US20090100876A1 - Method of manufacturing optical fiber base material and apparatus of the same - Google Patents

Method of manufacturing optical fiber base material and apparatus of the same Download PDF

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Publication number
US20090100876A1
US20090100876A1 US12/341,324 US34132408A US2009100876A1 US 20090100876 A1 US20090100876 A1 US 20090100876A1 US 34132408 A US34132408 A US 34132408A US 2009100876 A1 US2009100876 A1 US 2009100876A1
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United States
Prior art keywords
pressure
furnace tube
vessel
base material
ppm
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US12/341,324
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English (en)
Inventor
Dai Inoue
Hiroyuki Koide
Takaaki Nagao
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Shin Etsu Chemical Co Ltd
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Shin Etsu Chemical Co Ltd
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Filing date
Publication date
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Assigned to SHIN-ETSU CHEMICAL CO., LTD. reassignment SHIN-ETSU CHEMICAL CO., LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: INOUE, DAI, KOIDE, HIROYUKI, NAGAO, TAKAAKI
Publication of US20090100876A1 publication Critical patent/US20090100876A1/en
Priority to US13/947,923 priority Critical patent/US8839645B2/en
Abandoned legal-status Critical Current

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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]
    • C03B37/01446—Thermal after-treatment of preforms, e.g. dehydrating, consolidating, sintering
    • C03B37/0146—Furnaces therefor, e.g. muffle tubes, furnace linings
    • 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]
    • C03B37/018—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
    • 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

