CN102622840A - Peripheral security protection system based on single-optical-fiber cable - Google Patents

Peripheral security protection system based on single-optical-fiber cable Download PDF

Info

Publication number
CN102622840A
CN102622840A CN2012101020751A CN201210102075A CN102622840A CN 102622840 A CN102622840 A CN 102622840A CN 2012101020751 A CN2012101020751 A CN 2012101020751A CN 201210102075 A CN201210102075 A CN 201210102075A CN 102622840 A CN102622840 A CN 102622840A
Authority
CN
China
Prior art keywords
optical fiber
port
input
photodetector
connects
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
Application number
CN2012101020751A
Other languages
Chinese (zh)
Inventor
李超
宁提纲
李晶
裴丽
张婵
陈宏尧
油海东
周倩
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Beijing Jiaotong University
Original Assignee
Beijing Jiaotong University
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Beijing Jiaotong University filed Critical Beijing Jiaotong University
Priority to CN2012101020751A priority Critical patent/CN102622840A/en
Publication of CN102622840A publication Critical patent/CN102622840A/en
Pending legal-status Critical Current

Links

Abstract

The invention discloses a peripheral security protection system based on a single-optical-fiber cable, and the system is applicable to the fields of optical fiber communication, optical fiber sensing and the like. The output end of a light source (1) of the system is connected with the input end of a phase modulator (13); the output end of the phase modulator is connected with a first branch (101) of a Y branching device and a second branch (102) of the Y branching device is connected with the input end of a photoelectric detector (3); a third branch (103) of the Y branching device is connected with one end of an optical fiber (4); a knocking signal (5) is applied to the optical fiber; the output of the photoelectric detector is connected with the input end of an amplification circuit (6); the output of the amplification circuit is connected with the input end of a signal processing module (7); the output end of the signal processing module is connected with a display module (8) and a loudspeaker (9); and the end face of the tail end of the optical fiber is milled into a slope end face. The peripheral security protection system based on the single-optical-fiber cable has the advantages of simple structure and easiness for realization; and an interference field is formed only by single optical fiber so as to detect and position an invading signal.

