CN111162839A - Remote high-precision optical fiber breakpoint position detection method and system - Google Patents
Remote high-precision optical fiber breakpoint position detection method and system Download PDFInfo
- Publication number
- CN111162839A CN111162839A CN201911426355.6A CN201911426355A CN111162839A CN 111162839 A CN111162839 A CN 111162839A CN 201911426355 A CN201911426355 A CN 201911426355A CN 111162839 A CN111162839 A CN 111162839A
- Authority
- CN
- China
- Prior art keywords
- signal
- optical fiber
- laser
- breakpoint
- chirp
- 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.)
- Pending
Links
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/07—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
- H04B10/075—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal
- H04B10/079—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal using measurements of the data signal
- H04B10/0791—Fault location on the transmission path
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/07—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
- H04B10/071—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using a reflected signal, e.g. using optical time domain reflectometers [OTDR]
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Optical Communication System (AREA)
Abstract
The invention relates to a remote high-precision optical fiber breakpoint position detection method and system, and belongs to the field of optical fiber communication. The chirp signal is divided into two paths of same signals, one path of same signal acts on an electro-optic modulator to modulate emergent laser, and the other path of same signal acts as a reference signal and is sent into a mixer. The laser signal generated by the laser is sent to the electro-optical modulator to be modulated into a chirp pulse signal, and then enters the optical fiber to be tested through the circulator. In the optical fiber to be detected, an optical signal reflected by the Fresnel at the breakpoint is sent into the optical fiber attenuator after passing through the circulator, the single photon detector detects the attenuated Fresnel reflection signal, an output electric signal is mixed with a reference chirp signal, high-frequency components are removed, and the Fourier transform can obtain the frequency offset of the signal, so that the position information of the breakpoint is obtained. The invention adopts chirp pulse modulation and photon counting, simultaneously meets the requirements of long distance and high precision, and finally carries out precise positioning on the long-distance optical fiber breakpoint through detecting the optical signal reflected by the breakpoint Fresnel.
Description
Technical Field
The invention relates to the field of optical fiber communication, in particular to a detection technology of an optical fiber breakpoint position.
Background
Optical fiber communication uses light wave signals as information carriers, and is far superior to cable and microwave communication due to wide transmission frequency band, high anti-interference performance and reduced signal attenuation, and has become a main transmission mode in world communication. The optical fiber is used as a transmission medium in optical fiber communication, and is subject to aging, mechanical damage and other problems, once a breakpoint occurs, the optical fiber needs to be positioned and repaired immediately, otherwise, information loss is caused, and huge economic loss is caused to customers and operators. However, in the optical fiber communication system, the length of the optical fiber is too long, the installation environment is complex, and the rapid accurate positioning of the break point of the optical fiber is a difficult problem.
Generally, an Optical Time Domain Reflectometer (OTDR) is used to make pulsed laser enter into an optical fiber by using fresnel reflection characteristics at a break point of the optical fiber, then a back reflection signal is received at a receiving end, and the position of the break point of the optical fiber is obtained by comparing time differences of transmitting and receiving the pulsed light. The method has a simple principle and a popular device, is widely used, has developed a plurality of mature commercial products, has a measuring distance of about dozens of kilometers and has lower resolution in most parts. If the measurement distance is extended and the laser energy is increased, the resolution is further reduced by adopting a scheme of increasing the laser pulse width. The introduction of a more sensitive photoreceiver, such as a single photon detector, can extend the measurement distance somewhat, however, the resolution is not much improved over long distance measurements. Optical Frequency Domain Reflectometer (OFDR) is an optical fiber that uses rayleigh scattering in an optical fiber to locate a scattered signal by measuring the frequency of the rayleigh scattered signal generated by modulated probe light. Compared with the OTDR technology, the OFDR has the advantages of high spatial resolution, low requirement on the detection optical power and the like. However, OFDR has a very high requirement on the linearity of the frequency scanning of the light source, and if there is nonlinearity in the tuning of the light source, the scattering signal and the reference light at the same position will generate different beat frequencies at different times, thereby seriously affecting the spatial resolution of OFDR.
