CN205692299U - A kind of perimeter security system - Google Patents
A kind of perimeter security system Download PDFInfo
- Publication number
- CN205692299U CN205692299U CN201620521673.6U CN201620521673U CN205692299U CN 205692299 U CN205692299 U CN 205692299U CN 201620521673 U CN201620521673 U CN 201620521673U CN 205692299 U CN205692299 U CN 205692299U
- Authority
- CN
- China
- Prior art keywords
- bonder
- sensor fibre
- signal
- fibre
- optical
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Burglar Alarm Systems (AREA)
Abstract
This utility model embodiment provides a kind of perimeter security system, including: light source, bonder, light path adjust parts, sensor fibre and photodetector；The outfan of light source is connected with the first end of bonder, and the second end and the 3rd end of bonder are connected with the two ends of sensor fibre respectively, forms a Sagnac loop；Light path adjusts between the second end and the sensor fibre that parts are located at bonder, and for when the sensor fibre of Sagnac loop is disturbed, increase is through the transmission distance of a road optical signal of dither modulation；Photodetector is connected with the 4th end of bonder, for receiving the interference light signal that in sensor fibre, the two ways of optical signals of transmission is formed at bonder, and interference light signal is converted into voltage signal.This utility model embodiment can solve the problem that the problem of the blind area that defence area occurs, reduces failing to report of system.
Description
Technical field
This utility model relates to optical fiber and technical field of security and protection, particularly relates to a kind of perimeter security system.
Background technology
Along with the development of science and technology, the importance of safety precaution is the most aobvious prominent, and crucial place such as some garden, railways etc. etc. is to peace
The demand of anti-technology is more and more higher.
At present, the safety-protection system for defence area type develops rapidly both at home and abroad, and optics based on various fibre optic interferometers are tied
Structure research also gets more and more, and such as, is applied in safety-protection system by Sagnac interferometer optical texture, but at safety-protection system
In, when the Sagnac loop midpoint owing to being formed is disturbed, there is blind area, causes in the defence area easily making safety-protection system defend
Failing to report of existing system, causes the biggest puzzlement to monitoring personnel.
Utility model content
In view of this, this utility model embodiment provides a kind of perimeter security system, to solve the blind area of defence area appearance
Problem, reduces failing to report of system.
This utility model embodiment provides a kind of perimeter security system, including: light source, bonder, light path adjustment parts,
Sensor fibre and photodetector；
The outfan of described light source is connected with the first end of described bonder, and the second end and the 3rd end of described bonder divide
It is not connected with the two ends of sensor fibre, forms a Sagnac loop；
Described light path adjusts parts and is located between the second end of bonder and described sensor fibre, for as described Sa Genai
When the sensor fibre of gram ring is disturbed, increase the transmission distance of a road optical signal through dither modulation；
Described photodetector is connected with the 4th end of bonder, for receiving the two ways of optical signals of transmission in sensor fibre
The interference light signal formed at bonder, and described interference light signal is converted into voltage signal.
Further, described light path adjusts parts is fiber optic loop.
Further, described fiber optic loop is the annulus that Transmission Fibers is formed.
Further, described system also includes: the first polarization maintaining optical fibre and the second polarization maintaining optical fibre；
Described first polarization maintaining optical fibre is located between the second end of described bonder and light path adjustment parts；Described second protects partially
Optical fiber is located between described bonder the 3rd end and described sensor fibre, and polarisation protected by described first polarization maintaining optical fibre and described second
Fibre, the optical signal polarization direction being used to keep transmission is constant.
Further, described system also includes signal processor and warning system；
Described signal processor is connected with described photodetector and described warning system respectively, is used for receiving photodetection
The voltage signal of device output, and send control signal according to described voltage signal to described warning system；
Described warning system, for reporting to the police according to the control signal received.
Further, when wind, rain or sound wave carry out disturbance to sensor fibre, the interference light that described photodetector receives
Signal intensity is 0, and the voltage signal of output is 0；Described signal processor, is additionally operable to when the electricity receiving photodetector output
When pressure signal is 0, controls described warning system and do not report to the police.
Further, described system also includes that fence, described fence are used for fixing described sensor fibre.
Further, described sensor fibre is single-core fiber or twin-core fiber.
Further, when described sensor fibre is twin-core fiber, described system also includes tail end protection device；Described tail
End protection device is located on described fence, for protecting sensor fibre.
