CN115290179A - OPGW optical cable long-distance vibration monitoring system based on phi-OTDR technology - Google Patents
OPGW optical cable long-distance vibration monitoring system based on phi-OTDR technology Download PDFInfo
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Abstract
The invention discloses an OPGW optical cable long-distance vibration monitoring system based on a phi-OTDR technology, wherein a continuous optical signal output by a narrow linewidth laser is modulated into an optical pulse signal through a semiconductor optical amplifier, the optical pulse signal is modulated into a narrower pulse optical signal by an acousto-optic modulator, the narrow pulse optical signal is subjected to optical power amplification by an erbium-doped optical fiber amplifier, then is injected into a wavelength division multiplexer through a first circulator and is simultaneously injected into an optical fiber to be detected with an output optical signal of a Raman amplifier, the Raman amplifier performs distributed amplification on the optical signal in the optical fiber to be detected, the sensing distance of the system is increased, meanwhile, remote pumping is provided for the erbium-doped optical fiber to realize remote pump amplification, and the sensing distance of the system is further increased; and the backward Rayleigh scattering light signals are amplified by a second erbium-doped optical fiber amplifier, ASE noise is filtered by an optical filter, and the detection and the acquisition are carried out by a photoelectric detector and a data acquisition card. The system can be used for OPGW optical cable long-distance monitoring.
Description
Technical Field
The invention relates to the technical field of optics, in particular to an OPGW optical cable long-distance vibration monitoring system based on a phi-OTDR technology.
Background
An OPGW (Optical Fiber Composite Overhead Ground Wire) Optical cable is widely applied to an ultrahigh voltage (ultrahigh voltage) remote transmission line, is difficult to avoid the influence of external complex environmental factors such as wind vibration, ice coating, lightning stroke and the like in long-term operation, and easily causes local stress concentration to enlarge the sag, thereby reducing the distance between a Ground Wire and a lead Wire, reducing the effective range and even causing the connection of the Ground Wire and the lead Wire; it may also lead to fiber breakage due to mechanical fatigue, and may also manifest as increased attenuation, which in the severe cases may lead to accidents such as tower collapse. When the OPGW optical cable is used, the loss of the ground wire function or the optical fiber communication function can cause huge power failure loss and influence, and the safe and stable operation of the power grid is also endangered. Traditionally, ice coating, waving and lightning stroke are monitored in a manual inspection mode, and problems cannot be found and handled in time, so that optical cables or fiber cores are interrupted, and communication services are influenced.
A phi-OTDR (phase-induced optical time-domain reflectometer), wherein the phase-sensitive optical time-domain reflectometer reflects the vibration information of each point along the sensing optical fiber by using a backward Rayleigh scattering optical signal in the optical fiber, and the backward Rayleigh scattering optical signal is relatively stable when no vibration event occurs outside; when a vibration event occurs locally, the Rayleigh scattered light signals at corresponding positions fluctuate, and the position and frequency information of the vibration event is demodulated by carrying out differential processing and time domain Fourier transform on backward Rayleigh scattered light signals at different moments before and after the vibration event occurs, so that distributed vibration monitoring is realized. The phi-OTDR has been widely applied in the fields of perimeter security, oil and gas pipeline monitoring and the like.
In recent years, the phi-OTDR is applied to OPGW optical cable icing, galloping and lightning stroke monitoring, and certain results are obtained. The phi-OTDR realizes sensing based on backward Rayleigh scattered light signals, the signal intensity is weak, the signal-to-noise ratio of the tail end is poor at a sensing distance of 50km, and a farther sensing distance cannot be realized. Due to the long station distance of the OPGW optical cable, the whole line of the OPGW optical cable cannot be covered by using phi-OTDR double-end opposite measurement, and a monitoring blind area exists, so that the improvement of the phi-OTDR monitoring distance has great significance for the application of the monitoring on icing, galloping and lightning stroke of the OPGW optical cable.
Disclosure of Invention
To this end, the present invention provides an OPGW optical cable long distance vibration monitoring system based on a Φ -OTDR technique in an attempt to solve, or at least alleviate, at least one of the problems presented above.