Definitions

  • VAD is well-known as a method of manufacturing base materials for optical fibers. This method employs the following apparatus, for example.
  • glass particles produced with a core deposition burner and a cladding deposition burner disposed in a reaction chamber glass particles are deposited onto a tip of a starter mounted on a shaft which rotatably lifts up, so that a porous glass base material for optical fiber composed of a core layer and a cladding layer is manufactured.
  • the core layer may be SiO 2 with which GeO 2 is doped, and the cladding layer may be substantially pure SiO 2 .
  • the porous glass base material 1 manufactured as described above is dehydrated and sintered in a heating furnace.
  • the heating furnace has a furnace tube 2 which can be sealed, an electric furnace 3 which heats a part of or the whole of the furnace tube 2 , a gas introducing port 4 which introduces any gas into the furnace tube and a gas discharging port 5 which discharges the exhaust gas as shown in FIG. 1 , for example.
  • FIGS. 1A to 1C progressively show vitrifying the porous glass base material.
  • reference numeral 6 indicates a shaft which supports the porous glass base material 1 .
  • Dehydrating is performed by heating the base material at approximately 1,100 degrees Celsius in dehydrating gas composed of such as chlorine, oxygen and helium. Meanwhile, vitrifying is performed by heating the base material at approximately 1,500 degrees Celsius in an atmosphere containing such as helium.
  • the silica tube may be an electric-furnace-melted natural quartz glass tube such as HERALUX-E (trade name), available from Shin-Etsu Quartz Products Co., Ltd., which is made by pulverizing natural quartz and melting in an electric furnace (herein after referred to as a natural quartz tube).
  • HERALUX-E trade name
  • An optical fiber is obtained by drawing the optical fiber base material manufactured as above, and is provided for optical signal transmission. For example, light having a wavelength of 1,310 nm and 1,550 nm is modulated and transmitted through a single-mode fiber.
  • the transmission loss of the optical fiber at the wavelength of 1,310 nm is about 0.32 to 0.34 dB/km, however, it could infrequently become higher than usual, such as about 0.34 to 0.36 dB/km.
  • the transmission loss of the optical fiber at the wavelength of 1,550 nm is not very higher than a normal value.
  • transmission losses for a wide wavelength range, such as 900 nm to 1,600 nm are examined, the shorter the wavelength is, the larger the transmission loss is.
  • transmission loss has been acceptable, however, the market strictly requests for an optical characteristic in recent years, therefore, such transmission loss has come under a problem.
  • FIG. 2 shows a distribution of transmission losses for optical fibers at a wavelength of 1,310 nm, which are obtained by using a furnace tube of synthetic quartz and a furnace tube of natural quartz.
  • FIG. 3 shows an exemplary apparatus for manufacturing an optical fiber base material.
  • the conventional furnace tube employs a glass tube made of natural quartz that is manufactured by melting powdered natural quartz in an electric furnace (hereinafter referred to as a natural quartz furnace tube). It has been considered that increase of the transmission loss is caused by contaminating the optical fiber base material with impurities such a very small amount of ferrum and aluminum which are contained in the natural quartz. In addition, it has been considered that increase of the transmission loss is caused by contaminating the optical fiber base material in the furnace tube with a metal forming a furnace or a metal contained in carbon which diffuses and transmits through the tube wall due to corrosion.
  • the natural quartz furnace tube is progressively crystallized (into cristobalite) while it is used at a high temperature such as approximately 1,400 degrees Celsius.
  • the crystallization starts with impurities and crystallite as a core, which are contained in the natural quartz. After several hundred hours, most of the heated region is crystallized.
  • the electric-furnace-melted natural quartz contains aluminum equal to or more than 15 ppm, and the aluminum acts as the core of crystallization. It is considered that a small amount of impurities such as ferrum contained in the natural quartz separate out and diffuse in a crystal grain boundary during the crystallization. The diffusion rate of the impurities in the crystal grain boundary is very faster than a rate at which the impurities diffuse in amorphous glass.
  • a furnace tube is produced by so-called CVD method, that is, using vitrified synthetic quartz, which is obtained by hydrolyzing silicide such as SiCl 4 , (CH 3 )SiCl 3 , (CH 3 ) 2 SiCl 2 with oxyhydrogen flame to form a soot deposit, and melting the soot deposit in a heating furnace.
  • CVD method that is, using vitrified synthetic quartz, which is obtained by hydrolyzing silicide such as SiCl 4 , (CH 3 )SiCl 3 , (CH 3 ) 2 SiCl 2 with oxyhydrogen flame to form a soot deposit, and melting the soot deposit in a heating furnace.
  • the synthetic quartz that is made of a high-purity silicide as the raw material and made by depositing the high-purity silicide contains little impurity and crystallite.
  • the synthetic quartz contains aluminum equal to or less than 0.001 ppm as the core of crystallization. Accordingly, even if the synthetic quart is used under a high temperature, the crystallization very slowly progresses in comparison with the natural quartz. Consequently, the synthetic quartz contains little impurity, and a path through which impurities diffuse is not formed therein over the long term. Therefore, when the synthetic quartz having such feature is used as a furnace tube, it is considered that discharge of impurities into the furnace tube scarcely occur.
