system | |
| CN106404154B (en) | Optical fiber sound wave detection system | |
| CN108007603B (en) | Multi-parameter distribution measuring system based on asymmetric double-core optical fiber | |
| CN105021307A (en) | Method for realizing all-fiber distributed multi-parameter sensing | |
| CN103575313A (en) | Frequency division multiplexing device for multi-longitudinal mode ring cavity laser sensor based on beat frequency technology | |
| CN103940360A (en) | Strain monitoring device based on cascade chirped fiber gratings | |
| CN101319919B (en) | Method and device for demodulation of frequency domain optical fiber optical grating sensing network | |
| CN118603152A (en) | A distributed multi-parameter sensing system based on multi-core optical fiber | |
| CN113834509A (en) | A Weak Reflection Fiber Bragg Grating String Demodulator Based on Deep Learning | |
| CN115164956B (en) | Color and mode field collaborative coding distributed optical fiber sensing device | |
| CN115324566B (en) | Underground distributed temperature measurement system and method based on weak reflection fiber bragg grating | |
| CN201302458Y (en) | Fiber grating sensing network demodulating equipment | |
| CN119197607B (en) | A multi-parameter distributed optical fiber sensing system and method based on chirped pulses | |
| CN102175170A (en) | Detecting method and sensor for cracks of civil structure based on optical fiber long chirped grating frequency domain reflection technology | |
| CN106197741B (en) | Temperature-detecting device based on micro-nano long-period fiber grating sensor and method | |
| CN104458080A (en) | Optical fiber pressure sensing measurement method and device |
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 |