CN112147737A - Method for manufacturing high-temperature-resistant fiber Bragg grating - Google Patents
Method for manufacturing high-temperature-resistant fiber Bragg grating Download PDFInfo
- Publication number
- CN112147737A CN112147737A CN202011014362.8A CN202011014362A CN112147737A CN 112147737 A CN112147737 A CN 112147737A CN 202011014362 A CN202011014362 A CN 202011014362A CN 112147737 A CN112147737 A CN 112147737A
- Authority
- CN
- China
- Prior art keywords
- temperature
- bragg grating
- fiber bragg
- fiber
- grating
- 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.)
- Pending
Links
- 239000000835 fiber Substances 0.000 title claims abstract description 90
- 238000000034 method Methods 0.000 title claims abstract description 38
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 13
- 239000013307 optical fiber Substances 0.000 claims abstract description 43
- 238000010791 quenching Methods 0.000 claims abstract description 34
- 230000000171 quenching effect Effects 0.000 claims abstract description 33
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims abstract description 25
- 239000001257 hydrogen Substances 0.000 claims abstract description 25
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 25
- 238000010438 heat treatment Methods 0.000 claims abstract description 21
- 230000008929 regeneration Effects 0.000 claims abstract description 16
- 238000011069 regeneration method Methods 0.000 claims abstract description 16
- 238000001816 cooling Methods 0.000 claims abstract description 12
- 238000011068 loading method Methods 0.000 claims abstract description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 29
- 239000007788 liquid Substances 0.000 claims description 21
- 230000008569 process Effects 0.000 claims description 18
- 239000000243 solution Substances 0.000 claims description 11
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 claims description 10
- 230000003287 optical effect Effects 0.000 claims description 9
- 239000011780 sodium chloride Substances 0.000 claims description 7
- VWDWKYIASSYTQR-UHFFFAOYSA-N sodium nitrate Chemical compound [Na+].[O-][N+]([O-])=O VWDWKYIASSYTQR-UHFFFAOYSA-N 0.000 claims description 6
- FGIUAXJPYTZDNR-UHFFFAOYSA-N potassium nitrate Inorganic materials [K+].[O-][N+]([O-])=O FGIUAXJPYTZDNR-UHFFFAOYSA-N 0.000 claims description 4
- LPXPTNMVRIOKMN-UHFFFAOYSA-M sodium nitrite Substances [Na+].[O-]N=O LPXPTNMVRIOKMN-UHFFFAOYSA-M 0.000 claims description 4
- 239000002904 solvent Substances 0.000 claims description 4
- 239000007864 aqueous solution Substances 0.000 claims description 3
- 230000035484 reaction time Effects 0.000 claims description 3
- 238000001228 spectrum Methods 0.000 claims description 3
- 239000011259 mixed solution Substances 0.000 claims description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 14
- 239000010453 quartz Substances 0.000 description 10
- 238000006243 chemical reaction Methods 0.000 description 8
- 235000002639 sodium chloride Nutrition 0.000 description 8
- 238000012360 testing method Methods 0.000 description 5
- NFTZVZCNBKAQBH-UHFFFAOYSA-N O[Ge] Chemical compound O[Ge] NFTZVZCNBKAQBH-UHFFFAOYSA-N 0.000 description 4
- 206010034972 Photosensitivity reaction Diseases 0.000 description 4
- 239000001301 oxygen Substances 0.000 description 4
- 229910052760 oxygen Inorganic materials 0.000 description 4
- 230000036211 photosensitivity Effects 0.000 description 4
- 229920000642 polymer Polymers 0.000 description 4
- 229910008051 Si-OH Inorganic materials 0.000 description 3
- 229910006358 Si—OH Inorganic materials 0.000 description 3
- 238000000137 annealing Methods 0.000 description 3
- 239000011324 bead Substances 0.000 description 3
- 239000012267 brine Substances 0.000 description 3
- 230000008859 change Effects 0.000 description 3
- 239000003921 oil Substances 0.000 description 3
- 238000010583 slow cooling Methods 0.000 description 3
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 description 3
- 241001391944 Commicarpus scandens Species 0.000 description 2
- 229910002808 Si–O–Si Inorganic materials 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 238000005253 cladding Methods 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 239000005350 fused silica glass Substances 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- -1 hydroxyl silica Chemical compound 0.000 description 2
- XQSFXFQDJCDXDT-UHFFFAOYSA-N hydroxysilicon Chemical compound [Si]O XQSFXFQDJCDXDT-UHFFFAOYSA-N 0.000 description 2
- 238000003780 insertion Methods 0.000 description 2
- 230000037431 insertion Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- PVADDRMAFCOOPC-UHFFFAOYSA-N oxogermanium Chemical compound [Ge]=O PVADDRMAFCOOPC-UHFFFAOYSA-N 0.000 description 2