Disclosure of Invention
The invention provides a method and a system for detecting the position of a remote high-precision optical fiber breakpoint, aiming at the problems that the remote optical fiber breakpoint is difficult to accurately position, the system is complex and the like. The method adopts the technical means of combining chirp pulse modulation with photon counting, can meet the requirements of long distance and high precision at the same time, and finally accurately positions the long-distance optical fiber breakpoint through detecting the optical signal reflected by the breakpoint Fresnel.
The technical scheme of the invention is as follows:
a remote high-precision optical fiber breakpoint position detection method comprises the following steps:
(1) the chirp signal is divided into two paths of same signals through a power divider, one path of same signals acts on an electro-optic modulator to modulate emergent laser to generate a chirp optical pulse signal, and the other path of same signals is used as a local reference chirp signal and sent into a mixer.
(2) The laser generates continuous laser signals, the continuous laser signals are sent to the electro-optic modulator, the strength of the electro-optic modulator is modulated through chirp signals, and the electro-optic modulator is modulated into chirp pulse signals and then enters the optical fiber to be tested through the circulator.
(3) Sending an optical signal reflected by a Fresnel break point of the optical fiber to be tested into an optical fiber attenuator after passing through a circulator; the attenuation of the optical fiber attenuator is continuously adjustable, and the optical fiber attenuator is mainly used for guaranteeing the safe use of single photon detectors under different distances.
(4) The attenuated Fresnel reflection signal is detected by a single photon detector, the output electric signal is mixed with a reference chirp signal, high-frequency components in the mixed signal are removed through a low-pass filter, and the frequency offset of the signal is obtained through Fourier transform, so that the position information of a breakpoint is obtained.
The laser is a narrow linewidth laser, and is emitted as a continuous optical signal to ensure the linewidth of the laser, and the continuous optical signal is modulated into a chirp pulse signal through an electro-optical modulator.
The attenuation of the optical fiber attenuator is continuously adjustable and is controlled by the output feedback of the single photon detector. When the single-photon detector is in saturated output, the attenuation coefficient is increased; when the output of the single-photon detector is too small or no output is generated, the attenuation coefficient is reduced. According to the scheme, the single-photon detector can be guaranteed to be suitable for measuring breakpoint positions at different distances.
The single photon detector is an Avalanche Photodiode (APD) single photon detector in a GHz gated Geiger mode. The APD has compact structure, low power consumption, excellent performance and high cost performance, and the adoption of the APD as a detection device of echo signal light is one of the best choices for the practicability of the scheme. The GHz APD single-photon detector works in a quasi-continuous mode, can respond to weak return light signals, and expands the detection distance of breakpoints to a hundred kilometer level.
The breakpoint position information is mainly obtained through the following calculation process and formula:
the chirp signal expression is:
where k is the conversion of the chirp amplitude modulated signal, t is the time, f0In order to be the initial frequency of the frequency,
for the initial phase, k is B/T, where B is the modulation bandwidth of the chirp signal and T is the modulation time.
The return optical signal expression is: sR(t)＝I0MS (t- τ) in which IoLaser power, M is the loss coefficient, and tau is the laser signal flight time. We can follow the formula R ═ τ c0/2 calculating the location of the break point of the fiber, where c0Is the speed of light transmission in the optical fiber.
The mixing signal of the return optical signal and the local reference optical signal is:
SIF＝S(t)×SR(t)＝S(t)×l0MS(t-τ)
after low-pass filtering, the sum frequency signal is filtered out, the difference frequency signal is transformed into ∈ sinc (ω) × δ (ω -k τ) — > sinc (ω -k τ) through fourier transform, and τ ═ f can be obtainedIFAnd k, substituting the calculation formula of the position of the optical fiber breakpoint to obtain R ═ fIFc0T/2B。
In the calculation of the breakpoint position information, the output signal of the single photon detector is a digital signal, and the counted number reflects the intensity of the return light signal, that is, the output of the single photon detector is a chirp-modulated digital signal, and the position information of the breakpoint can be obtained after the digital signal is mixed with a local reference signal.
