CN107032595B - Preparation method and device for optical fiber preform rod by doping alkali metal - Google Patents
Preparation method and device for optical fiber preform rod by doping alkali metal Download PDFInfo
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- CN107032595B CN107032595B CN201710399990.4A CN201710399990A CN107032595B CN 107032595 B CN107032595 B CN 107032595B CN 201710399990 A CN201710399990 A CN 201710399990A CN 107032595 B CN107032595 B CN 107032595B
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- 229910052783 alkali metal Inorganic materials 0.000 title claims abstract description 114
- 150000001340 alkali metals Chemical class 0.000 title claims abstract description 110
- 239000013307 optical fiber Substances 0.000 title claims abstract description 37
- 238000002360 preparation method Methods 0.000 title claims abstract description 9
- 239000011521 glass Substances 0.000 claims abstract description 57
- 238000010438 heat treatment Methods 0.000 claims abstract description 55
- 238000009413 insulation Methods 0.000 claims abstract description 26
- 238000007789 sealing Methods 0.000 claims abstract description 15
- 230000008021 deposition Effects 0.000 claims abstract description 12
- 238000012545 processing Methods 0.000 claims abstract description 8
- 238000005253 cladding Methods 0.000 claims abstract description 7
- 239000012792 core layer Substances 0.000 claims abstract description 6
- 239000003513 alkali Substances 0.000 claims abstract description 4
- 238000005019 vapor deposition process Methods 0.000 claims abstract 2
- 239000007789 gas Substances 0.000 claims description 62
- 239000012535 impurity Substances 0.000 claims description 17
- 238000000034 method Methods 0.000 claims description 17
- 239000010410 layer Substances 0.000 claims description 13
- 239000002994 raw material Substances 0.000 claims description 13
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 7
- 229910052760 oxygen Inorganic materials 0.000 claims description 7
- 239000001301 oxygen Substances 0.000 claims description 7
- 239000002808 molecular sieve Substances 0.000 claims description 6
- 238000012806 monitoring device Methods 0.000 claims description 6
- URGAHOPLAPQHLN-UHFFFAOYSA-N sodium aluminosilicate Chemical group [Na+].[Al+3].[O-][Si]([O-])=O.[O-][Si]([O-])=O URGAHOPLAPQHLN-UHFFFAOYSA-N 0.000 claims description 6
- 229910052736 halogen Inorganic materials 0.000 claims description 5
- 150000002367 halogens Chemical class 0.000 claims description 5
- 238000012544 monitoring process Methods 0.000 claims description 5
- 229910001508 alkali metal halide Inorganic materials 0.000 claims description 4
- 150000008045 alkali metal halides Chemical class 0.000 claims description 4
- 229910001413 alkali metal ion Inorganic materials 0.000 claims description 4
- 239000011261 inert gas Substances 0.000 claims description 4
- 229910052792 caesium Inorganic materials 0.000 claims description 3
- 229910052744 lithium Inorganic materials 0.000 claims description 3
- 229910052751 metal Inorganic materials 0.000 claims description 3
- 239000002184 metal Substances 0.000 claims description 3
- 229910052759 nickel Inorganic materials 0.000 claims description 3
- 229910052700 potassium Inorganic materials 0.000 claims description 3
- 229910052701 rubidium Inorganic materials 0.000 claims description 3
- 229910052708 sodium Inorganic materials 0.000 claims description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 2
- 229910052789 astatine Inorganic materials 0.000 claims description 2
- 229910052794 bromium Inorganic materials 0.000 claims description 2
- 229910052799 carbon Inorganic materials 0.000 claims description 2
- 229910052801 chlorine Inorganic materials 0.000 claims description 2
- 229910052731 fluorine Inorganic materials 0.000 claims description 2
- 230000006698 induction Effects 0.000 claims description 2
- 229910052740 iodine Inorganic materials 0.000 claims description 2
- 150000002500 ions Chemical class 0.000 claims description 2
- 239000002019 doping agent Substances 0.000 claims 1
- 239000000843 powder Substances 0.000 claims 1
- 238000000151 deposition Methods 0.000 abstract description 9
- 238000004519 manufacturing process Methods 0.000 abstract description 9
- 238000009826 distribution Methods 0.000 abstract description 8
- 238000009792 diffusion process Methods 0.000 description 8
- 238000004321 preservation Methods 0.000 description 7
- 238000012360 testing method Methods 0.000 description 7
