CN110375779B - Device and method for improving OFDR frequency domain sampling rate - Google Patents
Device and method for improving OFDR frequency domain sampling rate Download PDFInfo
- Publication number
- CN110375779B CN110375779B CN201910688206.0A CN201910688206A CN110375779B CN 110375779 B CN110375779 B CN 110375779B CN 201910688206 A CN201910688206 A CN 201910688206A CN 110375779 B CN110375779 B CN 110375779B
- Authority
- CN
- China
- Prior art keywords
- frequency
- data acquisition
- signal
- fiber coupler
- module
- 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.)
- Active
Links
- 238000005070 sampling Methods 0.000 title claims abstract description 47
- 238000002168 optical frequency-domain reflectometry Methods 0.000 title claims abstract description 28
- 238000000034 method Methods 0.000 title claims abstract description 14
- 238000005259 measurement Methods 0.000 claims abstract description 40
- 239000013307 optical fiber Substances 0.000 claims abstract description 36
- 230000035559 beat frequency Effects 0.000 claims abstract description 24
- 239000000835 fiber Substances 0.000 claims description 16
- 238000010408 sweeping Methods 0.000 claims description 9
- 238000012545 processing Methods 0.000 claims description 5
- 238000012360 testing method Methods 0.000 claims description 3
- 230000008569 process Effects 0.000 claims description 2
- 230000009286 beneficial effect Effects 0.000 abstract description 4
- 230000008859 change Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 3
- 238000004891 communication Methods 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000009022 nonlinear effect Effects 0.000 description 1
- 238000000253 optical time-domain reflectometry Methods 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 230000003595 spectral effect Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000013519 translation Methods 0.000 description 1
- 230000001960 triggered effect Effects 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
- G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
- G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
- G01D5/353—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
- G01D5/35303—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using a reference fibre, e.g. interferometric devices
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
- G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
- G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
- G01D5/353—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
- G01D5/35306—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using an interferometer arrangement
- G01D5/35325—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using an interferometer arrangement using interferometer with two arms in reflection, e.g. Mickelson interferometer
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Instruments For Measurement Of Length By Optical Means (AREA)
- Investigating Or Analysing Materials By Optical Means (AREA)
Abstract
The invention relates to a device and a method for improving the frequency domain sampling rate of OFDR. The device comprises a sweep frequency laser, an optical fiber coupler, a measuring module, an auxiliary module, a data acquisition card and a computer. In the measurement module, beat frequency interference occurs between a reference arm signal and a measurement arm, and the generated beat frequency signal is acquired in a frequency domain such as a data acquisition card controlled by an external clock signal generated in the auxiliary module. And dividing N times of sampling according to the measurement length, and sequentially translating the frequency of the sampling signal for data acquisition by using a frequency shifter for adjustment under the condition that the frequency difference of two arms of the auxiliary module interferometer is fixed. And superposing the multiple acquired data and then carrying out FFT operation to obtain a final result. The method improves the OFDR frequency domain sampling rate, is beneficial to expanding the OFDR measurement range, can adjust the measurement range according to the user requirement, is convenient, has accurate result, and can meet the requirements of various measurement environments.
Description
Technical Field
The invention relates to the technical field of optical fiber sensing, in particular to a device for improving the frequency domain sampling rate of OFDR and a frequency domain sampling method.
Background
As one of the most promising techniques in the field of distributed optical fiber sensing, research and application of optical frequency domain reflectometry techniques have been a hot issue of great concern. Based on the combination of frequency domain analysis and optical heterodyne technology, compared with the traditional OTDR technology, the OFDR technology has higher resolution and larger dynamic range, and has wide application prospects in the aspects of optical communication measurement, strain, temperature sensing and the like in the fields of engineering and medical treatment.