According to one aspect of the invention, an OPGW (optical fiber composite overhead ground wire) optical cable long-distance vibration monitoring system based on a phi-OTDR (optical time domain reflectometer) technology is provided, and comprises a narrow-linewidth laser, a semiconductor optical amplifier, an acousto-optical modulator, a first erbium-doped optical fiber amplifier, a first circulator, a Raman amplifier, a wavelength division multiplexer, an optical fiber to be detected, an erbium-doped optical fiber, a second erbium-doped optical fiber amplifier, a second circulator, an optical filter, a photoelectric detector, a data acquisition card and a pulse generator; the optical signal output end of the narrow linewidth laser is communicated with the optical signal input end of the semiconductor optical amplifier, the optical signal output end of the semiconductor optical amplifier is communicated with the optical signal input end of the acousto-optic modulator, the optical signal output end of the acousto-optic modulator is communicated with the optical signal input end of the first erbium-doped optical fiber amplifier, the optical signal output end of the first erbium-doped optical fiber amplifier is communicated with the first optical signal port of the first circulator, the second optical signal port of the first circulator is communicated with the first port of the wavelength division multiplexer, the optical signal output end of the Raman amplifier is communicated with the second port of the wavelength division multiplexer, the third port of the wavelength division multiplexer is communicated with the optical fiber to be tested, and the optical fiber to be tested is communicated with the erbium-doped optical fiber at the same time; the third optical signal port of the first circulator is communicated with the optical signal input end of the second erbium-doped optical fiber amplifier, the optical signal output end of the second erbium-doped optical fiber amplifier is simultaneously communicated with the first optical signal port of the second circulator, the second optical signal port of the second circulator is communicated with the optical filter, the third optical signal port of the second circulator is communicated with the optical signal input end of the photoelectric detector, the electric signal output end of the photoelectric detector is communicated with the electric signal input end of the acquisition card, and the microwave signal output end of the pulse generator is respectively and simultaneously communicated with the optical semiconductor amplifier, the microwave signal loading end of the acousto-optic modulator and the trigger signal input end of the data acquisition card.
Furthermore, the narrow linewidth laser adopts a single-frequency narrow linewidth optical fiber laser, the output optical power is 11mW, and the wavelength is 1550.172nm.
Further, the extinction ratio of the semiconductor optical amplifier is 60dB.
Furthermore, the frequency shift of the first acousto-optic modulator is-200 MHz, and the extinction ratio is 50dB.
Further, the output optical power of the Raman amplifier is 600mW, and the wavelength is 1480nm.
Furthermore, the center wavelength of the optical filter is 1550.17nm, and the bandwidth is 2GHz.
Further, the detection bandwidth of the photoelectric balance detector is 50MHz.
According to the OPGW optical cable long-distance vibration monitoring system based on the phi-OTDR technology, the invention provides a direct detection type phi-OTDR system based on the combination of a semiconductor optical amplifier, an acousto-optic modulator cascade, a front-end distributed amplification technology and a remote pump technology, so that the OPGW optical cable long-distance monitoring system is realized, and at least one of the following beneficial effects can be realized:
1. the system of the invention adopts the front-end distributed first-order Raman amplification technology and the remote pump technology to realize the long-distance OPGW optical cable vibration monitoring, has the effects of being better than the effects of the relay EDFA amplification and the double-end amplification, eliminates the necessity of on-site remote power supply, and has the significance of remote sensing in practical application.
2. The system of the invention adopts a mode of cascading the semiconductor optical amplifier and the acousto-optic modulator, thereby fully improving the extinction ratio of the detection optical pulse; the continuous light signal leakage caused by the limited extinction ratio and the high duty ratio of the detection pulse light in the long-distance sensing system is effectively avoided, the system signal jitter is avoided, and the stability of the long-distance sensing system is further improved.
3. The system has larger sensing distance and better system stability; the traditional phi-OTDR technology is influenced by the nonlinear threshold of the optical fiber, the detection light pulse power cannot be too high, the sensing distance is limited, the system adopts the front-end distributed amplification technology and the remote pump technology to mix, the sensing distance is fully improved, and the system has good stability.
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To the accomplishment of the foregoing and related ends, certain illustrative aspects are described herein in connection with the following description and the annexed drawings, which are indicative of various ways in which the principles disclosed herein may be practiced, and all aspects and equivalents thereof are intended to be within the scope of the claimed subject matter. The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description read in conjunction with the accompanying drawings. Throughout this disclosure, like reference numerals generally refer to like parts or elements.