- 230000005540 biological transmission Effects 0.000 description 5
- 238000004891 communication Methods 0.000 description 4
- 229910001414 potassium ion Inorganic materials 0.000 description 3
- WCUXLLCKKVVCTQ-UHFFFAOYSA-M Potassium chloride Chemical compound [Cl-].[K+] WCUXLLCKKVVCTQ-UHFFFAOYSA-M 0.000 description 2
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- 238000005229 chemical vapour deposition Methods 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 238000005530 etching Methods 0.000 description 2
- 239000000835 fiber Substances 0.000 description 2
- 229910021645 metal ion Inorganic materials 0.000 description 2
- IOLCXVTUBQKXJR-UHFFFAOYSA-M potassium bromide Chemical compound [K+].[Br-] IOLCXVTUBQKXJR-UHFFFAOYSA-M 0.000 description 2
- FGIUAXJPYTZDNR-UHFFFAOYSA-N potassium nitrate Chemical compound [K+].[O-][N+]([O-])=O FGIUAXJPYTZDNR-UHFFFAOYSA-N 0.000 description 2
- JHJLBTNAGRQEKS-UHFFFAOYSA-M sodium bromide Chemical compound [Na+].[Br-] JHJLBTNAGRQEKS-UHFFFAOYSA-M 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- -1 alkali metal salt Chemical class 0.000 description 1
- 239000010425 asbestos Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000004927 fusion Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000007431 microscopic evaluation Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 229910052895 riebeckite Inorganic materials 0.000 description 1
- 239000000523 sample Substances 0.000 description 1
- 229910000029 sodium carbonate Inorganic materials 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 229910052723 transition metal Inorganic materials 0.000 description 1
- 238000009827 uniform distribution Methods 0.000 description 1
- 238000007740 vapor deposition Methods 0.000 description 1
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Classifications
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- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
- C03B37/01—Manufacture of glass fibres or filaments
- C03B37/012—Manufacture of preforms for drawing fibres or filaments
- C03B37/014—Manufacture of preforms for drawing fibres or filaments made entirely or partially by chemical means, e.g. vapour phase deposition of bulk porous glass either by outside vapour deposition [OVD], or by outside vapour phase oxidation [OVPO] or by vapour axial deposition [VAD]
- C03B37/018—Manufacture of preforms for drawing fibres or filaments made entirely or partially by chemical means, e.g. vapour phase deposition of bulk porous glass either by outside vapour deposition [OVD], or by outside vapour phase oxidation [OVPO] or by vapour axial deposition [VAD] by glass deposition on a glass substrate, e.g. by inside-, modified-, plasma-, or plasma modified- chemical vapour deposition [ICVD, MCVD, PCVD, PMCVD], i.e. by thin layer coating on the inside or outside of a glass tube or on a glass rod
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B2201/00—Type of glass produced
- C03B2201/06—Doped silica-based glasses
- C03B2201/30—Doped silica-based glasses doped with metals, e.g. Ga, Sn, Sb, Pb or Bi
- C03B2201/50—Doped silica-based glasses doped with metals, e.g. Ga, Sn, Sb, Pb or Bi doped with alkali metals
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Manufacture, Treatment Of Glass Fibers (AREA)
Abstract
The invention relates to a preparation method and a device for alkali metal doping of an optical fiber preform, which are characterized in that the inner wall of a glass liner tube is subjected to deposition processing by adopting an in-tube vapor deposition process and comprises a deposition part cladding and a core layer, wherein the glass liner tube after deposition processing is placed in a heating insulation box, two ends of the glass liner tube are respectively connected with an air inlet tube and an air outlet tube through sealing joints, the other ends of the air inlet tube and the air outlet tube are communicated with an alkali metal vapor source to form a closed circulating doping air supply source, the temperature in the heating insulation box is set to be 1000-2200 ℃, and the air supply temperature provided by the alkali metal vapor source is 200-1500 ℃. The invention can simultaneously dope alkali metal in the whole glass liner tube after deposition, has simple and controllable production process, short alkali doping time and high production efficiency, has uniform content distribution of the doped alkali metal and good processing quality, and reduces the use cost of equipment.
