CN108801153B - Optical fiber length measuring method and measuring device - Google Patents
Optical fiber length measuring method and measuring device Download PDFInfo
- Publication number
- CN108801153B CN108801153B CN201810638928.0A CN201810638928A CN108801153B CN 108801153 B CN108801153 B CN 108801153B CN 201810638928 A CN201810638928 A CN 201810638928A CN 108801153 B CN108801153 B CN 108801153B
- Authority
- CN
- China
- Prior art keywords
- signal
- optical fiber
- optical
- light
- microwave
- 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
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/02—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Length Measuring Devices By Optical Means (AREA)
Abstract
The invention relates to an optical fiber length measuring method, and belongs to the technical field of optical measurement. The method comprises the following steps: modulating the microwave signal intensity on a continuous optical carrier to generate a modulated optical signal; injecting the modulated optical signal serving as detection light from the first end of the optical fiber to be detected, and receiving a reflected optical signal of the second end of the optical fiber to be detected from the first end of the optical fiber to be detected; converting the reflected light signal into an electric signal, extracting a fundamental frequency signal from the electric signal, and measuring the phase change of the fundamental frequency signal relative to the microwave signal; and obtaining the length of the optical fiber to be measured according to the phase change. The invention also discloses an optical fiber length measuring device. Compared with the prior art, the invention can realize high-precision measurement of the optical fiber length in a large range.
Description
Technical Field
The invention relates to an optical fiber length measuring method and an optical fiber length measuring device, and belongs to the technical field of optical measurement.
Background
The commonly used optical fiber length measuring method mainly comprises a back scattering method, a pulse method and a phase shift method, wherein the back scattering method is used for measuring the length of the optical fiber by utilizing the Rayleigh scattering generated when light is transmitted in the optical fiber and the back scattering light generated by Fresnel reflection, and the optical time domain reflectometer developed by utilizing the principle is widely applied to the construction and maintenance of an optical fiber communication link. There are many unavoidable errors in this method, such as the error in the resolution of the instrument, the group delay of the optical fiber, and the back scattering loss coefficient. Therefore, the measurement precision of the optical time domain reflectometer is only meter magnitude, and the measurement error is increased along with the increase of the length of the optical fiber; the pulse method needs to observe the pulse superposition process of transmitted light in a reference optical fiber and a measured optical fiber, then calculates the length of the measured optical fiber by using the time difference of the two pulses, and is not suitable for accurately measuring a long optical fiber due to the fact that optical fiber dispersion can widen the optical pulse; the traditional phase shift method is a straight-through type measurement, both ends of an optical fiber must be connected into a measurement system, however, the length of the optical fiber needs to be fed back in real time in the optical fiber processing process, so the traditional straight-through type measurement method is very inconvenient, the measurement repeatability of the method is poor when the short optical fiber is measured, and the measurement precision can only reach the decimeter level. Therefore, the three methods cannot meet the requirements of each boundary on accurate measurement of the length of the optical fiber.
With the continuous development of optical fiber communication and optical fiber sensing technologies, the optical fiber length measuring system with large dynamic range and high precision has extremely important application value, and is especially important in accurately calibrating the length of an optical fiber and solving the problem of tracing the optical time domain reflectometry value. The currently used optical fiber length measurement technology is mainly an Optical Time Domain Reflectometer (OTDR), and its basic principle is that an optical fiber incident end face detects backscattered light and fresnel reflected light, and the obtained electrical signal is processed to obtain a breakpoint position. Although the measuring distance can reach hundreds of kilometers, the measuring precision of the method is greatly limited and can only reach a meter level. The accuracy of Optical Coherence Domain Reflectometry (OCDR) can reach 10 microns and the dynamic range of measurement can reach several kilometers, but it has high requirements on the stability and coherence of the light source. In 2005, Bing Qi et al proposed an asymmetric Sagnac interferometer based on frequency shift, where the measurement accuracy can reach the micron level and the dynamic range of a single-mode fiber can reach tens of kilometers. But the frequency of the interference signal minimum value point is not easy to read, so the software algorithm is not easy to realize. According to the high-precision optical fiber length measuring system proposed by beam key et al in 2012, a DFB light source is externally modulated, the modulated light respectively enters a circulator, a measured optical fiber and a reference light path after passing through a light beam splitter, and then the length of the measured optical fiber is obtained by reading the delay time of two paths of signals on an oscilloscope. When the long-distance optical fiber is measured, the pulse broadening caused by the optical fiber dispersion cannot be ignored, so that the delay time is read by a pulse delay method after modulated light is transmitted by the optical fiber of hundreds of kilometers, and the measurement uncertainty caused by the pulse broadening is very large. In 2013, researchers have proposed an optical fiber length measuring system, which obtains the length of a measured optical fiber by reading the time difference of modulation pulses by a method of combining a frequency meter and pattern analysis. The method has the measurement accuracy reaching centimeter level, and the measurement distance can not reach hundreds of kilometers due to pulse broadening caused by fiber dispersion, and is generally used for calibrating the length of multimode fiber and the length of short-distance single-mode fiber.