Description

Based on single fiber cable circumference safety-protection system
Technical field
The present invention relates to single fiber cable circumference safety-protection system, be applicable to fields such as Fibre Optical Sensor, optical fiber communication.
Background technology
Be applied to the zone of high security requirements such as place of military importance, bank, museum, airport, harbour or circumference demand for security on a large scale in the modern circumference safety-protection system, bringing into play important effect for timely discovery and location intrusion behavior.And along with development of fiber technology, optical fiber is being brought into play more and more important effect in the circumference safety-protection system in modern times.
At present, the circumference safety-protection system based on optical fiber mainly contains following method: optical power loss method, the method based on multimode optical fiber speckle sensor, optical time domain reflectometry, Sagnac interference field method.The optical power loss method is the purpose that the optical power change through real-time monitoring tested optical fiber receiving end reaches the identification undesired signal, and this method precision is low and can not accurately locate; Multimode optical fiber speckle sensor method be utilize light wave at multimode optical fiber because the interference between the different transmission mode forms speckle; Speckle image is changed by external disturbance and writes down speckle with CCD; Just can be disturbed on the perception multimode optical fiber; This method requires to use extraordinary multimode optical fiber, and cost is higher; Optical time domain reflectometry is back scattering and a Fresnel reflection principle of utilizing light, accepts back-scattered light, utilizes distance and time relation to detect the position of optical fiber disturbance, and this method measuring-signal is very faint, inapplicable detection of dynamic, and also its cost is higher; Sagnac interference field method is to utilize two optical fiber formation Sagnac interference fields in the optical cable to detect undesired signal; Like U.S. Pat 2003/0198425A1; This method needs two optical fiber; Along with the increase of transmission range, the double increase of the loss of optical fiber, the accuracy rate of optical cable identification reduces greatly.
Summary of the invention
Technical matters to be solved by this invention provides a kind of single fiber cable circumference safety-protection system.
Technical scheme of the present invention:
A kind of single fiber cable circumference safety-protection system; The input end of the output termination phase-modulator of this system source, first branch of the output termination Y splitter of phase-modulator, second branch of Y splitter connects the input end of photodetector; The 3rd branch of Y splitter connects an end of optical fiber; The invasion signal is applied on the optical fiber, and the output of photodetector connects the input end of amplifying circuit, and the output of amplifying circuit connects the input end of signal processing module; An output termination display module of signal processing module, another output termination loudspeaker;
The end surface grinding of optical fiber tail end becomes the inclined-plane end face.
The light that light source sends incides on the optical fiber through three port coupler after the phase-modulator modulation, and the light of returning through optical fiber tail end end face reflection arrives photodetector through coupling mechanism once more, and the interference pattern of two-beam is along fiber distribution; Form a string either overt or covert zone, interference pattern can not change under steady state (SS), and photodetector detects the light of same intensity; If there is the invasion signal to disturb, the position of interference pattern changes, and photodetector will detected twice light intensity change; For the first time directly arrive photodetector for the light intensity variable signal, for light intensity signal arrives photodetector for reflecting the back through fiber end face, light signal becomes electric signal through behind the photodetector for the second time; Send into signal processing module after amplifying through amplifying circuit again; Change the mistiming that arrives detector through twice light intensity signal, can calculate the position that the invasion signal takes place, concrete computing formula is: (wherein S is the distance of invasion point apart from photodetector to S=L-1/2* Δ t*C/n; L is a length of fiber; Δ t is the mistiming of twice light intensity signal arrival detector, and C is a light speed in a vacuum, and n is the refractive index of optical fiber); The signal of output shows through display module, and sound signal is transmitted through loudspeaker.
The Y splitter is replaced by three port coupler; The input end of the output termination phase-modulator of light source; First port of output termination three port coupler of phase-modulator; Second port of three port coupler connects the input end of photodetector, and the 3rd port of three port coupler connects an end of optical fiber;
The end surface grinding of optical fiber tail end becomes the planar end vertical with surface level.
The Y splitter is replaced by three port circulators; The input end of the output termination phase-modulator of light source; First port of the output termination three port circulators of phase-modulator; Second port of three port circulators connects the input end of photodetector, and the 3rd port of three port circulators connects an end of optical fiber;
The tail end of optical fiber connects reverberator.
Beneficial effect of the present invention: the single fiber cable circumference safety-protection system that the present invention proposes, simple in structure, be easy to realize; Only need simple optical fiber just can constitute interference field and detect and locate the invasion signal. when for example native system can be used the airport safety-protection system; When invading the interference of signal; Photodetector will detect the variation of twice light intensity signal; For the first time directly arrive photodetector, for light intensity signal arrives photodetector for reflecting the back through fiber end face, change the mistiming that arrives detector for the second time according to twice light intensity signal for the light intensity variable signal; Can calculate the position that the invasion signal takes place, send warning information.
The single fiber cable circumference safety-protection system that the present invention proposes can in time be discerned response to various intrusion events, and has long distance detection, high-precision fixed bit function, low energy dependence, high ambient tolerance, anti-electromagnetic interference (EMI), characteristic such as anticorrosive, simple in structure.
Description of drawings
Fig. 1 adopts the single fiber circumference safety-protection system structural representation of Y splitter.
Fig. 2 adopts the single fiber circumference safety-protection system structural representation of three port coupler.
Fig. 3 adopts the single fiber circumference safety-protection system structural representation of three port circulators.
Embodiment
Below in conjunction with accompanying drawing the present invention is further described.
Embodiment one, sees Fig. 1, a kind of single fiber cable circumference safety-protection system; The input end of the output termination phase-modulator 13 of the light source 1 of this system, first branch 101 of the output termination Y splitter of phase-modulator 13, second branch 102 of Y splitter connects the input end of photodetector 3; The 3rd branch 103 of Y splitter connects an end of optical fiber 4; Knocking 5 is applied on the optical fiber 4, and the output of photodetector 3 connects the input end of amplifying circuit 6, and the output of amplifying circuit 6 connects the input end of signal processing module 7; An output termination display module 8 of signal processing module 7, another output termination loudspeaker 9.