Description
Technical Field
The invention relates to a preparation method and a device for doping alkali metal in an optical fiber preform, belonging to the technical field of optical fiber communication.
Background
Optical fiber communication has the characteristics of large transmission capacity, long transmission distance, high transmission speed and the like, and is widely applied to optical communication networks such as long-distance trunk networks, metropolitan area networks, access networks and the like. The reduction of the optical fiber attenuation coefficient can effectively improve the transmission distance of an optical fiber communication system, greatly reduce the number and cost of relay stations, and has important significance for optimizing the structure of the transmission system and reducing the operation cost, especially submarine optical fibers.
The viscosity matching between the core layer and the cladding layer of the optical fiber can be optimized by doping alkali metal in the core layer and the inner cladding layer of the optical fiber, and the attenuation of the optical fiber is effectively reduced. At present, the diffusion method is generally adopted to dope alkali metal elements into the quartz glass tube. The method comprises introducing alkali metal element into a tube by heating high-purity alkali metal element or alkali metal salt (purity of 99.9% or more) raw material vapor, and heating the glass tube with external local heat source to diffuse the alkali metal element into the inner surface of the glass tube. After doping, the glass tube is heated to be shrunk, and in order to remove transition metal elements such as Ni and Fe added while doping the alkali metal elements, the inner surface of the glass tube needs to be etched to a certain thickness.
Patents US20140127507a1, US9229160B2, CN102627400B, CN102603179A, etc. all heat the alkali metal raw material put into the glass tube by a continuously moving heat source, and dope the alkali metal into the inner wall of the glass tube by an in-tube diffusion method, however, the process takes a long time, the doped alkali metal additionally occupies the collapsing equipment for 6-8 hours, the deposited liner tube is accumulated, the production efficiency is low, and the local heat source heats the glass tube has the disadvantages that the heating time is increased, the running time of the heat source is long, and the alkali metal content distribution is not uniform enough; in order to remove the impurity elements in the core layer, the etching time is also increased.
Disclosure of Invention
The invention aims to solve the technical problem of providing a preparation method and a device for doping alkali metal in an optical fiber preform aiming at the defects in the prior art, wherein the preparation method and the device have the advantages of simple and controllable production process, short alkali doping time, high production efficiency, uniform distribution of the content of the doped alkali metal and good processing quality.
The technical scheme of the preparation method for alkali metal doping adopted by the invention to solve the problems is as follows:
the method is characterized in that the glass liner tube after deposition processing is placed in a heating insulation box, two ends of the glass liner tube are respectively connected with an air inlet tube and an air outlet tube through sealing joints, the other ends of the air inlet tube and the air outlet tube are communicated with an alkali metal steam source to form a closed circulating doping air supply source, the temperature inside the heating insulation box is set to be 1000-2200 ℃, and the temperature of the air supply provided by the alkali metal steam source is 200-1500 ℃.
According to the scheme, the alkali metal steam source comprises a heater, the alkali metal steam source is connected with the gas tank, gas in the gas tank is one or more of inert gas, oxygen, freon and other auxiliary gases, the gas tank is used for constantly keeping stable positive pressure of the whole gas supply source, the range of the pressure value is 10-10000 Pa, and 1000-2000 Pa is preferred.
According to the scheme, the air inlet pipe is connected with an impurity filter in series, the alkali metal steam enters the glass liner pipe after being filtered, and the impurity filter is a molecular sieve and can only pass through alkali metal ion gas but not Ni, Fe and other impurity ions.
According to the scheme, the purity of the alkali metal raw material is more than 99.0%, and the alkali metal raw material is preferably powdery.
According to the scheme, the alkali metal steam source pipeline is provided with the online gas concentration monitoring device, the effective concentration of the alkali metal element gas is monitored and adjusted, and the concentration (in terms of weight content) of the alkali metal gas is controlled to be 10-20000ppm by controlling the temperature of the heater and the input amount of the auxiliary gas of the gas tank.
According to the scheme, one or more glass liner tubes are placed in the heating and heat preservation box, alkali is doped during heating, and the whole or most of the glass liner tubes are placed in the heating and heat preservation box.