Fig. 1 shows a schematic diagram of an OPGW optical cable long distance vibration monitoring system based on a Φ -OTDR technique according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a semiconductor optical amplifier and an acousto-optic modulator in cascade connection according to the present invention;
FIG. 3 shows a time domain diagram of 153km sensor signals of the system of the present invention;
fig. 4 shows a close-up view of 153km sensor signals in the system of the present invention.
Detailed Description
Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.
The embodiment of the invention provides an OPGW optical cable long-distance vibration monitoring system based on a phi-OTDR technology, which comprises a narrow linewidth laser, a semiconductor optical amplifier, an acousto-optic modulator, a first erbium-doped optical fiber amplifier, a first circulator, a Raman amplifier, a wavelength division multiplexer, an optical fiber to be detected, an erbium-doped optical fiber, a second erbium-doped optical fiber amplifier, a second circulator, an optical filter, a photoelectric detector, a data acquisition card and a pulse generator; the optical signal output end of the narrow linewidth laser is communicated with the optical signal input end of the semiconductor optical amplifier, the optical signal output end of the semiconductor optical amplifier is communicated with the optical signal input end of the acousto-optic modulator, the optical signal output end of the acousto-optic modulator is communicated with the optical signal input end of the first erbium-doped optical fiber amplifier, the optical signal output end of the first erbium-doped optical fiber amplifier is communicated with the first optical signal port of the first circulator, the second optical signal port of the first circulator is communicated with the first port of the wavelength division multiplexer, the optical signal output end of the Raman amplifier is communicated with the second port of the wavelength division multiplexer, the third port of the wavelength division multiplexer is communicated with the optical fiber to be tested, and the optical fiber to be tested is communicated with the erbium-doped optical fiber at the same time; the third optical signal port of the first circulator is communicated with the optical signal input end of a second erbium-doped optical fiber amplifier, the optical signal output end of the second erbium-doped optical fiber amplifier is simultaneously communicated with the first optical signal port of a second circulator, the second optical signal port of the second circulator is communicated with an optical filter, the third optical signal port of the second circulator is communicated with the optical signal input end of a photoelectric detector, the electric signal output end of the photoelectric detector is communicated with the electric signal input end of an acquisition card, and the microwave signal output end of a pulse generator is respectively and simultaneously communicated with the optical semiconductor amplifier, the microwave signal loading end of an acousto-optic modulator and the trigger signal input end of a data acquisition card.
Fig. 1 shows a schematic structural diagram of an OPGW optical cable long-distance vibration monitoring system based on a Φ -OTDR technique according to an embodiment of the present invention.
As shown in fig. 1, the OPGW optical cable long-distance vibration monitoring system based on the Φ -OTDR technology includes a narrow linewidth laser 1, a semiconductor optical amplifier 2, an acousto-optic modulator 3, a first erbium-doped fiber amplifier 4, a first circulator 5, a raman amplifier 6, a wavelength division multiplexer 7, an optical fiber to be measured 8, an erbium-doped fiber 9, a second erbium-doped fiber amplifier 10, a second circulator 11, an optical filter 12, a photodetector 13, a data acquisition card 14, and a pulse generator 15.
An optical signal output end of the narrow linewidth laser 1 is communicated with an optical signal input end of a semiconductor optical amplifier 2, an optical signal output end of the semiconductor optical amplifier 2 is communicated with an optical signal input end of an acousto-optic modulator 3, an optical signal output end of the acousto-optic modulator 3 is communicated with an optical signal input end of a first erbium-doped optical fiber amplifier 4, an optical signal output end of the first erbium-doped optical fiber amplifier 4 is communicated with a first optical signal port of a first circulator 5, a second optical signal port of the first circulator 5 is communicated with a first port of a wavelength division multiplexer 7, an optical signal output end of a Raman amplifier 6 is communicated with a second port of the wavelength division multiplexer 6, a third port of the wavelength division multiplexer 7 is communicated with an optical fiber 8 to be tested, the optical fiber 8 to be tested is communicated with an erbium-doped optical fiber 9, a third optical signal port of the first circulator 5 is communicated with an optical signal input end of a second erbium-doped optical fiber amplifier 10, an optical signal output end of the second circulator 10 is communicated with a first optical signal port of a second circulator 11, a second optical signal port of the second circulator 11 is communicated with an optical filter 12, a second optical signal port of the second circulator 11 is communicated with an optical signal input end of the semiconductor optical amplifier, an optical signal input end of the semiconductor optical amplifier 14, an optical signal generator 14, and an optical signal input end of the acousto-optic detector 2 is communicated with a data amplifier 14, and an optical signal input end of the semiconductor optical signal generator 14, and an optical signal input end of the optical signal generator 14 are respectively communicated with a data generator 14.
