JPS63277533A - Production of preform for alkali-resistant optical fiber and production device therefor - Google Patents

Production of preform for alkali-resistant optical fiber and production device therefor

Info

Publication number
JPS63277533A
JPS63277533A JP62112294A JP11229487A JPS63277533A JP S63277533 A JPS63277533 A JP S63277533A JP 62112294 A JP62112294 A JP 62112294A JP 11229487 A JP11229487 A JP 11229487A JP S63277533 A JPS63277533 A JP S63277533A
Authority
JP
Japan
Prior art keywords
raw material
glass raw
nozzle
base material
outlet
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP62112294A
Other languages
Japanese (ja)
Inventor
Tsuneo Kuwabara
恒夫 桑原
Atsushi Sasaki
淳 佐々木
Hiroaki Koga
古賀　広昭
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nippon Telegraph and Telephone Corp
Original Assignee
Nippon Telegraph and Telephone Corp
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 Nippon Telegraph and Telephone Corp filed Critical Nippon Telegraph and Telephone Corp
Priority to JP62112294A priority Critical patent/JPS63277533A/en
Publication of JPS63277533A publication Critical patent/JPS63277533A/en
Pending legal-status Critical Current

Links

Classifications

    • 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]
    • C03B37/01413—Reactant delivery systems
    • C03B37/0142—Reactant deposition burners
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B2201/00—Type of glass produced
    • C03B2201/02—Pure silica glass, e.g. pure fused quartz
    • 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
    • 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
    • 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
    • C03B2201/32—Doped silica-based glasses doped with metals, e.g. Ga, Sn, Sb, Pb or Bi doped with aluminium
    • 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
    • C03B2201/40—Doped silica-based glasses doped with metals, e.g. Ga, Sn, Sb, Pb or Bi doped with transition metals other than rare earth metals, e.g. Zr, Nb, Ta or Zn
    • 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
    • C03B2201/40—Doped silica-based glasses doped with metals, e.g. Ga, Sn, Sb, Pb or Bi doped with transition metals other than rare earth metals, e.g. Zr, Nb, Ta or Zn
    • C03B2201/42—Doped silica-based glasses doped with metals, e.g. Ga, Sn, Sb, Pb or Bi doped with transition metals other than rare earth metals, e.g. Zr, Nb, Ta or Zn doped with titanium
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B2207/00—Glass deposition burners
    • C03B2207/04—Multi-nested ports
    • C03B2207/06—Concentric circular ports
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B2207/00—Glass deposition burners
    • C03B2207/04—Multi-nested ports
    • C03B2207/12—Nozzle or orifice plates
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B2207/00—Glass deposition burners
    • C03B2207/04—Multi-nested ports
    • C03B2207/16—Non-circular ports, e.g. square or oval
    • 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
    • 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
    • C03B2207/26—Multiple ports for glass precursor
    • 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
    • C03B2207/26—Multiple ports for glass precursor
    • C03B2207/28—Multiple ports for glass precursor for different glass precursors, reactants or modifiers
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B2207/00—Glass deposition burners
    • C03B2207/30—For glass precursor of non-standard type, e.g. solid SiH3F
    • C03B2207/34—Liquid, e.g. mist or aerosol
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B2207/00—Glass deposition burners
    • C03B2207/46—Comprising performance enhancing means, e.g. electrostatic charge or built-in heater

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Optical Fibers, Optical Fiber Cores, And Optical Fiber Bundles (AREA)
  • Manufacture, Treatment Of Glass Fibers (AREA)

Abstract

PURPOSE:To obtain the titled parent material of three-layer structure having excellent alkali resistance, by blowing off a first, a second and a third glass raw materials from the central part of a nozzle toward the outer peripheral part to form a porous preform. CONSTITUTION:A glass raw material consisting of a main glass raw material and a raw material to enlarge refractive index is blown off from a first blow hole 9 set at the central part of a nozzle 1, the main glass raw material is emitted from a second blow hole 10 at the circumference of the blow hole 9 and a glass raw material consisting of the main glass raw material and a raw material to lessen melting rate in an alkali solution is sprayed from a third blow hole 11 set in the circumference of the blow hole 10 to grow a porous preform 3 on a substrate 2. Then the preform 3 is pulled up through a connecting bar 4 by a drive gear 5 in such a way that the distance between part of the preform 3 at the closest side to the nozzle 1 and the nozzle 1 is made constant, the rod-shaped preform 3 is grown and made into transparent glass.