- 230000008707 rearrangement Effects 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 238000011946 reduction process Methods 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- 239000000377 silicon dioxide Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 229910018557 Si O Inorganic materials 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000009529 body temperature measurement Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000002657 fibrous material Substances 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 150000002823 nitrates Chemical class 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- LIVNPJMFVYWSIS-UHFFFAOYSA-N silicon monoxide Inorganic materials [Si-]#[O+] LIVNPJMFVYWSIS-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/02—Optical fibres with cladding with or without a coating
- G02B6/02057—Optical fibres with cladding with or without a coating comprising gratings
- G02B6/02076—Refractive index modulation gratings, e.g. Bragg gratings
- G02B6/02123—Refractive index modulation gratings, e.g. Bragg gratings characterised by the method of manufacture of the grating
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
- G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
- G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
- G01D5/353—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
- G01D5/35306—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using an interferometer arrangement
- G01D5/35309—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using an interferometer arrangement using multiple waves interferometer
- G01D5/35316—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using an interferometer arrangement using multiple waves interferometer using a Bragg gratings
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Optics & Photonics (AREA)
- Optical Fibers, Optical Fiber Cores, And Optical Fiber Bundles (AREA)
Abstract
The invention relates to a method for manufacturing a high-temperature-resistant fiber Bragg grating, which comprises the following steps: carrying out hydrogen loading treatment on the single-mode optical fiber under a high-pressure condition; carrying out exposure writing on the optical fiber loaded with hydrogen by a phase mask method to obtain an optical fiber grating; carrying out high-temperature heat treatment on the fiber bragg grating by a thermal regeneration device; and carrying out rapid quenching and cooling treatment on the fiber bragg grating subjected to high-temperature heat treatment to obtain the high-temperature-resistant fiber bragg grating. The sensor manufactured by the high-temperature-resistant fiber Bragg grating can work in an environment with the temperature of more than 1100 ℃, and the manufactured high-temperature-resistant fiber Bragg grating has better mechanical property, thereby greatly reducing the brittle damage to the optical fiber caused by high-temperature treatment.
Description
Technical Field
The invention belongs to the technical field of fiber bragg grating manufacturing, and particularly relates to a manufacturing method of a high-temperature-resistant fiber bragg grating.
Background
The fiber bragg grating is a key device widely applied to the fields of optical fiber communication and optical fiber sensing. However, the photosensitive characteristic of the fiber bragg grating gradually degrades and even completely erases after the fiber bragg grating works in a high-temperature environment for a long time, so that the application of the fiber bragg grating in the field of high-temperature sensing is limited. The thermal-gravimetric fiber bragg grating which is formed by regrowing the fiber bragg grating after being erased at high temperature can stably work in a high-temperature environment of more than 1100 ℃ through high-temperature annealing, and the property is stable. The high-temperature sensing has wide application field, and is mostly applied in the field of industrial engineering. Such as temperature sensing of oil and gas well fields, temperature monitoring of blast furnaces and space engines of smelters, and the like. According to statistics, the failure rate of the traditional electronic sensor is increased along with the increase of the temperature, the error is increased after the traditional electronic sensor is used for a long time, and the danger of life safety is even brought in some special fields. The fiber grating encodes the wavelength during sensing, i.e. when the measurement is changed, the reflected wavelength is also changed. The code can be transmitted in long distance, so it is very suitable for sensing physical parameters in oil and gas exploitation well field and pipeline.
