CN201852651U - Photoelectric device for distributed optical fiber temperature sensor - Google Patents
Photoelectric device for distributed optical fiber temperature sensor Download PDFInfo
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- CN201852651U CN201852651U CN2010206010112U CN201020601011U CN201852651U CN 201852651 U CN201852651 U CN 201852651U CN 2010206010112 U CN2010206010112 U CN 2010206010112U CN 201020601011 U CN201020601011 U CN 201020601011U CN 201852651 U CN201852651 U CN 201852651U
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Abstract
The utility model relates to a photoelectric device for a distributed optical fiber temperature sensor, which belongs to the technical field of optical fiber sensors. The photoelectric device comprises tail optical fibers of both a first collimator and a second collimator, wherein wavelength-division multiplexing filters are arranged on transmitted light paths of the first collimator and the second collimator respectively; and band-pass filters are arranged on light paths of the two wavelength-division multiplexing filters respectively, wherein a first self-focusing lens and a second self-focusing lens are arranged on transmitted light paths of the two band-pass filters, and a first avalanche photodiode, a second avalanche photodiode and a temperature detecting head are arranged at the focal points of the two self-focusing lenses respectively. The distributed optical fiber temperature sensor can conveniently obtain accurate temperature information through the photoelectric device, and the temperature resolution of the system is further improved.
Description
Technical field
The utility model relates to a kind of electrooptical device, particularly relates to a kind of electrooptical device that is used for distributed optical fiber temperature sensor, belongs to technical field of optical fiber sensing.
Background technology
Since people such as J.P.Dakin in 1985 have successfully realized distributed temperature measuring technology based on Raman scattering first, people have carried out broad research to the various technology that realize distributed fiber temperature sensing, and wherein the distributed sensing technology based on Raman scattering has obtained practical application the most widely.Compare with traditional sensor, distributed optical fiber temperature sensor has the advantage of many brilliances: with optical fiber itself as sensing media, one-shot measurement just can obtain thousands of somes temperature informations along fiber distribution, has realized the measurement of continuous distribution formula, has reduced uncertainty of measurement; Far measuring distance, Measuring Time is short, is fit to remote real-time monitoring; Highly sensitive, the measuring accuracy height, rate of false alarm, rate of failing to report are low; Corrosion-resistant, water-fast, fire-resistant, electromagnetic interference (EMI) is immune, the reliability height, maintenance cost is low.
Ultimate principle based on the distributed optical fiber temperature sensor of Raman scattering is: the end at sensor fibre injects laser pulse, when laser pulse is propagated in optical fiber, owing to interacting, the thermal vibration of fibre core molecule and photon energy exchange takes place, the generation Raman scattering.Specifically, when the part energy of photon passes to the thermal vibration of molecule, will send the long photon of the original laser wave of wavelength ratio, be called Raman's Stokes (Raman Stokes) light; When the part energy of mol ht vibration passes to photon, will send the photon of the original laser wave length of wavelength ratio, be called Raman's anti-Stokes (Raman Anti-Stokes) light.Wherein, Raman's anti-Stokes light is very sensitive to temperature, and Raman's stokes light is to temperature-insensitive, so people demodulate temperature information with Raman's anti-Stokes light usually; And,, adopt Raman's stokes light usually as reference light in order to eliminate the influence of fibre loss and light source power fluctuation.The Raman scattering technology just can be located temperature information, thereby realize distributed fiber temperature sensing in conjunction with optical time domain reflection technology (OTDR, Optical Time Domain Reflectometer).This sensing technology is called as for Raman-DTS (Raman Distributed Temperature Sensing).