Description

【発明の詳細な説明】 ［産業上の利用分野］ 本発明は、耐アルカリ性にすぐれた光ファイバ用母材の
製造方法およびその製造装置に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing an optical fiber base material with excellent alkali resistance and an apparatus for manufacturing the same.

［従来の技術］ 従来の光ファイバ用母材の製造方法としては、たとえば
特開昭５２−１４３０３７号明細書に示されるような方
法がある。ここでは、第４図（Ａ）および（Ｂ）に示す
ようなノズルを用いる。すなわち、このノズル１００で
は、ガラス原料を吹出す第１吹出口１０１をノズル１０
０の中心部に配置し、・屈折率を前述のガラス原料より
小さくする第２のガラス原料を吹き出す第２吹出口１０
２および１０３を第１吹出し口１０１の周囲に配置する
。このノズル１００から粒子状にガラス原料を吹き出し
、その粒子状ガラス原料をノズル１００の前方にて集積
して多孔質母材を形成する。その多孔質母材のうち最も
ノズル側に位置する部分がノズル１００と一定距離を維
持するように、その多孔質母材を移動しながら棒状のガ
ラス焼結体を成長させる。次いで、この棒状の多孔質母
材を加熱して透明ガラス化して光ファイバ用母材を得る
。[Prior Art] As a conventional method for manufacturing an optical fiber preform, there is a method as disclosed in, for example, Japanese Unexamined Patent Publication No. 143037/1983. Here, a nozzle as shown in FIGS. 4(A) and 4(B) is used. That is, in this nozzle 100, the first outlet 101 for blowing out the glass raw material is connected to the nozzle 10.
0, and blows out a second glass raw material whose refractive index is smaller than that of the glass raw material mentioned above;
2 and 103 are arranged around the first air outlet 101. A glass raw material is blown out in the form of particles from this nozzle 100, and the particulate glass raw material is accumulated in front of the nozzle 100 to form a porous base material. A rod-shaped glass sintered body is grown while moving the porous base material so that the part of the porous base material located closest to the nozzle maintains a constant distance from the nozzle 100. Next, this rod-shaped porous preform is heated to make it transparent and vitrified to obtain an optical fiber preform.

この方法による光ファイバ用母材の製造法では、上述の
特開昭５２−１４３０３７号に述べられているように、
通常は第１吹出し口１０１からはＳｉＣｌ２などのガラ
ス主材料とＧｅＣｊ２４などガラスの屈折率を上昇させ
るための原料とを混合して高温ガスとともに吹出し、第
２吹出し口１０２および１０３からは５ｉＣｆＬ４など
のガラス主材料を吹出すことにより、中心部（以下コア
と呼ぶ）の屈折率を外周部（以下クラッドと呼ぶ）より
大きくした光ファイバ用母材を製造している。In this method of manufacturing an optical fiber preform, as described in the above-mentioned Japanese Patent Application Laid-Open No. 52-143037,
Normally, a glass main material such as SiCl2 and a raw material for increasing the refractive index of the glass such as GeCj24 are mixed and blown out from the first outlet 101 together with high-temperature gas, and from the second outlet 102 and 103, 5iCfL4, etc. By blowing a glass main material, an optical fiber preform is manufactured in which the refractive index of the central portion (hereinafter referred to as the core) is larger than that of the outer peripheral portion (hereinafter referred to as the cladding).

このようにして製造された母材のクラッドはほぼ５ｉｎ
２によりて構成されており、一般の光ファイバ用心線と
して用いられている。The cladding of the base material thus manufactured was approximately 5 inches.
2, and is used as a general optical fiber core wire.

［発明が解決しようとする問題点］ ところが、　５ｉｎ２はアルカリ溶液に対し容易に融解
するため、このような母材を線引きして高分子材料の被
覆を施すことによって得られた光ファイバ心線は、Ｎａ
ＯＨ溶液等のアルカリ溶液に浸漬されると、高分子材料
の被覆を通過してくるＮａ”、ＯＨ−イオン等により５
ｉ０２が融解して静的応力印加時の破断時間が著しく短
くなる。本発明者らの実験によると、外径０．１２５ｍ
ｍφの光ファイバに紫外線硬化樹脂を被覆して外径０．
２５ｍｍφとした光ファイバ心線を６０℃の０．００５
％Ｎａ０）１溶液に９日間浸漬したところ、同一応力印
加時の破断時間が初期の１７１．０００に短くなった。[Problems to be Solved by the Invention] However, since 5in2 easily melts in an alkaline solution, the optical fiber core obtained by drawing such a base material and coating it with a polymeric material is , Na
When immersed in an alkaline solution such as an OH solution, 5
i02 melts and the time to rupture when static stress is applied becomes significantly shorter. According to the inventors' experiments, the outer diameter is 0.125 m.
mφ optical fiber is coated with ultraviolet curing resin to give an outer diameter of 0.
0.005 of the optical fiber core wire with a diameter of 25 mm at 60°C.
% Na0)1 solution for 9 days, the rupture time when the same stress was applied was shortened to the initial value of 171.000.