According to the scheme, the flow of gas in each glass liner tube is 500-2500 sccm.
According to the above scheme, the alkali metal vapor source is loaded with an alkali metal raw material, which is an alkali metal halide, i.e. a compound composed of an alkali metal element and a halogen, wherein the alkali metal element includes Li, Na, K, Rb or Cs, the halogen includes F, Cl, Br, I or At, and the alkali metal halide is any combination of the alkali metal element and the halogen, such as KCl, NaCl, KBr, NaBr, and the like, but is not limited to these four. The alkali metal raw material may be other compounds containing alkali metal elements such as Li, Na, K, Rb, Cs, etc., for example, Na2CO3，KNO3，Na2SO3And so on.
In the above scheme, the vapor deposition method in the tube includes Plasma Chemical Vapor Deposition (PCVD), Modified Chemical Vapor Deposition (MCVD) and other methods for preparing an optical fiber preform by deposition in a glass liner tube.
The technical scheme of the device is as follows: the glass liner tube heat treatment device comprises a heating insulation box, wherein two longitudinal ends of the heating insulation box penetrate through the heating insulation box and are provided with heat insulation end plates, two longitudinal ends of the heating insulation box are respectively and correspondingly provided with a sealing joint which is connected with two ends of a glass liner tube in a sealing mode, the sealing joint at one end is connected with an air inlet tube, the sealing joint at the other end is connected with an air outlet tube, and the other ends of the air inlet tube and the air outlet tube are communicated with an alkali metal steam source to form.
According to the scheme, the alkali metal steam source comprises a heater, the alkali metal steam source is connected with the gas tank, gas in the gas tank is one or more of inert gas, oxygen, freon and other auxiliary gases, the gas tank is used for constantly keeping stable positive pressure of the whole gas supply source, the range of the pressure value is 10-10000 Pa, and 1000-2000 Pa is preferred.
According to the scheme, the air inlet pipe is connected with an impurity filter in series, alkali metal steam enters the glass liner pipe after being filtered, and the impurity filter is a molecular sieve; the alkali metal steam source pipeline is provided with an online gas concentration monitoring device for monitoring and adjusting the effective concentration of the alkali metal element gas.
According to the scheme, the heating and heat preservation box comprises a heat preservation and insulation layer, the heat preservation and insulation layer is coated by metal and is internally provided with a heating device, the heat preservation and insulation layer is arranged around the box body and extends towards two ends and is matched with the length of the glass liner tube, the heating devices are symmetrically distributed around the glass liner tube, and the heating devices are resistance furnaces, carbon rods, induction furnaces or infrared heaters.
The invention has the beneficial effects that: 1. the invention can simultaneously carry out alkali metal doping on a plurality of deposited glass liner tubes, and has simple process and stable processing performance; the occupied time of the deposition or fusion equipment can be saved, the utilization rate and the production efficiency of the equipment are improved, and the production cost is reduced; 2. the heating and heat preservation box can heat the whole effective deposition area of the glass liner tube and dope the area simultaneously, so that the doping time is saved, the time can be shortened to about 1/6, and the distribution of the alkali metal content is optimized; 3. in the invention, the impurity filter is added for alkali metal doping, so that impurity metal ions in the doping gas are effectively removed, the requirement on the purity of the alkali metal raw material is lowered, and the production cost is reduced; meanwhile, the time for eliminating impurity metal ions by etching can be reduced, the doping efficiency is improved, and the use cost of equipment is reduced; 4. the on-line gas concentration monitoring device can monitor the concentration of the doped gas in the alkali metal doping, accurately control the content of the alkali metal gas in the doped gas in real time on line, ensure that the content distribution of the alkali metal doped into the glass is more uniform, and overcome the problem of non-uniform alkali metal distribution in the glass tube by a diffusion method, thereby obviously reducing the attenuation of the optical fiber.
Drawings
Fig. 1 is a schematic structural diagram of an apparatus according to an embodiment of the present invention.
Fig. 2 is a schematic structural view of a heating and insulating box according to an embodiment of the present invention.
Fig. 3 is a sectional view of the heating and insulating cabinet according to the embodiment of the present invention.