For example, a section of erbium-doped fiber 9 can be fused into the fiber 8 to be tested, as shown in fig. 1, the fiber 8 to be tested has two sections, and a section of erbium-doped fiber 9 is located in the middle. It should be understood that the erbium-doped fiber 9 may be disposed at the middle position of the optical fiber 8 to be tested, or may be disposed at other positions of the optical fiber 8 to be tested, that is, the erbium-doped fiber 9 is welded between the two optical fibers 8 to be tested shown in fig. 1, and the lengths of the two optical fibers 8 to be tested may be the same or different.
As shown in fig. 1, a continuous optical signal output by a narrow linewidth laser 1 is modulated into an optical pulse signal by a semiconductor optical amplifier 2, the optical pulse signal is further modulated into a narrower pulsed optical signal by an acousto-optic modulator 3 by adjusting time delay to improve an extinction ratio, continuous light leakage caused by a low duty ratio of the optical pulse and a limited extinction ratio of a modulator is avoided, and a modulation flow is shown in fig. 2. As shown in fig. 2, the hatched portion below the semiconductor optical amplifier 2 represents the pulse optical signal obtained by modulation by the semiconductor optical amplifier 2, and the hatched portion below the acousto-optic modulator 3 represents the pulse optical signal obtained by sequential modulation by the semiconductor optical amplifier 2 and the acousto-optic modulator 3. In this embodiment, the inventor finds that there is a precedence relationship between the semiconductor optical amplifier and the acousto-optic modulator in the optical path, that is, there is a time delay, and it needs to match time, so as to ensure that the high level position of the pulse optical signal modulated by the semiconductor optical amplifier can exactly correspond to the modulation signal of the acousto-optic modulator in time, and then the pulse optical signal is modulated into a narrow optical pulse signal again, so as to improve the extinction ratio; if the time delay is not compensated, the acousto-optic modulator does not correspond to the optical pulse signal output by the semiconductor optical amplifier, so that the acousto-optic modulator modulates the high level of the input optical pulse signal into the low level, no optical pulse signal is output or the output is weak, and the performance is deteriorated.
Narrow pulse optical signals (namely, the narrower pulse optical signals) are subjected to optical power amplification by the erbium-doped optical fiber amplifier 4, then are injected into the wavelength division multiplexer 7 through the first circulator 5, output optical signals of the Raman amplifier 6 are simultaneously injected into the optical fiber 8 to be detected, the Raman amplifier 6 realizes distributed amplification of the optical signals in the optical fiber to be detected, the sensing distance of the system is increased, meanwhile, remote pump amplification is realized by providing remote pumping for the erbium-doped optical fiber 9, and the sensing distance of the system is further increased.
Backward Rayleigh scattering optical signals in the optical fibers are output by the first circulator 5 and then enter the second erbium-doped optical fiber amplifier 10 for optical power amplification, then are injected into the optical filter 12 by the second circulator 11 to filter ASE noise and improve the signal-to-noise ratio, and then are detected by the photoelectric detector 13, the output light current is collected by the data acquisition card 14, and the pulse generator 15 realizes the control of the semiconductor optical amplifier 2, the acousto-optic modulator 3 and the acquisition card 14.
As an example, the narrow linewidth laser 1 may employ, for example, a single-frequency narrow linewidth fiber laser, the output optical power being, for example, 11mW, and the wavelength being, for example, 1550.172nm.
As an example, the extinction ratio of the semiconductor optical amplifier 2 is, for example, 60dB.
As an example, the frequency shift of the first acousto-optic modulator 3 is, for example, -200MHz, and the extinction ratio is, for example, 50dB.
As an example, the output optical power of the raman amplifier 6 is, for example, 600mW and the wavelength is, for example, 1480nm.