Further, described tail end protection device includes shell and optical fiber heat-shrink tube；Described optical fiber heat-shrink tube is located at shell
In, it is used for fixing and connect described sensor fibre.
This utility model embodiment provide a kind of perimeter security system, by arrange light path adjust parts, add through
The transmission distance of one road optical signal of dither modulation, makes the two ways of optical signals returning to bonder before disturbance and phase place after disturbance
Difference changes so that photodetector can detect the change of interference light signal, prevents from occurring in defence area blind area, reduces system
Failing to report of system.
Accompanying drawing explanation
The detailed description that non-limiting example is made made with reference to the following drawings by reading, of the present utility model
Other features, objects and advantages will become more apparent upon:
Fig. 1 is the structure chart of a kind of perimeter security system that this utility model embodiment provides；
Fig. 2 is the structure chart of the another kind of perimeter security system that this utility model embodiment provides；
Fig. 3 is the structure chart of the fiber optic interferometric box that this utility model embodiment provides；
Fig. 4 is the structure chart of the another kind of perimeter security system that this utility model embodiment provides；
Fig. 5 is the structure chart of the tail end protection device that this utility model embodiment provides.
Detailed description of the invention
The utility model is described in further detail with embodiment below in conjunction with the accompanying drawings.It is understood that herein
Described specific embodiment is used only for explaining this utility model, rather than to restriction of the present utility model.Further need exist for
Bright, for the ease of describing, accompanying drawing illustrate only the part relevant to this utility model rather than full content.
Fig. 1 is the structure chart of a kind of perimeter security system that this utility model embodiment provides, the circumference security protection in this case
System is applicable to place crucial to railway, garden, residential block etc. and is monitored.As it is shown in figure 1, described perimeter security system bag
Include: light source 101, bonder 102, light path adjust parts 103, sensor fibre 104 and photodetector 105.
Wherein, the outfan of light source 101 is connected with the first end a of bonder 102, the second end b and the 3rd of bonder 102
Hold the c two ends respectively with sensor fibre 104 to be connected, form a Sagnac loop；Light path adjusts parts 103 and is located at bonder
Between second end b and the sensor fibre 104 of 102, for when the sensor fibre 104 of Sagnac loop is disturbed, increase warp
The transmission distance of one road optical signal of dither modulation；Photodetector 105 is connected with the 4th end d of bonder 102, is used for receiving
The interference light signal that in sensor fibre 104, the two ways of optical signals of transmission is formed at bonder 102, and interference light signal is changed
Become voltage signal.
In the present embodiment, adjust parts by arranging light path between the second end and the sensor fibre of bonder, increase
Through the transmission distance of a road optical signal of dither modulation, return to the two ways of optical signals of the bonder phase before disturbance and after disturbance
Potential difference changes so that photodetector can detect the change of interference light signal, blind area occurs, reach in preventing defence area
The purpose that minimizing system is failed to report.
Optionally, light source 101 uses FP coaxial laser or DFP coaxial laser, and uses the encapsulation of SFP module.This
In embodiment, light source uses FP coaxial laser or DFP coaxial laser Costco Wholesale low, it is possible to reduce the system of whole system
Make cost.Wherein, optionally, the breadth of spectrum line of light source is 4nm, makes photodetector accurately detect interference light signal, reduces
Failing to report of system.
Optionally, bonder 102 is 2 × 2 bonders, the optical signal that can be sent by light source 101 by 2 × 2 bonders
Being coupled into two ways of optical signals, in Fig. 1, the direction of arrow is the direction of the optical signal through bonder 102 coupling.
Further, optionally, it is fiber optic loop that light path adjusts parts 103, and fiber optic loop is the annulus that Transmission Fibers is formed.At this
In embodiment, the radius size of fiber optic loop is configured as required, it is possible to make the two ways of optical signals returning to bonder disturb
Phase contrast before Dong, after disturbance produces and changes.Or from saving the angle of material, the radius of fiber optic loop is arranged relatively as far as possible
Little, it is possible to adjust the optical path difference through the two ways of optical signals of dither modulation and return the two ways of optical signals at bonder in disturbance with realization
Before and disturbance after the purpose that changes of phase contrast, and fiber optic loop cost of manufacture is relatively low, it is possible to reduction is whole further
The cost of manufacture of system.Wherein light path adjustment parts 103 are not limited to fiber optic loop, it is also possible to be that other have adjustment through disturbance
The parts of the optical path difference function of the two ways of optical signals of modulation.