  • an optical fiber base material which is manufactured by using the furnace tube of synthetic quartz according to the mechanism described above can significantly reduce a risk of increasing the transmission loss in comparison with the conventional one.
  • crystallization of the synthetic quartz progresses by about 1 mm for 1,500 hours. Therefore, in a period obtained by multiplying the thickness of the synthetic quartz by 1,500 hours, a state in which the glass layer remains is maintained even if the synthetic quartz are used at a temperature equal to or more than 1,400 degrees Celsius, so that a risk of contaminating the optical fiber base material can be reduced.
  • the synthetic quartz is not easily crystallized in comparison with the natural quartz, the viscosity thereof decreases by heating. It is likely that a portion in which the viscosity reduces is deformed due to a difference in pressure between the inside and outside of the furnace tube. When the deformed furnace tube contacts an optical fiber base material during manufacture, the optical fiber base material damages. Therefore, it is preferable to monitor the pressure in the furnace tube and control so as not to result in excess differences between the inside and outside of the furnace tube.
  • an apparatus for manufacturing an optical fiber base material includes a pressure control mechanism 7 that controls a pressure in the furnace tube such that the difference in pressure is within a tolerance when the pressure of the inside or outside of the furnace tube is out of a predetermined tolerance.
  • the apparatus for manufacturing an optical fiber base material may include an intra-furnace tube pressure measuring unit 11 that measures a pressure in the furnace tube, and an extra-furnace tube pressure measuring unit 12 that measures a pressure adjacent to the heat source 3 outside the furnace tube.
  • an alarm device 8 may activate when the difference in pressure of the inside or outside of the furnace tube is out of a predetermined tolerance.
  • the exhaust port may be provided with an automatic valve 9 to automatically adjust a flow rate of the valve in order that the difference in pressure of the inside or outside of the furnace tube be within a predetermined tolerance.
  • the tolerance of the pressure in the furnace tube may be such as 0 Pa to 1300 Pa.
  • a pressure in the furnace as a pressure of the extra-furnace tube in order to know the difference in pressure between the inside and outside of the furnace tube.
  • the tolerance of the difference in pressure between the inside and outside of the furnace tube may be such as ⁇ 200 Pa to 450 Pa.
  • At least a portion of the furnace tube must be made of the synthetic quartz. Specifically, the portion which is heated at a high temperature by a heat source such as an electric furnace must be made of the synthetic quartz. Even if the other portion is made of the natural quartz, the effect of the invention is not hurt.
  • the synthetic quartz used in the embodiment contains little hydroxy group equal to or less than 1 ppm. Therefore, in view of the description of Patent document 1 that moisture contained in the furnace tube adversely affects the loss characteristic of the optical fiber around the wavelength of 1,380 nm, the synthetic quartz of the embodiment can be used for manufacturing the optical fiber containing little hydroxy group of which demand has rapidly grown in recent years without any problem although the furnace tube is manufactured by a method different from that of the above described Japanese Patent Application Publication No. 2004-002109. The step of eliminating adsorption moisture described as the above described Japanese Patent Application Publication No. 2004-002109. is applicable to the synthetic quartz furnace tube which is used in the present invention as well.
  • the porous glass base material which is deposited by VAD is separated into a first furnace tube of synthetic quartz and a second furnace tube of natural quartz, each of which thickness of the wall is 4 mm. Then, each furnace tube is dehydrated and sintered. Further, a cladding is added to each dehydrated and sintered base material, and the base material with the cladding is vitrified, so that an optical fiber base material is obtained.
  • the obtained optical fiber base materials are drawn respectively to measure the transmission loss at the wavelength of 1,310 nm, and then, a distribution of losses are compared.
  • the measured optical fibers are obtained by drawing the optical fiber base materials which are manufactured around the same time, of which 177 fibers are manufactured with the furnace tube of synthetic quartz and of which 1,059 fibers are manufactured with the furnace tube of natural quartz.
  • the furnace tube of synthetic quartz is taken out upon exceeding 6,000 hours over which the furnace tube of synthetic quartz is subjected to a high temperature more than 1,400 degrees Celsius, and the heated portion is examined. The result is that the glass layer is totally eliminated and entirely crystallized in a large part.
  • a vessel which accommodates a porous glass base material is made of synthetic quartz glass, which contains metal impurities less than those in the natural quartz glass. It is preferable that the content of aluminum of the synthetic quartz glass is equal to or less than one-tenth of the metal impurities of the natural quartz glass.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Materials Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Thermal Sciences (AREA)
  • Optics & Photonics (AREA)
  • General Physics & Mathematics (AREA)
  • Manufacture, Treatment Of Glass Fibers (AREA)
  • Glass Compositions (AREA)
  • Glass Melting And Manufacturing (AREA)
US12/341,324 2006-06-26 2008-12-22 Method of manufacturing optical fiber base material and apparatus of the same Abandoned US20090100876A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US13/947,923 US8839645B2 (en) 2006-06-26 2013-07-22 Method of manufacturing optical fiber base material and apparatus of the same

