CN201903408U - Novel optical fiber wavelength division multiplexer - Google Patents
Novel optical fiber wavelength division multiplexer Download PDFInfo
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- CN201903408U CN201903408U CN2010205537284U CN201020553728U CN201903408U CN 201903408 U CN201903408 U CN 201903408U CN 2010205537284 U CN2010205537284 U CN 2010205537284U CN 201020553728 U CN201020553728 U CN 201020553728U CN 201903408 U CN201903408 U CN 201903408U
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- stokes
- optical fiber
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Abstract
The utility model discloses a novel optical fiber wavelength division multiplexer, belonging to the technical field of optical fiber sensing. The utility model is mainly characterized in that the output end and the input end of an optical splitter are respectively connected with a filtering device, and backscattering light generated by sensing optical fibers, such as anti-Stokes light, Stokes light, Rayleigh scattering light and the like is separated to obtain the anti-Stokes light as a temperature measuring signal and the Rayleigh scattering light as a reference signal. By adopting the technical scheme, the novel optical fiber wavelength division multiplexer can reduce the loss of the anti-Stokes light signal to the maximum degree, improves the signal to noise ratio of a system and avoids the influence of stimulated Raman scattering.
Description
Technical field
The utility model relates to the distributing optical fiber sensing technical field, relates in particular to the light channel structure part of distributing optical fiber sensing technology.
Background technology
Distributed optical fiber temperature sensing system (RDTS) is based on Raman scattering principle dorsad, when laser pulse in optical fiber in the transmission course, can constantly produce scattered lights such as Raman scattering (Stokes, anti-Stokes), Rayleigh scattering and Brillouin scattering in the optical fiber, wherein back scattering can take place in a part, and we claim this part scattered light to be " back-scattering light ".RDTS adopts in the Raman scattering dorsad anti-Stokes as a kind of temperature-sensing system of responsive to temperature signal, for the influence of the factors such as ess-strain of eliminating light source power, temperature measuring optical cable environment of living in, need introduce one road signal more as a reference to the temperature demodulation.
Adopting stokes scattering light or Rayleigh scattering light as the reference signal usually in the RDTS product at present, wherein in the majority with stokes scattering light especially.But find that in use the influence that stokes scattering light is easy to be subjected to stimulated Raman scattering causes the nonlinear distortion of signal, reduces system stability.And simultaneously the loss of traditional Rayleigh demodulation structure is big, signal to noise ratio (S/N ratio) is low, the disadvantages such as influence that also influenced by stimulated Raman scattering.
The light signal that distributed optical fiber temperature sensing system relates to mainly comprises injection light pulse signal, Rayleigh scattering light signal (Rayleigh), stokes scattering light signal (Stokes) and anti Stokes scattering light signal (Anti-Stokes), and optical fibre wavelength division multiplexer set forth in the present invention is used to handle above light signal.
Summary of the invention
The purpose of this utility model is to overcome the shortcoming and defect of existing fiber wavelength division multiplexer, and a kind of novel optical fiber wavelength division multiplexer that stimulated Raman scattering influences, low-loss that is not subjected to is provided.
The purpose of this utility model is achieved in that
A kind of novel optical fiber wavelength division multiplexer comprises an optical splitter and two filters, it is characterized in that: the output terminal of described optical splitter is connected a filter respectively with input end.
The output terminal of described optical splitter connects a filter plate, only allows the anti-Stokes light signal in the transmission back-scattering light; Described optical splitter input end connects a bandpass filter, and described bandpass filter only allows the Rayleigh scattering light signal to pass through.
The output terminal of described optical splitter connects a filter plate, only allows the anti-Stokes light signal in the transmission back-scattering light; Described optical splitter input end connects a filter plate, and described filter plate only allows the Stokes light signal in the transmission back-scattering light.
The incident laser pulse signal injects from the optical splitter input end, and enter follow-up sensor fibre after being reflected through the filter plate that optical splitter arrives output terminal, backscattering takes place in incident laser pulse in the sensor fibre transmission course, Rayleigh scattering light signal in the backscattering light signal, Stokes light signal and anti-Stokes light signal are after filtration during wave plate 1, anti-Stokes light signal transmission filter wave plate 1 wherein enters into subsequent optical electric treatment unit, remaining backscattering light signal then enters optical splitter after filter plate 1 reflection, after the filtering of bandpass filter or filter plate or transmission, the Rayleigh scattering light signal of the i.e. cleaner Rayleigh scattering signal of acquisition that is separated of the Stokes light signal in the backscattering light signal has been filtering also Stokes and anti Stokes scattering.
Described optical splitter is mainly used in incident light is injected into sensor fibre, and back-scattering light is injected into rear end light, electric treatment unit, can be in coupling mechanism or the circulator a kind of.
The present invention is with respect to the advantage of prior art: at first, scattered light directly after filtration wave plate 1 obtain the anti-Stokes light signal, can farthest reduce the loss of anti-Stokes light signal, improved system signal noise ratio; Secondly, Rayleigh scattering signal is carried out necessary filtering, thereby avoided the influence of stimulated Raman scattering (mainly being that Stokes is non-linear); At last, the introducing of certainty ratio coupling mechanism or circulator can reduce the loss of input optical power, thereby has also improved system signal noise ratio.
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 structure of the present utility model below in conjunction with accompanying drawing.