The forming mechanism of the thermal regeneration fiber grating is complex, the regenerated fiber grating is modulated by oxygen, effective substances causing the regeneration of the grating are water molecules rich in oxygen, and the following chemical reactions can occur in the fiber writing process and the high-temperature regeneration process:
Si—O—Si+H2 
Si—OH+H—Si
Ge—O—Ge +H2 
Ge—OH+H—Ge
2(Si—OH)
Si—O—Si+H2O
2(Ge—OH)
Ge—O—Ge +H2O
the silica-germanium-oxygen bond in the optical fiber and hydrogen entering the fiber core in the hydrogen carrying process are subjected to chemical reaction under the action of ultraviolet light, so that the silica-oxygen bond and the germanium-oxygen bond are broken to generate hydroxyl silica and hydroxyl germanium, and the I-type optical fiber grating is generated. During the heating process, the hydroxyl silicon and the hydroxyl germanium are weakened, and germanium oxygen and silicon oxygen bonds are regenerated and water molecules are generated. Water molecules are weak in diffusion capacity in the optical fiber, so that the water molecules are dispersed in the corresponding part of the gate region to form refractive index modulation, and therefore, the regenerated optical fiber grating is generated. Because the water molecules are stable and the bond energy is larger, the regeneration grating is difficult to decompose under the high-temperature condition, and the regeneration grating has good high-temperature stability.
However, after high-temperature annealing treatment, the mechanical strength of the thermogravimetric fiber bragg grating is obviously reduced compared with that of the common fiber bragg grating, the brittleness is increased, and the thermogravimetric fiber bragg grating is easy to break, so that the thermogravimetric fiber bragg grating cannot meet the requirements of engineering application. According to the thermodynamic principle, in the high-temperature heat treatment process of the optical fiber in the high-temperature tube furnace, the temperature of the furnace is increased from room temperature all the time, and the temperature rise is an entropy increasing process for the quartz optical fiber. The optical fiber material is fused silica, and is amorphous at the moment; however, the subsequent cooling from high temperature to room temperature is the inverse process of the previous process, which is an entropy reduction process, the entropy reduction means that the ordering degree of the quartz is increased, or the slow cooling gives possibility of quartz molecule rearrangement, so that the ordering degree is increased, that is, the quartz optical fiber has a certain degree of microcrystallization, the occurrence of microcrystallization causes the stress distribution of the optical fiber to be significantly changed, and the microcrystalline interfaces are very easy to break, which is the reason that the stress intensity of the fiber grating is reduced after high temperature treatment, and the brittleness is significantly increased.
Disclosure of Invention
Aiming at the defects of the prior art, the invention aims to provide a method for manufacturing a high-temperature-resistant fiber Bragg grating, so as to solve the problems of overlarge brittleness and easy breakage of a regenerated fiber Bragg grating in the prior art.
In order to achieve the purpose, the invention adopts the technical scheme that:
a method for manufacturing a high-temperature-resistant fiber Bragg grating comprises the following steps:
carrying out hydrogen loading treatment on the single-mode optical fiber under a high-pressure condition;
carrying out exposure writing on the optical fiber loaded with hydrogen by a phase mask method to obtain an optical fiber grating;
carrying out high-temperature heat treatment on the fiber bragg grating by a thermal regeneration device;
and carrying out rapid quenching and cooling treatment on the fiber bragg grating subjected to high-temperature heat treatment to obtain the high-temperature-resistant fiber bragg grating.
Further, the pressure during the hydrogen loading treatment is 1MPa-15MPa, and the reaction time is 72-144 hours.
Further, the repetition frequency during exposure and writing is set to be 20-50HZ, the energy of the light Pulse is set to be 100-.
Further, the exposure writing is realized by an excimer laser; the output laser center wavelength of the excimer laser is 248 nm.
Further, the high-temperature heat treatment condition is that the fiber grating is heated from room temperature to 900 ℃ at the heating rate of 10 ℃/min, and the temperature is kept at 900 ℃ for 150 min.
Further, the quenching solvent is water-based quenching liquid; the water-based quenching liquid is saline water, trinitro water solution or PAG quenching liquid.
Further, the saline is a common salt solution; the trinitro aqueous solution is NaNO3、KNO3And NaNO2The mixed solution of (1).
Further, the thermal regeneration device comprises a broadband light source, an optical circulator, a high-temperature tube furnace and a spectrometer; the high-temperature tube furnace is used for heating the fiber bragg grating; the light emitted by the broadband light source reaches the fiber bragg grating through the circulator; the light reflected back by the fiber bragg grating enters the spectrometer through the circulator; the spectrometer is used for scanning the spectrum in real time to observe the erasing and growing conditions of the fiber grating.
