WO2022036861A1 - 光纤及光纤制备方法 - Google Patents

光纤及光纤制备方法 Download PDF

Info

Publication number
WO2022036861A1
WO2022036861A1 PCT/CN2020/124907 CN2020124907W WO2022036861A1 WO 2022036861 A1 WO2022036861 A1 WO 2022036861A1 CN 2020124907 W CN2020124907 W CN 2020124907W WO 2022036861 A1 WO2022036861 A1 WO 2022036861A1
Authority
WO
WIPO (PCT)
Prior art keywords
layer
optical fiber
depressed
coating layer
coating
Prior art date
Application number
PCT/CN2020/124907
Other languages
English (en)
French (fr)
Inventor
油光磊
曹珊珊
朱钱生
徐海涛
苏海燕
刘志忠
薛驰
薛济萍
Original Assignee
中天科技光纤有限公司
江苏中天科技股份有限公司
江东科技有限公司
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by 中天科技光纤有限公司, 江苏中天科技股份有限公司, 江东科技有限公司 filed Critical 中天科技光纤有限公司
Priority to EP20923680.1A priority Critical patent/EP3978969A4/en
Publication of WO2022036861A1 publication Critical patent/WO2022036861A1/zh

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C25/00—Surface treatment of fibres or filaments made from glass, minerals or slags
    • C03C25/10—Coating
    • C03C25/104—Coating to obtain optical fibres
    • C03C25/1065—Multiple coatings
    • C03C25/109—Multiple coatings with at least one organic coating and at least one inorganic coating
    • 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]
    • 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]
    • C03B37/01446—Thermal after-treatment of preforms, e.g. dehydrating, consolidating, sintering
    • 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
    • C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
    • C03B37/01—Manufacture of glass fibres or filaments
    • C03B37/02—Manufacture of glass fibres or filaments by drawing or extruding, e.g. direct drawing of molten glass from nozzles; Cooling fins therefor
    • C03B37/025—Manufacture of glass fibres or filaments by drawing or extruding, e.g. direct drawing of molten glass from nozzles; Cooling fins therefor from reheated softened tubes, rods, fibres or filaments, e.g. drawing fibres from preforms
    • C03B37/027—Fibres composed of different sorts of glass, e.g. glass optical fibres
    • 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
    • C03B37/02—Manufacture of glass fibres or filaments by drawing or extruding, e.g. direct drawing of molten glass from nozzles; Cooling fins therefor
    • C03B37/025—Manufacture of glass fibres or filaments by drawing or extruding, e.g. direct drawing of molten glass from nozzles; Cooling fins therefor from reheated softened tubes, rods, fibres or filaments, e.g. drawing fibres from preforms
    • C03B37/027—Fibres composed of different sorts of glass, e.g. glass optical fibres
    • C03B37/02718—Thermal treatment of the fibre during the drawing process, e.g. cooling
    • C03B37/02727—Annealing or re-heating
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C25/00—Surface treatment of fibres or filaments made from glass, minerals or slags
    • C03C25/10—Coating
    • C03C25/48—Coating with two or more coatings having different compositions
    • C03C25/50—Coatings containing organic materials only
    • 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
    • G02B6/02395—Glass optical fibre with a protective coating, e.g. two layer polymer coating deposited directly on a silica cladding surface during fibre manufacture
    • 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
    • G02B6/036—Optical fibres with cladding with or without a coating core or cladding comprising multiple layers
    • G02B6/03616—Optical fibres characterised both by the number of different refractive index layers around the central core segment, i.e. around the innermost high index core layer, and their relative refractive index difference
    • G02B6/03661—Optical fibres characterised both by the number of different refractive index layers around the central core segment, i.e. around the innermost high index core layer, and their relative refractive index difference having 4 layers only
    • 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
    • C03B2201/08—Doped silica-based glasses doped with boron or fluorine or other refractive index decreasing dopant
    • C03B2201/12—Doped silica-based glasses doped with boron or fluorine or other refractive index decreasing dopant doped with fluorine
    • 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
    • C03B2201/31—Doped silica-based glasses doped with metals, e.g. Ga, Sn, Sb, Pb or Bi doped with germanium
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B2203/00—Fibre product details, e.g. structure, shape
    • C03B2203/10—Internal structure or shape details
    • C03B2203/22—Radial profile of refractive index, composition or softening point
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B2203/00—Fibre product details, e.g. structure, shape
    • C03B2203/10—Internal structure or shape details
    • C03B2203/22—Radial profile of refractive index, composition or softening point
    • C03B2203/23—Double or multiple optical cladding profiles
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B2207/00—Glass deposition burners
    • C03B2207/20—Specific substances in specified ports, e.g. all gas flows specified
    • 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
    • G02B6/02004—Optical fibres with cladding with or without a coating characterised by the core effective area or mode field radius
    • 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
    • G02B6/02033—Core or cladding made from organic material, e.g. polymeric material
    • G02B6/02038—Core or cladding made from organic material, e.g. polymeric material with core or cladding having graded refractive index