光ファイバ心線は現在広く使用されており、例えば地下
線路で使用した場合、マンホール溜水等アルカリ性の地
下水に浸漬される可能性が十分にあり、このような場合
に、従来の方法により製造された光ファイバ用母材から
作製された光ファイバ心線はぎわめて破断じやすくなる
という信頼性上重大な欠点を有していた。Optical fiber cores are currently widely used, and when used in underground lines, for example, there is a good chance that they will be immersed in alkaline underground water such as manhole water. The optical fiber core wire produced from the optical fiber base material has a serious drawback in terms of reliability in that it is extremely easy to break.

このような問題点を解決する光ファイバ心線としては、
前記クラッドの外周に耐アルカリ性を有する成分（Ｚｒ
０２．ＴｉＯ２，Ａｊｉ！　２０３，５ｎ０２等）を含
んだ保護層を有する光ファイバ（特願昭６２−２７３５
１号「光ファイバ」）にプラスチック被覆を施すことが
考えられる。Optical fiber cores that solve these problems include:
A component having alkali resistance (Zr
02. TiO2, Aji! 203, 5n02, etc.) (Patent Application No. 62-2735)
It is conceivable to apply a plastic coating to the optical fiber (No. 1 "Optical Fiber").

このような光ファイバを作製するためには、母材自身を
コア、クラッドおよび保護層の３層構造とする必要があ
るが、現在の製造方法に用いている製造装置では、第４
図（Ａ）および（Ｂ）につき上述したように吹出し口が
第１吹出し口１０１と第２吹出し口１０２および１０３
の２ｆ８１類しか存在しないため、このような３層構造
の母材を製造することはできない。In order to manufacture such optical fibers, the base material itself must have a three-layer structure of a core, a cladding, and a protective layer, but the manufacturing equipment used in current manufacturing methods does not allow
As described above in FIGS. (A) and (B), the air outlets are the first air outlet 101 and the second air outlets 102 and 103.
Since only the 2f81 type exists, it is not possible to manufacture a base material with such a three-layer structure.

耐アルカリ性向上のために、従来の製造装置において、
第２吹出し口１０２および１０３より７、ｒＣｌｌ、　
ａ、　ＴｆＣｌ　４．　Ａｎ　Ｃ１１３，５ｎＣｕ　４
等を含有したガラス原料を吹出し、母材のクラッド部に
耐アルカリ性を有する成分（ＺｒＯｚ、ＴｉＯ２，Ａｌ
２　ｚ０３，５ｎ０２等）を含有させることはできるが
、これらの成分はすべて屈折率を上昇させる作用を有す
るため、このような方法で製造した母材から得られる光
ファイバ心線では、光伝送が行えなくなるという本末転
倒な結果を招来するという欠点がある。In order to improve alkali resistance, in conventional manufacturing equipment,
7 from the second outlet 102 and 103, rCll,
a, TfCl 4. An C113,5nCu 4
A glass raw material containing alkali-resistant components (ZrOz, TiO2, Al
2z03, 5n02, etc.), but since all of these components have the effect of increasing the refractive index, the optical fiber obtained from the base material manufactured by this method will have low optical transmission. The drawback is that it may lead to the undesirable result of not being able to do so.