OFDR systems use swept-frequency light sources. The influence of temperature change, device vibration and other factors can cause the output laser spectral line to change, and the wavelength does not periodically change along with the time and has certain jitter, which is called as the nonlinear effect of the light source. This phenomenon can limit the spatial resolution of OFDR and needs to be eliminated in practical systems. An auxiliary interferometer is usually added outside a main interferometer for measurement to generate beat frequency signals which serve as clock signals for data acquisition, the main interferometer is triggered to sample at equal frequency domain intervals, and the equal frequency domain sampling is converted into equal frequency domain sampling, so that the influence of light source nonlinearity is eliminated. According to the sampling theorem, the maximum frequency detectable by the OFDR system is determined by the arm difference of the auxiliary interferometer, and the maximum measurable range is half of the arm difference of the auxiliary interferometer.
In general, in the case of an OFDR system with well-defined interferometer arm differences, the system measurable distance is fixed. If the measurement range is required to be enlarged or reduced, the auxiliary interferometer needs to be manufactured and replaced again, otherwise, the problems of incapability of measuring the over-range or long measurement time, low speed and the like caused by measuring a short-distance optical fiber by a large-range system occur. Moreover, since the spatial resolution of OFDR is usually in the micron level, a single data point acquisition can reach several tens of millions in long-distance measurement, the sampling frequency interval is small, the conventional data acquisition card and computer are difficult to meet the requirements of data acquisition and arithmetic processing, and a high-performance module must be used, so the cost of the OFDR system is increased. Therefore, simplifying the complex operation of frequently replacing the auxiliary interferometer and effectively improving the measurement range of the OFDR system are all problems to be solved urgently.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a device and a method for improving the OFDR frequency domain sampling rate, which are used for realizing adjustable OFDR measurement distance and effectively expanding the OFDR measurement range.
The technical scheme adopted by the invention is as follows:
the device for improving the frequency domain sampling rate of the OFDR is characterized by comprising a frequency-sweeping laser, a first optical fiber coupler, a measuring module, an auxiliary module, a data acquisition card and a computer; wherein:
the frequency-sweeping laser is used for emitting linear frequency-sweeping light with periodically changed wavelength;
the first optical fiber coupler divides the linear sweep frequency light into two beams which respectively enter the measuring module and the auxiliary module;
the measuring module is used for acquiring a measuring signal and generating a beat frequency interference signal;
the auxiliary module is used for generating an external clock signal and triggering the data acquisition card to sample in an equal frequency domain; the auxiliary module comprises a first frequency shifter and a second frequency shifter which are connected in parallel, and the frequency difference delta v of the two frequency shifters0Fixed, the frequency difference Deltav0The sampling frequency interval under the current measurement length; after each sampling of the data acquisition card, the two frequency shifters shift the frequency by delta v0Triggering the data acquisition card to acquire data for the next time;
the data acquisition card samples beat frequency interference signals output by the measurement module in an equal frequency domain under the trigger of an external clock;
and the computer is used for carrying out operation processing on the acquired signals.
According to the technical scheme, the measuring module comprises a second optical fiber coupler, an optical fiber circulator, a device to be measured, a third optical fiber coupler and a first photoelectric detector; the light is divided into two paths through the second coupler, one path is used as a reference signal and directly enters the third optical fiber coupler, the other path enters the device to be tested through the circulator, the reflected light and the reference signal generate beat frequency interference at the third coupler, and the beat frequency interference signal is detected by the first photoelectric detector and converted into an electric signal.
In connection with the above technical solution, the auxiliary module further includes a fourth optical fiber coupler, a fifth optical fiber coupler, and a second photodetector; the first frequency shifter and the second frequency shifter are connected between the fourth optical fiber coupler and the fifth optical fiber coupler in parallel; light emitted by the fourth coupler respectively enters the first frequency shifter and the second frequency shifter; because the two frequency shifters have frequency difference, a beat frequency signal is generated, and the beat frequency signal is detected by the second photoelectric detector and used as an external clock to trigger the data acquisition card to perform equal-frequency domain sampling.
According to the technical scheme, the splitting ratio of the first optical fiber coupler is 90:10, 90% of laser enters the measuring module, and 10% of laser enters the auxiliary module; the splitting ratio of the second, third, fourth and fifth optical fiber couplers is 50: 50.
