CN201464025U - Fiber grating acoustic sensor - Google Patents
Fiber grating acoustic sensor Download PDFInfo
- Publication number
- CN201464025U CN201464025U CN2009200292470U CN200920029247U CN201464025U CN 201464025 U CN201464025 U CN 201464025U CN 2009200292470 U CN2009200292470 U CN 2009200292470U CN 200920029247 U CN200920029247 U CN 200920029247U CN 201464025 U CN201464025 U CN 201464025U
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- fiber grating
- sonic transducer
- fiber
- grating
- coupling mechanism
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Abstract
The utility model discloses a fiber grating acoustic sensor. The fiber grating acoustic sensor converts acoustic vibration signals into modulated optical signals to be transmitted by the optical fiber and then demodulates the modulated optical signals into electric signals. The fiber grating acoustic sensor has the advantages of rapid reaction speed, large demodulation range, high demodulation precision, simple process of the system, low cost, convenient use, and the like. A transaudient probe is connected with the light source through a coupler which is connected with a linear bevel filter; the linear bevel filter is connected with a demodulation circuit which is connected with a speaker; the transaudient probe mainly comprises a shell, a cantilever and a fiber grating, wherein one end of the cantilever with constant strength is fixed on the shell and the other end is in a free state; the sensor grating is attached on the lower surface along the axle of the cantilever with constant strength and is connected with the coupler through a transmission fiber; and a pressure inlet is left in the housing.
Description
Technical field
The utility model relates to a kind of fiber grating sonic transducer, it makes grating centre wavelength change with sound by the vibration of equi intensity cantilever, belongs to fiber grating sound sensor field.
Background technology
At special dimensions such as colliery, oil fields, the application of traditional electric class sonic transducer is restricted at present.Optical fiber has that anti-electromagnetic interference capability is strong, volume is little, simplicity of design, highly sensitive, advantage such as the loss of optical fiber own is low and corrosion-resistant, high temperature resistant, high pressure resistant, safe and reliable, has overcome the deficiency of electric class microphone, has been subjected to extensive concern both domestic and external.Especially fiber grating also has the measuring accuracy height except that the above-mentioned advantage with optical fiber, is convenient to networking, and distinct advantages such as Wavelength-encoding have been widely used in the measurement of physical parameters such as temperature, ess-strain and pressure.
But present optical fiber mike technique is ripe not enough, and existing optical fiber microphone mainly contains based on the Y type microphone of reflecting film structure and interfere type microphone.Reflective y-type optical fiber microphone is very high to the reflectivity and the elastic modulus requirement of reflectance coating, and measurement means is complicated with device, and optical power loss is big, and sensitivity is low, and cost is higher, and can not detect the following low frequency signal of 250Hz; Interference-type optical fiber sensing technology comparative maturity, and highly sensitive, but be affected by the external environment easily.Therefore, their widespread uses in industrial process have been limited to a great extent.
Summary of the invention
The purpose of this utility model is the deficiency that overcomes above-mentioned optical fiber microphone, a kind of fiber grating sonic transducer is provided, it is a kind ofly to convert voice signal the optical signalling of modulation to, and by Optical Fiber Transmission, the light signal of modulation is demodulated to the device of electric signal again, it is fast to have reaction velocity, the demodulation scope is big, the demodulation accuracy height, and system process is simple, advantages such as cost is low, and is easy to use.
For achieving the above object, the technical solution adopted in the utility model is:
A kind of fiber grating sonic transducer, it comprises transaudient probe, transaudient probe is connected with light source by coupling mechanism, coupling mechanism also is connected with linear hypotenuse wave filter simultaneously, linear hypotenuse wave filter is connected with demodulator circuit, demodulator circuit is connected with loudspeaker, described transaudient probe comprises shell, semi-girder and fiber grating, equi intensity cantilever one end is fixed on the shell, the other end is a free state, the sensor grating is attached to its lower surface along the axis of equi intensity cantilever, and is connected with coupling mechanism by Transmission Fibers; Shell leaves the entrance pressure mouth simultaneously.
Described sensor grating is an optical fiber Bragg raster, and centre wavelength is 1549.22nm, and three dB bandwidth is 0.21nm.