The invention further provides a remote high-precision optical fiber breakpoint position detection system which comprises a power divider, a narrow-linewidth laser, an electro-optical modulator, a frequency mixer, a circulator, an optical fiber attenuator, a single photon detector, a low-pass filter and a Fourier transform processor.
In the system, two paths of outputs of the power divider are respectively connected with an electro-optic modulator and a frequency mixer, the output of the narrow linewidth laser is connected with the electro-optic modulator, the electro-optic modulator is connected with a circulator, the output end of the circulator is connected with an optical fiber to be tested, the return end of the circulator is connected with an optical fiber attenuator and then connected with a single photon detector, the output of the single photon detector is connected with the frequency mixer, and then the single photon detector is connected with a Fourier transform processor through a low-pass filter.
The invention adopts the technical means of combining chirped pulse modulation with photon counting, can simultaneously meet the requirements of long distance and high precision, and finally accurately positions the long-distance optical fiber breakpoint through detecting the optical signal reflected by the breakpoint Fresnel.
Drawings
FIG. 1 is a schematic diagram of an optical fiber breakpoint measurement system according to the present invention;
FIG. 2 is a diagram of a Fourier transform spectrum after mixing filtering according to an embodiment of the present invention.
Detailed Description
The invention is further illustrated below with reference to the figures and examples.
As shown in fig. 1, the remote high-precision optical fiber breakpoint position detection system includes a power divider, a narrow linewidth laser, an electro-optical modulator, a mixer, a circulator, an optical fiber attenuator, a single photon detector, a low-pass filter, and a fourier transform processor. The two paths of outputs of the power divider are respectively connected with the electro-optical modulator and the frequency mixer, the output of the narrow linewidth laser is connected with the electro-optical modulator, the electro-optical modulator is connected with the circulator, the output end of the circulator is connected with the optical fiber to be detected, the return end of the circulator is connected with the optical fiber attenuator and then connected with the single photon detector, the output of the single photon detector is connected with the frequency mixer, and then connected with the Fourier transform processor after passing through the low-pass filter.
The system shown in fig. 1 is used for measuring an optical fiber breakpoint, a chirp signal is divided into two paths of same signals through a power divider, one path of same signals acts on an electro-optic modulator to modulate emergent laser to generate a chirp optical pulse signal, and the other path of same signals is used as a reference signal and is sent into a mixer. The narrow linewidth laser generates continuous laser signals, the continuous laser signals are sent to the electro-optic modulator to be modulated into chirp pulse signals, and then the chirp pulse signals enter the optical fiber to be tested through the circulator. In the optical fiber to be tested, the optical signal reflected by the Fresnel at the breakpoint is sent into the optical fiber attenuator after passing through the circulator. The attenuation of the optical fiber attenuator is continuously adjustable. Output feedback control of the single photon detector of the attenuation coefficient of the optical fiber attenuator: when the single-photon detector is in saturated output, the attenuation coefficient is increased; when the output of the single-photon detector is too small or no output is generated, the attenuation coefficient is reduced. Finally, the single photon detector detects the attenuated Fresnel reflection signal, and outputs an electric signal to be mixed with the reference chirp signal. The high frequency component in the mixed signal is removed by a low-pass filter, the frequency offset of the signal can be obtained by Fourier transform, and the position information of the breakpoint can be obtained.