On the basis of above-described embodiment, in FIG, described perimeter security system also includes the first polarization maintaining optical fibre 106
With the second polarization maintaining optical fibre 107.Wherein, the second end b and the light path adjustment parts 103 of bonder 102 are located at by the first polarization maintaining optical fibre 106
Between；Second polarization maintaining optical fibre 107 is located between bonder 102 the 3rd end c and sensor fibre 104, the first polarization maintaining optical fibre 106 and
Two polarization maintaining optical fibres 107, the optical signal polarization direction being used to keep transmission is constant.Polarisation is protected by the first polarization maintaining optical fibre and second
Fibre is prevented from the decline of optical signal polarization state, it is ensured that the concordance of interference light signal, the problem failed to report in solution system.
When using the perimeter security system shown in Fig. 1 to carry out security protection, the optical signal that light source 101 sends is through bonder 102
Being divided into two-way, wherein first via optical signal is from the second end b output of bonder 102, adjusts through the first polarization maintaining optical fibre 106, light path
After parts 103, sensor fibre the 104, second polarization maintaining optical fibre 107, the 3rd end c of bonder 102 enter bonder 102.Second
Road optical signal, from the 3rd end c output of bonder 102, adjusts parts through the second polarization maintaining optical fibre 107, sensor fibre 104, light path
103, after the first polarization maintaining optical fibre 106, the second end b of bonder 102 bonder 102 is entered.Two ways of optical signals is at bonder 102
Place forms interference light signal, and interference light signal is received by photodetector 105.When sensor fibre 104 is not by external disturbance
Time, because exporting two ways of optical signals (first via optical signal and second returning once again to bonder 102 respectively from bonder 102
Road optical signal) light path identical, two ways of optical signals interferes cancellation at bonder 102, thus photodetector 105 receive dry
Relating to the intensity of optical signal is 0 or more weak.
In the perimeter security system shown in Fig. 1, adjust parts 103 without arranging light path, then e point is circumference security protection
The midpoint of the Sagnac loop in system.When the midpoint e of Sagnac loop is by external disturbance, first after dither modulation
The light path that the midpoint e of road optical signal and the second road optical signals Sagnac loop returns to bonder 102 respectively is identical, so through disturbing
After dynamic modulation and return to the phase contrast of the first via optical signal at bonder 102 and the second road optical signal and be not changed in, therefore warp
Before interference light signal that first via optical signal after dither modulation and the second road optical signal are formed at bonder and dither modulation
The interference light signal that formed identical (before disturbance and after disturbance the intensity of interference light signal be 0).Therefore photodetector 105 is not
Being capable of detecting when the change of interference light signal, the midpoint e of Sagnac loop becomes the blind area in defence area, and system can not be the most pre-
Report.
After light path being set and adjusts parts 103, as it is shown in figure 1, when the midpoint e of Sagnac loop is by external disturbance
Time, first via optical signal and the second optical signal all can be disturbed modulation, first via optical signal and the phase place of the second road optical signal
All change, and phase place change is identical.So through the first via optical signal of dither modulation and the second road optical signal at Sa Genai
Phase contrast during gram ring midpoint e does not changes.
First via optical signal and the midpoint e of the second road optical signals Sagnac loop after dither modulation return to coupling respectively
The light path of clutch 102 differs, so first via optical signal after dither modulation and the second road optical signal are at bonder 102
Phase contrast compared with before disturbance, there occurs change.Therefore first via optical signal and the second road optical signal after dither modulation exists
The interference light signal formed at bonder 102 is different with the interference light signal formed before dither modulation, therefore photodetector energy
Enough detect the change of interference light signal, it is therefore prevented that the blind area occurred in defence area, decrease failing to report of perimeter security system.
Fig. 2 is the structure chart of the another kind of perimeter security system that this utility model embodiment provides, at above-described embodiment
On the basis of, as in figure 2 it is shown, described perimeter security system also includes that fence 108, fence 108 are used for fixing sensor fibre 104.