In connection with the above technical solution, the first frequency shifter and the second frequency shifter are devices capable of realizing a frequency shift function.
In connection with the above technical solution, the first frequency shifter and the second frequency shifter are electro-optical modulators or acousto-optical modulators.
The invention also provides a data acquisition method based on the device for improving the OFDR frequency domain sampling rate, which is characterized by comprising the following steps:
a. dividing the whole process into N times of sampling according to the measurement length; wherein, Delta v is the frequency difference of the two frequency shifters, Delta v0The sampling frequency interval under the current measurement length;
b. carrying out first data acquisition to obtain data N1(a1, a2 and a3 … …);
c. frequency shifting two frequency shifters by delta v0Acquiring data to obtain data N2(b1, b2 and b3 … …);
d. repeating the steps for N times to obtain N groups of data;
e. and superposing the N groups of data to obtain (a1, b1, c1 … … N1, a2, b2, c2 … … N2 and … …) as final acquisition data.
The frequency shift of the frequency shifter is delta v0 every time, the original sampling frequency interval is reduced by N times, and the frequency domain sampling rate of the OFDR system is effectively improved.
Compared with the prior art, the invention has the beneficial effects that: the invention utilizes two frequency shifters in the auxiliary module, and under the condition of fixed difference frequency, the frequency of the sampling signal is translated for multiple times to acquire data, and then the data acquired by the translation for multiple times are superposed and operated. The method reduces the original sampling frequency interval by N times, effectively improves the frequency domain sampling rate of the OFDR system, is beneficial to expanding the OFDR measurement range, can select proper frequency shift amount according to the measurement range, is beneficial to saving the measurement time, improves the measurement speed, is convenient and simple, and can adapt to variable measurement requirements.
Drawings
For the purposes of promoting an understanding of the principles of the invention, reference will now be made in detail to specific embodiments of the invention, examples of which are illustrated in the accompanying drawings.
FIG. 1 is a schematic diagram of an apparatus for increasing the frequency domain sampling rate of OFDR according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a single sampling frequency domain according to an embodiment of the present invention;
in fig. 1, 1 is a swept-frequency laser, 2 is a first fiber coupler, 3 is a fourth fiber coupler, 4 is a second fiber coupler, 5 is a first frequency shifter, 6 is a second frequency shifter, 7 is a fifth fiber coupler, 8 is a second photodetector, 9 is a fiber circulator, 10 is a device under test, 11 is a third fiber coupler, 12 is a first photodetector, 13 is a data acquisition card, and 14 is a computer.
Detailed Description
The following examples further describe the invention in conjunction with the accompanying drawings.
The device for improving the frequency domain sampling rate of the OFDR in the embodiment of the invention comprises a frequency-sweeping laser 1, a first optical fiber coupler 2, a measuring module b, an auxiliary module a, a data acquisition card 13 and a computer 14; wherein:
the frequency-sweeping laser 1 is used for emitting linear frequency-sweeping light with periodically changed wavelength;
the first optical fiber coupler 2 divides the linear sweep light into two beams, and the two beams respectively enter a measuring module b and an auxiliary module a;
the measuring module b is used for acquiring a measuring signal and generating a beat frequency interference signal;
the auxiliary module a is used for generating an external clock signal and triggering the data acquisition card 13 to sample in an equal frequency domain; the auxiliary module a comprises a first frequency shifter and a second frequency shifter which are connected in parallel, and the frequency difference delta v of the two frequency shifters0Fixed, the frequency difference Deltav0The sampling frequency interval under the current measurement length; after each sampling of the data acquisition card 13, the two frequency shifters shift the frequency by delta v0Then triggering the data acquisition card 13 to perform the next data acquisition;
the data acquisition card 13 performs equal frequency domain sampling on the beat frequency interference signal output by the measurement module b under the trigger of an external clock;
the computer 14 is used for performing operation processing on the acquired signals.