In this embodiment, the single photon detector is an APD single photon detector in a GHz gated geiger mode. The APD has compact structure, low power consumption, excellent performance and high cost performance, and the adoption of the APD as a detection device of echo signal light is one of the best choices for the practicability of the scheme. The GHz APD single-photon detector works in a quasi-continuous mode, can respond to weak return light signals, and expands the detection distance of breakpoints to a hundred kilometer level. The saturation counting rate of the APD single photon detector can reach up to hundreds of MHz, and when the output of the APD single photon detector reaches saturation or continuous direct current is output, the attenuation coefficient of the attenuator should be increased. On one hand, the safe use of the APD detector is guaranteed, and on the other hand, the accurate detection of breakpoint detection is realized by guaranteeing the effective output of the detector. The error counting of the APD single photon detector is mainly dark counting, generally in kHz level, and when the output of the detector is at dark counting level or slightly higher than the dark counting, the attenuation coefficient of the optical fiber attenuator is reduced and gradually reduced, so that the signal-to-noise ratio of the output of the detector is ensured.
The method for measuring the optical fiber breakpoint of the embodiment needs the following expression and calculation:
chirp signal expression:
where k is the conversion rate of the chirp-amplitude-modulated signal, k is B/T, where B is the modulation bandwidth of the chirp signal and T is the modulation time.
Return optical signal expression: sR(t)＝I0MS (t- τ) in which IoLaser power, M is the loss coefficient, and tau is the laser signal flight time. We can follow the formula R ═ τ c0/2 calculating the location of the break point of the fiber, where c0Is the speed of light transmission in the optical fiber.
The mixing signal of the return optical signal and the local reference optical signal is:
SIF＝S(t)×SR(t)＝S(t)×l0MS(t-τ)
after low-pass filtering, the sum frequency signal is filtered out, the difference frequency signal is transformed into ∈ sinc (ω) × δ (ω -k τ) — > sinc (ω -k τ) through fourier transform, and τ ═ f can be obtainedIFAnd k, substituting the calculation formula of the position of the optical fiber breakpoint to obtain R ═ fIFc0T/2B。
In a further embodiment, a chirp signal with an initial frequency of 20 MHz and a cut-off frequency of 50 MHz, that is, a sweep bandwidth of 30 MHz and a sweep time set to 0.001s is used to modulate an outgoing laser, and an optical fiber breakpoint with a length of about 34km is tested. The propagation speed of light in the optical fiber is 2.04X 108m/s. Finally, we obtain a filtered signal obtained by mixing the single-photon detector output signal with a local reference signal according to the fourier transform, the center frequency of which is 10012647 Hz, as shown in fig. 2. The method is substituted into an optical fiber breakpoint position calculation formula to obtain the position R which is 34043m, so that the accurate measurement of the breakpoint position is realized, and the superiority of the method and the system is verified.
The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (9)
1. A remote high-precision optical fiber breakpoint position detection method is characterized by comprising the following steps:
(1) dividing the chirp signal into two paths of same signals through a power divider, wherein one path of the same signals acts on an electro-optic modulator to modulate emergent laser to generate a chirp optical pulse signal, and the other path of the same signals is used as a local reference chirp signal and is sent into a mixer;
(2) using a laser to generate a continuous laser signal, sending the continuous laser signal into an electro-optic modulator, modulating the intensity of the electro-optic modulator through a chirp signal, and then entering an optical fiber to be tested through a circulator;
(3) sending an optical signal reflected by a Fresnel break point of the optical fiber to be tested into an optical fiber attenuator after passing through a circulator; the attenuation coefficient of the optical fiber attenuator is controlled by the output feedback of the single photon detector: when the single-photon detector is in saturated output, the attenuation coefficient is increased; when the output of the single-photon detector is too small or no output is generated, the attenuation coefficient is reduced;
(4) the attenuated Fresnel reflection signal is detected by a single photon detector, the output electric signal is mixed with a reference chirp signal, high-frequency components in the mixed signal are removed through a low-pass filter, and the frequency offset of the signal is obtained through Fourier transform, so that the position information of a breakpoint is obtained.