Wherein, optionally, sensor fibre 104 is single-core fiber, and perimeter security system uses the form that annular is installed.New in this practicality
In type embodiment, as in figure 2 it is shown, bonder, the first polarization maintaining optical fibre, light path adjustment parts and the second polarization maintaining optical fibre can be set
Put in a device, form fiber optic interferometric box 109.Fig. 3 is the structure chart of fiber optic interferometric box, as shown in Figures 2 and 3, optical fiber
The bonder 102 in box 109 is interfered to be connected with light source 101 and photodetector 105 respectively by the first Transmission Fibers 110, its
In the first Transmission Fibers 110 be the Transmission Fibers of twin-core.Connect light path in fiber optic interferometric box 109 and adjust the single biography of parts 103
Lose fibre 111 and the second polarization maintaining optical fibre 107 is connected with the twin-core in the second Transmission Fibers 115 respectively, the second Transmission Fibers 115
Twin-core two ends with sensor fibre 104 respectively are connected.
It should be noted that exemplary all parts in fiber optic interferometric box is arranged to as shown in Figure 3 of the present embodiment
Connected mode and structure, but the present embodiment simply a kind of example, in other embodiment of this utility model, fiber optic interferometric box
Middle all parts can also is that other connected mode or other structure are arranged, such as, and the first transmission of the twin-core in Fig. 3
Optical fiber 110 can also is that the Transmission Fibers of two singles, or the first Transmission Fibers 110 can be by its of fiber optic interferometric box 109
He exports in face, such as, and the first Transmission Fibers 110 and second Transmission Fibers 115 outbound course on fiber optic interferometric box 109
Identical.In addition, it is necessary to explanation, exemplary by fiber optic interferometric box 109 includes the second Transmission Fibers 115 in Fig. 3, it is used for
By single Transmission Fibers 111 light path adjusted parts 103 and the second polarization maintaining optical fibre 107 respectively with the two ends of sensor fibre 104
Connect, but a kind of example of the present embodiment, in other embodiments of the present utility model, fiber optic interferometric box can not wrap
Include the second Transmission Fibers 115, directly by single Transmission Fibers 111 light path adjusted parts 103 and the second polarization maintaining optical fibre 107 and
The two ends of sensor fibre connect.
On the basis of above-described embodiment, in fig. 2, described perimeter security system also includes signal processor 112 He
Warning system 113；Signal processor 112 is connected with photodetector 105 and warning system 113 respectively, is used for receiving light electrical resistivity survey
Survey the voltage signal of device 105 output, and send control signal according to voltage signal to warning system 113；Warning system 113, uses
In reporting to the police according to the control signal received.Wherein, when wind, rain or sound wave carry out disturbance to sensor fibre, photodetection
The interference light signal intensity that device 105 receives is 0, and the voltage signal of output is 0；Signal processor 112, is additionally operable to when receiving light
When the voltage signal of electric explorer 105 output is 0, controls warning system 113 and do not report to the police.Concrete, due to wind, rain, sound
Ripple is relatively big to sensor fibre 104 zone of action scope, there is multipair symmetrical point on sensor fibre 104, wherein every pair
Symmetrical point is identical to the distance of bonder 102, so coupling through wind, rain, the two ways of optical signals of acoustic perturbation modulation
Interfering cancellation at device 102, the intensity making the interference light signal that photodetector 105 detects is 0, and warning system 113 is not carried out
Report to the police, the situation of anti-locking system wrong report.
When using the perimeter security system shown in Fig. 2 to carry out security protection, if the sensor fibre being installed on fence 108
104 by external disturbance, sensor fibre 104 will have 2 and be disturbed.Such as, as in figure 2 it is shown, work as perimeter security system
In set up light path and adjust after parts, the midpoint of the Sagnac loop of formation is f point, when f point is by external disturbance, then at Sa
Point g point corresponding with f point on lattice Neck ring also can be disturbed, and because f point is the midpoint of Sagnac loop, adjusts through f point disturbance
The interference light signal that the two ways of optical signals of system produces, compared with before disturbance, does not change, but because g point is not Sagnac
The midpoint of ring, through g point dither modulation two ways of optical signals produce interference light signal compared with before disturbance, there occurs change.Institute
The change of interference light signal can be detected with photodetector.Therefore, the light path of increase adjusts parts, solves and there is blind area
Problem, it is possible to reduce system wrong report.