By way of example, the optical filter 12 has a center wavelength of, for example, 1550.17nm and a bandwidth of, for example, 2GHz.
As an example, the detection bandwidth of the photo-balanced detector is e.g. 50MHz.
The OPGW optical cable long-distance vibration monitoring system based on the phi-OTDR technology is characterized in that continuous optical signals output by a narrow-linewidth laser are modulated into optical pulse signals through a semiconductor optical amplifier, the optical pulse signals are further modulated into narrower pulse optical signals through an acoustic optical modulator, the optical power of the narrower pulse optical signals is amplified through an erbium-doped optical fiber amplifier, the narrower pulse optical signals are injected into a wavelength division multiplexer through a first circulator, output optical signals of a Raman amplifier are simultaneously injected into an optical fiber to be detected, the local position of the optical fiber to be detected is connected into the erbium-doped optical fiber to achieve remote pump amplification of the detected pulse optical signals, backward Rayleigh scattering optical signals in the optical fiber enter a second erbium-doped optical fiber amplifier to perform optical power amplification after being output through the first circulator, ASE noise is filtered through the second circulator, the signal-to-noise ratio is improved, the optical detector is used for detection, output optical current is collected through a data collection card, and a pulse generator is used for controlling the semiconductor optical amplifier, the acoustic optical modulator and the collection card.
Fig. 3 shows backward rayleigh scattered light signals collected by the collection card 14, in which it can be seen that the raman amplifier 6 performs distributed amplification on the rayleigh scattered light signals in the optical fiber to realize 87km distributed sensing, and the raman amplifier 6 simultaneously provides remote pumping for the erbium-doped optical fiber 9 connected at the position of 87km to realize remote pump amplification, so as to successfully further increase the sensing distance to 150km to realize long-distance sensing. Fig. 4 shows the local amplification of the backward rayleigh scattered light signal collected by the acquisition card 14, and it can be seen that the erbium-doped fiber 9 is far away from the position before pump amplification and the fiber tail end 150km has a better signal-to-noise ratio. In fig. 3 and 4, the distance is the distance between the current measurement position and the measurement starting point, and the intensity is the intensity of the backward rayleigh scattered light signal.
In order to avoid pulse aliasing in the optical fiber to be detected in the phi-OTDR system, only a single optical pulse signal with the width of T can exist in the optical fiber to be detected at the same time; the length of the optical fiber to be measured is set to be L, the refractive index is set to be n, the light wave propagation speed in vacuum is set to be c, the light wave propagation speed in the optical fiber is set to be c/n, and the duty ratio D of the obtained light pulse signal is shown in a formula I.
The formula I is as follows:
in a long-distance phi-OTDR system, T < < L and the duty ratio D of an optical pulse signal are lower, and in order to avoid continuous light leakage and system performance deterioration caused by the lower duty ratio and the limited extinction ratio of a modulation device, the semiconductor optical amplifier and the acousto-optic modulator are cascaded to improve the extinction ratio.
Further, the semiconductor optical amplifier 2 and the acousto-optic modulator 3 are modulated in cascade, and the flow of improving the extinction ratio is described as follows.
Setting single-frequency continuous light output by narrow-linewidth laser, amplitude value is A, and carrier frequency is f c At an initial phase of
During the time t, the light wave expression E (t) is shown as the formula two.
The formula II is as follows:
the continuous light E (t) is modulated into an optical pulse signal E by the semiconductor optical amplifier 2 1 (t), as shown in equation three.
The formula III is as follows:
wherein A is 1 Is the amplitude of the optical pulse signal; t is 1 Is the optical pulse signal width.
Optical pulse signal E 1 (t) further modulated by the acousto-optic modulator 3 into a narrow optical pulse signal E of optical extinction ratio 2 (t), as shown in equation four.
The formula four is as follows:
wherein, A 2 Is the amplitude of the optical pulse signal; Δ f is the frequency shift of the acousto-optic modulator 3; t is 2 Is the optical pulse signal width.
T in the above process 2 <T 1 Meanwhile, the time delay between the semiconductor optical amplifier 2 and the acousto-optic modulator 3 needs to be effectively adjusted through the pulse generator 15, and the optical pulse signal E generated by the modulation of the semiconductor optical amplifier 2 1 (t) an extinction ratio of 50dB 1 (t) further modulating the signal into a narrow optical pulse signal E with an extinction ratio larger than 100dB through an acousto-optic modulator 3 with an extinction ratio of 52dB 2 And (t), effectively avoiding continuous light leakage from deteriorating the performance of the system.