Fig. 4 is a sectional view of a heating and insulating cabinet according to an embodiment of the present invention.
FIG. 5 is a sectional view of a heating and insulating cabinet according to another embodiment of the present invention.
FIG. 6 is a graph showing the distribution of alkali metal content in the radial direction of an optical fiber according to the present invention and a glass tube heating diffusion method.
Detailed Description
The following further illustrates the invention in detail with reference to examples and the accompanying drawings.
Example (b):
a process for preparing the prefabricated optical fibre rod includes such steps as choosing KBr with 99.0% purity as alkali metal, choosing molecular sieve as impurity filter, and filling high-purity oxygen in gas tank. And monitoring the content of alkali metal potassium ions in the doping gas by using a mass spectrometer, normally controlling the temperature in the alkali metal steam source to be 750 ℃, the concentration of the alkali metal ions to be 10-20000ppm, preferably 2000ppm, the gas flow to be 1000sccm, and setting the temperature in the heating and heat-insulating box to be 1800 ℃. If the content of alkali metal potassium ions in the gas is low, the input of auxiliary gas oxygen can be reduced, and the temperature of an alkali metal steam source is increased; if the content of alkali metal potassium ions in the gas is higher, the input of auxiliary gas oxygen can be increased, and the temperature of the alkali metal steam source can be reduced.
The alkali metal doping device comprises a heating insulation box 11, wherein two longitudinal ends of the heating insulation box penetrate through the heating insulation box, namely two end heads of the two longitudinal ends of the heating insulation box are open, and are provided with heat insulation end plates 22, two longitudinal ends of the heating insulation box are respectively and correspondingly provided with a sealing joint 23 which is hermetically connected with two ends of a deposited glass liner tube 12, the sealing joint at one end is connected with an air inlet tube 13, the sealing joint at the other end is connected with an air outlet tube 14, the other ends of the air inlet tube and the air outlet tube are communicated with an alkali metal steam source 16 to form a closed circulating doping air supply source, the alkali metal steam source comprises a heater, and the heater can be a. The alkali metal steam source is connected with a gas tank 17, the gas inlet pipe is connected with an impurity filter 15 in series, the alkali metal steam enters the glass liner pipe after being filtered, and the impurity filter is a molecular sieve; the gas outlet pipe of the alkali metal steam source pipeline is connected in series with an on-line gas concentration monitoring device 18 for monitoring and adjusting the effective concentration of the alkali metal element gas. Heating insulation can is long case type, including thermal insulation layer 32, thermal insulation layer material is pottery or asbestos or quartzy, and thermal insulation layer is outer by the metal cladding, is provided with heating device 31 in the incasement, thermal insulation layer set up around the box to extend to both ends, with glass bushing pipe length phase-match, the glass bushing pipe slightly exceeds box both ends, the sealing joint's of being convenient for connection to by thermal-insulated end plate 22 configuration mutually, heating device 31 symmetric distribution around the glass bushing pipe.
The apparatus of fig. 1, with reference to fig. 4, was arranged with 4 liners, the specific diffusion steps being as follows:
1) placing 4 glass liner tubes 12 on which core cladding is deposited in a heating and insulating box 11, putting down a heat insulation baffle to ensure the heating and insulating box to be in a closed state, connecting each sealed joint pipeline, and raising the temperature of the heating and insulating box to 1800 ℃;
2) controlling the input amount of the alkali metal heater and the gas tank in the alkali metal vapor source, ensuring the concentration of alkali metal ions as a set value, continuously doping for 1 hour, normally setting the temperature of the alkali metal heater in the alkali metal vapor source to 750 ℃ and the O in the gas tank2The flow rate was 950 sccm;
3) and (3) lowering the doped tube to a collapsing bed, collapsing to obtain a solid core rod, drawing a prefabricated rod obtained by combining the core rod and an outer sleeve, wherein the content of alkali metal in the obtained optical fiber is 10-20000ppm (in terms of weight content), and the attenuation of the optical fiber at 1550nm is 0.150-0.175 dB/km.
In this embodiment, when the doping process parameters of the alkali metal raw material are different, the obtained preform is respectively drawn to prepare an optical fiber, and the obtained optical fiber is subjected to an attenuation test and an element content test, and the obtained results are shown in table 1.