従来の製造装置において、第１吹出し口１０１より　Ｚ
ｒＣｊ２４．ＴｉＯ２，Ａｌ１　Ｃ４２３，５ｎＣ１４
等を含有したガラス原料を吹出して、母材のコア部にＺ
ｎＯ２゜ＴｉＯ２，Ａｌｌ！　２０．、ＳｎＯ□等耐ア
等力アルカリ性る成分を含有させつつコアの屈折率をク
ラッドの屈折率より高くすることはできるものの、アル
カリ溶液による光ファイバ心線破断時間が短くなること
は、コアの外側にあるクラッドのアルカリ溶液による融
解により生じるのであるから、このような方法によりコ
アの耐アルカリ性を向上させても何の効果も生じない。In conventional manufacturing equipment, from the first outlet 101 Z
rCj24. TiO2, Al1 C423, 5nC14
Blow out the glass raw material containing etc. to form a Z
nO2゜TiO2, All! 20. Although it is possible to make the refractive index of the core higher than the refractive index of the cladding while containing alkaline resistant components such as SnO□, the fact that the breakage time of the optical fiber due to alkaline solution is shortened is that the outside of the core This is caused by the melting of the cladding in the alkaline solution, so even if the alkali resistance of the core is improved by such a method, no effect will be produced.

そこで、本発明の目的は、耐アルカリ性に優れた光ファ
イバを作成するために必要なコア、クラッドおよび耐ア
ルカリ性を有する保護層からなる３層構造の光ファイバ
用母材の製造方法およびその製造装置を提供することに
ある。SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for manufacturing an optical fiber base material having a three-layer structure consisting of a core, a cladding, and a protective layer having alkali resistance necessary for producing an optical fiber with excellent alkali resistance, and an apparatus for manufacturing the same. Our goal is to provide the following.

［問題点を解決するための手段］ かかる目的を達成するために、本発明製造方法は、ノズ
ルの中心部に配置した第１吹出口から第１ガラス原料を
吹き出し、第１吹出口の周囲に配置した第２吐出口から
第１ガラス原料よりも屈折率を小さくする第２ガラス原
料を吹き出し、第２吹出口の周囲に配置された第３吹出
口からアルカリ溶液に対する溶解速度を第２ガラス原料
より小さくする第３ガラス原料をを吹き出し、ノズルの
前方において第１．第２および第３ガラス原料を集積し
て多孔質母材を形成し、多孔質母材の最もノズルの側に
位置する部分がノズルと一定の距離を維持するように多
孔質母材を移動させて多孔質母材を棒状に成長させ、そ
の棒状の多孔質母材を加熱して透明ガラス化することを
特徴とする。[Means for Solving the Problems] In order to achieve the above object, the manufacturing method of the present invention blows out the first frit from the first blowout port arranged at the center of the nozzle, and blows out the first frit material around the first blowout port. A second glass raw material having a refractive index smaller than that of the first glass raw material is blown out from the second discharge port arranged, and a dissolution rate of the second glass raw material in the alkaline solution is adjusted from a third blow-off port arranged around the second glass raw material. The third glass raw material to be made smaller is blown out, and the first glass raw material is blown out in front of the nozzle. The second and third glass raw materials are accumulated to form a porous base material, and the porous base material is moved so that the part of the porous base material located closest to the nozzle maintains a certain distance from the nozzle. The method is characterized in that the porous base material is grown into a rod shape, and the rod-shaped porous base material is heated to turn it into transparent vitrification.

更にまた、本発明製造装置は、密封容器と、密封容器内
に配置されたガラス原料を吹き出すノズルと、ノズルの
前方に配置された基板と、基板を基板に対し垂直方向に
移動させる移動手段とを有する光ファイバ用母材の製造
装置において、第１ガラス原料を吹き出す少なくともひ
とつの第１吹出し口をノズルの中心部に配置し、屈折率
を第１吹出し口より吹き出す第１ガラス原料より小さく
するガラス原料を吹出す少なくともひとつの第２吹出し
口を第１吹出し口の周囲に配置し、アルカリ溶液に対す
る溶解速度を第２吹出°し口より吹出す第２ガラス原料
より小さくする第３ガラス原料を吹出す少なくともひと
つの第３吹出し口を第２吹出し口の周囲に配置したこと
を特徴とする。Furthermore, the manufacturing apparatus of the present invention includes a sealed container, a nozzle disposed in the sealed container for blowing out glass raw materials, a substrate disposed in front of the nozzle, and a moving means for moving the substrate in a direction perpendicular to the substrate. In the apparatus for manufacturing an optical fiber base material, at least one first outlet for blowing out the first glass raw material is arranged in the center of the nozzle, and the refractive index is made smaller than that of the first glass raw material blown out from the first outlet. A third glass raw material whose dissolution rate in an alkaline solution is smaller than that of the second glass raw material blown out from the second outlet, by disposing at least one second outlet for blowing out the glass raw material around the first outlet. The present invention is characterized in that at least one third outlet for blowing air is arranged around the second outlet.