The invention has the beneficial effects that: the process is improved on the basis of the conventional thermogravimetric fiber grating manufacturing, the flow of rapid quenching is added in the flow, and the water-based quenching liquid is used for rapidly quenching the fiber grating, so that the fiber grating is rapidly cooled, the high entropy of the quartz fiber can be effectively maintained, the microcrystallization can be avoided, the problem of fiber grating embrittlement can be further avoided, and the further application of the high-temperature-resistant fiber Bragg grating in the field of high-temperature sensing is facilitated.
Drawings
FIG. 1 is a schematic view of a thermal regeneration apparatus for fiber gratings;
FIG. 2 is a flow chart of the fabrication of a high temperature resistant fiber Bragg grating;
fig. 3 shows the temperature test result of the manufactured high temperature resistant fiber bragg grating.
Reference numerals: 1-broadband light source, 2-optical circulator, 3-high temperature tube furnace, 4-fiber grating, 5-spectrometer.
Detailed Description
The present invention will be described in further detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
As shown in fig. 2, a method for manufacturing a high temperature resistant fiber grating includes the following steps:
the method comprises the following steps: carrying out hydrogen loading treatment on the single-mode optical fiber in a high-pressure environment to enable the optical fiber to have photosensitivity;
the step of hydrogen-loading the optical fiber comprises: placing an optical fiber needing to carry hydrogen in a reaction kettle, then closing the locking reaction kettle, injecting high-pressure hydrogen into the reaction kettle through a pneumatic hydrogen booster pump, reacting for 72-144 hours under the high-pressure condition of 1-15 Mpa in the reaction kettle, carrying out hydrogen carrying treatment, discharging the high-pressure hydrogen through a hydrogen exhaust pipe after the hydrogen carrying treatment is finished, taking out the optical fiber in the reaction kettle, wherein the optical fiber carrying the high-pressure hydrogen has photosensitivity. The optical fiber can be single mode fiber, multimode fiber or double-clad fiber, the numerical aperture of the single mode fiber is 0.14, and the core diameter/outer diameter is 8.1/125 μm; the numerical aperture of the multimode optical fiber is 0.2, and the core diameter/outer diameter is 50 mu m/125 mu m; the core diameter/inner cladding/outer cladding of the double-clad fiber was 10 μm/66 μm/130 μm. It is preferable that the high pressure condition is set to 13MPa and the reaction time is set to 120 hours.
The principle that the optical fiber carries hydrogen to improve the photosensitivity of the optical fiber is as follows: and (3) placing the single-mode optical fiber in a hydrogen environment with certain pressure, and standing for a period of time. At this time, hydrogen will diffuse into the core of the fiber in the form of molecule, when the hydrogen-carrying fiber is irradiated by ultraviolet ray with specific wavelength, the hydrogen molecule reacts with Ge-O bond and Si-O bond in the fiber material to generate Ge-OH defect center and chemical bond with specific absorption band, and Si-OH, thereby improving the refractive index change of the hydrogen-carrying fiber. The modulation amplitude of the refractive index periodicity of the hydrogen-carrying optical fiber can reach 5.9x10-3. Compared with the change of the refractive index of the optical fiber without carrying hydrogen, the change of the refractive index is improved by two orders of magnitude, and the photosensitivity of the optical fiber is effectively improved.
Step two: using an excimer laser to perform exposure writing on the optical fiber loaded with hydrogen by using a phase mask method to manufacture an optical fiber grating; the center wavelength of the output laser of the excimer laser is 248 nm. The repetition frequency during writing is set to 20-50HZ, preferably 40 HZ; the optical Pulse energy is set to be 100-200mJ/Pulse, preferably 200 mJ/Pulse; the voltage of the excimer laser is set to be 18KV-22KV, preferably 20 KV; the number of exposure pulses at the time of writing is set to 2000-.