As shown in fig. 1, the measurement module b includes a second optical fiber coupler 4, an optical fiber circulator 9, a device under test 10, a third optical fiber coupler 11, and a first photodetector 12; the light is divided into two paths through the second coupler, one path is used as a reference signal and directly enters the third optical fiber coupler 11, the other path enters the device to be tested 10 through the circulator, the reflected light and the reference signal generate beat frequency interference at the third coupler, and the beat frequency interference signal is detected by the first photoelectric detector 12 and converted into an electric signal.
Further, the auxiliary module a further comprises a fourth optical fiber coupler 3, a fifth optical fiber coupler 7 and a second photodetector 8; the first frequency shifter and the second frequency shifter are connected in parallel between the fourth optical fiber coupler 3 and the fifth optical fiber coupler 7; light emitted by the fourth coupler enters a first frequency shifter 5 and a second frequency shifter 6 respectively; due to the frequency difference between the two frequency shifters, a beat frequency signal is generated, and the beat frequency signal is detected by the second photodetector 8 and used as an external clock to trigger the data acquisition card 13 to perform equal frequency domain sampling.
Due to the frequency difference between the two frequency shifters, a beat signal is generated. The beat signal is detected by the second photodetector 8 and used as an external clock to trigger the data acquisition card 13 to perform equal frequency domain sampling.
In the preferred embodiment of the present invention, the splitting ratio of the first fiber coupler 2 is 90:10, 90% of the laser light enters the measurement module b, and 10% of the laser light enters the auxiliary module a. The splitting ratio of the second, third, fourth and fifth optical fiber couplers is 50: 50.
The first frequency shifter 5 and the second frequency shifter 6 can be all devices capable of realizing frequency shifting functions, such as an electro-optical modulator, an acousto-optical modulator, and the like.
As shown in fig. 1, the laser emitted from the swept-source 1 is split into two parts by the 90:10 first fiber coupler 22, 90% of the light enters the measurement module b, and 10% of the light enters the auxiliary module a.
In the measurement module b, the outgoing light enters the reference arm and the signal arm respectively after passing through the second fiber coupler 44. The reference arm signal directly enters the third optical fiber coupler 11, the light in the signal arm enters the device to be measured 10 through the circulator 9, the reflected light and the reference light generate beat frequency interference at the coupling 11, and the generated beat frequency signal is converted into an electric signal by the photoelectric detector 12 and then collected by the data acquisition card 13.
In the auxiliary module a, laser entering the fourth optical fiber coupler 3 is divided into two paths, and the two paths enter the frequency shifter 5 and the frequency shifter 6 respectively. Since the frequency shifters have different frequency shifts, the optical frequencies of the two paths are different, and there is a difference frequency, so that the two beams interfere at the fifth fiber coupler 77 to generate a beat signal. The signal is a signal with equal frequency domain intervals, and after being converted into an electric signal by the second photodetector 8, the electric signal is used for triggering the data acquisition card 13 to perform equal frequency domain sampling on the beat frequency signal in the measurement module b.
As derived from the formula, the electrical signal converted by the second photodetector 8 is:
wherein f isa、fbThe frequency shift amounts of the frequency shifters 1 and 2, respectively. The signal being of period fa-fbI.e. the sampling frequency interval Δ ν ═ fa-fbThe maximum measurable range of the OFDR device is as follows:
let L be the length to be measured in a certain measurement0The optical fiber link of (1). As can be seen from the sampling theorem, the sampling frequency interval at this time is:
dividing the measurement into N times by the current sampling frequency interval, wherein:
and after the acquisition times N are determined, starting data acquisition. The method comprises the following steps:
the device is used for carrying out the first acquisition to obtain data N1(a1, a2 and a3 … …);
frequency shifting two frequency shifters by delta v0Data acquisition was carried out to obtain data N2(b1, b2, b3 … …)
Repeating the steps for N times to obtain N groups of data.
And superposing the N groups of data to obtain (a1, b1, c1 … … N1, a2, b2, c2 … … N2 and … …). And carrying out operation processing on the data to obtain a final result. Specifically, FFT operation.