Fig. 4 is the structure chart that this utility model embodiment provides another kind of perimeter security system, with the circumference shown in Fig. 2
Safety-protection system difference is: sensor fibre 104 is twin-core fiber, and perimeter security system uses the linear mode installed, and
And described perimeter security system also includes tail end protection device 114.
As shown in Figure 4, tail end protection device is located on fence 108, for protecting sensor fibre 104.Such as Fig. 5 institute
Showing, optionally, tail end protection device 114 includes shell 1141 and optical fiber heat-shrink tube 1142；Optical fiber heat-shrink tube 1142 is located at shell
In 1141, it is used for fixing and connect sensor fibre 104.
When using the perimeter security system shown in Fig. 4 to carry out security protection, if the sensor fibre 104 being installed on fence is subject to
To disturbance, then the twin-core in sensor fibre 104 will be disturbed simultaneously, and the light path owing to increasing adjusts parts and makes the Sa in system
The midpoint of lattice Neck ring is on a wherein core of sensor fibre 104, then another core at sensor fibre 104 is corresponding with midpoint
Point is not the midpoint of Sagnac loop, so when sensor fibre 104 is by external disturbance, photodetector 105 can be visited
Measure the change of interference light signal, solve the problem that there is blind area, decrease the wrong report of system.
What deserves to be explained is, the exemplary sensor fibre of single is installed on linear fence in the present embodiment
(shown in Fig. 2) or the sensor fibre of twin-core is installed on linear fence (shown in Fig. 3), but the present embodiment is one
Plant example, in other embodiments of the present utility model, the sensor fibre of the sensor fibre of single or twin-core can be installed
In the fence of other shapes, such as circle, rectangle etc., make fence around residential block, garden etc..
It should be noted that in the safety-protection system shown in Fig. 4, the structure of fiber optic interferometric box 109 and the fiber optic interferometric in Fig. 3
The structure of box can be identical, or the fiber optic interferometric box 109 in the safety-protection system shown in Fig. 4 can also be by Fig. 3
Two Transmission Fibers 115 are removed, directly use sensor fibre twin-core respectively with single Transmission Fibers 111 and the second polarization maintaining optical fibre
107 connect, and make the simple in construction of system, save cost of manufacture.
It should be noted that in addition it is also necessary to it is noted that the structural representation of the perimeter security system of Fig. 1-5 offer
In, perimeter security system has many something in common, and its something in common uses identical reference to carry out in every width accompanying drawing
Illustrate, and the identical structure of perimeter security system not all has a detailed description in each detailed description of the invention, art technology
Personnel it should be understood that the mutually isostructural specific descriptions in perimeter security system repeat no more in the description, art technology
Personnel can refer to relevant specific descriptions and understand the perimeter security system of different accompanying drawings.
Note, above are only preferred embodiment of the present utility model and institute's application technology principle.Those skilled in the art's meeting
Understand, this utility model is not limited to specific embodiment here, can carry out for a person skilled in the art various significantly
Change, readjust and substitute without departing from protection domain of the present utility model.Therefore, although by above example to this
Utility model is described in further detail, but this utility model is not limited only to above example, without departing from this reality
In the case of novel design, it is also possible to include other Equivalent embodiments more, and scope of the present utility model is by appended power
Profit claimed range determines.
Claims (10)
1. a perimeter security system, it is characterised in that including: light source, bonder, light path adjust parts, sensor fibre and
Photodetector；
The outfan of described light source is connected with the first end of described bonder, the second end of described bonder and the 3rd end respectively with
The two ends of sensor fibre connect, and form a Sagnac loop；
Described light path adjusts parts and is located between the second end of bonder and described sensor fibre, for when described Sagnac loop
Sensor fibre when being disturbed, increase the transmission distance of a road optical signal through dither modulation；
Described photodetector is connected with the 4th end of bonder, for receiving the two ways of optical signals transmitted in sensor fibre at coupling
The interference light signal formed at clutch, and described interference light signal is converted into voltage signal.
System the most according to claim 1, it is characterised in that it is fiber optic loop that described light path adjusts parts.
System the most according to claim 2, it is characterised in that described fiber optic loop is the annulus that Transmission Fibers is formed.
System the most according to claim 1, it is characterised in that also include: the first polarization maintaining optical fibre and the second polarization maintaining optical fibre；
Described first polarization maintaining optical fibre is located between the second end of described bonder and described light path adjustment parts；Described second protects partially
Optical fiber is located between described bonder the 3rd end and described sensor fibre, and polarisation protected by described first polarization maintaining optical fibre and described second
Fibre, the optical signal polarization direction being used to keep transmission is constant.
