CN1587913A - Optical fiber sensor - Google Patents
Optical fiber sensor Download PDFInfo
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- CN1587913A CN1587913A CN 200410060821 CN200410060821A CN1587913A CN 1587913 A CN1587913 A CN 1587913A CN 200410060821 CN200410060821 CN 200410060821 CN 200410060821 A CN200410060821 A CN 200410060821A CN 1587913 A CN1587913 A CN 1587913A
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- light
- polarized light
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- polarization beam
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Abstract
The invention relates to a optical fiber sensor, mainly using nanometer grating polarization beam splitter to divide incident light into two bundles of linearly polarized light with vertical polarization direction and they reach a reflecting mirror of uses two probe units to receive light with 5% light intensity as reference light, two bundles of linearly polarized light inflected back go through two blocks of different sensitive material to response one or several environmental parameters. Compared with traditional sensitive material, the structure can separately the advantage of polarization type having high sensitivity to environmental parameter, but also clearer analysis to reference light choice and environment change. The invention needn't to use polarization optical fiber so its resistance to antijamming is excellent and has advantages of small volume, simple structure and low cost.
Description
Technical field
The present invention relates to a kind of Fibre Optical Sensor, specifically, relate to a kind of nanometer grating polarization beam apparatus that utilizes and carry out the method and apparatus that beam splitting realizes that a plurality of environment parameters are measured.
Background technology
Along with the development and the maturation of close wavelength-division multiplex technology, Erbium-Doped Fiber Amplifier (EDFA) technology and Optical Time Division Multiplexing Technology, Fibre Optical Communication Technology just develops towards hypervelocity, jumbo direction, and progressively to all-optical network evolution.Under the fast development of optical communication industry drives, the research of Fibre Optical Sensor is become the application hot fields.As a member young in the sensor family, compare with the dynamo-electric sensor-based system of tradition, owing to have solenoid isolation, high sensitivity, easy remarkable advantage such as multiplexing, light and handy, for the environmental monitoring of industrial processes provides a kind of good means.In testing process, sensitive element is embedded in tested member body and the material usually, thereby in member or material routine work, realize real-time monitoring its safe handling, fault etc.And often have a plurality of environment parameters to wish to obtain monitoring simultaneously in the actual commercial Application.
Chinese patent CN1331795A has proposed a kind of technical scheme, utilize two the different polarization maintaining optical fibres that mix to the different measurements that realize temperature and stress of the response of environment parameter, polarization maintaining optical fibre is made up of the fused fiber splice that the plurality of sections optical axis direction rotates successively together, thereby can several environment parameters of independent measurement.The shortcoming of this structure is that structure is complicated, thereby the cost height, and reliability and stability are also undesirable.
Cost is the key factor that present limit fibre sensor is popularized, and the practical research that reduces cost has become a focus and key.
Therefore, need a kind ofly can either to measure a plurality of environment parameters simultaneously for example electromagnetic nature, temperature and stress etc., and sensor simple in structure, that cost is low.
Summary of the invention
The objective of the invention is to overcome problems such as the traditional fiber sensor can not be measured a plurality of environment parameters, cost height, it is low to propose a kind of cost, simple in structure, can carry out the Fibre Optical Sensor of a plurality of environment parameters.
The object of the present invention is achieved like this: a kind of Fibre Optical Sensor, mainly comprise light source, optical fiber 1, collimating apparatus 2, clear glass 4, nanometer grating polarization beam splitting/bundling device 5, sensitive material 6, reverberator, detector module, it is characterized in that: the light that light source sends is through general single mode fiber, collimating apparatus, clear glass incides nanometer grating polarization beam splitting/bundling device, be divided into the orthogonal two bundle polarized light (S in polarization direction, P), wherein a branch of S or P polarized light are reflected, be reflected again through total reflective mirror 3, propagate into another clear glass with another bundle P or S polarized light, reverberator, sensitive material, sensitive material is placed between two clear glasses, detector module is placed on the relevant position and detects S respectively, light intensity or the polarization state phase place of P after before the sensitive material delivered to the relevant information that detects the variable quantity that the signal analysis unit processing draws environment parameter again.Described reverberator is 90%, 93% or 95% mirror assembly.
Utilize the new material nanometer grating that the incident infrared laser is divided into the orthogonal two bundle polarized lights in polarization direction, pass through different sensitive materials respectively, utilize the physical processes such as optically-active characteristic, Kerr effect or photoelastic effect of sensitive material, temperature, electromagnetic field and ambient stress parameter are surveyed.Sensitive material is hot light, electric light, bullet light or optical activity material, to sensitivities such as temperature, voltage or stress, can respond a plurality of environment parameters.Can be ferromagnetic material, piezoelectric crystal etc.