In summary, the prior art has the following disadvantages: (1) the measurement precision of an Optical Time Domain Reflectometer (OTDR) is not high and can only reach a meter level; the measurement range of the Optical Coherence Domain Reflectometer (OCDR) is too small to perform long-distance optical fiber measurement, and the requirement on the light source is high. (2) The high-precision optical fiber length measuring system proposed by beam key et al measures the round-trip time difference in the measured optical fiber by adding a faraday rotating mirror, thus reducing the measuring dynamic range of the system. Therefore, a technique capable of performing highly accurate measurement over a wide range of fiber lengths is desired.
Disclosure of Invention
The technical problem to be solved by the invention is to overcome the defects of the prior art and provide an optical fiber length measuring method, which can realize high-precision measurement of the optical fiber length in a large range.
The invention specifically adopts the following technical scheme:
a method for measuring the length of optical fiber includes modulating the intensity of microwave signal to continuous optical carrier to generate modulated optical signal; injecting the modulated optical signal serving as detection light from the first end of the optical fiber to be detected, and receiving a reflected optical signal of the second end of the optical fiber to be detected from the first end of the optical fiber to be detected; converting the reflected light signal into an electric signal, extracting a fundamental frequency signal from the electric signal, and measuring the phase change of the fundamental frequency signal relative to the microwave signal; and obtaining the length of the optical fiber to be measured according to the phase change.
Preferably, the injection of the probe light from the first end of the optical fiber to be tested is realized by using an optical circulator, and the reflected light signal of the second end of the optical fiber to be tested is received from the first end of the optical fiber to be tested.
Preferably, the fundamental frequency signal is extracted using a filter and a phase change of the fundamental frequency signal with respect to the microwave signal is measured using a phase detector.
Preferably, the length of the optical fiber to be measured is calculated by the following formula:
in the formula, ωeIs the frequency of the microwave signal, c is the speed of light in vacuum, n is the refractive index of the fiber under test, τ0To detect the transit time of light in a measurement system, θ (ω)e) Is the phase change of the fundamental frequency signal relative to the microwave signal.
Further, the method further comprises: and carrying out multiple measurements under the condition of microwave signals with different frequencies, and eliminating random errors in the measurements by using the multiple measurement results.
The following technical scheme can be obtained according to the same invention concept:
an optical fiber length measuring device comprising:
the detection light generation module is used for modulating the microwave signal intensity on a continuous optical carrier to generate a modulated optical signal;
the detection light injection and receiving module is used for injecting the modulation light signal serving as detection light from the first end of the optical fiber to be detected and receiving a reflected light signal of the second end of the optical fiber to be detected from the first end of the optical fiber to be detected;
the photoelectric detection module is used for converting the reflected light signal into an electric signal;
the phase detection module is used for extracting a fundamental frequency signal from the electric signal and then measuring the phase change of the fundamental frequency signal relative to the microwave signal;
and the data processing and display module is used for obtaining the length of the optical fiber to be measured according to the phase change.
Preferably, the probe light injection and receiving module is an optical circulator.
Preferably, the phase detection module includes a filter and a phase detector, the filter is configured to extract the fundamental frequency signal, and the phase detector is configured to measure a phase change of the fundamental frequency signal relative to the microwave signal.
Preferably, the phase detection module calculates the length of the optical fiber to be measured by the following formula:
in the formula, ωeIs the frequency of the microwave signal, c is the speed of light in vacuum, n is the refractive index of the fiber under test, τ0To detect the transit time of light in a measurement system, θ (ω)e) Is the phase change of the fundamental frequency signal relative to the microwave signal.
Preferably, the microwave signal is a cosine form of the microwave signal.
Compared with the prior art, the technical scheme of the invention has the following beneficial effects:
the invention adopts the microwave photonics technology, transfers the characteristic extraction of the optical signal to the microwave signal, utilizes the mature and high-precision microwave signal analysis technology to extract the phase information, and then carries out the calculation of the optical fiber length, thereby greatly improving the measurement precision of the optical fiber length.