In the OPGW optical cable long-distance vibration monitoring system based on the Φ -OTDR technology according to the embodiment, the system realizes long-distance OPGW optical cable vibration monitoring by adopting a front-end distributed first-order raman amplification technology and a remote pump technology, has an effect compared with that of relay EDFA amplification and double-end amplification, eliminates the necessity of on-site remote power supply, and has a remote sensing meaning in practical application.
In the OPGW optical cable long-distance vibration monitoring system based on the Φ -OTDR technique according to the embodiment, the extinction ratio of the probe optical pulse is fully improved by adopting a mode of cascading the semiconductor optical amplifier and the acousto-optic modulator; the continuous light signal leakage caused by the limited extinction ratio and the high duty ratio of the detection pulse light in the long-distance sensing system is effectively avoided, the system signal jitter is avoided, and the stability of the long-distance sensing system is further improved.
The OPGW optical cable long-distance vibration monitoring system based on the phi-OTDR technology has larger sensing distance and better system stability; the traditional phi-OTDR technology is influenced by the nonlinear threshold of the optical fiber, the detection light pulse power cannot be too high, the sensing distance is limited, the system adopts the front-end distributed amplification technology and the remote pump technology to mix, the sensing distance is fully improved, and the system has good stability.
In the OPGW optical cable long-distance vibration monitoring system based on the Φ -OTDR technology according to the embodiment, the system realizes long-distance OPGW optical cable vibration monitoring by adopting a front-end distributed first-order raman amplification technology and a remote pump technology, eliminates the necessity of on-site remote power supply compared with relay EDFA amplification and double-end amplification, and has a remote sensing meaning in practical application. The extinction ratio of the detection light pulse is fully improved by adopting a mode of cascading the semiconductor optical amplifier and the acousto-optic modulator; the continuous light signal leakage caused by the limited extinction ratio and the high duty ratio of the detection pulse light in the long-distance sensing system is effectively avoided, the system signal jitter is avoided, and the stability of the long-distance sensing system is further improved. The traditional phi-OTDR technology is influenced by the nonlinear threshold of the optical fiber, the detection light pulse power cannot be too high, the sensing distance is limited, the system adopts the front-end distributed amplification technology and the remote pump technology to mix, the sensing distance is fully improved, and the system has good stability.
In the description provided herein, numerous specific details are set forth. It is understood, however, that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.
Similarly, it should be appreciated that in the foregoing description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. However, the disclosed method should not be interpreted as reflecting an intention that: that the invention as claimed requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.
Those skilled in the art will appreciate that the modules or units or components of the devices in the examples disclosed herein may be arranged in a device as described in this embodiment, or alternatively may be located in one or more devices different from the device in this example. The modules in the foregoing examples may be combined into one module or may additionally be divided into multiple sub-modules.
Those skilled in the art will appreciate that the modules in the device in an embodiment may be adaptively changed and disposed in one or more devices different from the embodiment. The modules or units or components in the embodiments may be combined into one module or unit or component, and furthermore, may be divided into a plurality of sub-modules or sub-units or sub-components. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and all of the processes or elements of any method or apparatus so disclosed, may be combined in any combination, except combinations where at least some of such features and/or processes or elements are mutually exclusive. Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise.
Moreover, those skilled in the art will appreciate that although some embodiments described herein include some features included in other embodiments, not others, combinations of features of different embodiments are meant to be within the scope of the invention and form different embodiments. For example, in the following claims, any of the claimed embodiments may be used in any combination.
Furthermore, some of the described embodiments are described herein as a method or combination of method elements that can be performed by a processor of a computer system or by other means of performing the described functions. A processor having the necessary instructions for carrying out the method or method elements thus forms a means for carrying out the method or method elements. Further, the elements of the apparatus embodiments described herein are examples of the following apparatus: the means for performing the functions performed by the elements for the purpose of carrying out the invention.
As used herein, unless otherwise specified the use of the ordinal adjectives "first", "second", "third", etc., to describe a common object, merely indicate that different instances of like objects are being referred to, and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner.