［作　用］ 本発明では、ガラスの焼結体を形成する際にガラス原料
を供給するノズルは、中心部に配置された第１吹出し口
と、その第１吹出し口の周囲に配置された第２吹出し口
と、その第２吹出し口の周囲に配置された第３吹出し口
を有し、第３吹出し口より吹き出させるガラス原料とし
てアルカリ溶液に対する溶解速度を小さくするガラス原
料を使用する。[Function] In the present invention, the nozzle for supplying glass raw materials when forming a glass sintered body has a first blowout port arranged in the center and a second blowout port arranged around the first blowout port. It has two blow-off ports and a third blow-off port disposed around the second blow-off port, and a glass raw material that has a low dissolution rate in an alkaline solution is used as the glass raw material to be blown out from the third blow-off port.

本発明によって光ファイバ用母材を製造すると、母材の
中心より順次にコア、このコアより屈折率の小さいクラ
ッドおよびアルカリ溶液に対してほとんど融解しない保
護層が配置された３層構造を有する光ファイバ用母材を
製造することができるので、この母材を線引きし高分子
の被覆を施すことにより、光の伝送が可能であり、かつ
アルカリ溶液浸漬時の信頼性が従来の光ファイバ心線に
比べて格段に向上した光ファイバ心線を実現できる。When an optical fiber base material is manufactured according to the present invention, the optical fiber has a three-layer structure in which a core, a cladding having a refractive index lower than the core, and a protective layer that hardly melts in an alkaline solution are arranged sequentially from the center of the base material. It is possible to manufacture a fiber base material, and by drawing this base material and coating it with a polymer, it is possible to transmit light, and the reliability when immersed in an alkaline solution is superior to that of conventional optical fiber cores. It is possible to realize a coated optical fiber that is significantly improved compared to the previous method.

本発明は、吹出し口が３種類あり、しかもそのうちの最
外周に配された第３吹出し口より吹出される原料が従来
の方法で用いる原料とは異なる。In the present invention, there are three types of blow-off ports, and the raw material blown out from the third blow-off port arranged at the outermost periphery is different from the raw material used in the conventional method.

［実施例］ 以下、図面を参照して本発明の詳細な説明する。[Example] Hereinafter, the present invention will be described in detail with reference to the drawings.

第１図は本発明による製造装置の一実施例の構成を示す
図である。ここで、１はガラス原料を吹出すノズル、２
は多孔質母材堆積のための出発材料としての基板、３は
基板２上に成長した多孔質母材、４は基板２を上方に引
上げるための連結棒、５は連結棒４の駆動装置、６はこ
れら各部１〜５を収容した密封容器、７は容器６に取り
つけた排気ダクト、８は排気ダクト７に取りつけた逆流
防止トラップである。ノズル１は第１吹出し口９°、第
２吹出し口１Ｇおよび第３吹出し口１１を有する。これ
ら吐出口９．１０および１１は、それぞれ、ひとつであ
ってもよく、あるいは複数個あってもよい。FIG. 1 is a diagram showing the configuration of an embodiment of a manufacturing apparatus according to the present invention. Here, 1 is a nozzle that blows out the glass raw material, 2
is a substrate as a starting material for porous base material deposition; 3 is a porous base material grown on the substrate 2; 4 is a connecting rod for pulling the substrate 2 upward; 5 is a driving device for the connecting rod 4. , 6 is a sealed container containing these parts 1 to 5, 7 is an exhaust duct attached to the container 6, and 8 is a backflow prevention trap attached to the exhaust duct 7. The nozzle 1 has a first outlet 9°, a second outlet 1G, and a third outlet 11. Each of these outlets 9, 10 and 11 may be one or more.

第２図はノズル１の詳細を示す断面図であり、その中心
に設けた第１吹出し口９の周囲に、第２吹出し口１０お
よび第２吹出し口１１を同心円状に配置する。FIG. 2 is a sectional view showing details of the nozzle 1, in which a second outlet 10 and a second outlet 11 are arranged concentrically around a first outlet 9 provided at the center.