Definitions

  • the present application relates to the technical field of optical communication, and in particular, to an optical fiber and a method for preparing the optical fiber.
  • optical fibers With the increase of domestic optical network construction and the limitation of pipeline resources, the difficulty of laying optical fibers increases, and the optical fibers often encounter small-angle bending during the laying process.
  • the existing optical fibers have large size and poor bending resistance performance. , when bending at a small angle, it is easy to cause signal loss and cause transmission interruption.
  • a first aspect of the embodiments of the present application provides an optical fiber, including a core layer and a cladding layer surrounding the core layer, the cladding layer including an inner cladding layer, a first depressed layer, a second depressed layer, and an outer cladding arranged by cladding,
  • the single-sided width of the first depressed layer is greater than the single-sided width of the second depressed layer
  • the relative refractive index of the first depressed layer is -0.03% to -0.06%
  • the relative refractive index of the second depressed layer is The ratio is -0.08% to -0.15%
  • the outer layer further includes a coating layer
  • the coating layer includes a first coating layer and a second coating layer arranged by cladding, and the second coating layer
  • the first depressed layer and the second depressed layer are both fluorine-doped layers
  • the width of one side of the first depressed layer is 3-5 ⁇ m
  • the second depressed layer is 3-5 ⁇ m wide.
  • the width on one side of the depressed layer is 2 to 4 ⁇ m.
  • the refractive index of the second depressed layer is a parabolic distribution within the gradient, decreasing from the first depressed layer to the outer cladding, and the distribution index is 1.2-2.2.
  • the diameter of the outer cladding is 124 ⁇ m ⁇ 126 ⁇ m.
  • the elastic modulus of the first coating layer is 0.3-0.4 Mpa
  • the thickness of the first coating layer is 12 ⁇ m-20 ⁇ m
  • the first coating layer The glass transition temperature is -40°C ⁇ -60°C.
  • the Young's modulus of the second coating layer is greater than 600 Mpa, and the thickness of the second coating layer is 12 ⁇ m ⁇ 18 ⁇ m.
  • the mode field diameter of the optical fiber is 8.4 ⁇ m ⁇ 9.4 ⁇ m.
  • the macro-bending loss of the optical fiber at a wavelength of 1550 nm is less than 0.1 dB;
  • the macrobending loss at the wavelength of 1625nm is less than 0.25dB.
  • a second aspect of the embodiments of the present application further provides a method for preparing the above-mentioned optical fiber, and the optical fiber preparation method includes:
  • the first mandrel loose body is prepared, the first burner, the second burner and the third burner are used for deposition from the inside to the outside in turn, and SiCl4 gas, GeCl4 gas, oxygen, combustible gas and argon are introduced into the first burner to form a doped gas.
  • Core layer of germanium pass SiCl4 gas, oxygen, combustible gas and argon gas in the second torch to form the inner cladding of pure silicon; pass SiCl4 gas, fluorine-containing gas, oxygen, combustible gas and argon in the third torch gas to form the first subsidence layer;
  • the first mandrel loose body prepared above is placed in chlorine to carry out dehydroxylation treatment, and then a vitrification process and an annealing process are performed to form a mandrel;
  • the mandrel prepared above is used as a target rod, and a second sunken layer and an outer cladding are deposited on the outer surface of the mandrel from the inside to the outside to generate a second loose body of the mandrel, and the second loose body of the mandrel is sintered. to obtain an optical fiber preform;
  • optical fiber preform prepared above is subjected to a wire drawing process, and is processed through a secondary heating, thermal insulation and annealing process to obtain a bare optical fiber;
  • Cool the bare optical fiber prepared above perform primary coating and secondary coating on the bare optical fiber to obtain a first coating layer and a second coating layer, and apply ultraviolet light to the first coating layer and the The second coating layer is cured to obtain an optical fiber.
  • the segmented heating resistance wires in the resistance furnace are controlled to form a gradient temperature field gradually decreasing from 1250°C to 800°C.
  • the diameter of the coating layer is reduced under the condition that the diameter of the cladding layer remains unchanged, thereby reducing the size of the optical fiber;
  • the structure of double-layer depression and graded depression of the first depression layer and the second depression layer can limit the leakage of the optical signal in the bending state of the optical fiber and improve the macro-bending loss of the optical fiber.
  • FIG. 1 is a schematic cross-sectional view of an optical fiber provided by an embodiment of the present application.
  • FIG. 2 is a schematic diagram of a cross-sectional view of a refractive index of an optical fiber provided by an embodiment of the present application.
  • FIG. 3 is a flowchart of a method for preparing an optical fiber provided by an embodiment of the present application.
  • the step distribution is the distribution of the refractive index of the fiber.
  • the refractive indices of the core and the cladding are uniformly distributed, and there is a refractive index difference between them.
  • the core refractive index is greater than the cladding refractive index.
  • the cladding boundary has a step, so it is called a step-type distribution.
  • Optical cable cut-off wavelength ⁇ cc According to IEC standard 60793-1-44, it is defined as the wavelength at which the optical signal no longer propagates as a single-mode signal after propagating 22 meters in the optical fiber. During the test, the fiber is obtained by winding one circle with a radius of 14cm and two circles with a radius of 4cm.
  • Mode Field Diameter (MFD, Mode Field Diameter) is used to characterize the distribution of fundamental mode light in the core region of a single-mode fiber.
  • the light intensity of the fundamental mode is the largest at the axis line of the core region, and gradually weakens with the distance from the axis line.
  • Elastic modulus (Elastic Modulus), generally defined as: the stress in a unidirectional stress state divided by the strain in that direction. In the elastic deformation stage of the material, its stress and strain become proportional (that is, in accordance with Hooke's law), and its proportionality coefficient becomes the elastic modulus.
  • Young's modulus a physical quantity used to characterize the ability of a solid material to resist deformation, measures the stiffness of an isotropic elastomer. Young's modulus is a common type of elastic modulus.
  • the wet-to-dry coating method means that the coating of the bare fiber is coated by two coating molds, and the inner layer is first coated on the surface of the bare fiber, and then the outer layer is coated; the wet-to-wet coating method, It means that the coating of the bare fiber can be coated by a coating die at the same time.
  • VAD Vacuum Arc Degassing
  • OVD Outside Vapour Deposition
  • the glass transition temperature refers to the temperature corresponding to the transition from a glassy state to a highly elastic state. Glass transition is an inherent property of amorphous polymer materials, and is a macroscopic manifestation of the transformation of polymer motion forms.
  • the glass transition temperature is the lowest temperature at which the molecular chain segment can move, and its level is directly related to the flexibility of the molecular chain. The greater the flexibility of the molecular chain, the lower the glass transition temperature; the greater the rigidity of the molecular chain, the higher the glass transition temperature.
  • An embodiment of the present application provides an optical fiber, which includes a core layer and a cladding layer surrounding the core layer, the cladding layer includes an inner cladding layer, a first depressed layer, a second depressed layer and an outer cladding arranged by cladding.
  • the one-side width of the depressed layer is greater than the one-sided width of the second depressed layer, the relative refractive index of the first depressed layer is -0.03% to -0.06%, and the relative refractive index of the second depressed layer is - 0.08% ⁇ -0.15%
  • the outer layer also includes a coating layer, and the coating layer includes a first coating layer and a second coating layer that are covered and arranged, and the diameter of the second coating layer is 175 ⁇ m ⁇ 195 ⁇ m.
  • the diameter of the coating layer is reduced under the condition that the diameter of the cladding layer remains unchanged, thereby reducing the size of the optical fiber;