While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this description, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as described herein. Furthermore, it should be noted that the language used in the specification has been principally selected for readability and instructional purposes, and may not have been selected to delineate or circumscribe the inventive subject matter. Accordingly, many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the appended claims. The present invention has been disclosed in an illustrative rather than a restrictive sense with respect to the scope of the invention, as defined in the appended claims.
Claims (7)
1. An OPGW optical cable long-distance vibration monitoring system based on a phi-OTDR technology is characterized in that the monitoring system comprises a narrow linewidth laser, a semiconductor optical amplifier, an acousto-optic modulator, a first erbium-doped optical fiber amplifier, a first circulator, a Raman amplifier, a wavelength division multiplexer, an optical fiber to be detected, an erbium-doped optical fiber, a second erbium-doped optical fiber amplifier, a second circulator, an optical filter, a photoelectric detector, a data acquisition card and a pulse generator;
the optical signal output end of the narrow linewidth laser is communicated with the optical signal input end of the semiconductor optical amplifier, the optical signal output end of the semiconductor optical amplifier is communicated with the optical signal input end of the acousto-optic modulator, the optical signal output end of the acousto-optic modulator is communicated with the optical signal input end of the first erbium-doped optical fiber amplifier, the optical signal output end of the first erbium-doped optical fiber amplifier is communicated with the first optical signal port of the first circulator, the second optical signal port of the first circulator is communicated with the first port of the wavelength division multiplexer, the optical signal output end of the Raman amplifier is communicated with the second port of the wavelength division multiplexer, the third port of the wavelength division multiplexer is communicated with the optical fiber to be tested, and the optical fiber to be tested is communicated with the erbium-doped optical fiber at the same time;
the third optical signal port of the first circulator is communicated with the optical signal input end of the second erbium-doped optical fiber amplifier, the optical signal output end of the second erbium-doped optical fiber amplifier is simultaneously communicated with the first optical signal port of the second circulator, the second optical signal port of the second circulator is communicated with the optical filter, the third optical signal port of the second circulator is communicated with the optical signal input end of the photoelectric detector, the electric signal output end of the photoelectric detector is communicated with the electric signal input end of the acquisition card, and the microwave signal output end of the pulse generator is respectively and simultaneously communicated with the optical semiconductor amplifier, the microwave signal loading end of the acousto-optic modulator and the trigger signal input end of the data acquisition card.
2. The monitoring system of claim 1, wherein the narrow linewidth laser employs a single frequency narrow linewidth fiber laser with an output optical power of 11mW and a wavelength of 1550.172nm.
3. A monitoring system according to claim 1 or 2, wherein the extinction ratio of the semiconductor optical amplifier is 60dB.
4. The monitoring system according to claim 1 or 2, wherein the first acousto-optic modulator has a frequency shift of-200 MHz and an extinction ratio of 50dB.
5. A monitoring system according to claim 1 or 2, wherein the output optical power of the raman amplifier is 600mW and the wavelength is 1480nm.
6. The monitoring system of claim 1 or 2, wherein the optical filter has a center wavelength of 1550.17nm and a bandwidth of 2GHz.
7. A monitoring system according to claim 1 or 2, wherein the detection bandwidth of the photoelectric balanced detector is 50MHz.
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Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101893476A (en) * | 2010-03-11 | 2010-11-24 | 上海华魏光纤传感技术有限公司 | Long-distance optical fiber vibration sensing system with distributed amplification |
| CN102506912A (en) * | 2011-09-29 | 2012-06-20 | 北京航空航天大学 | Optical fiber distributed disturbance sensor |
| CN102998025A (en) * | 2012-12-18 | 2013-03-27 | 华北电力大学（保定） | Measuring method for pulse pre-pump rayleigh BOTDA (Brilouin optical time domain analysis) temperature and strain |
| CN103152097A (en) * | 2013-03-12 | 2013-06-12 | 电子科技大学 | Long-distance polarization and phase-sensitive optical time domain reflectometer amplified by random laser |
| CN103364106A (en) * | 2013-07-16 | 2013-10-23 | 扬州森斯光电科技有限公司 | Brillouin optical time domain analyzing and sensing system based on ultra-long annular laser pumping |
| CN105067143A (en) * | 2015-07-02 | 2015-11-18 | 南京航空航天大学 | Homodyne Brillouin optical time domain reflectometer based on Raman amplification |
| 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 |
| CN108489598A (en) * | 2018-05-21 | 2018-09-04 | 浙江杰昆科技有限公司 | Phase sensitive optical time domain reflectometer phase simulates coherent demodulation system and method |
| KR20180123227A (en) * | 2017-05-08 | 2018-11-16 | 한양대학교 산학협력단 | Acoustic frequency detection based on phase optical time domain reflectometer system with Raman power amplifier |
| CN109632076A (en) * | 2019-01-31 | 2019-04-16 | 电子科技大学 | The amplification system and method for long-distance optical fiber distribution sound wave sensing |
| CN109974756A (en) * | 2019-04-11 | 2019-07-05 | 南京聚科光电技术有限公司 | Φ-the OTDR technique merged based on differential phase impulse ejection and time domain |
| CN110987231A (en) * | 2019-12-23 | 2020-04-10 | 上海拜安传感技术有限公司 | Distributed optical fiber system for rapidly monitoring temperature of superconductor |
| CN216524011U (en) * | 2022-01-17 | 2022-05-13 | 南京信息工程大学 | Long-distance Brillouin optical time domain reflectometer monitoring device |
| CN114719952A (en) * | 2022-03-23 | 2022-07-08 | 武汉理工大学 | Distributed optical fiber sound wave detection system and detection method |
-
2022
- 2022-08-10 CN CN202210956544.XA patent/CN115290179A/en active Pending
Patent Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101893476A (en) * | 2010-03-11 | 2010-11-24 | 上海华魏光纤传感技术有限公司 | Long-distance optical fiber vibration sensing system with distributed amplification |
| CN102506912A (en) * | 2011-09-29 | 2012-06-20 | 北京航空航天大学 | Optical fiber distributed disturbance sensor |
| CN102998025A (en) * | 2012-12-18 | 2013-03-27 | 华北电力大学（保定） | Measuring method for pulse pre-pump rayleigh BOTDA (Brilouin optical time domain analysis) temperature and strain |
| CN103152097A (en) * | 2013-03-12 | 2013-06-12 | 电子科技大学 | Long-distance polarization and phase-sensitive optical time domain reflectometer amplified by random laser |
| CN103364106A (en) * | 2013-07-16 | 2013-10-23 | 扬州森斯光电科技有限公司 | Brillouin optical time domain analyzing and sensing system based on ultra-long annular laser pumping |
| CN105067143A (en) * | 2015-07-02 | 2015-11-18 | 南京航空航天大学 | Homodyne Brillouin optical time domain reflectometer based on Raman amplification |
| 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 |
| KR20180123227A (en) * | 2017-05-08 | 2018-11-16 | 한양대학교 산학협력단 | Acoustic frequency detection based on phase optical time domain reflectometer system with Raman power amplifier |
| CN108489598A (en) * | 2018-05-21 | 2018-09-04 | 浙江杰昆科技有限公司 | Phase sensitive optical time domain reflectometer phase simulates coherent demodulation system and method |
| CN109632076A (en) * | 2019-01-31 | 2019-04-16 | 电子科技大学 | The amplification system and method for long-distance optical fiber distribution sound wave sensing |
| CN109974756A (en) * | 2019-04-11 | 2019-07-05 | 南京聚科光电技术有限公司 | Φ-the OTDR technique merged based on differential phase impulse ejection and time domain |
| CN110987231A (en) * | 2019-12-23 | 2020-04-10 | 上海拜安传感技术有限公司 | Distributed optical fiber system for rapidly monitoring temperature of superconductor |
| CN216524011U (en) * | 2022-01-17 | 2022-05-13 | 南京信息工程大学 | Long-distance Brillouin optical time domain reflectometer monitoring device |
| CN114719952A (en) * | 2022-03-23 | 2022-07-08 | 武汉理工大学 | Distributed optical fiber sound wave detection system and detection method |
Non-Patent Citations (2)
| Title |
|---|
| 巴德欣;董永康;: "分布式光纤传感技术及其在航空航天领域的应用展望", 宇航学报, no. 06, 30 June 2020 (2020-06-30) * |
| 张瑜;王东;白清;李哲哲;王宇;靳宝全;: "基于SOA脉冲调制的BOTDR应变检测系统", 传感技术学报, no. 12 * |
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