Drawings
Fig. 1 is a schematic structural view of a preferred embodiment of the optical fiber length measuring apparatus of the present invention.
Fig. 2 is a schematic diagram of a structure for generating probe light by a direct modulation method.
Fig. 3 is a schematic diagram of a structure for generating probe light by an external modulation method.
Detailed Description
Aiming at the defects of the conventional optical fiber length measuring method, the invention utilizes the microwave photonics technology and introduces the phase detection technology in the microwave field to overcome the defects of poor measuring precision, more interference factors of a pulse method, short measuring distance and the like of the conventional backscattering method; the method and the device realize high-precision measurement of the length of the optical fiber in a large range, when the measured length of the optical fiber is less than 10km, the measurement precision of the method and the device is superior to 0.0001m, and when the measured length of the optical fiber is more than 10km, the measurement precision of the method and the device is superior to 0.001 m.
Specifically, the optical fiber length measuring device of the present invention includes:
the detection light generation module is used for modulating the microwave signal intensity on a continuous optical carrier to generate a modulated optical signal;
the detection light injection and receiving module is used for injecting the modulation light signal serving as detection light from the first end of the optical fiber to be detected and receiving a reflected light signal of the second end of the optical fiber to be detected from the first end of the optical fiber to be detected;
the photoelectric detection module is used for converting the reflected light signal into an electric signal;
the phase detection module is used for extracting a fundamental frequency signal from the electric signal and then measuring the phase change of the fundamental frequency signal relative to the microwave signal;
and the data processing and display module is used for obtaining the length of the optical fiber to be measured according to the phase change.
For the public to understand, the technical scheme of the invention is explained in detail by a preferred embodiment and the accompanying drawings:
as shown in fig. 1, the optical fiber length measuring apparatus in this embodiment includes: the device comprises a detection light generating module, an optical circulator, a high-sensitivity photoelectric detection module made of an avalanche diode, a phase detection module, a data processing and display module and a system control module. The detection light generation module is used for modulating the microwave signal intensity on a continuous optical carrier to generate a modulated optical signal; the optical circulator is used for injecting the modulated optical signal serving as detection light from the first end of the optical fiber to be detected and receiving a reflected optical signal of the second end of the optical fiber to be detected from the first end of the optical fiber to be detected; the photoelectric detection module is used for converting the reflected light signal into an electric signal; the phase detection module is used for extracting a fundamental frequency signal from the electric signal and then measuring the phase change of the fundamental frequency signal relative to the microwave signal; the data processing and display module is used for obtaining the length of the optical fiber to be measured according to the phase change; the system control module is used for controlling the detection light generation module to generate detection light signals under the condition of microwave signals with different frequencies and controlling the phase detection module to carry out corresponding phase change, so that random errors in measurement can be eliminated in modes of mean value removal or mean value taking after extreme values removal and the like of multiple measurement results, and the accuracy of the measurement results is further improved.
When the optical fiber measurement is performed again, one end of the optical fiber to be measured is connected to one port 2 of the optical circulator as shown in fig. 1, and the output end of the detection light generation module and the input end of the high-sensitivity photoelectric detection module are respectively connected with the previous port 1 and the next port 3 of the optical circulator.
The probe light can be generated in two ways, one is an external modulation mode, one implementation of which is shown in fig. 2, and the laser source emits a light carrier wave to the MZM modulator, and then the light carrier wave is output through 99: the optical power divider 1 is divided into two paths, 1% of light enters a bias point controller for feedback, the bias point controller adjusts output voltage according to the power of the feedback light and loads the output voltage to a bias electrode of the MZM modulator, so that the bias point of the MZM modulator is located at a linear point, and then microwave signals output by a microwave source are loaded to an RF input port of the MZM modulator; the other is a direct modulation mode, which is configured as shown in fig. 3, and after the direct modulation laser source is turned on, the microwave signal output by the microwave source is applied to the RF input port of the direct modulation laser source.
The probe light signals generated by the two methods can be expressed as:
Eo(t)＝A(1+Mcos(ωet))exp(jωct) (1)
where A is the light field amplitude, ωeAnd ωcThe angular frequencies of the microwave signal and the optical carrier, respectively, and M is the amplitude modulation factor.