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
JP2006-175712 2006-06-26
JP2006175712 2006-06-26
JP2007164422A JP5867976B2 (ja) 2006-06-26 2007-06-21 光ファイバ母材の製造方法
JP2007-164422 2007-06-21
PCT/JP2007/062808 WO2008001775A1 (fr) 2006-06-26 2007-06-26 Procédé de production d'une préforme de fibre optique et appareil associé

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2007/062808 Continuation-In-Part WO2008001775A1 (fr) 2006-06-26 2007-06-26 Procédé de production d'une préforme de fibre optique et appareil associé

Related Child Applications (1)

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US13/947,923 Division US8839645B2 (en) 2006-06-26 2013-07-22 Method of manufacturing optical fiber base material and apparatus of the same

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US20090100876A1 true US20090100876A1 (en) 2009-04-23

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US12/341,324 Abandoned US20090100876A1 (en) 2006-06-26 2008-12-22 Method of manufacturing optical fiber base material and apparatus of the same
US13/947,923 Active US8839645B2 (en) 2006-06-26 2013-07-22 Method of manufacturing optical fiber base material and apparatus of the same

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US (2) US20090100876A1 (zh)
EP (1) EP2048120B1 (zh)
JP (1) JP5867976B2 (zh)
KR (1) KR101343683B1 (zh)
CN (1) CN104445914A (zh)
WO (1) WO2008001775A1 (zh)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5046753B2 (ja) * 2006-06-26 2012-10-10 信越化学工業株式会社 光ファイバ母材の製造方法及びその装置
JP5366303B2 (ja) * 2008-05-12 2013-12-11 信越石英株式会社 放電灯用合成シリカガラス、それで作成した放電灯ランプ及び該放電灯ランプを備えた放電灯装置、並びに前記放電灯用合成シリカガラスの製造方法

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5766291A (en) * 1994-04-28 1998-06-16 Heraeus Quarzglas Gmbh Method for producing heat-resistant synthetic quartz glass
US6543257B1 (en) * 1999-05-28 2003-04-08 The Furukawa Electric Co., Ltd. Dehydration and sintering apparatus for porous optical fiber preform
US20030221461A1 (en) * 2002-05-31 2003-12-04 Hiroshi Oyamada Preform and method for manufacturing same
US20060038695A1 (en) * 2004-08-18 2006-02-23 Isaacs Michael S Gas supply pressure alarm device

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US3957476A (en) * 1970-08-04 1976-05-18 Heraeus-Schott Quarzschmelze Gmbh Method of diffusing ions into quartz glass
JPS59184736A (ja) * 1983-04-06 1984-10-20 Furukawa Electric Co Ltd:The 光学系多孔質ガラスの透明ガラス化法
JPS6418932A (en) * 1987-07-13 1989-01-23 Fujikura Ltd Production of glass article and device therefor
JPH0218333A (ja) * 1988-07-05 1990-01-22 Sumitomo Electric Ind Ltd 多孔質母材の加熱処理方法
JP3188967B2 (ja) * 1994-06-17 2001-07-16 東京エレクトロン株式会社 熱処理装置
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JP3949425B2 (ja) 2001-11-01 2007-07-25 古河電気工業株式会社 光ファイバ母材の熱処理装置および方法
JP2003165736A (ja) * 2001-11-29 2003-06-10 Fujikura Ltd 光ファイバ母材の製造方法およびこれを用いた光ファイバ母材の製造装置
JP2003212559A (ja) * 2002-01-18 2003-07-30 Sumitomo Electric Ind Ltd ガラス母材の製造方法
JP2004231482A (ja) * 2003-01-31 2004-08-19 Sumitomo Electric Ind Ltd 炉心管の異常検出方法及び加熱炉
JP4315093B2 (ja) * 2004-10-28 2009-08-19 住友電気工業株式会社 ガラスの製造方法
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Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5766291A (en) * 1994-04-28 1998-06-16 Heraeus Quarzglas Gmbh Method for producing heat-resistant synthetic quartz glass
US6543257B1 (en) * 1999-05-28 2003-04-08 The Furukawa Electric Co., Ltd. Dehydration and sintering apparatus for porous optical fiber preform
US20030221461A1 (en) * 2002-05-31 2003-12-04 Hiroshi Oyamada Preform and method for manufacturing same
US20060038695A1 (en) * 2004-08-18 2006-02-23 Isaacs Michael S Gas supply pressure alarm device

Also Published As

Publication number Publication date
JP2008031033A (ja) 2008-02-14
JP5867976B2 (ja) 2016-02-24
US20130298611A1 (en) 2013-11-14
KR101343683B1 (ko) 2013-12-20
EP2048120B1 (en) 2017-01-11
EP2048120A4 (en) 2013-02-27
US8839645B2 (en) 2014-09-23
CN104445914A (zh) 2015-03-25
WO2008001775A1 (fr) 2008-01-03
EP2048120A1 (en) 2009-04-15
KR20090028700A (ko) 2009-03-19

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