Described equi intensity cantilever is that thickness is the carbon fibre material of 0.5mm.
Described sensor grating is attached to its lower surface by the agent of epoxy resin gluing along the axis of equi intensity cantilever.
Described entrance pressure mouth is over against the sensor grating, and the two is provided with at interval.
Described linear hypotenuse wave filter is based on the CWDM of filter sheet structure, and the reflection end of its input end and coupling mechanism is connected, and output terminal is connected with demodulator circuit.
Described linear hypotenuse wave filter hypotenuse center is 1550nm, and the sideband slope is 10dB/nm.
Described light source is the ASE wideband light source.
Described coupling mechanism is 2 * 2 fusion vertebral pulling type coupling mechanisms based on single-mode fiber, and splitting ratio is 50/50.
The utility model provides a kind of novel optical fiber microphone, and transaudient probe is made up of the beam of uniform strength, sensor grating and shell, and equi intensity cantilever is the acoustic pressure sensitive element, and the one end is fixed on the shell, and the other end is in free state.Fiber grating is as sensing element, is attached to its lower surface along the axis of equi intensity cantilever.Shell is a dielectric resin material, and upper surface leaves the entrance pressure mouth, and acoustic pressure can be acted on the semi-girder.
The utility model utilizes elasto-optical effect that acoustic pressure in the air produces the grating effect and elastic effect to the grating reflection wavelength fiber grating microphone that carried out modulation design, the light that wideband light source sends enters the sensor grating through coupling mechanism, equi intensity cantilever occurs bending and deformation under the acoustic pressure effect, cause the variation of sensor grating centre wavelength, the reflected light that carries voice signal enters photodetector through coupling mechanism and linear hypotenuse wave filter, when sensor grating centre wavelength changed, the light intensity that enters detector also can change.Demodulator circuit amplifies and filtering the electric signal of photodetector, can obtain the intensity and the frequency of voice signal, finally voice signal can be reduced through loudspeaker.
As can be seen from the above technical solutions, the utility model is based on full optical signal design, and transaudient probe does not have electron device, therefore has favorable waterproof property, does not have electric spark hidden danger, and anti-electromagnetic interference (EMI).Simultaneously, the utility model is convenient to networking, and can form quasi-distributed array.
The present invention has following characteristics and advantage:
(1) the utility model is simple in structure, and manufacture craft is simple, and sensing element is the normal optical fiber Bragg grating, and crucial making step sticks on the sensor grating along beam of uniform strength axis lower surface, and makes that the sensor grating is stressed evenly to get final product.
(2) the utility model is except circuit of light sources and demodulator circuit, and other parts all do not need electric signal, has realized separating of light signal and electric signal, can guarantee production safety.
(3) the utility model is cheap, practical device be common optical device, mature production technology, price is lower.
Description of drawings
Fig. 1 is the utility model fiber grating sonic transducer structural representation;
Fig. 2 is the voice signal excitation time-domain diagram that the utility model fiber grating sonic transducer detects;
Fig. 3 is the voice signal excitation frequency domain figure that the utility model fiber grating sonic transducer detects.
Wherein, 1. transaudient probe, 2. shell, 3. entrance pressure mouth, 4. equi intensity cantilever, 5. sensor grating, 6. Transmission Fibers, 7. light source, 8. coupling mechanism, 9. linear hypotenuse wave filter, 10. demodulator circuit, 11. loudspeakers.
Embodiment
Below in conjunction with accompanying drawing and embodiment the utility model is described further.
The fiber grating sonic transducer.In order to introduce the utility model in detail, will be described in detail specific embodiments in conjunction with the accompanying drawings:
Structural representation as shown in Figure 1, fiber grating sonic transducer described in the utility model comprises transaudient probe 1, light source 7, coupling mechanism 8, linear hypotenuse wave filter 9, demodulator circuit 10 and loudspeaker 11. transaudient probes 1 are by equi intensity cantilever 4, sensor grating 5 and shell 2 are formed. and equi intensity cantilever 4 one ends are fixed on the shell 2, the other end is in free state, sensor grating 5 is attached to its lower surface along the axis of equi intensity cantilever 4, and be connected with coupling mechanism 8 by Transmission Fibers 6, the while shell leaves entrance pressure mouth 3. light paths of the present utility model and is connected to: light source 7 is connected with the input end of coupling mechanism 8, the output terminal of coupling mechanism 8 is connected with transaudient probe 1, the reflector port of coupling mechanism 8 is connected with the input end of linear hypotenuse wave filter 9, the output terminal of linear hypotenuse wave filter 9 directly is connected with photodetector, and demodulator circuit 10 output ports directly are connected with loudspeaker 11.