Step three: carrying out high-temperature heat treatment on the fiber bragg grating by using a high-temperature tube furnace, and observing the erasing and growing conditions of the fiber bragg grating by using a thermal regeneration device of the fiber bragg grating;
as shown in fig. 1, the thermal regeneration apparatus for a fiber grating includes: a high-temperature tube furnace 3, a broadband light source 1, an optical circulator 2 and a spectrometer 5. The method specifically comprises the following steps: light emitted by the broadband light source 1 passes through the optical circulator 2 to the fiber grating 4, and light reflected by the fiber grating 4 enters the spectrometer 5 through the optical circulator 2. The high-temperature tube furnace 3 carries out high-temperature heat treatment on the fiber bragg grating 4, and the spectrometer 5 scans the spectrum in real time to observe the erasing and growing conditions of the fiber bragg grating. In a high-temperature tube furnace, the fiber grating is heated from room temperature to 900 ℃ at the heating rate of 10 ℃/min, and is kept at 900 ℃ for 150 min. The high-temperature tube furnace can work at 1100 ℃ for a long time with the highest temperature of 1200 ℃ and the temperature control precision of +/-1 ℃; the broadband light source adopts an ASE broadband light source with S + C + L wave band, and the wavelength range is 1460-1565 nm; the insertion loss between the communicated ports of the optical circulator is 1-2dB, and the insertion loss between the non-communicated ports of the optical circulator is more than 30 dB. Spectrometer wavelength range: 600-1700 nm, high wavelength resolution: 0.02nm, large dynamic range: 78dB, wide power range: +20 to-90 dBm, rapid measurement: 100nm span 0.2 seconds.
In the high-temperature heat treatment process in the high-temperature tube furnace, the furnace temperature is heated from room temperature all the time, the temperature rise is an entropy increase process for the quartz optical fiber, and the optical fiber is made of fused quartz and is amorphized at this time; however, the subsequent high temperature annealing and holding at high temperature for a period of time, and then slowly cooling to room temperature, the slow cooling process is the inverse process of the previous process, which is an entropy reduction process, the entropy reduction is the increase of the ordering degree of quartz, or the slow cooling process makes the rearrangement of quartz molecules possible, so that the ordering degree is increased, that is, the quartz fiber has a certain degree of microcrystallization, and the microcrystallization occurs, further the stress distribution of the fiber is significantly changed, and the microcrystallization interfaces are easily broken, which may be the reason for the decrease of the stress intensity of the fiber grating after the high temperature treatment and the significant increase of brittleness.
The fiber grating thermal regeneration principle is as follows: the silica-germanium-oxygen bond in the optical fiber and hydrogen entering the fiber core in the hydrogen carrying process are subjected to chemical reaction under the action of ultraviolet light, so that the silica-oxygen bond and the germanium-oxygen bond are broken to generate hydroxyl silica and hydroxyl germanium, and the I-type optical fiber grating is generated. During the heating process, the hydroxyl silicon and the hydroxyl germanium are weakened, and germanium oxygen and silicon oxygen bonds are regenerated and water molecules are generated. Water molecules are weak in diffusion capacity in the optical fiber, so that the water molecules are dispersed in the corresponding part of the gate region to form refractive index modulation, and therefore, the regenerated optical fiber grating is generated. Because the water molecules are stable and the bond energy is larger, the regeneration grating is difficult to decompose under the high-temperature condition, and the regeneration grating has good high-temperature stability. Step four: carrying out rapid quenching cooling treatment on the fiber grating in a quenching solvent after the high-temperature heat treatment is finished; the quenching solvent for quenching the fiber grating is water-based quenching liquid, and can be any one of saline water, trinitro water solution and PAG quenching liquid.
The saline is a normal salt (NaCl) solution. When the brine is used for quenching, the steam film can be immediately damaged, so that the object is fully contacted with the quenching liquid, the cooling capacity in a high-temperature area is improved, the cooling speed of the brine in the high-temperature area is twice of that of water, and the cooling speed of the brine in a low-temperature area is almost the same as that of water.
The aqueous trinitro solution is prepared by dissolving NaNO3（25%）、KNO3（20%）、NaNO2(20%) three nitrates were dissolved in water to form a supersaturated aqueous solution. The trinitro water solution damages the formation of steam film due to the precipitation of salt crystals at high temperature, and the cooling capacity is close to that of water, while the trinitro water solution has extremely high concentration and poor fluidity at low temperature, and the cooling capacity is close to that of oil.