上述した製造装置を用いて耐アルカリ光ファイバ用母材
を製造する方法は、ガラス原料を第１吹出し口９より高
温ガスとともに吹出し、第１吹出し口９より吹き出すガ
ラス原料より屈折率を小さくするガラス原料を第２吹出
し口より高温ガスとともに吹出し、第２吹出し口ｌＯよ
り吹出すガラス材料よりアルカリ溶液に対する融解速度
を小さくするガラス原料を第３吹出し口より高温ガスと
ともに吹出し、基板２上に多孔質母材３を形成する。こ
の際に生じるＣ１２などのガスを排気ダクト７を通して
容器６の外部に排気しながら多孔質母材３を成長させる
。この多孔質母材３の成長にともなって、多孔質母材３
の最もノズル１側の部分とノズル１どの距離が一定とな
るように連結棒４を介して駆動装置５により多孔質母材
３を引上げるように移動させて、棒状の多孔質母材３を
形成する。しかる後、この多孔質母材３を加熱して透明
ガラス化させる。The method of manufacturing a preform for an alkali-resistant optical fiber using the above-mentioned manufacturing apparatus is to blow out glass raw material from the first blowout port 9 together with high-temperature gas, and to produce a glass having a refractive index smaller than that of the glass raw material blown out from the first blowout port 9. The raw material is blown out from the second outlet along with high-temperature gas, and the glass raw material, which has a lower melting rate in an alkaline solution than the glass material blown out from the second outlet 10, is blown out from the third outlet along with the high-temperature gas to form a porous material on the substrate 2. A base material 3 is formed. The porous base material 3 is grown while exhausting the gas such as C12 generated at this time to the outside of the container 6 through the exhaust duct 7. With the growth of this porous base material 3, the porous base material 3
The rod-shaped porous base material 3 is moved so as to be pulled up by the drive device 5 via the connecting rod 4 so that the distance between the part closest to the nozzle 1 and the nozzle 1 is constant. Form. Thereafter, this porous base material 3 is heated to turn it into transparent vitrification.

ここで、第１吹出し口９より吹出すガラス原料としては
、例えば、５ｉＣ１１４などのガラス主原料と　ＧｅＣ
１，４などガラスの屈折率を大きくする原料とを混合し
たガラス原料を用いる。第２吹出し口ｌＯより吹出すガ
ラス原料としては、例えば、５ｉＣｕ４などのガラス主
原料のみを用いる。第３吹出し口１１から吹出すガラス
原料としては、例えば、５ｉＣｊ２　、などのガラス主
原料にＴｉＣＩＬ４゜ＺｒＣｊＺ　４．　ＡＪＺ　ＣＩ
Ｌｓ、　５ｎＣｆＬａなどの耐アルカリ性を向上させる
原料とを混合したガラス原料を使用する。Here, the glass raw materials blown out from the first outlet 9 include glass main raw materials such as 5iC114 and GeC.
A glass raw material mixed with a raw material that increases the refractive index of glass such as 1 and 4 is used. As the glass raw material blown out from the second blowing port IO, only a glass main raw material such as 5iCu4 is used, for example. The glass raw materials blown out from the third outlet 11 include, for example, glass main raw materials such as 5iCj2 and TiCIL4°ZrCjZ4. AJZ CI
A glass raw material mixed with a raw material that improves alkali resistance such as Ls and 5nCfLa is used.

このようにして製造された光ファイバ用母材は、第３図
に示すよう鰐、中心に配置されたコア１２と、そのコア
１２の外周に配置されたコア１２より屈折率の小さなり
ラッド１３と、そのクラッド１２の外周に配置された耐
アルカリ性に優れた成分（例えばＴｉＯ２，Ｚｒ０ｚ、
　Ａｊ２２０３，５ｎＯ２）を含有する保護層１４とか
らなる３層構造を有している。As shown in FIG. 3, the optical fiber base material manufactured in this manner has a core 12 arranged at the center, and rads 13 having a smaller refractive index than the core 12 arranged around the outer periphery of the core 12. and components with excellent alkali resistance (for example, TiO2, Zr0z,
It has a three-layer structure consisting of a protective layer 14 containing Aj2203,5nO2).

