CN201983851U - Bireflection delayed type locatable all-fiber vibration sensor - Google Patents
Bireflection delayed type locatable all-fiber vibration sensor Download PDFInfo
- Publication number
- CN201983851U CN201983851U CN2010205844526U CN201020584452U CN201983851U CN 201983851 U CN201983851 U CN 201983851U CN 2010205844526 U CN2010205844526 U CN 2010205844526U CN 201020584452 U CN201020584452 U CN 201020584452U CN 201983851 U CN201983851 U CN 201983851U
- Authority
- CN
- China
- Prior art keywords
- fiber
- sides
- fiber coupler
- bireflection
- vibration sensor
- 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.)
- Expired - Fee Related
Links
Images
Landscapes
- Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
Abstract
The utility model discloses a bireflection delayed type locatable all-fiber vibration sensor, which belongs to the technical field of fiber vibration sensors and is mainly and technically characterized in that: lights sent out by a light source are divided into two paths by a shunt and enter two sides of a fiber coupling; two ends of a sensing fiber are connected with one port at the two sides of the fiber coupling; two optical detection modules are arranged at the two sides of the fiber coupling; one ends of two delay fibers are connected with one port at the two sides of the fiber coupling; and the other ends of the two delay fibers are connected with a reflector. The technical problem that the location of a vibration event can not be judged in the prior art during vibration detection is solved; and the influences on a system caused by the factors like temperature shift of devices can be better eliminated; therefore, the system has better sensitivity and stability.
Description
Technical field
The utility model relates to the distributed optical fiber vibration sensing technical field, but relates in particular to location type distributed optical fiber vibration sensing technical field.
Background technology
Optical fibre vibration sensor because its detection range is long, response speed is fast, highly sensitive, particularly self non-radiating electromagnetic wave is not subjected to the advantage of essential safety such as electromagnetic interference (EMI) yet, has obtained in fields such as safety monitorings using widely.
At present, interferometric sensor is mainly based on following a few class technology: Sagnac interference technique, M-Z (Mach-Zehnder) interference technique, Michelson interference technique and Fabry-Peort interference technique.Interferometric sensor is mainly used to do vibration detection, but this technology can't be judged the position that vibration event takes place when doing vibration detection, and this uses to safety monitoring and brings very big inconvenience.The utility model proposes a kind of novel locate mode optical fibre vibration sensor, this sensor can be judged the position that vibration event takes place for this reason.
Summary of the invention
The purpose of this utility model is to overcome the shortcoming and defect of prior art, provides a kind of bireflection delaying type can locate full optical fibre vibration sensor, and this sensor can be judged the position that vibration event takes place.
The purpose of this utility model is achieved in that a kind of bireflection delaying type can locate full optical fibre vibration sensor, comprise light source, shunt, fiber coupler, the photodetection module, sensor fibre, postpone optical fiber and reflection unit, it is characterized in that, the light that light source sends is divided into the both sides that two-way enters fiber coupler by shunt, the two ends of sensor fibre connect a port of fiber coupler both sides, two photodetection modules are positioned at the both sides of fiber coupler, and two port other ends that postpone optical fiber one end connection fiber coupler both sides connect a reflection unit.
Shunt can be the device that optical fiber circulator or fiber coupler etc. have the beam split function.
Bireflection delaying type according to said structure can be located full optical fibre vibration sensor, the light that light source sends is divided into two-way through shunt and enters the fiber coupler left and right sides respectively, wherein, the light that enters from the fiber coupler right side can form interference in the photodetection module on right side, and the light that enters from the fiber coupler left side can form interference in the photodetection module in left side.
When the external world has vibration signal to act on sensor fibre, will cause the sensor fibre variations in refractive index, and then cause the variation of phase of light wave.Vibration signal to be detected is mainly extraneous gradual pressure signal and abnormal disturbances signal, and these two kinds of signals in fact all are that sensor fibre is produced the pressure effect.Do the time spent when optical fiber is under pressure, its variations in refractive index is:
Wherein P is a pressure, p
eBe strain optical coefficient, E is quartzy Young modulus.The phase change that is caused light wave by variations in refractive index is accordingly:
Wherein λ is an optical wavelength, and L is a sensor fibre length.
The detected light intensity signal of detector then can be write as:
I wherein
1, I
2Be the transmission light intensity in two reciprocity light paths of interferometer sensor fibre,
The expression disturbing signal acts on modulation phase potential difference (the Δ φ that the two-way light path produces on the sensor fibre
1-Δ φ
2),
Initial phase difference for two-way light.
As shown in Figure 1, when the extraneous vibration signal acts on sensor fibre, light two photodetection modules about both direction transfers to the left and right respectively.Detect relatively two photodetection modules and detect the position that the obvious interference fringe mistiming can judge that vibration event takes place.Suppose the oscillation point apart from fiber coupler left side port L1 rice, the needed time is t1, and apart from fiber coupler right side port L2 rice, the needed time is t2.The location Calculation formula is:
L1+L2＝L
L1-L2＝ΔtV
Finally obtain
L is the sensor fibre total length in the formula; Δ t is the mistiming of two-way sense light arrival detector, Δ t=t2-t1; V is the transmission speed of light in optical fiber.