When polarized light process Optical Fiber Transmission, environment parameter produces different influences to the phase place (being intensity, polarization state etc., is example with the phase place) of light signal, and this relation can characterize with following formula:
Δ
p＝α
pΔM+β
pΔN
Δ
s＝α
sΔM+β
sΔN
Δ wherein
pBe the phase change of p polarized light, α
pBe the variation factor of p polarized light environment parameter M, β
pVariation factor for p polarized light environment parameter N; Δ
sBe the phase change of s polarized light, α
sBe the variation factor of s polarized light environment parameter M, β
sVariation factor for s polarized light environment parameter N.Because the present invention has adopted two kinds of different sensitive materials, α
p≠ α
s, β
p≠ β
sTherefore, can guarantee that this linear equation in two unknowns group separates.
Detector assembly detects the phase change Δ of p polarized light and s polarized light respectively
pWith Δ
s, and be transported to intelligent processing unit and calculate environment parameter changes delta M and Δ N through programmed process.
Because nanometer grating to the insensitive characteristic of wavelength, has reduced the requirement to laser instrument, also can reduce the cost of Fibre Optical Sensor.The nanometer grating polarization beam apparatus has characteristics such as with low cost, low Insertion Loss and High Extinction Ratio in addition, can guarantee that this Fibre Optical Sensor has high precision and high sensitivity.
Fibre Optical Sensor of the present invention makes it to compare with the prior art Fibre Optical Sensor owing to adopted above-mentioned technical scheme, has following advantage and good effect:
1. adopting the orthogonal polarized light in two bundle polarization directions to enter into sensing element responds a plurality of environment parameters.
2. the new material nanometer grating carries out polarization beam splitting to the incident nonpolarized light, not only can reduce the Fibre Optical Sensor cost, but also has improved precision and sensitivity;
3. in the present invention, because do not need polarization maintaining optical fibre, so antijamming capability is strong, and designs simplification, cost is low.Polarization maintaining optical fibre and general single mode fiber differ 3 orders of magnitude on price at present.
Description of drawings
Fig. 1-existing polarization-type optical fiber temperature sensor;
Fig. 2-structural representation of the present invention;
Fig. 3-application structure synoptic diagram of the present invention;
Fig. 4-Another Application structural representation of the present invention;
Fig. 5-Another Application structural representation of the present invention;
Fig. 6-encapsulating structure synoptic diagram of the present invention;
Fig. 7-nanometer grating polarization beam splitting/bundling device structural drawing 1;
Fig. 8-nanometer grating polarization beam splitting/bundling device structural drawing 2;
Fig. 9-nanometer grating polarization beam splitting synoptic diagram 1; The nanocomposite optical crystal substrates is by the P polarized light total reflection of non-polarized incident light, and the S polarized light passes entirely.
Figure 10-nanometer grating polarization beam splitting synoptic diagram 2; The nanocomposite optical crystal substrates is by the S polarized light total reflection of non-polarized incident light, and the P polarized light passes entirely.
Figure 11 a-nanometer grating is to the scattering characteristic figure of non-polarized incident light p;
Figure 11 b-nanometer grating is to the scattering characteristic figure of non-polarized incident light s.
Embodiment
Further specify below in conjunction with drawings and Examples.
As shown in Figure 2, the infrared laser that from laser instrument, comes out through behind the collimation lens in clear glass 4 loss-free propagating into be mapped to nanometer grating polarization beam apparatus 5, be divided into the orthogonal two bundle polarized lights in polarization direction, wherein a branch of polarized light is reflected, be reflected again through total reflective mirror 3, propagate into clear glass 4,95% mirror assembly 7 with another bundle polarized light, enter into different sensitive material 6 afterwards respectively.Because the variation of varying environment parameter causes different phase change respectively, when entering two sensitive materials respectively as if two bundle polarized lights, the phase place that a plurality of environment parameters cause (intensity, polarization state etc.) changes will form a linear equation in two unknowns group.After these information via detecting units detect and deliver to signal processing unit (as computing machine) analytical calculation, just can draw the variable quantity of these environment parameters respectively.
Another embodiment was placed two blocks of gratings and is orientated orthogonal artificial nano material as shown in Figure 3 before two bundle polarized lights enter two collimating apparatuss in the left side simultaneously, polarization variations is converted into intensive quantity notes.