PAG quenching liquid is a high molecular polymer water-soluble quenching liquid, which is prepared by taking PAG polymer as a main material and adding other additives for providing auxiliary performance. The PAG quenching liquid is a novel quenching liquid and has the characteristics of safety, environmental protection, convenient use, low cost and the like. During the quenching of the workpiece, once the temperature of the liquid around the workpiece rises above the cloud point of the solution, the PAG polymer is desolventized from the solution and suspended in the quenching liquid in the form of fine liquid beads. The suspended PAG liquid beads adhere to the surface of the workpiece by virtue of the very good wettability thereof as soon as the PAG liquid beads contact the red hot workpiece, and the formed coating wraps the workpiece. The PAG quenching medium adjusts the cooling speed of water by the coating film, and avoids the quenching cracking of the workpiece. After the workpiece is cooled down, the polymer adhered to the workpiece can be dissolved back into the quenching liquid.
And carrying out temperature test on the prepared high-temperature-resistant fiber Bragg grating. And (3) placing the prepared high-temperature-resistant fiber Bragg grating in a high-temperature tube furnace for temperature test, wherein the test range is 50-1100 ℃. FIG. 3 shows the drift relationship between the wavelength and the temperature of the high temperature resistant fiber grating manufactured by the present invention under the temperature test of 50-1100 deg.C, and it can be seen from the figure that the manufactured high temperature resistant fiber grating has good linear temperature measurement performance and completely meets the requirements of the actual engineering.
The invention adds the rapid quenching process in the process of manufacturing the thermogravimetric fiber grating, and utilizes the water-based quenching liquid to rapidly quench the fiber grating, so that the fiber grating is rapidly cooled, the high entropy of the quartz fiber can be effectively maintained, the micro crystallization is avoided, and the problem of fiber grating embrittlement is further avoided.
The embodiments of the present invention are disclosed as the preferred embodiments, but not limited thereto, and those skilled in the art can easily understand the spirit of the present invention and make various extensions and changes without departing from the spirit of the present invention.
Claims (8)
1. A method for manufacturing a high-temperature-resistant fiber Bragg grating is characterized by comprising the following steps:
carrying out hydrogen loading treatment on the single-mode optical fiber under a high-pressure condition;
carrying out exposure writing on the optical fiber loaded with hydrogen by a phase mask method to obtain an optical fiber grating;
carrying out high-temperature heat treatment on the fiber bragg grating by a thermal regeneration device;
and carrying out rapid quenching and cooling treatment on the fiber bragg grating subjected to high-temperature heat treatment to obtain the high-temperature-resistant fiber bragg grating.
2. The method as claimed in claim 1, wherein the pressure of the hydrogen-loading process is 1Mpa-15Mpa, and the reaction time is 72-144 hours.
3. The method as claimed in claim 1, wherein the repetition frequency of the exposure writing is set to 20-50Hz, the optical Pulse energy is set to 100-200mJ/Pulse, the voltage is set to 18KV-22KV, and the number of exposure pulses is set to 2000-8000.
4. The method as claimed in claim 1, wherein the exposure and writing is performed by an excimer laser; the output laser center wavelength of the excimer laser is 248 nm.
5. The method as claimed in claim 1, wherein the high temperature heat treatment is performed by heating the fiber grating from room temperature to 900 ℃ at a heating rate of 10 ℃/min, and maintaining the temperature at 900 ℃ for 150 min.
6. The method as claimed in claim 1, wherein the quenching solvent is a water-based quenching liquid; the water-based quenching liquid is saline water, trinitro water solution or PAG quenching liquid.
7. The method as claimed in claim 6, wherein the saline solution is a normal saline solution; the trinitro aqueous solution is NaNO3、KNO3And NaNO2The mixed solution of (1).