従って、この母材を線引きして高分子の被覆を施した光
ファイバ心線では、アルカリ溶液に浸漬しても保護層１
４がほとんど融解しない。例えばＴｉ（ｈ　１５％、　
Ｚｒ０２５％、　５ｉｎ２８０％のガラスハ５ｔ（ｈ　
１００％のガラスに比べ融解速度は約１７１００になる
。その結果、本発明方法で製造した光ファイバ用母材で
形成した光ファイバにおいては、静的応力印加時の破断
時間はほとんど変化しない。Therefore, in an optical fiber coated with a polymer coating by drawing this base material, the protective layer remains intact even when immersed in an alkaline solution.
4 hardly melts. For example, Ti (h 15%,
Zr025%, 5in280% glass 5t (h
Compared to 100% glass, the melting rate is approximately 17100%. As a result, in the optical fiber formed from the optical fiber preform manufactured by the method of the present invention, the time to break when static stress is applied hardly changes.

［発明の効果］ 以上説明したように、本発明によって光ファイバ用母材
を製造すると、母材の中心より順次にコア、このコアよ
り屈折率の小さいクラッドおよびアルカリ溶液に対して
ほとんど融解しない保護層が配置された３層構造を有す
る光ファイバ用母材を製造することができるので、この
母材を線引きし高分子の被覆を施すことにより、光の伝
送が可能であり、かつアルカリ溶液浸漬時の信頼性が従
来の光ファイバ心線に比べて格段に向上した光ファイバ
心線を実現で診る。[Effects of the Invention] As explained above, when an optical fiber base material is manufactured according to the present invention, from the center of the base material, the core, the cladding having a refractive index lower than the core, and the protection that hardly melt against alkaline solutions are formed. It is possible to manufacture an optical fiber base material with a three-layer structure in which layers are arranged, so by drawing this base material and applying a polymer coating, it is possible to transmit light, and it is possible to make it possible to transmit light by immersing it in an alkaline solution. We will demonstrate the realization of a coated optical fiber that has significantly improved reliability over time compared to conventional coated optical fibers.

【図面の簡単な説明】[Brief explanation of drawings]

第１図は本発明による製造装置の一実施例の構成を示す
構成図、 第２図は本発明に用いられるノズルの一実施例子 を示す／面図、 第３図は本発明により得られた光ファイバ用母材の一例
を示す断面図、 第４図（Ａ）および（Ｂ）は従来のノズルの一例を示す
、それぞれ、平面図および断面図である。 １・・・ノズル、 ２・・・基板、 ３・・・多孔質母材、 ４・・・連結棒、 ５・・・駆動装置、 ６・・・密封容器、 ７・・・排気ダクト、 ８・・・逆流防止トラップ、 ９・・・第１吹出し口、 ｌＯ・・・第２吹出し口、 １１・・・第３吹出し口、 １２・・・コア、 １３・・・クラッド、 １４・・・保護層、 １００・・・ノズル、 １０１・・・第１吹出口、 １０２．１０３・・・第２吹出口。Fig. 1 is a block diagram showing the configuration of an embodiment of a manufacturing apparatus according to the present invention, Fig. 2 is a top view showing an embodiment of a nozzle used in the present invention, and Fig. 3 is a diagram showing the configuration of an embodiment of a manufacturing apparatus according to the present invention. A cross-sectional view showing an example of a preform for an optical fiber; FIGS. 4A and 4B are a plan view and a cross-sectional view, respectively, showing an example of a conventional nozzle. DESCRIPTION OF SYMBOLS 1... Nozzle, 2... Substrate, 3... Porous base material, 4... Connecting rod, 5... Drive device, 6... Sealed container, 7... Exhaust duct, 8 ... Backflow prevention trap, 9... First outlet, lO... Second outlet, 11... Third outlet, 12... Core, 13... Clad, 14... Protective layer, 100... Nozzle, 101... First outlet, 102.103... Second outlet.

Claims (1)