TABLE 1 alkali metal doping Process parameters and resulting fiber test results
Comparative example:
after PCVD deposition of the core cladding, the glass liner tube is put down to a collapsing bed, and the optical fiber perform is prepared by adopting a doping method in the glass tube, which comprises the following steps:
1) 5-50 g of alkali metal raw material KBr (purity 99.99%) is placed in a large-diameter glass tube;
2) doping: the air inlet end of the glass liner tube is introduced with O2(flow rate 1200sccm), and further comprises C2F6(1-3 sccm), turning on a heater to heat the large-diameter glass tube, setting the temperature of the heater to be 700-800 ℃, enabling the alkali metal raw material to form a gas state due to heating, bringing the gas into the glass lining tube, and diffusing and doping the alkali metal in the glass lining tube;
4) after doping, a solid core rod is obtained by high-temperature heating and collapsing in a collapsing lathe, the preform obtained by combining the core rod and an outer sleeve is drawn, the content of alkali metal in the obtained optical fiber is 20-2000 ppm (in terms of weight content), and the attenuation of the optical fiber at 1550nm is 0.156-0.175 dB/km.
In this embodiment, when the doping process parameters of the alkali metal raw material are different, the obtained preform is respectively drawn to prepare an optical fiber, and the obtained optical fiber is subjected to an attenuation test and an element content test, and the obtained results are shown in table 2.
TABLE 2 alkali metal doping Process parameters and resulting fiber test results
Control test:
taking the example of doping the same content of alkali metal in the center of the optical fiber (for example, K, the weight content of the alkali metal in the center of the optical fiber is 20-200 ppm), the alkali metal content in the center of the optical fiber is the same, the results obtained by the method of the present invention and the glass tube heating diffusion method are shown in fig. 2 (the content of the alkali metal element in the core layer of the optical fiber is measured by electron probe microscopic analysis), and the distribution of the alkali metal content in the radial direction of the optical fiber in the method of the present invention and the glass tube heating diffusion method is compared. As can be seen from fig. 5: the alkali metal doped by the glass tube heating diffusion method forms concentration gradient on the inner wall and the outer wall of the glass, so that the alkali metal in the optical fiber is gradually reduced along the radial direction and is unevenly distributed.
Claims (8)
1. A preparation method of an optical fiber perform doped with alkali metal comprises the steps of carrying out deposition processing on the inner wall of a glass liner tube by adopting a vapor deposition process in a tube, wherein the glass liner tube comprises a deposition part cladding layer and a core layer, and the preparation method is characterized in that the glass liner tube after deposition processing is placed in a heating insulation box, two ends of the glass liner tube are respectively connected with an air inlet tube and an air outlet tube through sealing joints, the other ends of the air inlet tube and the air outlet tube are communicated with an alkali metal vapor source to form a closed circulating doping air supply source, the temperature in the heating insulation box is set to be 1000-2200 ℃, and the temperature of the air source provided by the alkali metal; one or more glass liner tubes are placed in the heating and insulating box, alkali is doped during heating, and the whole or most of the glass liner tubes are placed in the heating and insulating box; the alkali metal steam source comprises a heater, the alkali metal steam source is connected with a gas tank, gas in the gas tank is one or more of inert gas, oxygen and freon auxiliary gas, the alkali metal steam source is used for constantly keeping stable positive pressure of the whole gas supply source, and the range of the pressure value is 10-10000 Pa.
2. The method of claim 1, wherein said inlet tube is connected in series with an impurity filter, and the alkali metal vapor enters the glass liner tube after being filtered, and said impurity filter is a molecular sieve which can only pass through the alkali metal ion gas, but not through the Ni and Fe impurity ions; the purity of the alkali metal raw material is more than 99.0 percent, and the alkali metal raw material is selected to be powder.
3. The method of claim 1 or 2, wherein the alkali metal vapor source line is equipped with an on-line gas concentration monitoring device for monitoring and adjusting the effective concentration of the alkali metal element gas, and the concentration of the alkali metal gas is controlled to be 10 to 20000ppm by controlling the temperature of the heater and the input of the auxiliary gas in the gas tank.
4. The method for preparing an alkali metal doped optical fiber preform according to claim 1 or 2, wherein the gas flow rate in each glass liner tube is 500 to 2500 sccm.