When around the utility model voice signal being arranged, sound pressure signal enters transaudient probe by the entrance pressure mouth 3 on the shell 2, on the effect ability equi intensity cantilever 4.Equi intensity cantilever 4 occurs bending and deformation with acoustic pressure, and the intensity of distortion is relevant with the intensity and the frequency of sound pressure signal with frequency.Equi intensity cantilever 4 causes the variation of stickup sensor grating 5 grid cycle thereon, and then causes the variation of centre wavelength.The reflected light of sensor grating 5 carries voice signal and propagates into linear hypotenuse wave filter 9, and wavelength signals is changed into light intensity signal.The photodetector of demodulator circuit 10 is transformed into electric signal with the light intensity signal that detects, and through processing and amplifying, finally by loudspeaker 11 voice signal is reduced.
Concrete manufacturing process of the present utility model is: at first, carbon fibre material is made equi intensity cantilever 4, and its characteristic is analyzed; Then, sensor grating 5 is sticked on its lower surface along equi intensity cantilever 4 axis directions, will guarantee during stickup that sensor grating 5 and equi intensity cantilever 4 combine closely, will guarantee that simultaneously sensor grating 5 is stressed evenly; Then, the equi intensity cantilever 4 of pasting sensor grating 5 is fixed on the sensor outer housing 2, and guarantees that equi intensity cantilever 4 is parallel with the one side that shell 2 leaves entrance pressure mouth 3; Then, encapsulation process is carried out at the position of transaudient probe 1 except that entrance pressure mouth 3; At last light source 7, coupling mechanism 8, linear hypotenuse wave filter 9 and demodulator circuit 10 are packaged together.
In order to realize the purpose of this utility model, 300Hz and 4KHz simple signal test experiments have been carried out at first respectively.The setting signal source is that frequency is the sinusoidal signal of 300Hz, 4KHz respectively, detects the single-frequency response characteristic of this microphone in the people speaks audio frequency range.The waveform of the utility model output has good signal-to-noise.This explanation the utility model is a highly sensitive empirical model, and has generality.Subsequently, detect the frequency response characteristic of voice signal of the present utility model, this sonic transducer has extraordinary frequency response in the frequency range of 0～4kHz, can transmit voice signal undistortedly.
In actual engineering, be placed under the coal mine transaudient probe 1 or the field produces scene, the miscellaneous part of this utility model all is placed in the pulpit, transmits light signal and returns the reflectance spectrum of the sensor grating 5 that carries voice signal by optical cable.Therefore this sonic transducer situ part does not need electric signal, can effectively guarantee production safety.
Claims (9)
1. fiber grating sonic transducer, it comprises transaudient probe, transaudient probe is connected with light source by coupling mechanism, coupling mechanism also is connected with linear hypotenuse wave filter simultaneously, linear hypotenuse wave filter is connected with demodulator circuit, demodulator circuit is connected with loudspeaker, it is characterized in that, described transaudient probe comprises shell, semi-girder and fiber grating, equi intensity cantilever one end is fixed on the shell, the other end is a free state, and the sensor grating is attached to its lower surface along the axis of equi intensity cantilever, and is connected with coupling mechanism by Transmission Fibers; Shell leaves the entrance pressure mouth simultaneously.
2. fiber grating sonic transducer as claimed in claim 1 is characterized in that, described sensor grating is an optical fiber Bragg raster, and centre wavelength is 1549.22nm, and three dB bandwidth is 0.21nm.
3. fiber grating sonic transducer as claimed in claim 1 is characterized in that, described equi intensity cantilever is that thickness is the carbon fibre material of 0.5mm.