【特許請求の範囲】 １）ノズルの中心部に配置した第１吹出口から第１ガラ
ス原料を吹き出し、 前記第１吹出口の周囲に配置した第２吐出口から前記第
１ガラス原料よりも屈折率を小さくする第２ガラス原料
を吹き出し、 前記第２吹出口の周囲に配置された第３吹出口からアル
カリ溶液に対する溶解速度を前記第２ガラス原料より小
さくする第３ガラス原料をを吹き出し、 前記ノズルの前方において前記第１、第２および第３ガ
ラス原料を集積して多孔質母材を形成し、 前記多孔質母材の最も前記ノズルの側に位置する部分が
前記ノズルと一定の距離を維持するように前記多孔質母
材を移動させて前記多孔質母材を棒状に成長させ、 その棒状の多孔質母材を加熱して透明ガラス化すること
を特徴とする耐アルカリ光ファイバ用母材の製造方法。 ２）特許請求の範囲第１項記載の耐アルカリ光ファイバ
用母材の製造方法において、前記第３吹出し口より吹き
出す前記第３ガラス原料としてＺｒＣｌ＿４、ＴｉＣｌ
＿４、ＡｌＣｌ＿３、ＳｎＣｌ＿４、ＢＣｌ＿３からな
る原料群のうちの少なくともひとつの原料を含んだガラ
ス原料を使用することを特徴とする耐アルカリ光ファイ
バ用母材の製造方法。 ３）密封容器と、 該密封容器内に配置されたガラス原料を吹き出すノズル
と、 該ノズルの前方に配置された基板と、 該基板を前記基板に対し垂直方向に移動させる移動手段
とを有する光ファイバ用母材の製造装置において、 第１ガラス原料を吹き出す少なくともひとつの第１吹出
し口を前記ノズルの中心部に配置し、 屈折率を前記第１吹出し口より吹き出す前記第１ガラス
原料より小さくする第２ガラス原料を吹出す少なくとも
ひとつの第２吹出し口を前記第１吹出し口の周囲に配置
し、 アルカリ溶液に対する溶解速度を前記第２吹出し口より
吹出す前記第２ガラス原料より小さくする第３ガラス原
料を吹出す少なくともひとつの第３吹出し口を前記第２
吹出し口の周囲に配置したことを特徴とする耐アルカリ
光ファイバ用母材の製造装置。[Claims] 1) A first glass raw material is blown out from a first blow-off port disposed at the center of the nozzle, and the first glass raw material is refracted more than the first glass raw material from a second discharge port disposed around the first blow-off port. blowing out a second glass raw material whose dissolution rate in an alkaline solution is smaller than that of the second glass raw material from a third blower outlet disposed around the second blower outlet; The first, second, and third glass raw materials are accumulated in front of a nozzle to form a porous base material, and a portion of the porous base material located closest to the nozzle is at a certain distance from the nozzle. The porous base material is grown into a rod shape by moving the porous base material such that the porous base material is maintained, and the rod-shaped porous base material is heated to become transparent vitrified. Method of manufacturing wood. 2) In the method for manufacturing a preform for an alkali-resistant optical fiber according to claim 1, the third glass raw material blown out from the third outlet includes ZrCl_4, TiCl
_4, AlCl_3, SnCl_4, and BCl_3 A method for producing a base material for an alkali-resistant optical fiber, characterized by using a glass raw material containing at least one raw material from the raw material group consisting of AlCl_3, SnCl_4, and BCl_3. 3) A light comprising a sealed container, a nozzle disposed in the sealed container to blow out the glass raw material, a substrate disposed in front of the nozzle, and a moving means for moving the substrate in a direction perpendicular to the substrate. In an apparatus for producing a fiber base material, at least one first outlet for blowing out a first glass raw material is arranged in the center of the nozzle, and the refractive index is made smaller than that of the first glass raw material blown out from the first glass raw material. At least one second blowout port for blowing out the second glass raw material is arranged around the first blowout port, and a third glass material whose dissolution rate in the alkaline solution is smaller than that of the second glass raw material blown out from the second blowout port. At least one third outlet for blowing out the glass raw material is connected to the second outlet.
An apparatus for manufacturing a base material for an alkali-resistant optical fiber, characterized in that the base material is arranged around an outlet.
JP62112294A 1987-05-11 1987-05-11 Production of preform for alkali-resistant optical fiber and production device therefor Pending JPS63277533A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP62112294A JPS63277533A (en) 1987-05-11 1987-05-11 Production of preform for alkali-resistant optical fiber and production device therefor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP62112294A JPS63277533A (en) 1987-05-11 1987-05-11 Production of preform for alkali-resistant optical fiber and production device therefor

Publications (1)

Publication Number Publication Date
JPS63277533A true JPS63277533A (en) 1988-11-15

Family

ID=14583088

Family Applications (1)

Application Number Title Priority Date Filing Date
JP62112294A Pending JPS63277533A (en) 1987-05-11 1987-05-11 Production of preform for alkali-resistant optical fiber and production device therefor

Country Status (1)

Country Link
JP (1) JPS63277533A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2018017524A (en) * 2016-07-25 2018-02-01 鹿島建設株式会社 Monitoring device and monitoring method

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2018017524A (en) * 2016-07-25 2018-02-01 鹿島建設株式会社 Monitoring device and monitoring method

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