One of gordian technique of Raman-DTS is how to isolate Raman's anti-Stokes light and stokes light, and unique wavelength division multiplex device is realized to need design usually.In the process that laser pulse transmits in optical fiber, except meeting produces Raman's anti-Stokes light and stokes light, also can produce Rayleigh scattering light, its wavelength is identical with the laser pulse wavelength of input.And for Raman's anti-Stokes light and stokes light, the Rayleigh scattering light intensity is high a lot; Usually, a strength ratio stokes light Senior Three order of magnitude of Rayleigh scattering light is than high four orders of magnitude of anti-Stokes light.Therefore, extracting stokes light and anti-Stokes light under strong Reyleith scanttering light noise background, and prevent that stokes light and anti-Stokes light from crosstalking mutually, become difficult point, also is core technology.In order accurately to demodulate temperature information, usually to the insulated degree requirement of this wavelength division multiplex device greater than 60dB.
Accompanying drawing 2 is that publication number is the disclosed a kind of principle model figure that are used for the wavelength division multiplex device of distributed optical fiber temperature sensor of CN 101696896 Chinese patent application.Wherein, the 21st, optical circulator, the 22nd, the filter plate of anti-Stokes wavelength, the 23rd, the filter plate of Stokes wavelength.Laser pulse is injected by port one, and outputs to port 2 by optical circulator 21, and port 2 connects sensor fibre; Back-scattering light in the sensor fibre returns port 2, and outputs to the filter plate 22 of anti-Stokes wavelength by optical circulator 21; Anti-Stokes transmittance filter plate 22 is by port 3 outputs; Filtered 22 of stokes light and Rayleigh scattering light reflect, and output to the filter plate 23 of Stokes wavelength, and Stokes transmittance filter plate 23 is by port 4 outputs.Thereby isolate anti-Stokes light and stokes light.The isolation of this wavelength division multiplex device depends primarily on the transmission isolation of two filter plates 22,23, usually such filter plate the transmission isolation about 35dB.Therefore, the isolation of device is difficult to surpass 40dB.
Accompanying drawing 3 is that publication number is the principle model figure that the disclosed another kind of CN 101696896 Chinese patent application is used for the wavelength division multiplex device of distributed optical fiber temperature sensor.Wherein, the 31st, 1X3 bidirectional coupler, the 32nd, the filter plate of anti-Stokes wavelength, the 33rd, the filter plate of Stokes wavelength.Laser pulse is injected by port one, and outputs to port 2 by 1X3 bidirectional coupler 31, and port 2 connects sensor fibre; Back-scattering light in the sensor fibre returns port 2, and by 1X3 bidirectional coupler 31; Leach anti-Stokes light and stokes light respectively with the filter plate 32 of anti-Stokes wavelength, the filter plate 33 of Stokes wavelength, and respectively by port 3 and port 4 outputs.Thereby isolate anti-Stokes light and stokes light.At first, what this wavelength division multiplex device adopted is the 1X3 bidirectional coupler, and (excess loss of 10log (1/9)=9.5dB) has weakened utilizable anti-Stokes light and Stokes light intensity greatly can to introduce about 9.5dB; Secondly, the isolation of device is difficult to surpass 40dB, and reason is the same.
If in distributed optical fiber temperature sensor, use the wavelength division multiplex device of above-mentioned routine, because isolation is not enough, can cause crosstalking mutually of anti-Stokes light and stokes light, and the interference of Rayleigh scattering light, the result is difficult to obtain temperature information and high resolving power accurately, under the serious situation even cause temperature curve distortion, system's cisco unity malfunction.
The utility model content
The purpose of this utility model is to overcome the above-mentioned deficiency of prior art, a kind of electrooptical device that is used for distributed optical fiber temperature sensor with high-isolation, low insertion loss is provided, thereby can directly obtain the electric signal of anti-Stokes light and stokes light accurately, and then can obtain temperature information accurately, improved the temperature resolution and the degree of accuracy of system.