Fig. 2 is a schematic diagram of a single sample in the frequency domain. In each sampling, the data acquisition card 13 performs data acquisition on the rising edge (or the falling edge) of the trigger signal to complete N times of sampling.
It is to be noted in particular that Δ ν of the invention0Is variable, and can adjust the delta v according to different length measurement requirements0And the measurement length can be adjusted.
It will be readily understood by those skilled in the art that the drawings and examples herein described are for illustrative purposes only and are not intended to limit the scope of the present invention, and that any modifications, equivalent substitutions, improvements and the like made without departing from the spirit and principles of the present invention are intended to be covered by the claims herein.
Claims (7)
1. A device for improving the frequency domain sampling rate of OFDR is characterized by comprising a frequency-sweeping laser, a first optical fiber coupler, a measuring module, an auxiliary module, a data acquisition card and a computer; wherein:
the frequency-sweeping laser is used for emitting linear frequency-sweeping light with periodically changed wavelength;
the first optical fiber coupler divides the linear sweep frequency light into two beams which respectively enter the measuring module and the auxiliary module;
the measuring module is used for acquiring a measuring signal and generating a beat frequency interference signal;
the auxiliary module is used for generating an external clock signal and triggering the data acquisition card to sample in an equal frequency domain; the auxiliary module comprises a parallel first frequency shifterAnd a second frequency shifter, the frequency difference Deltav of the two frequency shifters0Fixed, the frequency difference Deltav0The sampling frequency interval under the current measurement length; after each sampling of the data acquisition card, the two frequency shifters shift the frequency by delta v0Triggering the data acquisition card to acquire data for the next time;
the data acquisition card samples beat frequency interference signals output by the measurement module in an equal frequency domain under the trigger of an external clock;
and the computer is used for carrying out operation processing on the acquired signals.
2. The apparatus of claim 1, wherein the measurement module comprises a second fiber coupler, a fiber circulator, a device under test, a third fiber coupler, a first photodetector; the light is divided into two paths through the second coupler, one path is used as a reference signal and directly enters the third optical fiber coupler, the other path enters the device to be tested through the circulator, the reflected light and the reference signal generate beat frequency interference at the third coupler, and the beat frequency interference signal is detected by the first photoelectric detector and converted into an electric signal.
3. The apparatus of claim 2, wherein the auxiliary module further comprises a fourth fiber coupler, a fifth fiber coupler, a second photodetector; the first frequency shifter and the second frequency shifter are connected between the fourth optical fiber coupler and the fifth optical fiber coupler in parallel; light emitted by the fourth coupler respectively enters the first frequency shifter and the second frequency shifter; because the two frequency shifters have frequency difference, a beat frequency signal is generated, and the beat frequency signal is detected by the second photoelectric detector and used as an external clock to trigger the data acquisition card to perform equal-frequency domain sampling.
4. The apparatus according to claim 3, wherein the first fiber coupler has a splitting ratio of 90:10, 90% of the laser light enters the measurement module, 10% of the laser light enters the auxiliary module; the splitting ratio of the second, third, fourth and fifth optical fiber couplers is 50: 50.
5. The apparatus of claim 3, wherein the first frequency shifter and the second frequency shifter are frequency shifting capable devices.
6. The apparatus of claim 3, wherein the first frequency shifter and the second frequency shifter are electro-optic modulators or acousto-optic modulators.