The end surface grinding of optical fiber 4 tail ends becomes the inclined-plane end face.
The light that light source 1 sends incides on the optical fiber through the Y splitter after phase-modulator 13 modulation, and the light of returning through optical fiber 4 tail end end face reflections arrives photodetector 3 through coupling mechanism once more, and incident light and catoptrical interference pattern are along fiber distribution; Form a string either overt or covert zone, interference pattern can not change under steady state (SS), and photodetector 3 detects the light of same intensity; If there is the invasion signal to disturb, the position of interference pattern changes, and photodetector 3 detected twice light intensity change; For the first time directly arrive photodetector for the light intensity variable signal, for light intensity signal arrives photodetector for reflecting the back through fiber end face, light signal becomes electric signal through behind the photodetector 3 for the second time; Send into signal processing module 7 after amplifying through amplifying circuit 6 again; Through the mistiming of twice light intensity variable signal variation, can calculate the position that the invasion signal takes place, concrete computing formula is: (wherein S is for invading the distance of point apart from photodetector for S=L-1/2* Δ t*C/n; L is a length of fiber; Δ t is the mistiming of twice light intensity signal arrival detector, and C is a light speed in a vacuum, and n is the refractive index of optical fiber); The signal of output shows through display module 8, and sound signal is transmitted through loudspeaker 9.
The described light source of present embodiment is a white light source, and fiber lengths is 10km, and the end face reflection rate of optical fiber tail end is 1%, and the modulating frequency of phase-modulator is 100HZ.
Embodiment two, see Fig. 2, a kind of single fiber cable circumference safety-protection system; Second port 22 that the input end of the output termination phase-modulator 13 of the light source 1 of this safety-protection system, the output termination of phase-modulator 13 connect first port, 21, three port coupler of three port coupler connects the input end of photodetector 3; The 3rd port 23 of three port coupler connects an end of optical fiber 4; Knocking 5 is applied on the optical fiber 4, and the output of photodetector 3 connects the input end of amplifying circuit 6, and the output of amplifying circuit 6 connects the input end of signal processing module 7; The output termination display module 8 of signal processing module 7, another output termination loudspeaker 9.
The end surface grinding of optical fiber 4 tail ends becomes the planar end vertical with surface level.
The light that light source 1 sends incides on the optical fiber through three port coupler after phase-modulator 13 modulation, and the light of returning through optical fiber 4 tail end end face reflections arrives photodetector 3 through coupling mechanism once more, and incident light and catoptrical interference pattern are along fiber distribution; Form a string either overt or covert zone, interference pattern can not change under steady state (SS), and photodetector 3 detects the light of same intensity; If there is the invasion signal to disturb, the position of interference pattern changes, and photodetector 3 detected twice light intensity change; For the first time directly arrive photodetector for the light intensity variable signal, for light intensity signal arrives photodetector for reflecting the back through fiber end face, light signal becomes electric signal through behind the photodetector 3 for the second time; Send into signal processing module 7 after amplifying through amplifying circuit 6 again; Through the mistiming of twice light intensity variable signal variation, can calculate the position that the invasion signal takes place, concrete computing formula is: (wherein S is for invading the distance of point apart from photodetector for S=L-1/2* Δ t*C/n; L is a length of fiber; Δ t is the mistiming of twice light intensity signal arrival detector, and C is a light speed in a vacuum, and n is the refractive index of optical fiber); The signal of output shows through display module 8, and sound signal is transmitted through loudspeaker 9.
The described light source of present embodiment is the 1310nm LASER Light Source, and fiber lengths is 30km, and the end face reflection rate of optical fiber tail end is 4%, and the modulating frequency of phase-modulator is 1000HZ.
Embodiment three, see Fig. 3, a kind of single fiber cable circumference safety-protection system; Second port one 12 that the input end of the output termination phase-modulator 13 of this system source 1, the output termination of phase-modulator 13 connect first port one, 11, the three port circulators of three port circulators connects the input end of photodetector 3; The 3rd port one 13 of three port circulators connects an end of optical fiber 4; Knocking 5 is applied on the optical fiber 4, and the output of photodetector 3 connects the input end of amplifying circuit 6, and the output of amplifying circuit 6 connects the input end of signal processing module 7; The output termination display module 8 of signal processing module 7, another output termination loudspeaker 9.
Optical fiber 4 tail ends connect reverberator 10.
The light that light source 1 sends incides on the optical fiber through three port circulators after phase-modulator 13 modulation, and the light of returning through optical fiber 4 tail end end face reflections arrives photodetector 3 through coupling mechanism once more, and incident light and catoptrical interference pattern are along fiber distribution; Form a string either overt or covert zone, interference pattern can not change under steady state (SS), and photodetector 3 detects the light of same intensity; If there is the invasion signal to disturb, the position of interference pattern changes, and photodetector 3 detected twice light intensity change; For the first time directly arrive photodetector for the light intensity variable signal, for light intensity signal is to arrive photodetector through after the reflector reflects, light signal becomes electric signal through behind the photodetector 3 for the second time; Send into signal processing module 7 after amplifying through amplifying circuit 6 again; Through the mistiming of twice light intensity variable signal variation, can calculate the position that the invasion signal takes place, concrete computing formula is: (wherein S is for invading the distance of point apart from photodetector for S=L-1/2* Δ t*C/n; L is a length of fiber; Δ t is the mistiming of twice light intensity signal arrival detector, and C is a light speed in a vacuum, and n is the refractive index of optical fiber); The signal of output shows through display module 8, and sound signal is transmitted through loudspeaker 9.
The described light source of present embodiment is the 1550nm light source, and fiber lengths is 100km, and the end face reflection rate of optical fiber tail end is 90%, and the modulating frequency of phase-modulator is 2000HZ.
Foregoing only is the detailed description to preferred embodiment of the present invention; And protection scope of the present invention is not limited to foregoing; Those skilled in the art can carry out various distortion and modification to the present invention according to the bright thought of we, and these should belong to protection scope of the present invention.Device used in the present invention is commercially available device.