In order to realize utility model purpose of the present utility model, the technical scheme that the utility model provides is as follows:
A kind of electrooptical device that is used for distributed optical fiber temperature sensor, comprise the first collimating apparatus tail optical fiber of importing laser and the second collimating apparatus tail optical fiber of external sensor fibre, the transmitted light path of described first collimating apparatus is provided with the wavelength-division multiplex filter plate of optical maser wavelength, and the transmitted light path of described second collimating apparatus is provided with the wavelength-division multiplex filter plate of anti-Stokes wavelength; The wavelength-division multiplex filter plate reflected light path of described optical maser wavelength is provided with the band pass filter of the Stokes wavelength of pair of parallel arrangement, settle first GRIN Lens on the band pass filter transmitted light path of described two Stokes wavelength, the focus place of described first GRIN Lens settles first avalanche photodide, near the arrangement first temperature detecting head of described first avalanche photodide; The wavelength-division multiplex filter plate of described anti-Stokes wavelength is arranged on the wavelength-division multiplex filter plate transmitted light path of optical maser wavelength the wavelength-division multiplex filter plate transmitted light of optical maser wavelength is reflexed to the position of second collimating apparatus; Settle the band pass filter of anti-Stokes wavelength on the wavelength-division multiplex filter plate transmitted light path of described anti-Stokes wavelength, settle second GRIN Lens on the band pass filter transmitted light path of described anti-Stokes wavelength, the focus place of described second GRIN Lens settles second avalanche photodide, near the arrangement second temperature detecting head of described second avalanche photodide.
During work, laser pulse through the wavelength-division multiplex filter plate transmission of optical maser wavelength, through the wavelength-division multiplex filter plate reflection of anti-Stokes wavelength, is coupled into second collimating apparatus from the tail optical fiber input of first collimating apparatus again, injects sensor fibre.The back-scattering light that produces in the sensor fibre returns from second collimating apparatus, anti-Stokes light in the back-scattering light, the wavelength-division multiplex filter plate of transmission anti-Stokes wavelength, the band pass filter of transmission anti-Stokes wavelength then, be coupled to second avalanche photodide through second GRIN Lens again, be converted to the electric signal output of anti-Stokes light.Stokes light in the back-scattering light, respectively through the wavelength-division multiplex filter plate of anti-Stokes wavelength and the wavelength-division multiplex filter plate reflection of optical maser wavelength, the band pass filter of two Stokes wavelength of transmission then, be coupled to first avalanche photodide through first GRIN Lens again, be converted to the electric signal output of stokes light.
Because the isolation of anti-Stokes light is mainly guaranteed by the wavelength-division multiplex filter plate of an anti-Stokes wavelength and the band pass filter of an anti-Stokes wavelength, therefore can be higher than 70dB; And the isolation of stokes light is mainly guaranteed by the band pass filter of two Stokes wavelength, therefore also can be higher than 70dB.
Conclusion is got up, the utlity model has following beneficial effect: realized a kind of electrooptical device technically, the light path isolation that can guarantee stokes light, anti-Stokes light and Rayleigh scattering light three satisfies the harsh requirement of current distributed optical fiber temperature sensor to isolation fully all greater than 70dB.The insertion loss of anti-Stokes light and stokes light can be satisfied current distributed optical fiber temperature sensor to inserting the requirement of loss fully respectively less than 2dB and 2.4dB.Integrated avalanche photodide and temperature detecting head can directly be exported stable, the electric signal of anti-Stokes light and stokes light accurately.Therefore, utilize electrooptical device of the present utility model, can obtain temperature information accurately very easily, improved the temperature resolution of system at distributed optical fiber temperature sensor.
Description of drawings
Fig. 1 is example structure synoptic diagram of the utility model.Among the figure:
101,102-collimating apparatus tail optical fiber 103,104-collimating apparatus
The wavelength-division multiplex filter plate of 105-optical maser wavelength
106, the band pass filter of 107-Stokes wavelength
The wavelength-division multiplex filter plate of 108-anti-Stokes wavelength
The band pass filter of 109-anti-Stokes wavelength
110,111-GRIN Lens 112,115-avalanche photo diode (APD)
113,116-APD reverse voltage input end 114-anti-Stokes electrical signal
117-Stokes electrical signal 118,119-temperature detecting head
The 120-device outer case
Fig. 2 is CN 101696896 disclosed principle model figure.Among the figure:
The filter plate of 21-optical circulator 22-anti-Stokes wavelength
The filter plate of 23-Stokes wavelength
Fig. 3 is CN 101696896 disclosed another kind of principle model figure.Among the figure:
The filter plate of 31-1X3 bidirectional coupler 32-anti-Stokes wavelength
The filter plate of 33-Stokes wavelength
Fig. 4 is the fundamental diagram of Fig. 1 embodiment.