7. A data acquisition method based on the apparatus for increasing the frequency domain sampling rate of OFDR as claimed in any of claims 1-6, comprising the following steps:
a. dividing the whole process into N times of sampling according to the measurement length; wherein, Delta v is the frequency difference of the two frequency shifters, Delta v0The sampling frequency interval under the current measurement length;
b. carrying out first data acquisition to obtain data N1(a1, a2 and a3 … …);
c. frequency shifting two frequency shifters by delta v0Acquiring data to obtain data N2(b1, b2 and b3 … …);
d. repeating the steps for N times to obtain N groups of data;
e. the N groups of data are superimposed to obtain (a1, b1, c1 … …, a2, b2, c2 … … and … …) as final acquisition data.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910688206.0A CN110375779B (en) | 2019-07-29 | 2019-07-29 | Device and method for improving OFDR frequency domain sampling rate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910688206.0A CN110375779B (en) | 2019-07-29 | 2019-07-29 | Device and method for improving OFDR frequency domain sampling rate |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110375779A CN110375779A (en) | 2019-10-25 |
| CN110375779B true CN110375779B (en) | 2021-06-04 |
Family
ID=68256691
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910688206.0A Active CN110375779B (en) | 2019-07-29 | 2019-07-29 | Device and method for improving OFDR frequency domain sampling rate |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110375779B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111397644B (en) * | 2020-03-26 | 2022-02-08 | 南京大学 | Compensation method for nonlinear tuning effect of laser for optical frequency domain reflectometer |
| CN115235367B (en) * | 2022-07-26 | 2023-04-25 | 北京理工大学 | High-precision double-frequency optical frequency domain reflectometer with large strain measurement range |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4789240A (en) * | 1985-05-28 | 1988-12-06 | Litton Systems, Inc. | Wavelength switched passive interferometric sensor system |
| US6160826A (en) * | 1991-04-29 | 2000-12-12 | Massachusetts Institute Of Technology | Method and apparatus for performing optical frequency domain reflectometry |
| CN102420650A (en) * | 2011-08-09 | 2012-04-18 | 天津大学 | Laser nonlinear scanning device and method for suppressing optical frequency domain reflectometer |
| CN204142467U (en) * | 2014-09-20 | 2015-02-04 | 江苏骏龙电力科技股份有限公司 | A kind of OFDR experimental system |
| CN107328429A (en) * | 2017-08-09 | 2017-11-07 | 武汉隽龙科技股份有限公司 | The device and method for closely sensing stability can be improved in optical frequency domain reflection technology |
| CN107515017A (en) * | 2017-07-20 | 2017-12-26 | 北京航天控制仪器研究所 | A kind of optical frequency domain reflectometer of light wave frequency shift modulation |
| CN107576341A (en) * | 2017-08-09 | 2018-01-12 | 武汉隽龙科技股份有限公司 | The apparatus and method that polarization decay is eliminated in OFDR |
| CN208672199U (en) * | 2018-10-16 | 2019-03-29 | 河南师范大学 | A Device for Distributed Strain Sensing Using Optical Frequency Domain Reflectance |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7282698B2 (en) * | 2005-09-08 | 2007-10-16 | Baker Hughes Incorporated | System and method for monitoring a well |
| WO2014105911A1 (en) * | 2012-12-24 | 2014-07-03 | Luna Innovations Incorporated | Dispersion correction in optical frequency-domain reflectometry |
-
2019
- 2019-07-29 CN CN201910688206.0A patent/CN110375779B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4789240A (en) * | 1985-05-28 | 1988-12-06 | Litton Systems, Inc. | Wavelength switched passive interferometric sensor system |
| US6160826A (en) * | 1991-04-29 | 2000-12-12 | Massachusetts Institute Of Technology | Method and apparatus for performing optical frequency domain reflectometry |
| CN102420650A (en) * | 2011-08-09 | 2012-04-18 | 天津大学 | Laser nonlinear scanning device and method for suppressing optical frequency domain reflectometer |
| CN204142467U (en) * | 2014-09-20 | 2015-02-04 | 江苏骏龙电力科技股份有限公司 | A kind of OFDR experimental system |
| CN107515017A (en) * | 2017-07-20 | 2017-12-26 | 北京航天控制仪器研究所 | A kind of optical frequency domain reflectometer of light wave frequency shift modulation |
| CN107328429A (en) * | 2017-08-09 | 2017-11-07 | 武汉隽龙科技股份有限公司 | The device and method for closely sensing stability can be improved in optical frequency domain reflection technology |