2. The method for detecting the breakpoint position of a remote high-precision optical fiber according to claim 1, wherein the chirp signal expression is as follows:
where k is the conversion of the chirp amplitude modulated signal, t is the time, f0In order to be the initial frequency of the frequency,
for the initial phase, k is B/T, where B is the modulation bandwidth of the chirp signal and T is the modulation time.
3. The method for detecting the breakpoint position of the long-distance high-precision optical fiber according to claim 2, wherein the expression of the optical signal reflected by the breakpoint fresnel is as follows: sR(t)＝I0MS (t- τ) in which IoLaser power, M is the loss coefficient, and tau is the laser signal flight time.
4. The method for detecting the breakpoint position of the long-distance high-precision optical fiber according to claim 3, wherein the frequency mixing signal of the output signal of the detector and the local reference chirp signal is:
SIF＝S(t)×SR(t)＝S(t)×I0MS(t-τ)
5. the method according to claim 4, wherein the obtaining of the position information of the break point by obtaining the frequency shift of the signal through Fourier transform is performed by Fourier transforming a difference frequency signal obtained after low-pass filtering into ^ sinc (ω) × (ω -k τ) · sinc (ω -k τ) and obtaining τ ═ f ^ fIFK, substituting into the calculation formula R ═ τ c for the fiber breakpoint position0(ii)/2, obtaining the position R ═ f of the break point of the optical fiberIFc0T/2B, wherein c0Is the speed of light transmission in the optical fiber.
6. The system for realizing the remote high-precision optical fiber breakpoint position detection method in the claims 1-5 is characterized by comprising a power divider, a narrow linewidth laser, an electro-optical modulator, a frequency mixer, a circulator, an optical fiber attenuator, a single photon detector, a low-pass filter and a Fourier transform processor;
the two paths of outputs of the power divider are respectively connected with an electro-optic modulator and a frequency mixer, the output of the narrow linewidth laser is connected with the electro-optic modulator, the electro-optic modulator is connected with a circulator, the output end of the circulator is connected with an optical fiber to be tested, the return end of the circulator is connected with an optical fiber attenuator and then connected with a single photon detector, the output of the single photon detector is connected with the frequency mixer, and then connected with a processor through a low-pass filter;
the chirp signal is divided into two paths of same signals by the power divider, one path of same signal acts on the electro-optic modulator to modulate the emergent laser to generate a chirp optical pulse signal, and the other path of same signal is used as a reference signal and is sent into the frequency mixer; the narrow linewidth laser generates a continuous laser signal, the continuous laser signal is sent to the electro-optic modulator to be modulated into a chirp pulse signal, and then the chirp pulse signal enters the optical fiber to be tested through the circulator; in the optical fiber to be tested, the optical signal reflected by the Fresnel at the breakpoint is sent into the optical fiber attenuator after passing through the circulator, and the attenuation coefficient of the optical fiber attenuator is controlled by the output feedback of the single-photon detector: the single photon detector detects the attenuated Fresnel reflection signal, the output electric signal and the reference chirp signal are mixed through a mixer, high-frequency components in the mixed signal are removed through a low-pass filter, the frequency offset of the signal is obtained through Fourier transform in a processor, and the position information of a breakpoint is obtained through calculation.
7. The system of claim 6, wherein the laser is a narrow linewidth laser, and the laser emits a continuous optical signal to ensure its linewidth, and is modulated into a chirped pulse signal by an electro-optical modulator.
8. The system of claim 6, wherein the attenuation of the fiber optic attenuator is continuously adjustable and feedback controlled by the output of the single photon detector to increase the attenuation coefficient when the single photon detector is saturated with output; when the output of the single-photon detector is too small or no output is generated, the attenuation coefficient is reduced.