  • the structure of double-layer depressions and graded depressions is adopted in the fiber optic cable, which can limit the leakage of optical signals in the bending state of the optical fiber and improve the macro-bending loss of the optical fiber.
  • An optical fiber 100 provided by an embodiment of the present application includes a core layer 10 , a cladding layer 20 , and a coating layer 30 that are sequentially clad from the inside to the outside.
  • the optical fiber 100 is a single-mode optical fiber.
  • the refractive index distribution between the core layer 10 and the cladding layer 20 is a step distribution.
  • the refractive index profile of the optical fiber 100 adopts a step-by-step double-dimple structure inside the cladding layer 20 .
  • the core layer 10 is doped with germanium to increase its refractive index.
  • the refractive index of the core layer 10 relative to the pure silicon core is 0.35%-0.50%. In one embodiment, the relative refractive index of the core layer 10 is one of 0.35%, 0.38%, 0.40%, 0.42%, 0.44%, 0.46%, 0.48% or 0.50%.
  • the diameter of the core layer 10 is 8.4 ⁇ m ⁇ 9.4 ⁇ m. In one embodiment, the diameter of the core layer 10 is one of 8.4 ⁇ m, 8.6 ⁇ m, 8.8 ⁇ m, 9.0 ⁇ m, 9.2 ⁇ m or 9.4 ⁇ m.
  • the cladding layer 20 covers the outside of the core layer 10 , and the cladding layer 20 includes an inner cladding layer 21 , a first sunken layer 22 , a second sunken layer 23 and an outer cladding 24 , which are sequentially coated from the inside to the outside.
  • the inner cladding layer 21 is a pure silicon layer.
  • the refractive index distributions of the inner cladding layer 21 and the core layer 10 are step-type distributions, and the refractive index distribution of the inner cladding layer 21 relative to the pure silicon core is 0%-0.02%.
  • the refractive index of the inner cladding layer 21 relative to the pure silicon core is one of 0%, 0.005%, 0.01%, 0.015% or 0.02%.
  • the width of one side of the inner cladding layer 21 is 4 to 7.5 ⁇ m.
  • the one-side width of the inner cladding layer 21 may be one of 4 ⁇ m, 4.5 ⁇ m, 5.0 ⁇ m, 5.5 ⁇ m, 6.0 ⁇ m, 6.5 ⁇ m, 7.0 ⁇ m or 7.5 ⁇ m.
  • the first depressed layer 22 is a fluorine-doped layer, and the refractive index of the optical fiber 100 can be reduced by fluorine-doped treatment.
  • the refractive index of the first depressed layer 22 relative to the pure silicon core is -0.03% to -0.06%. In one embodiment, the relative refractive index of the first depressed layer 22 is one of -0.03%, -0.04%, -0.05%, and -0.06%.
  • the one-side width of the first sunken layer 22 is greater than the one-side width of the second sunken layer 23 .
  • the one-side width of the first depressed layer 22 is 3-5 ⁇ m. In one embodiment, the one-side width of the first depressed layer 22 may be one of 3.5 ⁇ m, 4.0 ⁇ m, 4.5 ⁇ m or 5 ⁇ m.
  • the second depressed layer 23 is a fluorine-doped layer, and the refractive index of the optical fiber 100 is further reduced by a deep fluorine-doped process, preventing the optical signal from leaking in an extremely bent state, and reducing the additional loss when the optical fiber 100 is bent.
  • the relative refractive index of the second sunken layer 23 is in a gradient inner parabolic distribution, and the distribution index ⁇ is 1.2-2.2.
  • the relative refractive index of the second sunken layer 23 is from the first sunken layer 22 to the outer envelope. Layer 24 is gradually lowered.
  • the relative refractive index of the second depressed layer 23 is -0.08% to -0.15%.
  • the relative refractive index of the second depressed layer 23 is -0.08%, -0.06%, -0.04%, -0.02%, 0%, 0.02%, 0.04%, 0.06%, 0.08%, 0.10 %, 0.12% or 0.15%.
  • the width of one side of the second sunken layer 23 is 2 to 4 ⁇ m. In one embodiment, the one-side width of the second sunken layer 23 may be one of 2.5 ⁇ m, 3.0 ⁇ m, 3.5 ⁇ m or 4 ⁇ m.
  • the outer layer 24 is a pure silicon layer, and the diameter of the outer layer 24 is 124 ⁇ m ⁇ 126 ⁇ m. In one embodiment, the diameter of the outer cladding 24 may be one of 124 ⁇ m, 124.5 ⁇ m, 125 ⁇ m, 125.5 ⁇ m or 126 ⁇ m.
  • the coating layer 30 includes a first coating layer 31 and a second coating layer 32 disposed on the outer layer 24 from the inside to the outside.
  • the first coating layer 31 adopts violet light coating resin, and the thickness of the first coating layer 31 is 12 ⁇ m ⁇ 20 ⁇ m. In one embodiment, the thickness of the first coating layer 31 may be one of 12 ⁇ m, 13 ⁇ m, 14 ⁇ m, 15 ⁇ m, 16 ⁇ m, 17 ⁇ m, 18 ⁇ m, 19 ⁇ m or 20 ⁇ m.
  • the elastic modulus of the first coating layer 31 is 0.3-0.4 Mpa. In one embodiment, the elastic modulus of the first coating layer 31 is one of 0.3Mpa, 0.32Mpa, 0.34Mpa, 0.36Mpa, 0.38Mpa or 0.4Mpa.
  • the second coating layer 32 adopts violet light coating resin, and the thickness of the second coating layer 32 is 12 ⁇ m ⁇ 18 ⁇ m.
  • the thickness of the second coating layer 32 may be one of 12 ⁇ m, 13 ⁇ m, 14 ⁇ m, 15 ⁇ m, 16 ⁇ m, 17 ⁇ m or 18 ⁇ m, and the diameter of the second coating layer 32 is 175 ⁇ m ⁇ 195 ⁇ m.
  • the diameter of the second coating layer 32 may be one of 175 ⁇ m, 180 ⁇ m, 185 ⁇ m, 190 ⁇ m or 195 ⁇ m.
  • the Young's modulus of the second coating layer 32 is greater than 600Mpa, which improves the mechanical strength of the optical fiber 100.
  • the present application by setting the modulus of the first coating layer 31 to be lower than the modulus of the second coating layer 32 , the additional loss of the optical fiber during bending can be reduced.
  • the present application reduces the diameter of the coating layer 30 under the condition that the diameter of the cladding layer 20 remains unchanged, so that the size of the optical fiber 100 is greatly reduced, and the core density of the optical cable per unit cross-sectional area is effectively increased by 190% , reduce the outer diameter of the optical cable by 50%.
  • optical fiber 100 provided in this application can be used to manufacture ultra-fine air-blown micro-cables and ultra-dense optical cables, and is applied to market demands such as fiber-to-the-home (FITH, Fiber to the home), 5G dense distribution construction, and data centers.
  • FITH fiber-to-the-home
  • 5G dense distribution construction 5G dense distribution construction
  • the cable cutoff wavelength of the optical fiber 100 is below 1260 nm, it is suitable for optical communication in the O-band to the L-band.
  • the mode field diameter of the optical fiber 100 is 8.4 ⁇ m ⁇ 9.4 ⁇ m. In one embodiment, the mode field diameter of the optical fiber 100 may be one of 8.4 ⁇ m, 8.6 ⁇ m, 8.8 ⁇ m, 9.0 ⁇ m, 9.2 ⁇ m, or 9.4 ⁇ m.
  • the zero-dispersion wavelength of the optical fiber 100 is 1300-1324 nm. In one embodiment, the zero dispersion wavelength of the optical fiber 100 is one of 1300 nm, 1305 nm, 1310 nm, 1315 nm, 1320 nm or 1324 nm.
  • the mode field diameter of the above-mentioned optical fiber 100 provided by the present application satisfies the mode field diameter standard of a single-mode optical fiber, so it can be compatible with conventional single-mode optical fibers (eg, G.652 optical fiber and bend-resistant G.657 optical fiber).
  • conventional single-mode optical fibers eg, G.652 optical fiber and bend-resistant G.657 optical fiber.
  • the optical fiber 100 has low macrobending loss.
  • the macro bending loss of the optical fiber 100 at a wavelength of 1550 nm is less than 0.1 dB in the state of bending for one turn; the macro bending loss of the optical fiber 100 at a wavelength of 1625 nm is The bending loss is less than 0.25dB.
  • FIG. 3 is a flowchart of an optical fiber preparation method provided by an embodiment of the present application.
  • the optical fiber preparation method is designed according to the refractive index structure of the optical fiber 100 and is used to prepare the optical fiber 100.
  • the optical fiber The preparation method includes the following steps:
  • the core layer, the inner cladding layer and the first sunken layer are obtained by continuous deposition processing using a VAD (Vacuum Arc Degassing) process.
  • VAD Vauum Arc Degassing
  • SiCl4 gas and GeCl4 gas are passed into the first torch through argon gas as a transport carrier.
  • the gas flow rate of GeCl gas may be 200ml/min; the corresponding gas flow rate of argon may be 200ml/min; the combustible gas may be hydrogen, and the gas flow rate of hydrogen may be 4ml/min;
  • the gas flow rate may be 35ml/min; the gas flow rate of SiCl4 gas may be 5ml/min, and the corresponding argon gas flow rate may be 150ml/min;
  • the flame temperature of the first torch may be 725°C.
  • the diameter of the obtained core layer is 8.4 ⁇ m to 9.4 ⁇ m, and the relative refractive index is 0.35% to 0.50%.
  • the SiCl4 gas was passed into the second torch via argon as a transport carrier.
  • the combustible gas may be hydrogen.
  • the gas flow rates of hydrogen and oxygen were 6ml/min and 60ml/min respectively; the gas flow rate of SiCl4 gas was 15ml/min, the corresponding argon gas flow rate was 150ml/min, and the flame temperature of the second torch was 1200°C.
  • the single-side width of the obtained inner cladding layer is 4-7.5 ⁇ m, and the refractive index relative to the pure silicon core is 0%-0.02%.
  • the fluorine-containing gas may be CF4 gas, and the combustible gas may be hydrogen.
  • the gas flow rate of SiCl4 gas is 15 ⁇ 20ml/min.
  • the gas flow rate of the SiCl4 gas is one of 15ml/min, 16ml/min, 17ml/min, 18ml/min, 19ml/min or 20ml/min.
  • the corresponding gas flow of argon may be 150 ml/min.
  • the gas flow rate of the fluorine-containing gas is 300 to 400 ml/min.
  • the gas flow rate of the fluorine-containing gas is one of 300ml/min, 320ml/min, 340ml/min, 360ml/min, 380ml/min or 400ml/min.
  • the corresponding gas flow of argon may be 200 ml/min.
  • the gas flow rates of oxygen and combustible gas were 35ml/min and 4ml/min, respectively.
  • the flame temperature in the third torch is 900-1100°C. In one embodiment, the flame temperature of the third burner is one of 900°C, 950°C, 1000°C, 1050°C or 1100°C.
  • the single-side width of the prepared first depressed layer is 3-5 ⁇ m, and the refractive index relative to the pure silicon core is -0.03% to -0.06%.
  • the temperature in the dehydroxylation treatment is controlled at 1200-1250°C.
  • the annealing process includes annealing at 1000°C to 1150°C for 2 to 4 hours to eliminate residual stress.
  • the second sunken layer and the outer cladding can be deposited on the outer surface of the core rod from the inside to the outside through the OVD process to generate the second loose core rod body, and the second loose core rod body is sintered to obtain the optical fiber prefabricated Great.
  • a fluorine-containing gas CF4 is introduced into the fourth torch, and the gas flow rate of the CF4 gas is 850-1000 ml/min.
  • the gas flow of the CF4 gas is 850ml/min, 860ml/min, 870ml/min, 880ml/min, 890ml/min, 900ml/min, 910ml/min, 920ml/min, 930ml/min, One of 940ml/min, 950ml/min, 960ml/min, 970ml/min, 980ml/min, 990ml/min or 1000ml/min.
  • the flame temperature of the fourth torch is 1000-1100°C.
  • the flame temperature of the fourth burner is one of 1000°C, 1020°C, 1040°C, 1060°C, 1080°C or 1100°C.
  • the one-side width of the second depressed layer is 2 to 4 ⁇ m, and the relative refractive index is -0.08% to -0.15%.
  • the optical fiber preform enters the drawing furnace from the top of the drawing furnace to be melted and drawn to obtain the bare optical fiber.
  • different drawing temperatures and drawing speeds can be set.
  • the wire drawing temperature includes 1950-2150° C.
  • the wire-drawing speed is 500-2500 m/min
  • the wire-drawing tension is 50 g-200 g.
  • the optical fiber preform enters a resistance furnace after drawing, and the optical fiber preform is subjected to secondary heating, heat preservation and annealing through the resistance furnace, and strong infrared heat radiation is generated through the uniform heat radiation method of resistance heating, To achieve the purpose of secondary heating annealing.
  • the resistance furnace is provided with infrared monitoring equipment, the infrared monitoring equipment is connected to the control terminal in communication, and the infrared monitoring equipment is used to transmit the monitored infrared output power to the control terminal, and the control terminal controls the control terminal.
  • the temperature in the resistance furnace ensures that the surface temperature of the optical fiber forms a gradient temperature field that gradually decreases from 1250°C to 800°C.
  • the resistance furnace is provided with segmented heating resistance wires, and the heating resistance wires can be arranged in segments according to the range of the gradient temperature field.
  • the heating resistance wire may be a silicon carbon resistance wire.
  • for the gradient temperature field of 1250° C. to 800° C.
  • the heating resistance wire can be divided into 4 sections, and each section corresponds to a different temperature range.
  • a gradient temperature field of 1250° C. to 800° C. can be realized in the resistance furnace.
  • the length of the heat preservation and annealing zone is 2-3m, so that the temperature fluctuation of the fiber surface is within the range of ⁇ 10°C, and the internal stress is fully released within the gradient annealing temperature range to reduce the Rayleigh heat dissipation caused by uneven density distribution.
  • the cooled and annealed optical fiber is coated through a coating die.
  • the primary coating and the secondary coating can be separately wet-dry coating through two coating dies.
  • the bare optical fiber is firstly coated by the first coating die to obtain the first coating. layer; then, the first coating layer is coated by a second coating die to obtain a second coating layer.
  • the primary coating and the secondary coating may be performed wet-to-wet coating by one coating die simultaneously, for example, the surface of the bare optical fiber may be simultaneously performed once by a third coating die Coating and secondary coating to obtain the first coating layer and the second coating layer.
  • the thickness of the first coating layer is 12 ⁇ m ⁇ 20 ⁇ m, the elastic modulus of the first coating layer is 0.3 ⁇ 0.4Mpa; the glass transition temperature of the first coating layer is -60°C ⁇ -40 °C.
  • the present application can ensure the normal operation of the optical fiber at low temperature.
  • the glass transition temperature of the first coating layer is relatively low, ranging from -40°C to -60°C, that is, the flexibility of the first coating layer is relatively large, so as to ensure that the optical fiber 100 is not brittle and normal at low temperatures. run.
  • the thickness of the second coating layer is 12 ⁇ m ⁇ 18 ⁇ m, and the diameter of the second coating layer is 175 ⁇ m ⁇ 195 ⁇ m.
  • the Young's modulus of the second coating layer is greater than 600 Mpa, which ensures the mechanical strength of the optical fiber 100 .
  • the coating die is filled with acrylic resin paint, the coating die includes a guide die hole and an exit die hole, the size of the exit die hole of the coating die is designed, and the gap of the primary exit die hole relative to the bare optical fiber is kept at 15-20 ⁇ m , an internal centering pressure is formed between the guide die hole and the exit die hole to ensure that the bare fiber is in the center of the coating die, preventing the bare fiber from rubbing against the edge of the coating die and causing microcracks in the fiber, reducing the The strength of the fiber during stretching.
  • the resin coating of the bare optical fiber needs to be cured by ultraviolet light.
  • a UV (Ultra-Violet Ray, ultraviolet) light source is used.
  • the input power of the ultraviolet light source is 2KW to 7KW, and the radiation energy of the light source is 18 ⁇ 25W/cm 2 , 90% of the radiation wavelength of the light source is concentrated in the range of 365nm-405nm.
  • the input power of the UV light source can be automatically adjusted steplessly from 0% to 100% according to the wire drawing speed.
  • the input power of the UV light source is proportional to the wire drawing speed. the higher the input power.
  • the power of primary curing (corresponding to primary coating) is controlled at 300W-1500W, and the power of secondary curing (corresponding to secondary coating) is controlled at 500W-6000W.
  • the curing degree of the two-layer coating layer is at the level of 90% to 95%, which realizes the full curing of the coating layer resin and avoids the problem of additional attenuation of the optical fiber caused by over-curing.
  • the optical fiber 100 is taken up into a coil through a pulling device.
  • adjusting the take-up tension of the optical fiber to 40g-65g can reduce the external stress when the optical fibers 100 are superimposed, reduce the additional loss caused by the micro-bending of the optical fibers 100, and keep the attenuation of the optical fibers 100 at a low level.
  • a fixed tension is applied, and the fixed tension can be 40g, 45g, 50g, 55g, 60g and 65g.
  • an optimal tension is applied according to the number of bending turns and the bending radius of the optical fiber, so as to minimize the external stress when the optical fibers are superimposed.
  • the mapping relationship between the optimal tension and the number of bending turns and the bending radius is preset.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Organic Chemistry (AREA)
  • Materials Engineering (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Manufacturing & Machinery (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Optics & Photonics (AREA)
  • General Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Surface Treatment Of Glass Fibres Or Filaments (AREA)
  • Optical Fibers, Optical Fiber Cores, And Optical Fiber Bundles (AREA)

Abstract

一种光纤（100）及其制备方法。光纤（100）包括芯层（10）与围绕芯层（10）的包层（20），包层（20）包括包覆设置的内包层（21）、第一下陷层（22）、第二下陷层（23）与外包层（24），第一下陷层（22）的单侧宽度大于第二下陷层（23）的单侧宽度，第一下陷层（22）的相对折射率为-0.03％～-0.06％，第二下陷层（23）的相对折射率为-0.08％～-0.15％，外包层（24）外还包括涂覆层（30），涂覆层（30）包括包覆设置的第一涂覆层（31）与第二涂覆层（32），第二涂覆层（32）的直径为175μm～195μm。能够降低光纤（100）尺寸，提高光纤（100）的抗弯曲性能。

Description

光纤及光纤制备方法 技术领域
本申请涉及光通信技术领域，尤其涉及一种光纤及光纤制备方法。
背景技术
目前，国内光纤光缆厂家在小尺寸光纤领域处于试验和探索阶段，市场上常规单模光纤的最小尺寸为200μm，包层直径为125μm，涂层直径为250μm，采用内外涂层两层保护。如何设计适用于超高密度光缆的小尺寸抗弯曲光纤，且光纤性能完全满足使用要求并没有公开报道。
随着国内光网络建设的增多以及管道资源的限制，光纤的敷设难度增加，且光纤在敷设过程中，经常会遇到小角度弯曲，现有的光纤由于其尺寸较大、抗弯曲性能不佳，在进行小角度弯曲时，很容易造成信号损失，造成传输中断。
发明内容
鉴于此，有必要提出一种光纤及光纤制备方法，能够降低光纤尺寸，提高光纤的抗弯曲性能。
本申请实施例第一方面提供一种光纤，包括芯层与围绕所述芯层的包层，所述包层包括包覆设置的内包层、第一下陷层、第二下陷层与外包层，所述第一下陷层的单侧宽度大于所述第二下陷层的单侧宽度，所述第一下陷层的相对折射率为-0.03％～-0.06％，所述第二下陷 层的相对折射率为-0.08％～-0.15％，所述外包层外还包括涂覆层，所述涂覆层包括包覆设置的第一涂覆层与第二涂覆层，所述第二涂覆层的直径为175μm～195μm。
进一步地，在本申请提供的上述光纤中，所述第一下陷层与所述第二下陷层均为掺氟层，所述第一下陷层的单侧宽度为3～5μm，所述第二下陷层的单侧宽度为2～4μm。
进一步地，在本申请提供的上述光纤中，所述第二下陷层的折射率为梯度内抛物线形分布，自所述第一下陷层至所述外包层递减，分布指数为1.2～2.2。
进一步地，在本申请提供的上述光纤中，所述外包层直径为124μm～126μm。
进一步地，在本申请提供的上述光纤中，所述第一涂覆层的弹性模量为0.3～0.4Mpa，所述第一涂覆层的厚度为12μm～20μm，所述第一涂覆层的玻璃化转变温度为-40℃～-60℃。
进一步地，在本申请提供的上述光纤中，所述第二涂覆层的杨氏模量大于600Mpa，所述第二涂覆层的厚度为12μm～18μm。
进一步地，在本申请提供的上述光纤中，所述光纤的模场直径为8.4μm～9.4μm。
进一步地，在本申请提供的上述光纤中，当所述光纤的弯曲半径为7.5mm时，在弯曲1圈状态下，所述光纤在波长1550nm时的宏弯曲损耗小于0.1dB；所述光纤在波长1625nm时的宏弯曲损耗小于0.25dB。
本申请实施例第二方面还提供一种制备上述光纤的方法，所述光纤制备方法包括：
制备第一芯棒松散体，采用第一喷灯、第二喷灯及第三喷灯由内 向外依次进行沉积，在第一喷灯中通入SiCl4气体、GeCl4气体、氧气、可燃气体及氩气，形成掺锗的芯层；在第二喷灯中通入SiCl4气体、氧气、可燃气体及氩气，形成纯硅的内包层；在第三喷灯中通入SiCl4气体，含氟气体，氧气，可燃气体和氩气，形成第一下陷层；
将上述制备的第一芯棒松散体置于氯气中进行脱羟处理，然后进行玻璃化工艺与退火工艺形成芯棒；
将上述制备的芯棒作为靶棒，在芯棒的外表面由内而外沉积第二下陷层与外包层，产生第二芯棒松散体，并对所述第二芯棒松散体进行烧结处理得到光纤预制棒；
将上述制备的光纤预制棒进行拉丝处理，并通过二次加热保温退火工艺处理，得到裸光纤；
冷却上述制备的裸光纤，对所述裸光纤进行一次涂覆与二次涂覆，得到第一涂覆层与第二涂覆层，并通过紫外光对所述第一涂覆层与所述第二涂覆层进行固化处理得到光纤。
进一步地，在本申请提供的上述光纤制备方法中，在二次加热保温退火工艺中，控制电阻炉中分节加热电阻丝形成1250℃～800℃逐步降低的梯度温场。
本申请实施例提供的光纤及光纤制备方法，在包层的直径不变的情况下，降低涂层的直径，进而降低光纤的尺寸；此外，本申请提及的光纤通过在包层折射率设计中采用第一下陷层与第二下陷层双层凹陷、分级凹陷的结构，能够限制光纤在弯曲状态下光信号的泄露，改善光纤的宏弯曲损耗。
附图说明
图1是本申请一实施例提供的光纤的一剖面示意图。
图2是本申请一实施例提供的光纤的折射率剖面示意图。
图3是本申请一实施例提供的光纤制备方法的流程图。
如下具体实施方式将结合上述附图进一步说明本发明。
主要元件符号说明
光纤 100
芯层 10
包层 20
内包层 21
第一下陷层 22
第二下陷层 23
外包层 24
涂覆层 30
第一涂覆层 31
第二涂覆层 32
具体实施方式
为了能够更清楚地理解本发明的上述目的、特征和优点，下面结合附图和具体实施例对本发明进行详细描述。需要说明的是，在不冲突的情况下，本申请的实施例及实施例中的特征可以相互组合。
在下面的描述中阐述了很多具体细节以便于充分理解本发明，所描述的实施例是本发明一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本发明保护的 范围。
除非另有定义，本文所使用的所有的技术和科学术语与属于本发明的技术领域的技术人员通常理解的含义相同。本文中在本发明的说明书中所使用的术语只是为了描述具体的实施例的目的，不是旨在于限制本发明。
本发明中涉及的一些术语的定义和说明如下。
阶跃型分布就是光纤的折射率的分布方式，纤芯和包层的折射率都是均匀分布，而它们之间有一个折射率差，纤芯折射率大于包层折射率，在纤芯和包层边界有一个台阶，所以称之为阶跃型分布。
光缆截止波长λcc：根据IEC的标准60793-1-44中定义为光信号在光纤中传播了22米之后不再作为单模信号进行传播的波长。在测试时需通过对光纤绕一个半径14cm的圈，两个半径4cm的圈来测试获得。
模场直径(MFD，Mode Field Diameter)，用来表征在单模光纤的纤芯区域基模光的分布状态。基模在纤芯区域轴心线处光强最大，并随着偏离轴心线的距离增大而逐渐减弱。
弹性模量(Elastic Modulus)，一般定义为：单向应力状态下应力除以该方向的应变。材料在弹性形变阶段，其应力和应变成正比例关系(即符合胡克定律)，其比例系数成为弹性模量。
杨氏模量(Young's modulus)，用于表征固体材料抵抗形变能力的物理量，衡量的是一个各向同性弹性体的刚度。杨氏模量是弹性模量中常见的一种。
湿对干涂覆方式，是指裸光纤的涂层分别被两个涂覆模具涂覆，先在裸光纤表面进行内层涂覆，然后再进行外层涂覆；湿对 湿涂覆方式，是指裸光纤的涂层能同时经过一个涂覆模具涂覆。
VAD(Vacuum Arc Degassing)是指汽相轴向沉积法；OVD(Outside Vapour Deposition)是指外部汽相沉积法。
玻璃化转变温度(Tg)是指由玻璃态转变为高弹态所对应的温度。玻璃态转变是非晶态高分子材料固有的性质，是高分子运动形式转变的宏观体现。玻璃化温度是分子链段能运动的最低温度，其高低与分子链的柔性有直接关系。分子链的柔性越大，玻璃化温度就低；分子链的刚性越大，玻璃化温度就高。
本申请实施例提供一种光纤，包括芯层与围绕所述芯层的包层，所述包层包括包覆设置的内包层、第一下陷层、第二下陷层与外包层，所述第一下陷层的单侧宽度大于所述第二下陷层的单侧宽度，所述第一下陷层的相对折射率为-0.03％～-0.06％，所述第二下陷层的相对折射率为-0.08％～-0.15％，所述外包层外还包括涂覆层，所述涂覆层包括包覆设置的第一涂覆层与第二涂覆层，所述第二涂覆层的直径为175μm～195μm。
本申请实施例提供的光纤及光纤制备方法，在包层的直径不变的情况下，降低涂层的直径，进而降低光纤的尺寸；此外，本申请提及的光纤通过在包层折射率设计中采用双层凹陷、分级凹陷的结构，能够限制光纤在弯曲状态下光信号的泄露，改善光纤的宏弯曲损耗。下面结合附图，对本申请的一些实施方式作详细说明。
请一并参阅图1与图2，本申请实施例提供的光纤100包括由内而外依次包覆设置的芯层10、包层20及涂覆层30。在一实施方式中，所述光纤100为单模光纤。所述芯层10与所述包层20间的折射率分布呈阶跃型分布。所述光纤100的折射率剖面采用所述包层20内部逐级双凹陷结构。
所述芯层10掺锗，用于提高其折射率。所述芯层10相对纯硅芯的折射率为0.35％～0.50％。在一实施方式中，所述芯层10的相对折射率为0.35％、0.38％、0.40％、0.42％、0.44％、0.46％、0.48％或者0.50％中一种。所述芯层10的直径为8.4μm～9.4μm，在一实施方式中，所述芯层10的直径为8.4μm、8.6μm、8.8μm、9.0μm、9.2μm或者9.4μm中一种。
所述包层20包覆于所述芯层10外侧，所述包层20包括由内而外依次包覆设置的内包层21、第一下陷层22、第二下陷层23与外包层24。
所述内包层21为纯硅层。所述内包层21与所述芯层10的折射率分布呈阶跃型分布，所述内包层21相对于纯硅芯的折射率为0％～0.02％。在一实施方式中，所述内包层21相对于纯硅芯的折射率为0％、0.005％、0.01％、0.015％或者0.02％中一种。所述内包层21的单侧宽度为4～7.5μm。在一实施方式中，所述内包层21的单侧宽度可以为4μm、4.5μm、5.0μm、5.5μm、6.0μm、6.5μm、7.0μm或者7.5μm中一种。
所述第一下陷层22为掺氟层，通过掺氟处理，能够降低光纤100的折射率。所述第一下陷层22的相对纯硅芯的折射率为-0.03％～-0.06％。在一实施方式中，所述第一下陷层22的相对折射率为-0.03％、-0.04％、-0.05％以及-0.06％中一种。所述第一下陷层22的单侧宽度大于所述第二下陷层23的单侧宽度。所述第一下陷层22的单侧宽度为3～5μm，在一实施方式中，所述第一下陷层22的单侧宽度可以为3.5μm、4.0μm、4.5μm或者5μm中一种。
所述第二下陷层23为掺氟层，通过深掺氟工艺进一步降低光纤100的折射率，阻止其在极度弯曲状态下的光信号泄露，降低光纤100 弯曲时的附加损耗。所述第二下陷层23的相对折射率为梯度内抛物线形分布方式，分布指数ɑ在1.2～2.2，所述第二下陷层23的相对折射率自所述第一下陷层22至所述外包层24逐步降低。所述第二下陷层23的相对折射率为-0.08％～-0.15％。在一实施方式中，所述第二下陷层23的相对折射率为-0.08％、-0.06％、-0.04％、-0.02％、0％、0.02％、0.04％、0.06％、0.08％、0.10％、0.12％或者0.15％中一种。所述第二下陷层23的单侧宽度为2～4μm。在一实施方式中，所述第二下陷层23的单侧宽度可以为2.5μm、3.0μm、3.5μm或者4μm中一种。
所述外包层24为纯硅层，所述外包层24直径为124μm～126μm。在一实施方式中，所述外包层24的直径可以为124μm、124.5μm、125μm、125.5μm或者126μm中一种。
所述涂覆层30包括由内而外包覆于所述外包层24设置的第一涂覆层31与第二涂覆层32。
所述第一涂覆层31采用紫光涂覆树脂，所述第一涂覆层31的厚度为12μm～20μm。在一实施方式中，所述第一涂覆层31的厚度可以为12μm、13μm、14μm、15μm、16μm、17μm、18μm、19μm或者20μm中一种。所述第一涂覆层31的弹性模量为0.3～0.4Mpa。在一实施方式中，所述第一涂覆层31的弹性模量为0.3Mpa、0.32Mpa、0.34Mpa、0.36Mpa、0.38Mpa或者0.4Mpa中一种。
所述第二涂覆层32采用紫光涂覆树脂，所述第二涂覆层32的厚度为12μm～18μm。在一实施方式中，所述第二涂覆层32的厚度可以为12μm、13μm、14μm、15μm、16μm、17μm或者18μm的一种，所述第二涂覆层32的直径为175μm～195μm。在一实施方式中，所述第二涂覆层32的直径可以为175μm、180μm、185μm、190μm或者195μm中一种。所述第二涂覆层32的杨氏模量大于600Mpa，提升光 纤100的机械强度。本申请通过设置所述第一涂覆层31的模量低于所述第二涂覆层32的模量，能够降低光纤在弯曲时的附加损耗。此外，本申请在所述包层20的直径尺寸不变的情况下，降低所述涂覆层30的直径，使得光纤100的尺寸大幅降低，有效提升单位横截面积光缆的纤芯密度190％，降低光缆外径50％。
本申请提供的上述光纤100可用于制造超细气吹微缆、超密度光缆，应用于光纤到户(FITH，Fiber to the home)、5G密集分布建设、数据中心等市场需求中。
所述光纤100的光缆截止波长在1260nm以下时，适用于O波段到L波段全波段的光通信。
所述光纤100的模场直径为8.4μm～9.4μm。在一实施方式中，所述光纤100的模场直径可以为8.4μm、8.6μm、8.8μm、9.0μm、9.2μm或者9.4μm中一种。所述光纤100的零色散波长为1300～1324nm。在一实施方式中，所述光纤100的零色散波长为1300nm、1305nm、1310nm、1315nm、1320nm或者1324nm中一种。本申请提供的上述光纤100的模场直径满足单模光纤的模场直径标准，因此，其能够与常规单模光纤(例如，G.652光纤与抗弯曲型G.657光纤)兼容。
所述光纤100具有较低的宏弯曲损耗。示例性地，当所述光纤100的弯曲半径为7.5mm时，在弯曲1圈状态下，所述光纤100在波长1550nm时的宏弯曲损耗小于0.1dB；所述光纤100在波长1625nm时的宏弯曲损耗小于0.25dB。
请参阅图3，图3是本申请一实施例提供的光纤制备方法的流程图，所述光纤制备方法按照上述光纤100的折射率结构设计，用于制备上述光纤100，具体地，所述光纤制备方法包括如下步骤：
S31、制备第一芯棒松散体，采用第一喷灯、第二喷灯及第三喷 灯由内向外依次进行沉积，在第一喷灯中通入SiCl4气体、GeCl4气体、氧气、可燃气体及氩气，形成掺锗的芯层；在第二喷灯中通入SiCl4气体、氧气、可燃气体及氩气，形成纯硅的内包层；在第三喷灯中通入SiCl4气体，含氟气体，氧气，可燃气体和氩气，形成第一下陷层；
采用VAD(Vacuum Arc Degassing)工艺连续沉积处理得到所述芯层、所述内包层与所述第一下陷层。
优选地，在制备芯层的工艺过程中，SiCl4气体和GeCl4气体通过氩气作为运输载体通入第一喷灯中。在一实施方式中，GeCl4气体的气体流量可为200ml/min；对应的氩气的气体流量可为200ml/min；所述可燃气体可以为氢气，氢气的气体流量可为4ml/min；氧气的气体流量可为35ml/min；SiCl4气体的气体流量可为5ml/min，对应的氩气的气体流量为150ml/min；第一喷灯的火焰温度可为725℃。制得的芯层的直径为8.4μm～9.4μm，相对折射率为为0.35％～0.50％。
在制备内包层的工艺过程中，SiCl4气体通过氩气作为运输载体通入第二喷灯中。在一实施方式中，所述可燃气体可为氢气。氢气和氧气的气体流量分别为6ml/min和60ml/min；SiCl4气体的气体流量为15ml/min，对应的氩气的气体流量为150ml/min，第二喷灯的火焰温度为1200℃。制得的内包层的单侧宽度为4～7.5μm，相对于纯硅芯的折射率为0％～0.02％。
在制备第一下陷层的工艺过程中，所述含氟气体可为CF4气体，所述可燃气体可为氢气。SiCl4气体的气体流量为15～20ml/min。在一实施方式中，SiCl4气体的气体流量为15ml/min、16ml/min、17ml/min、18ml/min、19ml/min或者20ml/min中一种。对应的氩气的气体流量可为150ml/min。含氟气体的气体流量300～400ml/min。在 一实施方式中，含氟气体的气体流量为300ml/min、320ml/min、340ml/min、360ml/min、380ml/min或者400ml/min中一种。对应的氩气的气体流量可为200ml/min。氧气和可燃气体的气体流量分别为35ml/min和4ml/min。所述第三喷灯中的火焰温度900～1100℃。在一实施方式中，所述第三喷灯的火焰温度为900℃、950℃、1000℃、1050℃或者1100℃中一种。制得的第一下陷层的单侧宽度为3～5μm，相对纯硅芯的折射率为-0.03％～-0.06％。
S32、将上述制备的第一芯棒松散体置于氯气中进行脱羟处理，然后进行玻璃化工艺与退火工艺形成芯棒。
优选地，脱羟处理中温度控制在1200～1250℃。退火工艺包括在1000℃～1150℃下退火2～4小时，以消除残余应力。
S33、将上述制备的芯棒作为靶棒，在芯棒的外表面由内而外沉积第二下陷层与外包层，产生第二芯棒松散体，并对所述第二芯棒松散体进行烧结处理得到光纤预制棒。
优选地，可通过OVD工艺在芯棒的外表面由内而外沉积第二下陷层与外包层，产生第二芯棒松散体，并对所述第二芯棒松散体进行烧结处理得到光纤预制棒。
在第二下陷层的工艺过程中，在第四喷灯中通入含氟气体CF4，CF4气体的气体流量850～1000ml/min。在一实施方式中，所述CF4气体的气体流量为850ml/min、860ml/min、870ml/min、880ml/min、890ml/min、900ml/min、910ml/min、920ml/min、930ml/min、940ml/min、950ml/min、960ml/min、970ml/min、980ml/min、990ml/min或者1000ml/min中一种。第四喷灯的火焰温度为1000～1100℃。在一实施方式中，所述第四喷灯的火焰温度为1000℃、1020℃、1040℃、1060℃、1080℃或者1100℃中一种。所述第二下陷层的单侧宽度为 2～4μm，相对折射率为-0.08％～-0.15％。
S34、将上述制备的光纤预制棒进行拉丝处理，并通过二次加热保温退火工艺处理，得到裸光纤。
光纤预制棒从拉丝炉的顶部进入拉丝炉进行熔融拉丝处理可制得裸光纤。优选地，根据光纤预制棒的棒径不同，可设置不同的拉丝温度与拉丝速度。在一实施方式中，所述拉丝温度包括1950～2150℃，所述拉丝速度为500～2500m/min，拉丝张力为50g～200g。
在本申请的至少一实施方式中，光纤预制棒拉丝完成后进入电阻炉，通过电阻炉对光纤预制棒进行二次加热保温退火，通过电阻加热的均匀热辐射方式，产生强烈的红外热辐射，达到二次加热退火的目的。
所述电阻炉中设有红外监测设备，所述红外监测设备与控制终端通信连接，所述红外监测设备用于将监测到的红外输出功率传输至所述控制终端，所述控制终端控制所述电阻炉内温度，保证光纤表面温度形成1250℃～800℃逐步降低的梯度温场。示例性地，所述电阻炉内设有分节加热电阻丝，所述加热电阻丝可根据梯度温场的范围分节设置。在一实施方式中，所述加热电阻丝可以为硅碳电阻丝。示例性地，对于本申请提及的1250℃～800℃的梯度温场，所述加热电阻丝可分为4节，每一节对应不同的温度范围。通过所述控制终端独立控制4节加热电阻丝，能够在电阻炉内实现1250℃～800℃的梯度温场。保温退火区长度为2～3m，使得光纤表面的温度波动在±10℃范围内，在梯度退火温度区间内充分释放内应力，减少密度分布不均匀导致的瑞利散热。
S35、冷却上述制备的裸光纤，对所述裸光纤进行一次涂覆与二次涂覆得到第一涂覆层与第二涂覆层，并通过紫外光对所述第一涂覆 层与所述第二涂覆层进行固化处理得到光纤。
在本申请的至少一实施方式中，冷却退火后的光纤经涂覆模具进行涂覆。所述一次涂覆与所述二次涂覆可以分别通过两个涂覆模具进行分开湿干涂覆，例如，先通过第一涂覆模具对所述裸光纤进行涂覆，得到第一涂覆层；接着，通过第二涂覆模具对所述第一涂覆层进行涂覆，得到第二涂覆层。在其他实施方式中，所述一次涂覆与所述二次涂覆可以同时通过一个涂覆模具进行湿对湿涂覆，例如，通过第三涂覆模具同时对所述裸光纤的表面进行一次涂覆与二次涂覆，得到第一涂覆层与第二涂覆层。所述第一涂覆层的厚度为12μm～20μm，所述第一涂覆层的弹性模量为0.3～0.4Mpa；所述第一涂覆层的玻璃化转变温度为-60℃～-40℃。本申请能够保证光纤在低温下正常运行。所述第一涂覆层的玻璃化转变温度较低，为-40℃～-60℃，也即所述第一涂覆层的柔性较大，从而保证光纤100在低温下不脆化、正常运行。所述第二涂覆层的厚度为12μm～18μm，所述第二涂覆层的直径为175μm～195μm。所述第二涂覆层的杨氏模量大于600Mpa，保证光纤100的机械强度。
所述涂覆模具内充满丙烯酸树脂涂料，所述涂覆模具包括引导模孔与出口模孔，设计涂覆模具的出口模孔尺寸，一次出口模孔相对于裸光纤的空隙保持在15～20μm，在所述引导模孔和所述出口模孔之间形成内部对中压力，保证裸光纤在涂覆模具处于中心位置，防止裸光纤擦到涂覆模具的边缘而导致光纤产生微裂纹，降低光纤在拉伸过程中的强度。
所述裸光纤的树脂涂覆后需经过紫外光固化，在紫外光固化工艺中，采用UV(Ultra-Violet Ray，紫外线)光源，紫外光源的输入功率在2KW～7KW，光源辐射能量在18～25W/cm 2，光源辐射波长90％ 集中365nm～405nm范围内。此外，紫外光源的输入功率可以根据拉丝速度对应的自动进行0％～100％无级调节，所述紫外光源的输入功率与所述拉丝速度成正比，所述拉丝速度越大，所述紫外光源的输入功率越大。一次固化(对应于一次涂覆)的功率控制在300W～1500W，二次固化(对应于二次涂覆)的功率控制在500W～6000W。通过上述对紫外光固化工艺的参数设置，能够提升紫外光的利用效率，使紫外光源有效地辐射在光纤100的表面，减少紫外光能耗；此外，本申请提供的紫外光固化过程保证光纤100的两层涂覆层的固化度在90％～95％的水平，实现涂覆层树脂的充分固化，同时避免过固化而导致的光纤附加衰减增加的问题。
在涂覆层固化后，光纤100经过牵引设备收线成盘。在收线过程中，调整光纤的收线张力为40g～65g，能够减少光纤100叠加时的外部应力，降低光纤100微弯导致的附加损耗，使光纤100的衰减保持在较低的水平。在一实施方式中，在光纤的收线端，施加一固定张力，所述固定张力可以为40g、45g、50g、55g、60g以及65g。在其他实施方式中，在光纤的收线端，根据所述光纤的弯曲圈数与弯曲半径，施加最优张力，最大程度地减少光纤叠加时的外部应力。所述最优张力与所述弯曲圈数、所述弯曲半径的映射关系为预先设置的。
以上说明仅仅是对本发明一种优化的具体实施方式，但在实际的应用过程中不能仅仅局限于这种实施方式。对本领域的普通技术人员来说，根据本发明的技术构思做出的其他变形和改变，都应该属于本发明的保护范围。

Claims (10)

  1. 一种光纤，包括芯层与围绕所述芯层的包层，其特征在于，所述包层包括包覆设置的内包层、第一下陷层、第二下陷层与外包层，所述第一下陷层的单侧宽度大于所述第二下陷层的单侧宽度，所述第一下陷层的相对折射率为-0.03％～-0.06％，所述第二下陷层的相对折射率为-0.08％～-0.15％，所述外包层外还包括涂覆层，所述涂覆层包括包覆设置的第一涂覆层与第二涂覆层，所述第二涂覆层的直径为175μm～195μm。
  2. 根据权利要求1所述的光纤，其特征在于，所述第一下陷层与所述第二下陷层均为掺氟层，所述第一下陷层的单侧宽度为3～5μm，所述第二下陷层的单侧宽度为2～4μm。
  3. 根据权利要求1所述的光纤，其特征在于，所述第二下陷层的折射率为梯度内抛物线形分布，自所述第一下陷层至所述外包层递减，分布指数为1.2～2.2。
  4. 根据权利要求1所述的光纤，其特征在于，所述外包层直径为124μm～126μm。
  5. 根据权利要求1所述的光纤，其特征在于，所述第一涂覆层的弹性模量为0.3～0.4Mpa，所述第一涂覆层的厚度为12μm～20μm，所述第一涂覆层的玻璃化转变温度为-40℃～-60℃。
  6. 根据权利要求1所述的光纤，其特征在于，所述第二涂覆层的杨氏模量大于600Mpa，所述第二涂覆层的厚度为12μm～18μm。
  7. 根据权利要求1所述的光纤，其特征在于，所述光纤的模场直径为8.4μm～9.4μm。
  8. 根据权利要求1所述的光纤，其特征在于，当所述光纤的弯 曲半径为7.5mm时，在弯曲1圈状态下，所述光纤在波长1550nm时的宏弯曲损耗小于0.1dB；所述光纤在波长1625nm时的宏弯曲损耗小于0.25dB。
  9. 一种制备上述权利要求1至8任意一项所述的光纤的方法，其特征在于，所述光纤制备方法包括：
    制备第一芯棒松散体，采用第一喷灯、第二喷灯及第三喷灯由内向外依次进行沉积，在第一喷灯中通入SiCl4气体、GeCl4气体、氧气、可燃气体及氩气，形成掺锗的芯层；在第二喷灯中通入SiCl4气体、氧气、可燃气体及氩气，形成纯硅的内包层；在第三喷灯中通入SiCl4气体，含氟气体，氧气，可燃气体和氩气，形成第一下陷层；
    将上述制备的第一芯棒松散体置于氯气中进行脱羟处理，然后进行玻璃化工艺与退火工艺形成芯棒；
    将上述制备的芯棒作为靶棒，在芯棒的外表面由内而外沉积第二下陷层与外包层，产生第二芯棒松散体，并对所述第二芯棒松散体进行烧结处理得到光纤预制棒；
    将上述制备的光纤预制棒进行拉丝处理，并通过二次加热保温退火工艺处理，得到裸光纤；
    冷却上述制备的裸光纤，对所述裸光纤进行一次涂覆与二次涂覆，得到第一涂覆层与第二涂覆层，并通过紫外光对所述第一涂覆层与所述第二涂覆层进行固化处理得到光纤。
  10. 根据权利要求9所述的光纤制备方法，其特征在于，在二次加热保温退火工艺中，控制电阻炉中分节加热电阻丝形成1250℃～800℃逐步降低的梯度温场。
PCT/CN2020/124907 2020-08-18 2020-10-29 光纤及光纤制备方法 WO2022036861A1 (zh)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP20923680.1A EP3978969A4 (en) 2020-08-18 2020-10-29 OPTICAL FIBER AND METHOD FOR PREPARING OPTICAL FIBER