8. The method according to claim 1, wherein the thermal regeneration device comprises a broadband light source, an optical circulator, a high-temperature tube furnace and a spectrometer; the high-temperature tube furnace is used for heating the fiber bragg grating; the light emitted by the broadband light source reaches the fiber bragg grating through the circulator; the light reflected back by the fiber bragg grating enters the spectrometer through the circulator; the spectrometer is used for scanning the spectrum in real time to observe the erasing and growing conditions of the fiber grating.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011014362.8A CN112147737A (en) | 2020-09-24 | 2020-09-24 | Method for manufacturing high-temperature-resistant fiber Bragg grating |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011014362.8A CN112147737A (en) | 2020-09-24 | 2020-09-24 | Method for manufacturing high-temperature-resistant fiber Bragg grating |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112147737A true CN112147737A (en) | 2020-12-29 |
Family
ID=73896560
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011014362.8A Pending CN112147737A (en) | 2020-09-24 | 2020-09-24 | Method for manufacturing high-temperature-resistant fiber Bragg grating |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112147737A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113551819A (en) * | 2021-08-24 | 2021-10-26 | 南京邮电大学 | High-temperature-resistant fiber Bragg grating pressure sensor |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1336560A (en) * | 2000-07-31 | 2002-02-20 | 日本电气硝子株式会社 | Material for optical device fitting having optical fiber |
| CN108441792A (en) * | 2018-04-17 | 2018-08-24 | 益阳仪纬科技有限公司 | A kind of aluminium alloy and its heat treatment method |
| CN108866442A (en) * | 2018-07-19 | 2018-11-23 | 湖南长高新材料股份有限公司 | The heat treatment method and product of superhigh carbon steel |
-
2020
- 2020-09-24 CN CN202011014362.8A patent/CN112147737A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1336560A (en) * | 2000-07-31 | 2002-02-20 | 日本电气硝子株式会社 | Material for optical device fitting having optical fiber |
| CN108441792A (en) * | 2018-04-17 | 2018-08-24 | 益阳仪纬科技有限公司 | A kind of aluminium alloy and its heat treatment method |
| CN108866442A (en) * | 2018-07-19 | 2018-11-23 | 湖南长高新材料股份有限公司 | The heat treatment method and product of superhigh carbon steel |
Non-Patent Citations (2)
| Title |
|---|
| DINUSHA SERANDI GUNAWARDENA等: "Resurgent regenerated fiber Bragg gratings and thermal annealing techniques for ultra-high temperature sensing beyond 1400 degrees C", 《OPTICS EXPRESS》 * |
| 刘日照等: "高温热重生光纤布拉格光栅制备及其性能研究", 《光子学报》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113551819A (en) * | 2021-08-24 | 2021-10-26 | 南京邮电大学 | High-temperature-resistant fiber Bragg grating pressure sensor |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Cook et al. | Regenerated femtosecond fibre Bragg gratings | |
| CA2541735C (en) | Conditioning optical fibers for improved ionizing radiation response | |
| JP3270353B2 (en) | Manufacturing method of optical waveguide | |
| JP4086320B2 (en) | Optical means | |
| CN112147737A (en) | Method for manufacturing high-temperature-resistant fiber Bragg grating | |
| GB2378259A (en) | An optical waveguide filter with an irradiated long period grating | |
| Watanabe et al. | Two-step refractive index changes by photoisomerization and photobleaching processes in the films of non-linear optical polyurethanes and a urethane–urea copolymer | |
| CN114415287B (en) | Hydrogen-resistant carbon-coated fiber grating string and preparation method and preparation device thereof | |
| Dong et al. | Enhanced high temperature properties of overexposed FBG fabricated by femtosecond laser | |
| Grobnic et al. | Ultrafast IR laser writing of strong Bragg gratings through the coating of high Ge-doped optical fibers | |
| CN100363765C (en) | Method and apparatus for the photosensitization of optical fiber | |
| CN115236797B (en) | High-temperature-resistant weak fiber grating array and preparation method thereof | |
| Voloshin et al. | Absorption loss at high temperatures in aluminum-and copper-coated optical fibers | |
| US20120219260A1 (en) | Optical fiber and method for manufacturing silica glass | |
| Tao et al. | Photosensitive polymer optical fibres and gratings | |
| Zhang et al. | Thermal quenching effect on BAC-P in bismuth/erbium co-doped optical fibre | |
| Shang et al. | Fast thermal regeneration of weak fiber Bragg gratings | |
| Jiang et al. | Review of fabrication and packaging of UV-induced FBGs for high temperature sensing | |
| Chen et al. | The role of color-centered models in the fiber-forming process | |
| Liu et al. | Medium Temperature Resistance Drawing-Tower Grating Array Fabrication | |
| Pissadakis | Laser processing of optical fibers: new photosensitivity findings, refractive index engineering and surface structuring | |
| Tang et al. | High-temperature resistance weak fiber Bragg grating array fabrication | |
| Homa et al. | High temperature exposure to Deuterium of optical fibers with Bragg gratings | |
| He et al. | Ultrafast-laser-induced negative-index fiber Bragg gratings with enhanced thermal stability | |
| JPH08286039A (en) | Manufacture of optical fiber type diffraction grating |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20201229 |
|
| RJ01 | Rejection of invention patent application after publication |