| CN107576341A (en) * | 2017-08-09 | 2018-01-12 | 武汉隽龙科技股份有限公司 | The apparatus and method that polarization decay is eliminated in OFDR |
| CN208672199U (en) * | 2018-10-16 | 2019-03-29 | 河南师范大学 | A Device for Distributed Strain Sensing Using Optical Frequency Domain Reflectance |
Non-Patent Citations (2)
| Title |
|---|
| 基于光频域反射计的光纤分布式传感中光谱分辨率提升技术;张超等;《光学学报》;20170831;第37卷(第8期);第1-6页 * |
| 基于窄带光纤激光器的光频域反射计研究;叶蕾;《光纤与电缆及其应用技术》;20130531(第5期);第38-41页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110375779A (en) | 2019-10-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108827601A (en) | A kind of measuring device of fibre optic interferometer arm length difference | |
| CN112923960B (en) | Optical fiber parameter measuring device for correcting nonlinear tuning effect | |
| CN108801153B (en) | Optical fiber length measuring method and measuring device | |
| CN107219002B (en) | A kind of ultrahigh resolution spectral measurement method and system | |
| CN106643522A (en) | Optical-fiber low-coherence interference displacement demodulation device and method based on photoelectric oscillator | |
| CN106895790A (en) | Distributing optical fiber sensing resolution method is lifted in a kind of probe beam deflation | |
| CN112129491B (en) | Optical fiber time delay measurement method and device based on single optical frequency comb interference | |
| CN103414513B (en) | A kind of pulsed light dynamic extinction ratio measurement mechanism and method with high dynamic range | |
| CN105021310B (en) | High precision optical fiber grating temperature-sensing system | |
| CN105865754B (en) | A kind of measurement apparatus of fibre optic interferometer arm length difference | |
| CN101625279A (en) | Device for positioning optical fiber breakpoints and method for confirming breakpoint positions | |
| CN110375779B (en) | Device and method for improving OFDR frequency domain sampling rate | |
| CN111912516B (en) | Phase-synchronized optical fiber distributed vibration measurement device, driver and method | |
| CN212030564U (en) | Light source frequency shift calibration auxiliary channel structure and optical fiber vibration measuring device | |
| CN110332951B (en) | Device and method for realizing remote sensing in optical frequency domain reflection technology | |
| CN108844717A (en) | A kind of measurement method of fibre optic interferometer arm length difference | |
| CN113340571B (en) | Optical delay measurement method and device based on light vector analysis | |
| CN210486914U (en) | Device for realizing far-end sensing in optical frequency domain reflection technology | |
| Sivanathan et al. | Development of a hardware for frequency scanning interferometry for long range measurement | |
| CN114337804B (en) | Device and method for increasing length of white light interferometry link | |
| CN116929422A (en) | F-P cavity sensing system based on OFDR technology | |
| CN212254333U (en) | Phase synchronization optical fiber distributed vibration measuring device and driver | |
| CN115711633A (en) | Phase noise accurate correction optical frequency domain reflectometer of loop structure reference interferometer | |
| CN115452015A (en) | Double-scale reference interference phase noise accurate correction optical frequency domain reflectometer | |
| CN110440899B (en) | Common-path dual-wavelength quadrature phase demodulation system |
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 | ||
| TA01 | Transfer of patent application right |
Effective date of registration: 20210105 Address after: 430074 room 02, 9 / F, building 1, SBI Chuangye street, Dongxin Road, Donghu New Technology Development Zone, Wuhan City, Hubei Province Applicant after: Wuhan Haoheng Technology Co.,Ltd. Address before: No. 999, Gaoxin Avenue, Donghu New Technology Development Zone, Wuhan City, Hubei Province, 430074 Applicant before: WUHAN JUNNO TECH Co.,Ltd. |
|
| TA01 | Transfer of patent application right | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CB03 | Change of inventor or designer information |
Inventor after: Wen Yongqiang Inventor after: Wang Huiwen Inventor after: Zhang Xiaolei Inventor after: Zhang Xiaoqiao Inventor before: Wang Huiwen Inventor before: Zhang Xiaolei Inventor before: Wen Yongqiang Inventor before: Zhang Xiaoqiao |
|
| CB03 | Change of inventor or designer information |