9. The system of claim 6 in which the single photon detector is an Avalanche Photodiode (APD) single photon detector in GHz gated Geiger mode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911426355.6A CN111162839A (en) | 2019-12-31 | 2019-12-31 | Remote high-precision optical fiber breakpoint position detection method and system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911426355.6A CN111162839A (en) | 2019-12-31 | 2019-12-31 | Remote high-precision optical fiber breakpoint position detection method and system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111162839A true CN111162839A (en) | 2020-05-15 |
Family
ID=70560818
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911426355.6A Pending CN111162839A (en) | 2019-12-31 | 2019-12-31 | Remote high-precision optical fiber breakpoint position detection method and system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111162839A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112713929A (en) * | 2020-12-02 | 2021-04-27 | 广东工业大学 | Optical time domain reflectometer based on chirped pulses |
| CN113238246A (en) * | 2021-05-06 | 2021-08-10 | 武汉科技大学 | Method and device for simultaneously measuring distance and speed based on pulse sequence and storage medium |
| CN113252089A (en) * | 2021-06-24 | 2021-08-13 | 广东电网有限责任公司 | Distributed optical fiber sensing device |
| CN114878141A (en) * | 2022-04-22 | 2022-08-09 | 成都飞机工业（集团）有限责任公司 | Airborne optical cable connection fault positioning method and system |
| CN118249185A (en) * | 2023-12-28 | 2024-06-25 | 中国航空工业集团公司北京长城计量测试技术研究所 | Laser offset frequency locking device and method based on electro-optic modulator sideband modulation |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101236253A (en) * | 2008-03-07 | 2008-08-06 | 中国科学院上海光学精密机械研究所 | High-precision speed and distance measuring laser radar system and speed and distance measuring method |
| CN101625279A (en) * | 2009-08-03 | 2010-01-13 | 浙江大学 | Device for positioning optical fiber breakpoints and method for confirming breakpoint positions |
| 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 |
| CN105425244A (en) * | 2015-12-16 | 2016-03-23 | 哈尔滨工业大学 | Front mixing chirp modulation photon counting laser radar |
| CN105487067A (en) * | 2015-12-25 | 2016-04-13 | 哈尔滨工业大学 | Distance signal processing method for rough measurement and accurate measurement, processing module and chirped modulation photon counting laser radar system based on module |
| CN108072504A (en) * | 2016-11-15 | 2018-05-25 | 上海朗研光电科技有限公司 | Breakpoints of optical fiber positioning and length measurement method based on high-speed single photon detector |
-
2019
- 2019-12-31 CN CN201911426355.6A patent/CN111162839A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101236253A (en) * | 2008-03-07 | 2008-08-06 | 中国科学院上海光学精密机械研究所 | High-precision speed and distance measuring laser radar system and speed and distance measuring method |
| CN101625279A (en) * | 2009-08-03 | 2010-01-13 | 浙江大学 | Device for positioning optical fiber breakpoints and method for confirming breakpoint positions |
| 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 |
| CN105425244A (en) * | 2015-12-16 | 2016-03-23 | 哈尔滨工业大学 | Front mixing chirp modulation photon counting laser radar |
| CN105487067A (en) * | 2015-12-25 | 2016-04-13 | 哈尔滨工业大学 | Distance signal processing method for rough measurement and accurate measurement, processing module and chirped modulation photon counting laser radar system based on module |
| CN108072504A (en) * | 2016-11-15 | 2018-05-25 | 上海朗研光电科技有限公司 | Breakpoints of optical fiber positioning and length measurement method based on high-speed single photon detector |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112713929A (en) * | 2020-12-02 | 2021-04-27 | 广东工业大学 | Optical time domain reflectometer based on chirped pulses |
| CN112713929B (en) * | 2020-12-02 | 2022-02-18 | 广东工业大学 | Optical time domain reflectometer based on chirped pulses |
| CN113238246A (en) * | 2021-05-06 | 2021-08-10 | 武汉科技大学 | Method and device for simultaneously measuring distance and speed based on pulse sequence and storage medium |
| CN113252089A (en) * | 2021-06-24 | 2021-08-13 | 广东电网有限责任公司 | Distributed optical fiber sensing device |