Fig. 5 is the insertion loss synoptic diagram that anti-Stokes light among Fig. 1 embodiment and stokes light are gone through.
Embodiment
The electrooptical device that the utility model is used for distributed optical fiber temperature sensor below in conjunction with accompanying drawing and specific embodiment is done and is described in further detail, and this description does not limit protection domain of the present utility model.
As shown in Figure 1, present embodiment is used for the electrooptical device of distributed optical fiber temperature sensor by collimating apparatus tail optical fiber 101,102, collimating apparatus 103,104, the wavelength-division multiplex filter plate 105 of optical maser wavelength, the band pass filter 106 of Stokes wavelength, 107, the multiplexing filter plate 108 of anti-Stokes wavelength, the band pass filter 109 of anti-Stokes wavelength, GRIN Lens 110,111, avalanche photo diode (APD) 112,115, APD reverse voltage input end 113,116, anti-Stokes electrical signal 114, Stokes electrical signal 117, temperature detecting head 118,119, device outer case 120 assemblies such as grade constitute.Its basic structure can be described as: comprise the first collimating apparatus tail optical fiber 101 of importing laser and the second collimating apparatus tail optical fiber 102 of external sensor fibre, the transmitted light path of described first collimating apparatus 103 is provided with the wavelength-division multiplex filter plate 105 of optical maser wavelength, and the transmitted light path of described second collimating apparatus 104 is provided with the wavelength-division multiplex filter plate 108 of anti-Stokes wavelength; Wavelength-division multiplex filter plate 105 reflected light paths of described optical maser wavelength are provided with the band pass filter 106,107 of the Stokes wavelength of pair of parallel arrangement, settle first GRIN Lens 111 on band pass filter 106,107 transmitted light paths of described two Stokes wavelength, the focus place of described first GRIN Lens 111 settles first avalanche photodide 115, near the arrangement first temperature detecting head 119 of described first avalanche photodide 115; The wavelength-division multiplex filter plate 108 of described anti-Stokes wavelength is arranged on wavelength-division multiplex filter plate 105 transmitted light paths of optical maser wavelength wavelength-division multiplex filter plate 105 transmitted lights of optical maser wavelength are reflexed to the position of second collimating apparatus 104; Settle the band pass filter 109 of anti-Stokes wavelength on wavelength-division multiplex filter plate 108 transmitted light paths of described anti-Stokes wavelength, settle second GRIN Lens 110 on band pass filter 109 transmitted light paths of described anti-Stokes wavelength, the focus place of described second GRIN Lens 110 settles second avalanche photodide 112, near the arrangement second temperature detecting head 118 of described second avalanche photodide 112.
The principle of work of present embodiment electrooptical device as shown in Figure 4, laser pulse is from the tail optical fiber input of a collimating apparatus of electrooptical device of the present utility model, wavelength-division multiplex filter plate transmission through optical maser wavelength, wavelength-division multiplex filter plate through the anti-Stokes wavelength reflects again, be coupled into another collimating apparatus, inject sensor fibre; The back-scattering light that produces in the sensor fibre returns from collimating apparatus; Anti-Stokes light in the back-scattering light, the wavelength-division multiplex filter plate of transmission anti-Stokes wavelength, the band pass filter of transmission anti-Stokes wavelength then, be coupled to avalanche photodide through GRIN Lens again, be converted to electric signal output, the entire path of anti-Stokes light is a → b → c → d → c → e → f (as shown in Figure 4); Stokes light in the back-scattering light, respectively through the wavelength-division multiplex filter plate of anti-Stokes wavelength and the wavelength-division multiplex filter plate reflection of optical maser wavelength, the band pass filter of two Stokes wavelength of transmission then, be coupled to avalanche photodide through GRIN Lens again, be converted to electric signal output, the entire path of stokes light is a → b → c → d → c → b → g → h.The isolation of anti-Stokes light is mainly guaranteed by the wavelength-division multiplex filter plate of an anti-Stokes wavelength and the band pass filter of an anti-Stokes wavelength, can be higher than 70dB (35dB+35dB); The isolation of stokes light is mainly guaranteed by the band pass filter of two Stokes wavelength, can be higher than 70dB (35dB+35dB).