4. fiber grating sonic transducer as claimed in claim 1 is characterized in that, described sensor grating is attached to its lower surface by the agent of epoxy resin gluing along the axis of equi intensity cantilever.
5. fiber grating sonic transducer as claimed in claim 1 is characterized in that, described entrance pressure mouth is over against the sensor grating, and the two is provided with at interval.
6. fiber grating sonic transducer as claimed in claim 1 is characterized in that, described linear hypotenuse wave filter is based on the CWDM of filter sheet structure, and the reflection end of its input end and coupling mechanism is connected, and output terminal is connected with demodulator circuit.
7. as claim 1 or 6 described fiber grating sonic transducers, it is characterized in that described linear hypotenuse wave filter hypotenuse center is 1550nm, the sideband slope is 10dB/nm.
8. fiber grating sonic transducer as claimed in claim 1 is characterized in that, described light source is the ASE wideband light source.
9. fiber grating sonic transducer as claimed in claim 1 is characterized in that, described coupling mechanism is 2 * 2 fusion vertebral pulling type coupling mechanisms based on single-mode fiber, and splitting ratio is 50/50.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009200292470U CN201464025U (en) | 2009-07-10 | 2009-07-10 | Fiber grating acoustic sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009200292470U CN201464025U (en) | 2009-07-10 | 2009-07-10 | Fiber grating acoustic sensor |
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| CN201464025U true CN201464025U (en) | 2010-05-12 |
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| CN2009200292470U Expired - Fee Related CN201464025U (en) | 2009-07-10 | 2009-07-10 | Fiber grating acoustic sensor |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102169272A (en) * | 2011-04-08 | 2011-08-31 | 山东大学 | Method for demodulating wavelength of fiber grating by utilizing linear tilt filter |
| WO2013007071A1 (en) * | 2011-07-12 | 2013-01-17 | Chen Xiangli | Sensor for probing geological disaster and monitoring and alarming device thereof |
| CN103269249A (en) * | 2013-06-05 | 2013-08-28 | 辽宁卓异装备制造有限公司 | Mining optical fiber type audio acquisition device and mining audio communication system |
| CN111854922A (en) * | 2020-07-29 | 2020-10-30 | 中国人民解放军国防科技大学 | High-sensitivity one-dimensional plane cantilever beam type optical fiber sensor and three-dimensional vector hydrophone |
| CN111879970A (en) * | 2020-08-31 | 2020-11-03 | 防灾科技学院 | Temperature insensitive FBG acceleration sensor and method based on strain chirp effect |
| CN112033908A (en) * | 2020-07-30 | 2020-12-04 | 大连理工大学 | Single-light-source optical fiber photoacoustic gas sensing system and method |
-
2009
- 2009-07-10 CN CN2009200292470U patent/CN201464025U/en not_active Expired - Fee Related
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102169272A (en) * | 2011-04-08 | 2011-08-31 | 山东大学 | Method for demodulating wavelength of fiber grating by utilizing linear tilt filter |
| WO2013007071A1 (en) * | 2011-07-12 | 2013-01-17 | Chen Xiangli | Sensor for probing geological disaster and monitoring and alarming device thereof |
| CN103269249A (en) * | 2013-06-05 | 2013-08-28 | 辽宁卓异装备制造有限公司 | Mining optical fiber type audio acquisition device and mining audio communication system |
| CN111854922A (en) * | 2020-07-29 | 2020-10-30 | 中国人民解放军国防科技大学 | High-sensitivity one-dimensional plane cantilever beam type optical fiber sensor and three-dimensional vector hydrophone |
| CN112033908A (en) * | 2020-07-30 | 2020-12-04 | 大连理工大学 | Single-light-source optical fiber photoacoustic gas sensing system and method |
| CN111879970A (en) * | 2020-08-31 | 2020-11-03 | 防灾科技学院 | Temperature insensitive FBG acceleration sensor and method based on strain chirp effect |
| CN111879970B (en) * | 2020-08-31 | 2022-06-24 | 防灾科技学院 | Temperature insensitive FBG acceleration sensor and method based on strain chirp effect |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20100512 Termination date: 20120710 |