After the detection light is transmitted to the optical fiber to be detected through the optical circulator, the detection light is reflected back to the end of the optical fiber to reach the high-sensitivity photoelectric detection module, and the light field at the moment can be expressed as follows:
Er(t)＝A(1+Mcos(ωe(t-τ0-τD)))exp(jωc(t-τ0-τD)) (2)
wherein, tau0Is the transit time of the probe light in the measurement system, τDIs the transmission time of the probe light in the fiber under test.
After the reflected detection light undergoes photoelectric conversion, the electric field of the reflected detection light can be expressed as:
wherein η represents a photoelectric conversion coefficient.
As can be seen from equation (3), the electrical signal has a dc component, a fundamental frequency signal and a double frequency signal. The phase detection module extracts a fundamental frequency signal through a filter and then phase-discriminates the fundamental frequency signal to obtain the frequency omegaeThe phase change of the microwave signal of (2) can be expressed as:
θ(ωe)＝-ωe(τ0+τD) (4)
the length of the optical fiber to be measured is obtained from the formula (4):
where c is the speed of light in vacuum, n is the refractive index of the fiber under test (available from the instruction manual of the fiber manufacturer), and τ0Can be obtained by calibration (e.g. a measurement device can be calibrated using a standard optical fibre of known length).
The invention preferably adopts cosine microwave signals to carry out optical double-sideband modulation, thereby avoiding the influence of optical fiber dispersion on the measurement result and being beneficial to reducing the measurement error.
During the measurement, omega can be changed for a plurality of timeseObtaining a set of L values, and averagingThereby removing random errors.
Claims (10)
1. The method for measuring the length of the optical fiber is characterized in that the intensity of a microwave signal is modulated on a continuous optical carrier to generate a modulated optical signal; injecting the modulated optical signal serving as detection light from the first end of the optical fiber to be detected, and receiving a reflected optical signal of the second end of the optical fiber to be detected from the first end of the optical fiber to be detected; converting the reflected light signal into an electric signal, extracting a fundamental frequency signal from the electric signal, and measuring the phase change of the fundamental frequency signal relative to the microwave signal; and obtaining the length of the optical fiber to be measured according to the phase change.
2. The method of claim 1, wherein injecting probe light from the first end of the fiber under test and receiving a reflected light signal from the second end of the fiber under test from the first end of the fiber under test are performed using an optical circulator.
3. The method of claim 1, wherein the fundamental frequency signal is extracted using a filter and a phase change of the fundamental frequency signal relative to the microwave signal is measured using a phase detector.
4. The method of claim 1, wherein the length of the optical fiber under test is calculated by:
in the formula, ωeIs the frequency of the microwave signal, c is the speed of light in vacuum, n is the refractive index of the fiber under test, τ0To detect the transit time of light in a measurement system, θ (ω)e) Is the phase change of the fundamental frequency signal relative to the microwave signal.
5. The method of any one of claims 1 to 4, further comprising: and carrying out multiple measurements under the condition of microwave signals with different frequencies, and eliminating random errors in the measurements by using the multiple measurement results.
6. An optical fiber length measuring device, comprising:
the detection light generation module is used for modulating the microwave signal intensity on a continuous optical carrier to generate a modulated optical signal;
the detection light injection and receiving module is used for injecting the modulation light signal serving as detection light from the first end of the optical fiber to be detected and receiving a reflected light signal of the second end of the optical fiber to be detected from the first end of the optical fiber to be detected;
the photoelectric detection module is used for converting the reflected light signal into an electric signal;
the phase detection module is used for extracting a fundamental frequency signal from the electric signal and then measuring the phase change of the fundamental frequency signal relative to the microwave signal;
and the data processing and display module is used for obtaining the length of the optical fiber to be measured according to the phase change.
7. The apparatus of claim 6, wherein the probe light injection and receiving module is an optical circulator.
8. The apparatus of claim 6, wherein the phase detection module comprises a filter for extracting the baseband signal and a phase detector for measuring a phase change of the baseband signal relative to the microwave signal.
9. The apparatus of claim 6, wherein the phase detection module calculates the length of the optical fiber under test by:
in the formula, ωeIs the frequency of the microwave signal, c is the speed of light in vacuum, n is the refractive index of the fiber under test, τ0For detecting light under testTime of flight in a quantum system, θ (ω)e) Is the phase change of the fundamental frequency signal relative to the microwave signal.