Accompanying drawing 5 has illustrated that the insertion loss of anti-Stokes light and stokes light is respectively less than 2dB and 2.4dB.The reverse voltage input end and the signal output part of two avalanche photodides, and the output terminal of two temperature detecting heads connects modulate circuit respectively.The temperature detecting head is used for providing the temperature information of avalanche photodide to modulate circuit, and then regulates the reverse voltage of avalanche photodide, makes the gain of avalanche photodide keep stable.Finally, the electric signal of anti-Stokes light and stokes light can be stablized, be exported accurately to this electrooptical device.
In the present embodiment, because the laser pulse wavelength of input is that 1550nm, bandwidth are 1nm, stokes wave is about to 1663nm, bandwidth and is about 3nm, the anti-Stokes wavelength is about 1450nm, bandwidth is about 3nm, so selecting the centre of homology wavelength of the wavelength-division multiplex filter plate of anti-Stokes wavelength is 1450nm, transmission bandwidth is 14nm, and transmission isolation and insertion loss are respectively 35dB and 0.3dB, 1457nm is a reflection bandwidth to 1680nm, and it is 0.2dB that loss is inserted in reflection; The centre of homology wavelength of the wavelength-division multiplex filter plate of optical maser wavelength is 1550nm, transmission bandwidth is 14nm, transmission isolation and insertion loss are respectively 35dB and 0.3dB, and 1420nm is reflection bandwidth to 1543nm, 1557nm to 1680nm, and it is 0.2dB that loss is inserted in reflection; The centre of homology wavelength of the band pass filter of anti-Stokes wavelength is 1450nm, and transmission bandwidth is 14nm, and transmission isolation and insertion loss are respectively 35dB and 0.3dB; The centre of homology wavelength of the band pass filter of Stokes wavelength is 1663nm, and transmission bandwidth is 14nm, and transmission isolation and insertion loss are respectively 35dB and 0.3dB.
In addition, present embodiment also has following concrete ins and outs:
1, the incident angle between the wavelength-division multiplex filter plate of first collimating apparatus of external input laser pulse and optical maser wavelength is about 20 degree (20 ± 2 degree); Incident angle between the wavelength-division multiplex filter plate of second collimating apparatus and anti-Stokes wavelength also is about 20 degree (20 ± 2 degree).
2, the end face degree of GRIN Lens has anti-reflection film, and the focus of GRIN Lens is positioned at the light of avalanche photodide and accepts face.
3, avalanche photodide is the indium gallium arsenic avalanche photodide of TO encapsulation, and two temperature detecting heads are close to two avalanche photodides respectively.
4, this device is placed in the stainless steel casing.
Except that above embodiment, the utility model can also have other embodiment, and all technical schemes that does not break away from the utility model innovation essence all drop in the protection domain that the utility model requires.