System the most according to claim 1, it is characterised in that also include signal processor and warning system；
Described signal processor is connected with described photodetector and described warning system respectively, is used for receiving described photodetection
The voltage signal of device output, and send control signal according to described voltage signal to described warning system；
Described warning system, for reporting to the police according to the described control signal received.
System the most according to claim 5, it is characterised in that when wind, rain or sound wave carry out disturbance to described sensor fibre
Time, the interference light signal intensity that described photodetector receives is 0, and the voltage signal of output is 0；Described signal processor, also
For when the voltage signal receiving the output of described photodetector is 0, controlling described warning system and do not report to the police.
System the most according to claim 1, it is characterised in that also include: fence, described fence is used for fixing described sensing
Optical fiber.
System the most according to claim 7, it is characterised in that described sensor fibre is single-core fiber or twin-core fiber.
System the most according to claim 8, it is characterised in that when described sensor fibre is twin-core fiber, described system
Also include tail end protection device；Described tail end protection device is located on described fence, for protecting described sensor fibre.
System the most according to claim 9, it is characterised in that described tail end protection device includes shell and optical fiber pyrocondensation
Pipe；
Described optical fiber heat-shrink tube is located in described shell, is used for fixing and connect described sensor fibre.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620521673.6U CN205692299U (en) | 2016-06-01 | 2016-06-01 | A kind of perimeter security system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620521673.6U CN205692299U (en) | 2016-06-01 | 2016-06-01 | A kind of perimeter security system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN205692299U true CN205692299U (en) | 2016-11-16 |
Family
ID=57263477
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201620521673.6U Active CN205692299U (en) | 2016-06-01 | 2016-06-01 | A kind of perimeter security system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN205692299U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| 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 |
-
2016
- 2016-06-01 CN CN201620521673.6U patent/CN205692299U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| 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 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN100561144C (en) | Distributed optical fiber vibration sensing method and device | |
| WO2017036304A1 (en) | Distributed optical fiber perimeter security system, and sound restoration system and method | |
| CN101242224B (en) | An optical fiber pipe monitoring system | |
| CN101871809B (en) | Defense area optical fiber distribution type vibration sensor and perimeter alarm system adopting same | |
| US11378423B2 (en) | Long-distance optical cable physical safety monitoring system | |
| CN102721459B (en) | Optical fiber hydrophone array adopting reflective quasi-reciprocity optical path | |
| CN105974172A (en) | All-fiber current transformer based on polarization maintaining fiber temperature sensor | |
| CN106404154A (en) | Optical fiber acoustic wave detection system | |
| CN105825606A (en) | Perimeter security and protection system | |
| CN112525238A (en) | Distributed optical fiber sensing system utilizing Mach-Zehnder interferometer filtering characteristics | |
| CN105371942A (en) | Distributed optical-fiber coal mine rescue positioning system | |
| CN205692299U (en) | A kind of perimeter security system | |
| CN111076803A (en) | High-sensitivity two-dimensional vibration monitoring sensing head | |
| Kepak et al. | Fibre optic portable rail vehicle detector | |
| CN206291958U (en) | Optical fiber acoustic detection system | |
| CN102646308A (en) | Perimeter security system based on single optical fiber and fiber bragg grating of single optical fiber | |
| CN102721458A (en) | Optical fiber hydrophone adopting reflective quasi-reciprocity optical path | |
| CN205483251U (en) | Optic fibre perimeter security protection system light path structure | |
| CN101956567A (en) | Intrinsic safety all-fiber underground monitoring system | |
| CN205003805U (en) | Distributed optical fiber perimeter security protection system and sound reduction system | |
| CN105783996B (en) | It is a kind of to measure sound wave and the fibre optical sensor of pressure simultaneously | |
| CN103777250A (en) | Novel all-optical-fiber perimeter security system | |
| CN110706435A (en) | Optical fiber perimeter intrusion alarm system based on 3 x 3 coupler | |
| CN205786792U (en) | A kind of all-fiber current transformator based on optical fiber temperature sensor | |
| CN203812352U (en) | Long distance optical fiber circumference invasion alarming system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |