CN107357004A - A kind of low decay single-mode fiber and preparation method thereof - Google Patents

A kind of low decay single-mode fiber and preparation method thereof Download PDF

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Publication number
CN107357004A
CN107357004A CN201710538633.1A CN201710538633A CN107357004A CN 107357004 A CN107357004 A CN 107357004A CN 201710538633 A CN201710538633 A CN 201710538633A CN 107357004 A CN107357004 A CN 107357004A
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CN
China
Prior art keywords
optical fiber
described
layer
mode fiber
characterised
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CN201710538633.1A
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Chinese (zh)
Inventor
陈刚
朱继红
杨轶
汪洪海
王瑞春
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长飞光纤光缆股份有限公司
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Priority to CN201710538633.1A priority Critical patent/CN107357004A/en
Publication of CN107357004A publication Critical patent/CN107357004A/en

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Classifications

    • CCHEMISTRY; METALLURGY
    • C03GLASS; MINERAL OR SLAG WOOL
    • C03BMANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B37/00Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
    • C03B37/01Manufacture of glass fibres or filaments
    • C03B37/02Manufacture of glass fibres or filaments by drawing or extruding, e.g. direct drawing of molten glass from nozzles; Cooling fins therefor
    • C03B37/025Manufacture 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
    • C03B37/027Fibres composed of different sorts of glass, e.g. glass optical fibres
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS, OR APPARATUS
    • G02B6/00Light guides
    • G02B6/02Optical fibre with cladding with or without a coating
    • G02B6/02004Optical fibre with cladding with or without a coating characterised by the core effective area or mode field radius
    • G02B6/02009Large effective area or mode field radius, e.g. to reduce nonlinear effects in single mode fibres
    • G02B6/02014Effective area greater than 60 square microns in the C band, i.e. 1530-1565 nm
    • G02B6/02019Effective area greater than 90 square microns in the C band, i.e. 1530-1565 nm
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS, OR APPARATUS
    • G02B6/00Light guides
    • G02B6/02Optical fibre with cladding with or without a coating
    • G02B6/028Optical fibre with cladding with or without a coating with core or cladding having graded refractive index
    • G02B6/0281Graded index region forming part of the central core segment, e.g. alpha profile, triangular, trapezoidal core
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS, OR APPARATUS
    • G02B6/00Light guides
    • G02B6/02Optical fibre with cladding with or without a coating
    • G02B6/036Optical fibre with cladding with or without a coating core or cladding comprising multiple layers
    • G02B6/03616Optical 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
    • G02B6/03638Optical 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 3 layers only
    • G02B6/03655Optical 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 3 layers only arranged - + +

Abstract

The present invention relates to a kind of low decay single-mode fiber and preparation method thereof, described sandwich layer diameter a is 7.0~8.0 μm, refractive index contrast △ 1 is 0.10~0.20%, coat inner cladding and surrounding layer outside sandwich layer successively from inside to outside, described inner cladding diameter b is 25~28 μm, refractive index contrast △ 2 is 0.05~0.25%, and described outer cladding diameter c is 124~126 μm, and refractive index contrast △ 3 is 0.05~0.25%.The present invention manufactures plug by VAD techniques, form sandwich layer and inner cladding, target rod is used as using this plug, surrounding layer is deposited outside this target rod by OVD techniques, form surrounding layer, the prefabricated rods of full covering fluorine doped are formed after oversintering, this prefabricated rods is carried out into wire drawing under 1500~3300m/min drawing speed is made optical fiber.The present invention mixes germanium amount by reducing sandwich layer and improves the low decay that optical fiber is realized in the matching of core covering viscosity, and preparation technology of the present invention is relatively simple, low manufacture cost, and process stabilizing, and output qualification rate is high.

Description

A kind of low decay single-mode fiber and preparation method thereof

Technical field

The present invention relates to a kind of low decay single-mode fiber and preparation method thereof, belong to technical field of optical fiber communication.

Background technology

Fiber optic communication has the characteristics that big transmission capacity, long transmission distance, transmission speed are fast, is widely used in long distance line The optical communication networks such as net, Metropolitan Area Network (MAN) and access network.The single-mode fiber for meeting ITU-T G.652D standards is the most frequently used communication Optical fiber.The transmission range of optical fiber telecommunications system can be effectively improved by reducing single-mode fiber attenuation coefficient, greatly reduce relay station Quantity and cost, to optimization Transmission system structure and cut operating costs significant.

The reason for optical fiber generation attenuation, mainly has:Absorption loss, including Intrinsic Gettering and Impurity Absorption;Scattering loss, bag Include linear scattering, nonlinear scattering and the imperfect scattering of structure etc.;Additional attenuation, including microbending loss, macrobending loss and continue Loss etc..One of most important loss is Rayleigh scattering loss in scattering loss, and it is a kind of linear scattering, its size with The biquadratic of optical wavelength is inversely proportional.Caused by fluctuation of concentration caused by Rayleigh scattering loss and dopant and viscosity of material mismatch Density fluctuation is relevant.

It is to reduce the most effective and most economical method of optical fiber attenuation to reduce the concentration of dopant material and optimize Section Design. In Chinese patent CN201410423830.5 and CN201410473879.1, three sandwich layers being gradually reduced using refractive index come Optimize section so that core layer mixes the reduction of germanium amount, and core covering viscosity, which matches, to be improved, so as to by reducing Rayleigh scattering To reduce the attenuation coefficient of optical fiber.In Chinese patent CN103149630B, using double inner cladding structures, to sandwich layer and covering Dopant optimize, match core covering viscosity, reduce drawing tensile force stress caused by sandwich layer, declined so as to reduce optical fiber Subtract.In Chinese patent CN105223645A, pass through VAD process deposits germnium doped core layers and the sagging inner cladding of fluorine doped, its fluorine doped layer Radius be 12~16 μm, do surrounding layer with pure silicon sleeve pipe, declined in the optical fiber that 1550nm wavelength is obtained less than 0.180dB/km Subtract.In these patents, the pad value obtained approaches with low attenuation optical fiber standard comparing, but low attenuation optical fiber ratio it is not high, Optical fiber attenuation level remains to be further improved.In United States Patent (USP) US9020316 B2, F sandwich layers and F coverings, core are mixed using mixing Layer is alpha parabola, and its highest refractive index contrast is 0, and cladding relative refractive difference is -0.3%~-1.5%, can To obtain than relatively low decay.In United States Patent (USP) US2015/0329404A1, by VAD starting rod on deposit internal layer and Outer layer soot, alkali metal is mixed when internal layer deposits, by sintering circuit outer layer mix fluorine (relative index of refraction contribute- 0.5%~-0.25%), can obtain than relatively low decay.Relatively low optical fiber can be obtained in this two United States Patent (USP)s to decline Subtract, but covering doping F amount is very big, and technique controlling difficulty is big, and cost is also very high.

The content of the invention

The content of the invention is introduced for convenience, is defined as follows term:

Prefabricated rods:The radial refractive index distribution being made up of sandwich layer and covering meets fiber design requirement and can be directly drawn into The glass bar or assembly of designed optical fiber;

Plug:Solid glass prefabricated component containing sandwich layer and part of clad;

Radius:The distance between this layer of external boundary and central point;

Refractive index profile:Relation between optical fiber or preform (including plug) glass refraction and its radius;

Refractive index contrast:

Δ %=[(n (i)2–n(0)2)/(2n(i)2)] × 100% ≈ [n (i)-n (0)]/n (0) × 100%

N (i) and n (0) is respectively the refractive index of corresponding i-th layer of optical fiber and the refractive index of pure silicon dioxide glassy layer;

The contribution amount of fluorine (F):Fluorine doped (F) quartz glass relative to pure quartz glass relative index of refraction difference (Δ F), with This come represent fluorine doped (F) measure;

The contribution amount of germanium (Ge):Mix relative index of refraction difference (Δ of germanium (Ge) quartz glass relative to pure quartz glass Ge), measured with this to represent to mix germanium (Ge);

Δtotal:For the difference of the refractive index of sandwich layer and inner cladding contribution, Δ total=Δ 1- Δs 2;

Δ 1 and Δ 2 are respectively the refractive index contrast of sandwich layer and inner cladding;

OVD techniques:The quartz glass of thickness needed for Outside Vapor deposition and sintering process preparation;

VAD techniques:The quartz glass of thickness needed for axial vapor deposition and sintering process preparation;

Target rod:Center bar in OVD or VAD techniques, product is deposited on to be grown above;

Soot:The loosening body being made up of SiO2 that deposition is formed in OVD or VAD techniques;

Soot-on-rod:Using plug as target rod, in the assembly that outside deposition soot is formed;

Bare fibre:Refer to the glass fiber that coat is free of in optical fiber;

Low attenuation optical fiber:Meet that decay is less than 0.325dB/km at 1310nm wavelength, decays at 1383nm wavelength and is less than Single-mode fiber of the decay less than 0.185dB/km at 0.325dB/km, 1550nm wavelength;

Low attenuation optical fiber yield ratio:[low attenuation optical fiber length]/[optical fiber total length] * 100%.

The technical problems to be solved by the invention are to be directed to above-mentioned the shortcomings of the prior art, there is provided a kind of low decay Single-mode fiber and preparation method thereof, germanium amount is mixed by reducing sandwich layer and improves the low decay that optical fiber is realized in the matching of core covering viscosity, Optical fiber preparation technology is relatively simple, low manufacture cost, and process stabilizing, and output qualification rate is high.

The present invention is to solve the problems, such as that used optical fiber technology scheme set forth above is:Include sandwich layer and covering, its It is 7.0~8.0 μm to be characterised by described sandwich layer diameter a, and refractive index contrast △ 1 is 0.10~0.20%, and sandwich layer is outer from interior Outwards coat inner cladding and surrounding layer successively, described inner cladding diameter b is 25~28 μm, refractive index contrast △ 2 for- 0.05~-0.25%, described outer cladding diameter c are 124~126 μm, and refractive index contrast △ 3 is -0.05~-0.25%.

By such scheme, the difference Δ total=Δ 1- Δs 2 of the refractive index of the sandwich layer and inner cladding contribution for 0.30~ 0.38%.

By such scheme, described sandwich layer is that germanium-doped silica glassy layer or germanium fluorine are co-doped with silica glass layer.

By such scheme, described inner cladding is that fluorine doped silica glass layer or germanium fluorine are co-doped with silica glass Layer.

By such scheme, described surrounding layer is fluorine doped silica glass layer, and the contribution amount of fluorine is Δ %=-0.29% ~-0.05%.

By such scheme, mode field diameter of the optical fiber at 1310nm wavelength is 8.4~9.6 microns.

By such scheme, attenuation coefficient of the optical fiber at 1310nm wavelength is less than or equal to 0.335dB/km, preferably Under the conditions of be less than or equal to 0.324dB/km, more preferably under the conditions of be less than or equal to 0.314dB/km, at 1550nm wavelength Attenuation coefficient is less than or equal to 0.195dB/km, is less than or equal to 0.184dB/km under optimum condition, more preferably under the conditions of be less than Or equal to 0.178dB/km.

By such scheme, the optical fiber has the cable cut-off wavelength less than or equal to 1260nm.

By such scheme, the zero-dispersion wavelength of the optical fiber is 1300nm~1324nm;Optical fiber is at zero-dispersion wavelength Chromatic dispersion gradient is less than or equal to 0.092ps/ (nm2*km)。

The technical scheme of preparation method of the present invention is:Plug soot is manufactured by VAD techniques, forms sandwich layer and inner cladding, Glass plug is obtained after this plug soot is dehydrated, sintered, plug is used as target rod after annealing, with this plug As target rod, surrounding layer is deposited outside this target rod by OVD techniques, obtains fluorine doped surrounding layer, by the soot-on-rod rods Obtain being available for the prefabricated rods of wire drawing after being dehydrated, sintered and being annealed, by this prefabricated rods 1500~3300m/min wire drawing Wire drawing is carried out under speed and forms optical fiber.

By such scheme, the fluorine-containing raw material of certain flow, described fluorine-containing original are passed through inside, in the deposition process of surrounding layer Expect for the one or more in CF4, SF6, C2F6, SiF4.

By such scheme, the drawing speed during optical fiber processing is 1000m/min~3300m/min.

By such scheme, the drawing speed during optical fiber processing is 1500m/min~3000m/min.

By such scheme, the drawing speed during optical fiber processing is 1800m/min~2800m/min.

By such scheme, the drawing speed during optical fiber processing is 2000m/min~2500m/min.

By such scheme, the drawing tensile force of the bare fibre during optical fiber processing is 100g~350g.

By such scheme, the drawing tensile force of the bare fibre during optical fiber processing is 120g~300g.

By such scheme, the drawing tensile force of the bare fibre during optical fiber processing is 130g~250g.

By such scheme, the drawing tensile force of the bare fibre during optical fiber processing is 140g~200g.

The beneficial effects of the present invention are:1. the present invention is directly using plug as target rod in outside deposition fluorine doped outsourcing Layer, it is relatively low without using expensive fluorine doped outer tube, cost;2. fluorine doped outer tube maximum outside diameter is 150mm, and this hair It is bright to make>The large-sized fluorine doped surrounding layer of 200mm external diameters, be advantageous to improve single prefabricated stick drawn wire length, be advantageous to drop Low cost;3. optical fiber of the present invention reduces sandwich layer by full covering fluorine doped mixes germanium amount, the matching of core covering viscosity is improved, makes light Fine decay effectively reduces;4. the drawing speed of low attenuation optical fiber is normally no higher than 2000m/min, and the present invention by wrapping entirely Layer fluorine doped reduces the intrinsic loss of optical fiber, influenceed by drawing speed it is smaller, can be under >=3000m/min drawing speed Obtain low attenuation optical fiber;5. present invention process is stable, low attenuation optical fiber yield ratio is high, can reach more than 90%.

Brief description of the drawings

Fig. 1 is the process chart of one embodiment of the invention.

Fig. 2 is the diagrammatic cross-section of one embodiment of the present of invention optical fiber, and a be sandwich layer diameter in figure, and b is straight for inner cladding Footpath, c are outer cladding diameter (i.e. bare-fiber diameter).

The contrast for the relative index of refraction contribution that Fig. 3 is fiber core layer Ge obtained by the present invention and routine techniques

Embodiment

With reference to embodiment, the present invention is described in further detail.

The method that the present invention prepares low decay single-mode fiber, as depicted in figs. 1 and 2, passes through VAD process deposits plugs Soot, comprising sandwich layer and inner cladding, and the fluorine-containing raw material of certain flow is passed through in inner cladding deposition process, described is fluorine-containing Raw material is the one or more in CF4, SF6, C2F6, SiF4, obtains fluorine doped inner cladding, this plug soot is dehydrated, burnt Glass plug is obtained after knot, plug is used as target rod after annealing, and outsourcing is deposited outside this target rod by OVD techniques Layer, the fluorine-containing raw material of certain flow is passed through during deposition, described fluorine-containing raw material is in CF4, SF6, C2F6, SiF4 One or more, fluorine doped surrounding layer is obtained, obtain being available for wire drawing after the soot-on-rod rods are dehydrated, are sintered and annealed Prefabricated rods, the refractive indexes of the prefabricated rods, the relative index of refraction contribution Δ %=-0.29% of surrounding layer are tested using PK2600 ~-0.05%.The prefabricated rods of the covering containing fluorine doped are subjected to wire drawing, drawing speed is 2500~3300m/min, and bare fibre is drawn Thread tension is 100g~350g.Embodiment prepare low attenuation optical fiber geometry and doping parameters it is as shown in table 1, fiber cores Layer Δ 1 carries out refractive index contribution by mixing germanium, mixes germanium amount and is greatly decreased than Standard single-mode fiber, surrounding layer Δ 3 and inner cladding Δ 2 Keep close, to ensure the balance of optical fiber parameter;Technological parameter, drawing process parameter and the low decay light of fluorine doped surrounding layer Fine yield ratio is as shown in table 2, and low attenuation optical fiber yield ratio is 99.2%~100.0%, is in highest drawing speed Under conditions of 3300m/min, low attenuation optical fiber ratio can still reach more than 99%, and Standard single-mode fiber is in this high speed Lower is difficult to have low attenuation optical fiber output.Gained optical fiber Specifeca tion speeification is as shown in table 3, in decaying to for 1310nm wavelength 0.295dB/km~0.309dB/km, 0.174dB/km~0.180dB/km is decayed in 1550nm wavelength.Obtained by embodiment Optical fiber decays to 0.265dB/km~0.324dB/km 1383nm wavelength.A kind of section signal of optical fiber obtained by embodiment Figure is as shown in Fig. 2 but not limited to this.The contrast of the present invention and routine techniques gained fiber core layer Ge relative index of refraction contribution As shown in figure 3, sandwich layer, which mixes germanium amount, reduces 50% or so, sandwich layer mix germanium amount significantly reduction can effectively lower optical fiber attenuation, Low attenuation optical fiber ratio is improved, particularly improves the low attenuation optical fiber ratio under high-speed wire-drawing.

The low attenuation optical fiber structure of table 1 and doping parameters

Technological parameter, drawing process parameter and the low attenuation optical fiber ratio of the fluorine doped surrounding layer of table 2

The Specifeca tion speeification of the low attenuation optical fiber of table 3

Claims (10)

1. a kind of low decay single-mode fiber, includes sandwich layer and covering, it is characterised in that described sandwich layer diameter a is 7.0~8.0 μm, refractive index contrast △ 1 is 0.10~0.20%, coats inner cladding and surrounding layer outside sandwich layer successively from inside to outside, described Inner cladding diameter b is 25~28 μm, and refractive index contrast △ 2 is -0.05~-0.25%, and described outer cladding diameter c is 124 ~126 μm, refractive index contrast △ 3 is -0.05~-0.25%.
2. the low decay single-mode fiber as described in claim 1, it is characterised in that the refractive index contribution of the sandwich layer and inner cladding Difference Δ total=Δ 1- Δs 2 be 0.30~0.38%.
3. the low decay single-mode fiber as described in claim 1 or 2, it is characterised in that described sandwich layer is germanium-doped silica glass Glass layer or germanium fluorine are co-doped with silica glass layer;Described inner cladding is that fluorine doped silica glass layer or germanium fluorine are co-doped with two Silicon oxide glass layers.
4. the low decay single-mode fiber as described in claim 3, it is characterised in that described surrounding layer is fluorine doped silica glass Glass layer, the contribution amount of fluorine is Δ %=-0.29%~-0.05%.
5. the low decay single-mode fiber as described in claim 1 or 2, it is characterised in that mould of the optical fiber at 1310nm wavelength Field diameter is 8.4~9.6 microns.
6. the low decay single-mode fiber as described in claim 1 or 2, it is characterised in that the optical fiber declining at 1310nm wavelength Subtract coefficient and be less than or equal to 0.324dB/km, the attenuation coefficient at 1550nm wavelength is less than or equal to 0.184dB/km.
7. the low decay single-mode fiber as described in claim 1 or 2, it is characterised in that the optical fiber, which has, to be less than or equal to 1260nm cable cut-off wavelength;The zero-dispersion wavelength of the optical fiber is 1300nm~1324nm;Optical fiber is at zero-dispersion wavelength Chromatic dispersion gradient be less than or equal to 0.092ps/ (nm2*km)。
8. a kind of preparation method of low decay single-mode fiber, it is characterised in that plug soot is manufactured by VAD techniques, forms sandwich layer And inner cladding, glass plug is obtained after this plug soot is dehydrated, sintered, plug is used as target rod after annealing, Using this plug as target rod, surrounding layer is deposited outside this target rod by OVD techniques, obtains fluorine doped surrounding layer, by the soot- On-rod rods obtain being available for the prefabricated rods of wire drawing after being dehydrated, sintered and being annealed, by this prefabricated rods in 1500~3300m/min Drawing speed under carry out wire drawing formed optical fiber.
9. the preparation method of the low decay single-mode fiber as described in claim 8, it is characterised in that the drawing during optical fiber processing Silk speed is 1000m/min~3300m/min.
10. the preparation method of the low decay single-mode fiber as described in claim 8 or 9, it is characterised in that during the optical fiber processing The drawing tensile force of bare fibre be 100g~350g.
CN201710538633.1A 2017-07-04 2017-07-04 A kind of low decay single-mode fiber and preparation method thereof CN107357004A (en)

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TW425481B (en) * 1999-01-18 2001-03-11 Sumitomo Electric Industries Optical fiber and its production method
CN1472150A (en) * 2002-07-29 2004-02-04 江苏法尔胜光子公司 Method for producing fibre-optical precast stick
CN102998742A (en) * 2012-12-13 2013-03-27 长飞光纤光缆有限公司 Anti-bending single mode fiber with small mode field
CN103149630A (en) * 2013-03-06 2013-06-12 长飞光纤光缆有限公司 Low-attenuation single-mode optical fiber
CN103842306A (en) * 2011-08-09 2014-06-04 古河电气工业株式会社 Optical fiber base material and method for manufacturing optical fiber
US20150023642A1 (en) * 2013-07-16 2015-01-22 Corning Incorporated High bandwidth mmf and method of making

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TW425481B (en) * 1999-01-18 2001-03-11 Sumitomo Electric Industries Optical fiber and its production method
CN1472150A (en) * 2002-07-29 2004-02-04 江苏法尔胜光子公司 Method for producing fibre-optical precast stick
CN103842306A (en) * 2011-08-09 2014-06-04 古河电气工业株式会社 Optical fiber base material and method for manufacturing optical fiber
CN102998742A (en) * 2012-12-13 2013-03-27 长飞光纤光缆有限公司 Anti-bending single mode fiber with small mode field
CN103149630A (en) * 2013-03-06 2013-06-12 长飞光纤光缆有限公司 Low-attenuation single-mode optical fiber
US20150023642A1 (en) * 2013-07-16 2015-01-22 Corning Incorporated High bandwidth mmf and method of making

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