Claims (3)

1. optical cable circumference safety-protection system based on single fiber; It is characterized in that: the input end of the output termination phase-modulator (13) of this system source (1); First branch (101) of the output termination Y splitter of phase-modulator (13); Second branch (102) of Y splitter connects the input end of photodetector (3), and the 3rd branch (103) of Y splitter connects an end of optical fiber (4), and knocking (5) is applied on the optical fiber (4); The output of photodetector (3) connects the input end of amplifying circuit (6); The output of amplifying circuit (6) connects the input end of signal processing module (7), an output termination display module (8) of signal processing module (7), and another exports termination loudspeaker (9);
The end surface grinding of optical fiber (4) tail end becomes the inclined-plane end face.
2. the optical cable circumference safety-protection system based on single fiber according to claim 1; It is characterized in that: the Y splitter is replaced by three port coupler; The input end of the output termination phase-modulator (13) of light source (1); First port (21) of output termination three port coupler of phase-modulator (13), second port (22) of three port coupler connects the input end of photodetector (3), and the 3rd port (23) of three port coupler connects an end of optical fiber (4);
The end surface grinding of optical fiber (4) tail end becomes the planar end vertical with surface level.
3. the optical cable circumference safety-protection system based on single fiber according to claim 1; It is characterized in that: the Y splitter is replaced by three port circulators; The input end of the output termination phase-modulator (13) of light source (1); First port (111) of the output termination three port circulators of phase-modulator (13), second port (112) of three port circulators connects the input end of photodetector (3), and the 3rd port (113) of three port circulators connects an end of optical fiber (4);
The tail end of optical fiber (4) connects reverberator (10).
CN2012101020751A 2012-04-09 2012-04-09 Peripheral security protection system based on single-optical-fiber cable Pending CN102622840A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN2012101020751A CN102622840A (en) 2012-04-09 2012-04-09 Peripheral security protection system based on single-optical-fiber cable

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN2012101020751A CN102622840A (en) 2012-04-09 2012-04-09 Peripheral security protection system based on single-optical-fiber cable

Publications (1)

Publication Number Publication Date
CN102622840A true CN102622840A (en) 2012-08-01

Family

ID=46562735

Family Applications (1)

Application Number Title Priority Date Filing Date
CN2012101020751A Pending CN102622840A (en) 2012-04-09 2012-04-09 Peripheral security protection system based on single-optical-fiber cable

Country Status (1)

Country Link
CN (1) CN102622840A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104574742A (en) * 2015-01-04 2015-04-29 中国石油天然气股份有限公司 Optical fiber circumference security and protection system based on phi-OTDR technology
CN105825606A (en) * 2016-06-01 2016-08-03 北京佳讯飞鸿电气股份有限公司 Perimeter security and protection system
CN106530559A (en) * 2016-12-20 2017-03-22 厦门大学 Serial-type multi-defense area optical fiber perimeter intrusion sensing system

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1996037867A1 (en) * 1995-05-25 1996-11-28 Aktsionernoe Obschestvo Zakrytogo Tipa 'ntf Intersvyaz' Fibre-optic intruder alarm system
WO2001039148A1 (en) * 1999-11-24 2001-05-31 Future Fibre Technologies Pty Ltd A method of perimeter barrier monitoring and systems formed for that purpose
KR20020008457A (en) * 2000-07-20 2002-01-31 권영한 Intrusion warning apparatus using an optical fiber
CN101051869A (en) * 2007-05-17 2007-10-10 上海光朗信通讯技术有限公司 Safety monitor system of optical cable communication line
CN102034327A (en) * 2009-09-24 2011-04-27 上海华魏光纤传感技术有限公司 Multi-defense area locating type optical fiber vibration intrusion detection system
CN102095434A (en) * 2010-09-02 2011-06-15 上海华魏光纤传感技术有限公司 Reflection type full optical fiber interference system