| CN114878141A (en) * | 2022-04-22 | 2022-08-09 | 成都飞机工业（集团）有限责任公司 | Airborne optical cable connection fault positioning method and system |
| CN114878141B (en) * | 2022-04-22 | 2023-08-04 | 成都飞机工业（集团）有限责任公司 | Airborne optical cable connection fault positioning method and system |
| CN118249185A (en) * | 2023-12-28 | 2024-06-25 | 中国航空工业集团公司北京长城计量测试技术研究所 | Laser offset frequency locking device and method based on electro-optic modulator sideband modulation |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111162839A (en) | Remote high-precision optical fiber breakpoint position detection method and system | |
| CN110780310B (en) | Polarization diversity dual-channel speed measuring and distance measuring coherent laser radar measuring method and device | |
| US9571189B2 (en) | In-service monitoring of a fiberoptic network | |
| CN106226778A (en) | A kind of coherent lidar system of high resolution measurement remote object | |
| JPH026724A (en) | Method and apparatus for testing optical transmission medium | |
| CN104618013B (en) | A kind of related optical time domain reflectometer based on all -fiber wide range chaos light source | |
| CN114035174B (en) | Dual-channel dual-chirp linear frequency modulation continuous wave laser radar method and device | |
| CN105158770A (en) | Coherent wind measurement laser radar system with adjustable range resolution | |
| WO2015010581A1 (en) | Coherent optical time domain reflectometry coded based on detection frequency | |
| CN104697557B (en) | Circular frequency shifting based BOTDR (Brillouin Optical Time Domain Reflectometer) coherent detection device and method | |
| CN115015886B (en) | Dual-channel pseudo-random code phase modulation distance measurement and speed measurement laser radar method and device | |
| CN102636121A (en) | High-precision optical fiber length measuring system | |
| Elghandour et al. | Modeling and comparative study of various detection techniques for FMCW LIDAR using optisystem | |
| CN110082000B (en) | Multi-parameter distributed intelligent optical fiber sensing system | |
| CN212320747U (en) | Linear frequency modulation's distributed optical fiber sensing device | |
| WO2023160490A1 (en) | Signal transmission method and apparatus | |
| CN110071759B (en) | Optical cable fault positioning device and method based on polarized white light interference | |
| CN111239754A (en) | Laser radar system based on frequency-adjustable continuous wave and imaging method thereof | |
| CN110375960A (en) | A kind of device and method based on super continuum source OTDR | |
| CN113295097B (en) | Optical fiber length measuring method and device based on optical wave element analyzer group delay | |
| CN207720138U (en) | A kind of OTDR devices based on multi-channel optical fibre optical monitoring signal | |
| CN206990196U (en) | Suitable for centimetre class precision optical time domain reflection test device of wide warm working environment | |
| CN112187347B (en) | Device and method for measuring length of optical fiber | |
| CN204128693U (en) | A kind of wideband frequency modulation pulse laser Waveform testing device | |
| Hiramatsu et al. | A novel phase-noise cancelled optical frequency domain reflectometry using modulation sidebands |
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 | ||
| TA01 | Transfer of patent application right |
Effective date of registration: 20210126 Address after: Room 4, 13 / F, 11 / F, 106 west section of Jinkai Avenue, Yubei District, Chongqing 401121 Applicant after: Chongqing Research Institute of East China Normal University Applicant after: SHANGHAI LANGYAN OPTOELECTRONICS TECHNOLOGY Co.,Ltd. Applicant after: EAST CHINA NORMAL University Applicant after: University of Shanghai for Science and Technology Address before: Room 4, 13 / F, 11 / F, 106 west section of Jinkai Avenue, Yubei District, Chongqing 401123 Applicant before: Chongqing Research Institute of East China Normal University Applicant before: EAST CHINA NORMAL University Applicant before: University of Shanghai for Science and Technology |
|
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20200515 |