According to above-mentioned formula and can obtain the position in oscillation point, thus the location of realizing full optical fibre vibration sensor.
Described reflection unit can be a kind of in catoptron or the fiber end face plating reflectance coating.
Compared to prior art, the beneficial effects of the utility model are:
The utility model proposes a kind of bireflection delaying type and can locate full optical fibre vibration sensor, this sensor can be judged the position that vibration event takes place.This sensor can better be eliminated because the influence that factors such as device temperature drift cause system makes system have better sensitivity and stability according to the design of reciprocity optical interference circuit.In addition, the optical component that this device optical interference circuit adopts, have simple in structure, volume is little, in light weight, characteristics such as be convenient to install, cost is low.
Description of drawings
Fig. 1 is an embodiment one described in the utility model.
Fig. 2 is an embodiment two described in the utility model.
Embodiment
Further specify concrete implementation step of the present utility model below in conjunction with accompanying drawing.
Embodiment 1: as Fig. 1, light source 1 links to each other with 2 * 2 fiber couplers 2, two output terminals of 2 * 2 fiber couplers 2 are connected to the both sides port of 4 * 4 fiber couplers 3, the two ends of sensor fibre 4 connect a port of 4 * 4 fiber couplers, 3 both sides, photodetection module 9 and photodetection module 10 lay respectively at the both sides of 4 * 4 fiber couplers 3, delay optical fiber 7 is connected a port of 4 * 4 fiber couplers, 3 both sides with delay optical fiber 5 one ends, the other end connects a catoptron 8 and catoptron 6.
The light that light source 1 sends is divided into two-way through 2 * 2 fiber couplers 2 and enters 4 * 4 fiber couplers, 3 left and right sides respectively, wherein, the light that enters from 4 * 4 fiber couplers, 3 right sides can form interference in photodetection module 10, and the light that enters from 4 * 4 fiber couplers, 3 left sides can form interference in photodetection module 9.
When the external world has vibration signal to act on sensor fibre 4, will cause sensor fibre 4 variations in refractive index, and then cause the variation of phase of light wave.Vibration signal to be detected is mainly extraneous gradual pressure signal and abnormal disturbances signal, and these two kinds of signals in fact all are that sensor fibre 4 is produced the pressure effect.
When the extraneous vibration signal acts on sensor fibre 4, light respectively to the left and right both direction transfer to photodetection module 9 and photodetection module 10.Detect relatively two photodetection modules and detect the position that the obvious interference fringe mistiming can judge that vibration event takes place.Suppose oscillation point distance 4 * 4 fiber couplers 3 left side port L1 rice, the needed time is t1, distance 4 * 4 fiber couplers 3 right side port L2 rice, and the needed time is t2.The location Calculation formula is:
L1+L2＝L
L1-L2＝ΔtV
Finally obtain
L is sensor fibre 4 total lengths in the formula; Δ t is the mistiming of two-way sense light arrival detector, Δ t=t2-t1; V is the transmission speed of light in optical fiber.
According to above-mentioned formula and can obtain the position in oscillation point, thus the location of realizing full optical fibre vibration sensor.
Embodiment 2: as shown in Figure 2, light source 1 links to each other with 2 * 2 fiber couplers 2, an output terminal of 2 * 2 fiber couplers 2 is connected the input end of fiber coupler 11, another output terminal is connected the input end of fiber coupler 12, photodetection module 9 and photodetection module 10 are connected to the input end of fiber coupler 11 and fiber coupler 12, the output terminal of fiber coupler 11 and fiber coupler 12 is connected the both sides port of 3 * 3 fiber couplers 3, the two ends of sensor fibre 4 connect a port of 3 * 3 fiber couplers, 3 both sides, delay optical fiber 7 is connected a port of 3 * 3 fiber couplers, 3 both sides with delay optical fiber 5 one ends, the other end connects a catoptron 8 and catoptron 6.
The described bireflection delaying type of present embodiment can be located the positioning principle of full optical fibre vibration sensor and specifically be calculated with above-mentioned embodiment 1.
This sensor can better be eliminated because the influence that factors such as device temperature drift cause system makes system have better sensitivity and stability according to the design of reciprocity optical interference circuit.In addition, the optical component that this device optical interference circuit adopts, have simple in structure, volume is little, in light weight, characteristics such as be convenient to install, cost is low.
Claims (5)
1. a bireflection delaying type can be located full optical fibre vibration sensor, comprise light source, shunt, fiber coupler, photodetection module, sensor fibre, delay optical fiber and reflection unit, it is characterized in that, the light that light source sends is divided into the both sides that two-way enters fiber coupler by shunt, the two ends of sensor fibre connect a port of fiber coupler both sides, two photodetection modules are positioned at the both sides of fiber coupler, article two, postpone the port that optical fiber one end connects the fiber coupler both sides, the other end connects a reflection unit.