10. The apparatus of claim 6, wherein the microwave signal is a cosine form of the microwave signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810638928.0A CN108801153B (en) | 2018-06-20 | 2018-06-20 | Optical fiber length measuring method and measuring device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810638928.0A CN108801153B (en) | 2018-06-20 | 2018-06-20 | Optical fiber length measuring method and measuring device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108801153A CN108801153A (en) | 2018-11-13 |
| CN108801153B true CN108801153B (en) | 2020-04-21 |
Family
ID=64083916
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810638928.0A Active CN108801153B (en) | 2018-06-20 | 2018-06-20 | Optical fiber length measuring method and measuring device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108801153B (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112129243B (en) * | 2020-09-04 | 2022-02-15 | 电子科技大学 | Quasi-distributed optical fiber torsion angle measuring device and method based on photoelectric oscillator |
| CN112187347B (en) * | 2020-09-18 | 2022-06-03 | 常州大学 | Device and method for measuring length of optical fiber |
| CN113091617B (en) * | 2021-03-29 | 2022-05-10 | 电子科技大学 | Multimode optical fiber optical path change measuring system |
| CN113029007B (en) * | 2021-04-27 | 2024-02-06 | 北京星网船电科技有限公司 | Method and device for measuring length of optical fiber tourbillon and readable storage medium |
| CN113295097B (en) * | 2021-05-25 | 2022-10-28 | 中国电子科技集团公司第四十一研究所 | Optical fiber length measuring method and device based on optical wave element analyzer group delay |
| CN113340571B (en) * | 2021-05-29 | 2023-11-10 | 南京航空航天大学 | Optical time delay measurement method and device based on optical vector analysis |
| CN114252022B (en) * | 2021-12-21 | 2023-02-24 | 南京航空航天大学 | Optical fiber multi-dimensional monitoring method and device based on GNSS signals |
| CN114440773B (en) * | 2022-02-08 | 2023-06-27 | 广东电网有限责任公司 | Optical path length determining method, device, signal controller, demodulation system and medium |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101319878A (en) * | 2008-07-15 | 2008-12-10 | 浙江大学 | Method and device for high-precision large-range measuring size of optical fiber |
| CN102680981A (en) * | 2012-05-29 | 2012-09-19 | 浙江大学 | Distance measurement method and device based on orthogonal locking of microwave photon signals |
| CN203396489U (en) * | 2013-08-27 | 2014-01-15 | 中国电子科技集团公司第四十四研究所 | A micro photoelectric detector for measuring the length and the signal phase of a fiber |
| CN104279959A (en) * | 2014-09-30 | 2015-01-14 | 中国电子科技集团公司第四十一研究所 | New method for precisely measuring optical fiber length by adoption of vector network analyzer |
| CN104330104A (en) * | 2014-10-31 | 2015-02-04 | 浙江大学 | Measuring device for interferential sensor arm length difference |
| CN106643522A (en) * | 2016-12-28 | 2017-05-10 | 西南交通大学 | Optical-fiber low-coherence interference displacement demodulation device and method based on photoelectric oscillator |
| CN106907997A (en) * | 2017-03-17 | 2017-06-30 | 张家港市欧微自动化研发有限公司 | A kind of displacement measurement signal analysis method based on optic fiber displacement sensor system |
| CN106969714A (en) * | 2017-05-02 | 2017-07-21 | 中国航空工业集团公司北京长城计量测试技术研究所 | A kind of method of the fine length of precise measuring |
| CN107917669A (en) * | 2017-11-15 | 2018-04-17 | 苏州润桐专利运营有限公司 | A kind of optical fibre displacement sensor demodulation method |
| CN107976300A (en) * | 2017-11-15 | 2018-05-01 | 苏州润桐专利运营有限公司 | A kind of measuring method of beat length of polarization maintaining optical fiber |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7362923B2 (en) * | 2006-08-07 | 2008-04-22 | Northrop Grumman Corporation | Systems and methods for measuring signal phase shift caused by optical fibers |
| CN103591895B (en) * | 2013-11-07 | 2017-06-27 | 中国电子科技集团公司第四十一研究所 | A kind of optical fiber length measuring system and measuring method |
| CN105865754B (en) * | 2016-05-18 | 2018-01-19 | 哈尔滨工程大学 | A kind of measurement apparatus of fibre optic interferometer arm length difference |
| CN106643832A (en) * | 2017-02-23 | 2017-05-10 | 鞍山睿科光电技术有限公司 | Phase-sensitive optical time-domain reflectometer based on linear frequency-modulation pulse and measurement method of phase-sensitive optical time-domain reflectometer |
-
2018
- 2018-06-20 CN CN201810638928.0A patent/CN108801153B/en active Active
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101319878A (en) * | 2008-07-15 | 2008-12-10 | 浙江大学 | Method and device for high-precision large-range measuring size of optical fiber |
| CN101319878B (en) * | 2008-07-15 | 2010-12-22 | 浙江大学 | Method and device for high-precision large-range measuring size of optical fiber |
| CN102680981A (en) * | 2012-05-29 | 2012-09-19 | 浙江大学 | Distance measurement method and device based on orthogonal locking of microwave photon signals |
| CN203396489U (en) * | 2013-08-27 | 2014-01-15 | 中国电子科技集团公司第四十四研究所 | A micro photoelectric detector for measuring the length and the signal phase of a fiber |
| CN104279959A (en) * | 2014-09-30 | 2015-01-14 | 中国电子科技集团公司第四十一研究所 | New method for precisely measuring optical fiber length by adoption of vector network analyzer |
| CN104330104A (en) * | 2014-10-31 | 2015-02-04 | 浙江大学 | Measuring device for interferential sensor arm length difference |
| CN106643522A (en) * | 2016-12-28 | 2017-05-10 | 西南交通大学 | Optical-fiber low-coherence interference displacement demodulation device and method based on photoelectric oscillator |
| CN106907997A (en) * | 2017-03-17 | 2017-06-30 | 张家港市欧微自动化研发有限公司 | A kind of displacement measurement signal analysis method based on optic fiber displacement sensor system |
| CN106969714A (en) * | 2017-05-02 | 2017-07-21 | 中国航空工业集团公司北京长城计量测试技术研究所 | A kind of method of the fine length of precise measuring |
| CN107917669A (en) * | 2017-11-15 | 2018-04-17 | 苏州润桐专利运营有限公司 | A kind of optical fibre displacement sensor demodulation method |
| CN107976300A (en) * | 2017-11-15 | 2018-05-01 | 苏州润桐专利运营有限公司 | A kind of measuring method of beat length of polarization maintaining optical fiber |
Non-Patent Citations (1)
| Title |
|---|
| 基于相位调制光链路的光纤长度测量系统;叶全意等;《中国激光》;20130531;第40卷(第5期);全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108801153A (en) | 2018-11-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108801153B (en) | Optical fiber length measuring method and measuring device | |
| CN103591895B (en) | A kind of optical fiber length measuring system and measuring method | |
| CN104279959B (en) | A kind of new method of the fine length of use vector network analyzer precise measuring | |
| CN101839698B (en) | BOTDR (Brillouin Optical Time Domain Reflectometer) for calibrating optical power of reference light and calibrating method thereof | |
| CN108827601A (en) | A kind of measuring device of fibre optic interferometer arm length difference | |
| CN110411335B (en) | Differential sine phase modulation laser interference nano displacement measuring device and method | |
| US5268741A (en) | Method and apparatus for calibrating a polarization independent optical coherence domain reflectometer | |
| CN101949685B (en) | Fiber laser self-mixing interferometer and measurement method thereof | |
| CN109547098B (en) | Microwave photon time delay measurement calibrating device | |
| CN106017333B (en) | Double excitation single-frequency interference nano displacement measuring device and method based on phase-modulation | |
| CN111693255B (en) | Device and method for measuring frequency drift of laser light source | |
| CN110207733B (en) | Optical fiber interferometer arm length difference measuring device and method based on sweep frequency laser | |
| WO2021128677A1 (en) | Optical-borne microwave interference-based optical fiber time delay measurement method and device | |
| CN102636121A (en) | High-precision optical fiber length measuring system | |
| WO2021082377A1 (en) | Phase derivation-based optical component delay measurement method, and device | |
| Wang et al. | High-accuracy optical time delay measurement in fiber link | |
| CN108844717A (en) | A kind of measurement method of fibre optic interferometer arm length difference | |
| CN202676133U (en) | High-precision optical fiber length measuring system | |
| CN111912516A (en) | Phase-synchronized optical fiber distributed vibration measurement device, driver and method | |
| CN109269418B (en) | Optical fiber calibration system based on gas absorption cell calibration and use method | |
| CN109831249B (en) | Device for measuring differential time delay of polarization maintaining optical fiber spindle | |
| CN1664538A (en) | On-line testing method and device for integrated optical modulator for optic fiber gyroscope | |
| CN111220284A (en) | Laser line width measuring system and method based on short delay self-homodyne coherent envelope | |
| CN107796422B (en) | Optical fiber displacement sensor demodulating equipment | |
| CN110375779B (en) | Device and method for improving OFDR frequency domain sampling rate |
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 |