Embodiment 1: as Fig. 1, filter plate 1 links to each other with the output terminal of coupling mechanism 4, and the input end of coupling mechanism 4 connects a bandpass filter 5, and filter plate 1 only allows the transmission anti-Stokes light, reflects non-anti-Stokes light; 5 of bandpass filter allow Rayleigh scattering light to pass through, and coupling mechanism 4 is 2 * 2 coupling mechanisms, and the splitting ratio of coupling mechanism 4 ports is 90% (port 6): 10% (port 7).
The incident laser pulse signal injects from coupling mechanism 4 input ends, and the filter plate 1 that arrives output terminal through coupling mechanism 4 is reflected to port 2, because in RDTS, port 2 can directly or be connected with sensor fibre indirectly, backscattering takes place in incident laser pulse in the sensor fibre transmission course, Rayleigh scattering light signal in the backscattering light signal, Stokes light signal and anti-Stokes light signal are after filtration during wave plate 1, anti-Stokes light signal transmission filter wave plate 1 wherein enters into subsequent optical electric treatment unit, remaining backscattering light signal then enters branch/coupler 4 after filter plate 1 reflection, after the filtering of bandpass filter 5, Stokes light signal in the backscattering light signal is filtered, promptly obtain cleaner Rayleigh scattering signal, the Rayleigh scattering light signal of be filtering also Stokes and anti Stokes scattering.Rayleigh scattering light signal after the filtration enters subsequent optical electric treatment unit from port 8.So far, finish the extraction of responsive to temperature signal (anti Stokes scattering signal) and reference signal (Rayleigh scattering signal).
Embodiment 2: as Fig. 2, filter plate 1 links to each other with the output terminal of circulator 4, and the input end of coupling mechanism 4 connects filter plate 6, and filter plate 1 only allows the transmission anti-Stokes light, reflects non-anti-Stokes light; Filter plate 6 only allows the transmission stokes light, reflects non-stokes light.
The incident laser pulse signal injects from circulator 4 input ends, and the filter plate 1 that arrives output terminal through circulator 4 is reflected to port 2, because in RDTS, port 2 can directly or be connected with sensor fibre indirectly, backscattering takes place in incident laser pulse in the sensor fibre transmission course, Rayleigh scattering light signal in the backscattering light signal, Stokes light signal and anti-Stokes light signal are after filtration during wave plate 1, anti-Stokes light signal transmission filter wave plate 1 wherein enters into subsequent optical electric treatment unit, remaining backscattering light signal then enters circulator 4 after filter plate 1 reflection, after filtration during wave plate 2, Stokes light transmission filter plate 2 wherein is from port 9 outputs, at this moment, has only cleaner Rayleigh scattering signal in the back-scattering light, the Rayleigh scattering light signal of be filtering also Stokes and anti Stokes scattering.Rayleigh scattering light signal after the filtration enters subsequent optical electric treatment unit from port 8.So far, finish the extraction of responsive to temperature signal (anti Stokes scattering signal) and reference signal (Rayleigh scattering signal).
Claims (4)
1. novel optical fiber wavelength division multiplexer, it is characterized in that: the output terminal of optical splitter is connected a filter respectively with input end.
2. novel optical fiber wavelength division multiplexer according to claim 1 is characterized in that: the output terminal of described optical splitter connects a filter plate, only allows the anti-Stokes light signal in the transmission back-scattering light; Described optical splitter input end connects a bandpass filter, and described bandpass filter only allows the Rayleigh scattering light signal to pass through.
3. novel optical fiber wavelength division multiplexer according to claim 1 is characterized in that: the output terminal of described optical splitter connects a filter plate, only allows the anti-Stokes light signal in the transmission back-scattering light; Described optical splitter input end connects a filter plate, and described filter plate only allows the Stokes light signal in the transmission back-scattering light
4. according to claim 1,2 or 3 described novel optical fiber wavelength division multiplexers, it is characterized in that: described optical splitter can be a kind of in fiber coupler or the optical fiber circulator.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010205537284U CN201903408U (en) | 2010-09-30 | 2010-09-30 | Novel optical fiber wavelength division multiplexer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010205537284U CN201903408U (en) | 2010-09-30 | 2010-09-30 | Novel optical fiber wavelength division multiplexer |
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| Publication Number | Publication Date |
|---|---|
| CN201903408U true CN201903408U (en) | 2011-07-20 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN2010205537284U Expired - Fee Related CN201903408U (en) | 2010-09-30 | 2010-09-30 | Novel optical fiber wavelength division multiplexer |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104483737A (en) * | 2014-11-27 | 2015-04-01 | 中国计量学院 | Multi-input multi-output terahertz wave multiplexer with asymmetric hole-shaped hollow structure |
| CN104111127B (en) * | 2014-07-28 | 2017-01-25 | 北京航天易联科技发展有限公司 | Optical wavelength division multiplexer bandwidth selecting device |
-
2010
- 2010-09-30 CN CN2010205537284U patent/CN201903408U/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104111127B (en) * | 2014-07-28 | 2017-01-25 | 北京航天易联科技发展有限公司 | Optical wavelength division multiplexer bandwidth selecting device |
| CN104483737A (en) * | 2014-11-27 | 2015-04-01 | 中国计量学院 | Multi-input multi-output terahertz wave multiplexer with asymmetric hole-shaped hollow structure |
| CN104483737B (en) * | 2014-11-27 | 2017-03-29 | 中国计量学院 | The multiple-input, multiple-output THz wave multiplexer of asymmetric poroid engraved structure |
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| 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: 20110720 Termination date: 20140930 |
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| EXPY | Termination of patent right or utility model |