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202010830293.1 2020-08-18
CN202010830293.1A CN111929764A (zh) 2020-08-18 2020-08-18 光纤及光纤制备方法

Publications (1)

Publication Number Publication Date
WO2022036861A1 true WO2022036861A1 (zh) 2022-02-24

Family

ID=73305075

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2020/124907 WO2022036861A1 (zh) 2020-08-18 2020-10-29 光纤及光纤制备方法

Country Status (3)

Country Link
EP (1) EP3978969A4 (zh)
CN (1) CN111929764A (zh)
WO (1) WO2022036861A1 (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115010360A (zh) * 2022-07-14 2022-09-06 中天科技精密材料有限公司 一种光纤预制棒的制备方法、光纤预制棒及光纤

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112499961A (zh) * 2020-12-07 2021-03-16 中天科技光纤有限公司 光纤及其制备方法
CN114371530A (zh) * 2020-12-24 2022-04-19 中天电力光缆有限公司 光纤结构、光纤结构的生产方法及光缆结构
CN115636581B (zh) * 2022-11-08 2023-12-12 中天科技光纤有限公司 光纤预制件、光纤拉丝装置以及光纤拉丝方法
CN115951445B (zh) * 2023-03-15 2023-05-16 中天科技光纤有限公司 抗弯曲高耐压光纤及其制备方法

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2009089608A1 (en) * 2008-01-17 2009-07-23 Institut National D'optique Multi-cladding fiber
CN101622561A (zh) * 2007-01-08 2010-01-06 康宁股份有限公司 抗弯曲多模光纤
CN105204110A (zh) * 2015-10-31 2015-12-30 长飞光纤光缆股份有限公司 一种具有较低差分模群时延的少模光纤
US20170242186A1 (en) * 2016-02-24 2017-08-24 Corning Incorporated Multimode fiber with intermediate clad layer
CN111320373A (zh) * 2018-12-15 2020-06-23 中天科技精密材料有限公司 光纤预制棒以及制备方法
CN111399113A (zh) * 2020-04-24 2020-07-10 长飞光纤光缆股份有限公司 一种小外径弯曲不敏感单模光纤

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4852968A (en) * 1986-08-08 1989-08-01 American Telephone And Telegraph Company, At&T Bell Laboratories Optical fiber comprising a refractive index trench
US8588569B2 (en) * 2011-11-30 2013-11-19 Corning Incorporated Low bend loss optical fiber
CN102590933B (zh) * 2012-01-10 2015-07-01 长飞光纤光缆股份有限公司 一种弯曲不敏感单模光纤
JP2016171208A (ja) * 2015-03-12 2016-09-23 株式会社フジクラ 光ファイバ、ファイバアンプ、及びファイバレーザ
CN106443876B (zh) * 2016-10-20 2019-09-10 长飞光纤光缆股份有限公司 一种低串扰少模光纤
CN109081575A (zh) * 2017-06-14 2018-12-25 中天科技精密材料有限公司 光纤预制棒及其制造方法
CN209989257U (zh) * 2018-12-15 2020-01-24 中天科技精密材料有限公司 光纤预制棒

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101622561A (zh) * 2007-01-08 2010-01-06 康宁股份有限公司 抗弯曲多模光纤
WO2009089608A1 (en) * 2008-01-17 2009-07-23 Institut National D'optique Multi-cladding fiber
CN105204110A (zh) * 2015-10-31 2015-12-30 长飞光纤光缆股份有限公司 一种具有较低差分模群时延的少模光纤
US20170242186A1 (en) * 2016-02-24 2017-08-24 Corning Incorporated Multimode fiber with intermediate clad layer
CN111320373A (zh) * 2018-12-15 2020-06-23 中天科技精密材料有限公司 光纤预制棒以及制备方法
CN111399113A (zh) * 2020-04-24 2020-07-10 长飞光纤光缆股份有限公司 一种小外径弯曲不敏感单模光纤

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP3978969A4 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115010360A (zh) * 2022-07-14 2022-09-06 中天科技精密材料有限公司 一种光纤预制棒的制备方法、光纤预制棒及光纤
CN115010360B (zh) * 2022-07-14 2024-04-09 中天科技精密材料有限公司 一种光纤预制棒的制备方法、光纤预制棒及光纤

Also Published As

Publication number Publication date
CN111929764A (zh) 2020-11-13
EP3978969A1 (en) 2022-04-06
EP3978969A4 (en) 2023-07-19

Similar Documents

Publication Publication Date Title
WO2022036861A1 (zh) 光纤及光纤制备方法
CN107850728B (zh) 具有大有效面积和低弯曲损耗的光纤
CN107810436B (zh) 具有氟和氯共掺杂芯区域的低损耗光纤
JP6632600B2 (ja) 高塩素含有量の低減衰光ファイバー
JP5674593B2 (ja) 低損失光ファイバ、およびその製造方法
US8687936B2 (en) Optical fiber, optical transmission system, and method of making optical fiber
KR101577635B1 (ko) 벤딩에 민감하지 않은 단일모드 광섬유
WO2021164443A1 (zh) 一种细径光纤及其制备方法
CN106772788B (zh) 一种截止波长位移单模光纤
KR101577962B1 (ko) 일종의 벤딩에 민감하지 않은 단일모드 광섬유
WO2011147272A1 (zh) 一种抗弯曲多模光纤
JP6129270B2 (ja) 曲げ耐性のマルチモード光ファイバ
CN104316994A (zh) 一种低衰减弯曲不敏感单模光纤
WO2012064579A1 (en) Multi-core optical fiber ribbons and methods for making the same
JP2011102964A (ja) 光ファイバおよび光ファイバ製造方法
CN102645699A (zh) 一种低衰减弯曲不敏感单模光纤
KR20130116009A (ko) 광섬유
CN109061793B (zh) 一种七芯小径单模光纤及其制造方法
CN103323908A (zh) 一种单模光纤及其制造方法
CN107608023A (zh) 一种阶跃型超低衰减少模光纤
WO2023240881A1 (zh) 一种陆地用g.654.e光纤及其制作工艺
WO2012100581A1 (zh) 一种抗弯曲多模光纤
US20210116634A1 (en) Optical fibers having core regions with reduced alpha profiles
CN107479129A (zh) 一种高带宽多模光纤
CN113946012B (zh) 一种抗弯曲光纤及其制备方法

Legal Events

Date Code Title Description
ENP Entry into the national phase

Ref document number: 2020923680

Country of ref document: EP

Effective date: 20210917

NENP Non-entry into the national phase

Ref country code: DE