Spirit of the present invention can also be applied to measure the properties of materials parameter, as shown in Figure 4.When two bundle polarized lights entered condensed state to be measured or biochemical material simultaneously, the intensity that the material behavior parameter causes, phase place or polarization variations can be formed a linear equation in two unknowns group.These information via Computer Analysis can draw these characteristic parameters respectively after calculating.Two detector datas on the right are used for doing intensity, the calibration of phase data.When this sensor need carry out phase measurement, the light that laser instrument sends should be pulse or modulation signal.Than the general optical fiber sensor, abundant one times of the quantity of information that this design can provide.The precision height, but simple in structure.During for the Polarization-Sensitive characteristic (electric polarization characteristic) of strengthening condensed state to be measured or biochemical material, can add in the East and West direction of material to be measured or north-south a static state or alternating electric field, as shown in Figure 5.
Figure 6 shows that a kind of packaged type, internal elements all in the dash box all are passive blocks, and are fixed in the resistant to elevated temperatures outer package box of precision-fit; Therefore this sensor probe can be applicable to highfield, various rugged surroundings such as high temperature.Be connected with a multifiber cable between sensor probe and signal processing unit and the light source/detector etc.
A Primary Component realizing these structures is the nanometer grating polarization beam apparatus, this device polarization spectro excellent performance, and spectroscopic distance (Walk off), the adjustable angle scope of two bundle polarized lights are big, and it is as shown in the table.This characteristic guarantees to allow two bundle polarized lights pass through sensitive material 1 and 2 respectively with bigger spectroscopic distance.
| The Walk-Off spacing | ????0.7mm????? | ????1.4mm | ????2.5mm | |
| Birefringece crystal YVO 4Δn＝0.204 | Length D | ????7mm | ????14mm | ????25mm |
| Price (RMB) | ????120 | ????260 | So long crystal can not be provided | |
| Insert loss | ????＜0.1dB | |||
| Adopt the Walk-Off of nano artificial material | Length DAnd incident angle | ????7mm ? ????θ＝8° | ? ??14mm??θ＝8° ? | ? 20mm???θ＝8° |
| ????5mm ? ????θ＝12° | ??10mm??θ＝12° | 14mm???θ＝12° | ||
| ????3.6mm ????θ＝15° | ??7.2mm?θ＝15° | 10mm???θ＝15° | ||
| Price | Compare with crystal at present similar substantially, but the price reduction leeway big | |||
| Insert loss | ????＜0.18dB | |||
It can have following two kinds of structures:
1. as shown in Figure 7, thick metal grizzly bar (as gold or aluminium etc.) directly is deposited on substrate (being generally dielectric materials such as the silicon dioxide) surface, and a kind of cycle of formation is at the periodic structure of sub-micrometer scale.Because the effect of plasma polarization priming effect, be different from usual Bragg reflection rule (to the lambda1-wavelength sensitivity), this periodic structure is very responsive to the polarization of incident light direction, (as Fig. 9 P polarized light with as Figure 10 S polarized light) can be reflected fully perpendicular to the polarized light of metal grizzly bar direction in the polarization direction, the polarization direction is parallel to the polarized light of metal grizzly bar direction then by transmission (as Fig. 9 S polarized light with as Figure 10 P polarized light).It is little that this structure has an Insertion Loss, extinction ratio height, multiple advantage such as with low cost.Shortcoming is can cause the surface of this artificial material very fragile after introducing the metal grizzly bar.Though existing in the past people attempts doing diaphragm on grating, diaphragm adheres to too poor on metal gate.
2. as shown in Figure 8, thick metal grizzly bar is deposited on channel bottom with the periodic dielectric structure of substrate homogeneity.The advantage of this structure has been to overcome the fragile shortcoming in surface of Fig. 7 structure, will protect membrane cover at dielectric surface.At present light fast with regard to this structure application relevant patent, Figure 11 a has provided this structure to P scattering of light coefficient-incident angle curve map, Figure 11 b has provided this structure to S scattering of light coefficient-incident angle curve map.
Claims (7)
1, a kind of Fibre Optical Sensor, mainly comprise light source, optical fiber, collimating apparatus, clear glass, nanometer grating polarization beam splitting/bundling device, sensitive material, reverberator, detector module, it is characterized in that: the light that light source sends is through optical fiber, collimating apparatus, clear glass incides nanometer grating polarization beam splitting/bundling device, be divided into the orthogonal two bundle polarized light (S in polarization direction, P), wherein a branch of S or P polarized light are reflected, be reflected again through total reflective mirror, propagate into another clear glass with another bundle P or S polarized light, reverberator, sensitive material, sensitive material is placed between two clear glasses, detector module is placed on the relevant position and detects S respectively, light intensity or the polarization state phase place of P after before the sensitive material delivered to the relevant information that detects the variable quantity that the signal analysis unit processing draws two environment parameters again.