2. bireflection delaying type according to claim 1 can be located full optical fibre vibration sensor, it is characterized in that, two output terminals of described shunt directly are connected the input port of fiber coupler both sides, two photodetection modules also are directly connected to the input port of fiber coupler both sides, and fiber coupler is 4 * 4 fiber couplers.
3. bireflection delaying type according to claim 1 can be located full optical fibre vibration sensor, it is characterized in that, two output terminals of described shunt connect a fiber coupler respectively, two photodetection modules also are connected to the input end of these two fiber couplers, and the output terminal of these two fiber couplers is connected to a port of 3 * 3 fiber coupler both sides.
4. bireflection delaying type according to claim 1 can be located full optical fibre vibration sensor, it is characterized in that: described shunt can be a kind of in fiber coupler, the circulator.
5. bireflection delaying type according to claim 1 can be located full optical fibre vibration sensor, it is characterized in that: described reflection unit can be a kind of in catoptron or the fiber end face plating reflectance coating.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010205844526U CN201983851U (en) | 2010-10-29 | 2010-10-29 | Bireflection delayed type locatable all-fiber vibration sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010205844526U CN201983851U (en) | 2010-10-29 | 2010-10-29 | Bireflection delayed type locatable all-fiber vibration sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201983851U true CN201983851U (en) | 2011-09-21 |
Family
ID=44611310
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2010205844526U Expired - Fee Related CN201983851U (en) | 2010-10-29 | 2010-10-29 | Bireflection delayed type locatable all-fiber vibration sensor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201983851U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104457583A (en) * | 2014-11-24 | 2015-03-25 | 上海光亮光电科技有限公司 | Optical fiber length measuring device and method |
| CN112558291A (en) * | 2019-09-26 | 2021-03-26 | 成都理想境界科技有限公司 | Optical fiber scanning device, scanning detection method and scanning display equipment |
-
2010
- 2010-10-29 CN CN2010205844526U patent/CN201983851U/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104457583A (en) * | 2014-11-24 | 2015-03-25 | 上海光亮光电科技有限公司 | Optical fiber length measuring device and method |
| CN112558291A (en) * | 2019-09-26 | 2021-03-26 | 成都理想境界科技有限公司 | Optical fiber scanning device, scanning detection method and scanning display equipment |
| CN112558291B (en) * | 2019-09-26 | 2024-03-05 | 成都理想境界科技有限公司 | Optical fiber scanning device, scanning detection method and scanning display equipment |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101839759B (en) | Few-mode fiber oblique raster-based vibration sensing system | |
| CN102168808B (en) | Distributed optical fiber vibration sensor | |
| CN102636217B (en) | Sensing device based on joint detection of Brillouin optical time domain analysis and Mach-Zehnder interference | |
| CN103090813B (en) | A kind of high resolving power sensor-based system based on OFDR systematic survey beat length of polarization maintaining optical fiber and strain | |
| CN100338449C (en) | Temperature sensor of polarization-preserving fiber in reflection type | |
| JP6763567B2 (en) | Fiber optic sensor | |
| CN101706329B (en) | Optical fiber temperature sensor | |
| CN103063872A (en) | Highly-reliable fiber bragg grating acceleration sensor with function of automatical temperature supplementing | |
| CN105716755A (en) | Sensitivity enhanced sensor based on Loyt-Sagnac interferometer | |
| CN102313141A (en) | Optical fiber vibration sensing system for pipeline leakage detection | |
| CN100357742C (en) | Acceleration sensor | |
| CN106768398A (en) | The method of testing and device of a kind of source phase noise | |
| CN101581586B (en) | Distributed optical fiber sagnac positioning sensor inhibiting dead zone of sensor | |
| CN111308125B (en) | Acceleration detection method based on optical fiber Sagnac interferometer and acceleration meter | |
| CN201983851U (en) | Bireflection delayed type locatable all-fiber vibration sensor | |
| CN202119528U (en) | Full optical path symmetric positioning-capable all-fiber vibration sensor | |
| CN101458100A (en) | Demodulation system of FBG sensor and demodulation method thereof | |
| CN201373781Y (en) | Semiconductor absorption optical fiber temperature detection device | |
| CN206709787U (en) | A kind of double chirp gratings strain demodulating system based on piezoelectric ceramics | |
| CN102003993A (en) | Double-reflection delay type locatable all optical fiber vibrating sensor | |
| CN103234590A (en) | Underground optical fiber flow sensor in oil field | |
| CN102162750A (en) | All-path symmetric type positioning all-fiber vibration sensor | |
| CN103134627B (en) | Temperature insensitive stress sensor based on low birefringence polarization maintaining fiber loop mirror (PM-FLM) | |
| CN101025845A (en) | Perimeter defense optical fiber sensor | |
| CN103134776A (en) | Liquid refractive index absolute measurement sensor based on D-type polarization maintaining optical fibre |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20110921 Termination date: 20141029 |
|
| EXPY | Termination of patent right or utility model |