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1996037867A1 (en) * 1995-05-25 1996-11-28 Aktsionernoe Obschestvo Zakrytogo Tipa 'ntf Intersvyaz' Fibre-optic intruder alarm system
WO2001039148A1 (en) * 1999-11-24 2001-05-31 Future Fibre Technologies Pty Ltd A method of perimeter barrier monitoring and systems formed for that purpose
KR20020008457A (en) * 2000-07-20 2002-01-31 권영한 Intrusion warning apparatus using an optical fiber
CN101051869A (en) * 2007-05-17 2007-10-10 上海光朗信通讯技术有限公司 Safety monitor system of optical cable communication line
CN102034327A (en) * 2009-09-24 2011-04-27 上海华魏光纤传感技术有限公司 Multi-defense area locating type optical fiber vibration intrusion detection system
CN102095434A (en) * 2010-09-02 2011-06-15 上海华魏光纤传感技术有限公司 Reflection type full optical fiber interference system

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104574742A (en) * 2015-01-04 2015-04-29 中国石油天然气股份有限公司 Optical fiber circumference security and protection system based on phi-OTDR technology
CN104574742B (en) * 2015-01-04 2017-06-06 中国石油天然气股份有限公司 A kind of optical fiber perimeter safety-protection system based on Φ OTDR techniques
CN105825606A (en) * 2016-06-01 2016-08-03 北京佳讯飞鸿电气股份有限公司 Perimeter security and protection system
CN106530559A (en) * 2016-12-20 2017-03-22 厦门大学 Serial-type multi-defense area optical fiber perimeter intrusion sensing system

Similar Documents

Publication Publication Date Title
CN102506904B (en) Spontaneous Brillouin scattering optical time domain reflectometer based on superconductive nanowire single-proton detector
CN203561437U (en) Random-position fiber-distributed sound wave sensor
CN103630229B (en) A kind of differential coherence time domain scatter-type distributed optical fiber vibration sensing method and system
CN103115633B (en) Utilize phase generated carrier to reduce and interfere path loose (instead) to penetrate the method for light interference
CN101634571B (en) Optical pulse raster distributed fiber sensing device
CN104236697A (en) Distribution type optical fiber vibration detection method and system based on wavelength division multiplexing
CN102928063B (en) Distributive optical fiber vibration sensing system based on wave division multiplex technology
CN104792343A (en) Single-ended structure dynamic measuring Brillouin optical fiber sensing system and sensing method
CN207894512U (en) Vibration sensor based on φ-OTDR
CN107036734A (en) A kind of fully distributed fiber temperature or the method for sensing and sensor of strain
CN101893476A (en) Long-distance optical fiber vibration sensing system with distributed amplification
CN206695897U (en) A kind of distributed optical fiber vibration positioning sensor system based on double-wavelength light source
CN207180866U (en) A kind of distributed vibration positioning sensor system based on MZ interference and Φ OTDR
CN105043586A (en) Few-mode fiber based Raman distributed temperature measurement system and temperature measurement method
CN110501062B (en) Distributed optical fiber sound sensing and positioning system
CN102646308A (en) Perimeter security system based on single optical fiber and fiber bragg grating of single optical fiber
CN101441092A (en) Perimeter protection sensing positioning system based on coherent light time domain reflection
CN104567959A (en) Large-dynamic interference type optical fiber sensor based on two-channel unbalanced interferometer
CN108254062A (en) A kind of phase sensitive optical time domain reflection vibration detection device based on chaotic modulation
CN102622840A (en) Peripheral security protection system based on single-optical-fiber cable
CN110307920A (en) Based on noise-modulated fiber optic temperature, stress sensing system and measurement method
CN103234590B (en) Underground optical fiber flow sensor in oil field
CN102393182B (en) Narrow-bandwidth Brillouin optical timedomain reflectometer (OTDR) based on sensing optical fiber of three-layer structure
CN104482858B (en) A kind of high sensitivity and high-precision fiber identification scaling method and system
CN102401730A (en) Self-organized optical fiber cable identification instrument

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C02 Deemed withdrawal of patent application after publication (patent law 2001)
WD01 Invention patent application deemed withdrawn after publication

Application publication date: 20120801