5. A method of preparing an alkali metal dopant for an optical fiber preform according to claim 1 or 2 wherein the source of alkali metal vapor contains an alkali metal source which is an alkali metal halide, the alkali metal element comprises Li, Na, K, Rb or Cs, the halogen comprises F, Cl, Br, I or At, and the alkali metal halide is any combination of the alkali metal element and the halogen.
6. The device for doping the alkali metal in the optical fiber preform is characterized by comprising a heating and heat-insulating box, wherein two longitudinal ends of the heating and heat-insulating box penetrate through the heating and heat-insulating box and are provided with heat-insulating end plates, two longitudinal ends of the heating and heat-insulating box are respectively and correspondingly provided with a sealing joint which is connected with two ends of a glass liner tube in a sealing way, the sealing joint at one end is connected with an air inlet tube, the sealing joint at the other end is connected with an air outlet tube, and the other ends of the air inlet tube and the air outlet tube are communicated; the alkali metal steam source comprises a heater, the alkali metal steam source is connected with a gas tank, gas in the gas tank is one or more of inert gas, oxygen and freon auxiliary gas, the alkali metal steam source is used for constantly keeping stable positive pressure of the whole gas supply source, and the range of the pressure value is 10-10000 Pa.
7. The apparatus for doping alkali metal into an optical fiber preform according to claim 6, wherein the gas inlet tube is connected in series with an impurity filter, the alkali metal vapor enters the glass liner tube after being filtered, and the impurity filter is a molecular sieve; the alkali metal steam source pipeline is provided with an online gas concentration monitoring device for monitoring and adjusting the effective concentration of the alkali metal element gas.
8. The apparatus according to claim 6, wherein the heating and thermal insulating box comprises a thermal insulating layer, the thermal insulating layer is covered with metal and is provided with a heating device therein, the thermal insulating layer is disposed along the periphery of the box body and extends towards the two ends to match the length of the glass liner tube, the heating device is symmetrically disposed around the glass liner tube, and the heating device is a resistance furnace, a carbon rod, an induction furnace or an infrared heater.
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| CN108002698B (en) * | 2017-11-29 | 2020-01-14 | 长飞光纤光缆股份有限公司 | Method for manufacturing optical fiber preform |
| CN109231811A (en) * | 2018-11-16 | 2019-01-18 | 长飞光纤光缆股份有限公司 | A kind of preform implantation equipment |
| CN109133608B (en) * | 2018-11-16 | 2022-02-01 | 长飞光纤光缆股份有限公司 | Doping equipment for optical fiber preform |
| CN112441734B (en) * | 2019-08-30 | 2023-10-03 | 中天科技精密材料有限公司 | Optical fiber preform, preparation method thereof and powder rod deposition equipment |
| CN116589177B (en) * | 2023-05-06 | 2025-06-17 | 杭州富通通信技术股份有限公司 | Ultra-low loss optical fiber and preparation method thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101196593A (en) * | 2006-12-04 | 2008-06-11 | 德雷卡通信技术公司 | optical fiber |
| CN102603179A (en) * | 2011-01-20 | 2012-07-25 | 住友电气工业株式会社 | Optical fiber preform, optical fiber, and method of manufacturing optical fiber preform |
Family Cites Families (4)
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| JP6551109B2 (en) * | 2014-11-20 | 2019-07-31 | 住友電気工業株式会社 | Optical fiber |
| CN106007359B (en) * | 2016-07-22 | 2018-11-23 | 长飞光纤光缆股份有限公司 | A kind of preparation method of preform |
| CN106219962B (en) * | 2016-07-22 | 2019-09-10 | 长飞光纤光缆股份有限公司 | A method of preparing preform |
| CN106396362B (en) * | 2016-08-29 | 2019-04-16 | 长飞光纤光缆股份有限公司 | A kind of preparation method of preform |
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Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101196593A (en) * | 2006-12-04 | 2008-06-11 | 德雷卡通信技术公司 | optical fiber |
| CN102603179A (en) * | 2011-01-20 | 2012-07-25 | 住友电气工业株式会社 | Optical fiber preform, optical fiber, and method of manufacturing optical fiber preform |
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