Claims (7)
1. electrooptical device that is used for distributed optical fiber temperature sensor, it is characterized in that: comprise the first collimating apparatus tail optical fiber (101) of importing laser and the second collimating apparatus tail optical fiber (102) of external sensor fibre, the transmitted light path of described first collimating apparatus (103) is provided with the wavelength-division multiplex filter plate (105) of optical maser wavelength, and the transmitted light path of described second collimating apparatus (104) is provided with the wavelength-division multiplex filter plate (108) of anti-Stokes wavelength; Wavelength-division multiplex filter plate (105) reflected light path of described optical maser wavelength is provided with the band pass filter (106,107) of the Stokes wavelength of pair of parallel arrangement, settle first GRIN Lens (111) on the band pass filter of described two Stokes wavelength (106, the 107) transmitted light path, the focus place of described first GRIN Lens (111) settles first avalanche photodide (115), near the arrangement first temperature detecting head (119) of described first avalanche photodide (115); The wavelength-division multiplex filter plate (108) of described anti-Stokes wavelength is arranged on wavelength-division multiplex filter plate (105) transmitted light path of optical maser wavelength wavelength-division multiplex filter plate (105) transmitted light of optical maser wavelength is reflexed to the position of second collimating apparatus (104); Settle the band pass filter (109) of anti-Stokes wavelength on wavelength-division multiplex filter plate (108) transmitted light path of described anti-Stokes wavelength, settle second GRIN Lens (110) on the band pass filter of described anti-Stokes wavelength (109) transmitted light path, the focus place of described second GRIN Lens (110) settles second avalanche photodide (112), near the arrangement second temperature detecting head (118) of described second avalanche photodide (112).
2. according to the described electrooptical device that is used for distributed optical fiber temperature sensor of claim 1, it is characterized in that: the reverse voltage input end and the signal output part of described two avalanche photodides, and the output terminal of two temperature detecting heads connects modulate circuit respectively.
3. according to claim 1 or the 2 described electrooptical devices that are used for distributed optical fiber temperature sensor, it is characterized in that: the incident angle between the wavelength-division multiplex filter plate of described first collimating apparatus and optical maser wavelength, and the incident angle between the wavelength-division multiplex filter plate of described second collimating apparatus and anti-Stokes wavelength is 20 ± 2 degree.
4. according to the described electrooptical device that is used for distributed optical fiber temperature sensor of claim 3, it is characterized in that: the end face degree of described GRIN Lens has anti-reflection film.
5. according to the described electrooptical device that is used for distributed optical fiber temperature sensor of claim 4, it is characterized in that: the light of described avalanche photodide is accepted the focus that face is positioned at GRIN Lens.
6. according to the described electrooptical device that is used for distributed optical fiber temperature sensor of claim 5, it is characterized in that: described avalanche photodide is the indium gallium arsenic avalanche photodide of TO encapsulation, and described temperature detecting head is close to corresponding avalanche photodide.
7. according to the described electrooptical device that is used for distributed optical fiber temperature sensor of claim 6, it is characterized in that: described electrooptical device is placed in the stainless steel casing.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010206010112U CN201852651U (en) | 2010-11-11 | 2010-11-11 | Photoelectric device for distributed optical fiber temperature sensor |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010206010112U CN201852651U (en) | 2010-11-11 | 2010-11-11 | Photoelectric device for distributed optical fiber temperature sensor |
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| CN201852651U true CN201852651U (en) | 2011-06-01 |
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| CN2010206010112U Expired - Lifetime CN201852651U (en) | 2010-11-11 | 2010-11-11 | Photoelectric device for distributed optical fiber temperature sensor |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102012284A (en) * | 2010-11-11 | 2011-04-13 | 金海新源电气江苏有限公司 | Photoelectronic device for distributed optical fiber temperature sensor |
| CN114859475A (en) * | 2022-05-25 | 2022-08-05 | 珠海光焱科技有限公司 | High-power bandwidth filter |
-
2010
- 2010-11-11 CN CN2010206010112U patent/CN201852651U/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102012284A (en) * | 2010-11-11 | 2011-04-13 | 金海新源电气江苏有限公司 | Photoelectronic device for distributed optical fiber temperature sensor |
| CN102012284B (en) * | 2010-11-11 | 2012-06-27 | 金海新源电气江苏有限公司 | Photoelectronic device for distributed optical fiber temperature sensor |
| CN114859475A (en) * | 2022-05-25 | 2022-08-05 | 珠海光焱科技有限公司 | High-power bandwidth filter |
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