2, Fibre Optical Sensor according to claim 1 is characterized in that: described reverberator is 90%, 93% or 95% mirror assembly.
3, Fibre Optical Sensor according to claim 1 is characterized in that: S, P polarized light the sensitive material of process be two kinds of different sensitive materials, that is to say the environment parameter variation factor difference of polarized light.
4, according to claim 1,2 or 3 described Fibre Optical Sensors, it is characterized in that: the structure of described nanometer grating polarization beam splitting/bundling device is that thick metal grizzly bar directly is deposited on media such as silicon dioxide to be on the surface of substrate, to form the periodic structure of a kind of cycle in sub-micrometer scale.
5, according to claim 1,2 or 3 described Fibre Optical Sensors; it is characterized in that: the structure of described nanometer grating polarization beam splitting/bundling device is that thick metal grizzly bar is deposited on the channel bottom with the periodic dielectric structure of substrate homogeneity, has covered the protective seam of one deck and substrate homogeneity on it.
6, Fibre Optical Sensor according to claim 4 is characterized in that: the spectroscopic distance of described nanometer grating polarization beam splitting/bundling device is between 7-20mm, and the adjustable angle scope is at the 5-25 degree.
7, Fibre Optical Sensor according to claim 5 is characterized in that: the spectroscopic distance of described nanometer grating polarization beam splitting/bundling device is between 7-20mm, and the adjustable angle scope is at the 5-25 degree.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2004100608210A CN100380099C (en) | 2004-09-09 | 2004-09-09 | Optical fiber sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2004100608210A CN100380099C (en) | 2004-09-09 | 2004-09-09 | Optical fiber sensor |
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| Publication Number | Publication Date |
|---|---|
| CN1587913A true CN1587913A (en) | 2005-03-02 |
| CN100380099C CN100380099C (en) | 2008-04-09 |
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|---|---|---|---|
| CNB2004100608210A Active CN100380099C (en) | 2004-09-09 | 2004-09-09 | Optical fiber sensor |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100575926C (en) * | 2005-12-01 | 2009-12-30 | 中国科学院电子学研究所 | The reflection type optical-fiber bio sensing device |
| CN102053380A (en) * | 2010-12-27 | 2011-05-11 | 周立兵 | Nano structure-based wavelength-insensitive polarizing beam splitter, device packaging method and manufacture of beam splitting unit |
| CN102096156A (en) * | 2011-01-06 | 2011-06-15 | 南京大学 | Online light polarization controller based on optical fiber end face metal wire grating and manufacturing method thereof |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61169822A (en) * | 1985-01-23 | 1986-07-31 | Hoya Corp | Orthogonal polarization type optical frequency shifter |
| JPH0816739B2 (en) * | 1988-12-22 | 1996-02-21 | 日本電気株式会社 | Wavelength add / drop element |
| US6049377A (en) * | 1996-08-16 | 2000-04-11 | Cam C. Lau | Five-axis/six-axis laser measuring system |
| KR20010023064A (en) * | 1997-08-19 | 2001-03-26 | 웨이니 이.스완. | Large scale high multiplexed optical fiber sensor network |
| US6201237B1 (en) * | 1998-12-18 | 2001-03-13 | Corning Incorporated | Fiber optic sensor |
| CA2385008A1 (en) * | 1999-09-14 | 2001-03-22 | Bradley A. Scott | Beamsplitter device producting parallel output beams |
| JP2004214323A (en) * | 2002-12-27 | 2004-07-29 | Toshiba Corp | Fiber laser device, image display device and stimulation method in up-conversion fiber laser device |
-
2004
- 2004-09-09 CN CNB2004100608210A patent/CN100380099C/en active Active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100575926C (en) * | 2005-12-01 | 2009-12-30 | 中国科学院电子学研究所 | The reflection type optical-fiber bio sensing device |
| CN102053380A (en) * | 2010-12-27 | 2011-05-11 | 周立兵 | Nano structure-based wavelength-insensitive polarizing beam splitter, device packaging method and manufacture of beam splitting unit |
| CN102096156A (en) * | 2011-01-06 | 2011-06-15 | 南京大学 | Online light polarization controller based on optical fiber end face metal wire grating and manufacturing method thereof |
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|---|---|
| CN100380099C (en) | 2008-04-09 |
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