JPH06293530A - Method for manufacturing optical fiber preform - Google Patents
Method for manufacturing optical fiber preformInfo
- Publication number
- JPH06293530A JPH06293530A JP7928793A JP7928793A JPH06293530A JP H06293530 A JPH06293530 A JP H06293530A JP 7928793 A JP7928793 A JP 7928793A JP 7928793 A JP7928793 A JP 7928793A JP H06293530 A JPH06293530 A JP H06293530A
- Authority
- JP
- Japan
- Prior art keywords
- optical fiber
- fiber preform
- gas
- bubbles
- preform
- 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
Links
- 239000013307 optical fiber Substances 0.000 title claims abstract description 29
- 238000000034 method Methods 0.000 title claims description 20
- 238000004519 manufacturing process Methods 0.000 title claims description 6
- 239000011521 glass Substances 0.000 claims description 12
- 239000000843 powder Substances 0.000 claims description 5
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 5
- 239000010453 quartz Substances 0.000 claims description 3
- 238000010438 heat treatment Methods 0.000 abstract description 6
- 239000000463 material Substances 0.000 description 7
- 238000005253 cladding Methods 0.000 description 2
- 238000002791 soaking Methods 0.000 description 2
- 238000004017 vitrification Methods 0.000 description 2
- 238000001816 cooling Methods 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000004868 gas analysis Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
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]
- C03B37/01446—Thermal after-treatment of preforms, e.g. dehydrating, consolidating, sintering
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Physics & Mathematics (AREA)
- General Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Thermal Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Glass Melting And Manufacturing (AREA)
- Manufacture, Treatment Of Glass Fibers (AREA)
Abstract
(57)【要約】
【目的】線引き後の光ファイバ中に、気泡を発生させな
い。
【構成】コア及びクラッドからなる光ファイバ用の透明
ガラス化された母材を、真空雰囲気下、５００〜１２０
０℃で加熱処理する。(57) [Summary] [Purpose] No bubbles are generated in the optical fiber after drawing. [Structure] A transparent vitrified preform for an optical fiber, which is composed of a core and a clad, is placed in a vacuum atmosphere for 500 to 120
Heat treatment at 0 ° C.
Description
【０００１】[0001]
【産業上の利用分野】本発明はＶＡＤ法特に外付ＶＡＤ
法による光ファイバ母材の製造方法に関するものであ
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the VAD method, especially external VAD.
The present invention relates to a method for manufacturing an optical fiber preform by the method.
【０００２】[0002]
【従来の技術】ＶＡＤ法などに作られた透明ガラスロッ
ドを清浄にし、この表面にＶＡＤ法と同じように原料ガ
ス及び焼料ガスをバーナーに供給し、バーナーの火炎中
で生成させたガラス微粉末を吹きつけて堆積させ、その
後約１６００℃に加熱しＨｅガスとＣＬ2 ガス雰囲気
下、透明ガラス化し光ファイバ母材を得る。その後酸水
素バーナーで透明ガラス化した棒状の光ファイバ母材両
端部表面を清浄化し約２０００℃の炉内に入れて母材先
端を軟化させて線引きし、外径１２５μｍの光ファイバ
を作る。2. Description of the Related Art A transparent glass rod made by the VAD method or the like is cleaned, and a raw material gas and a burning gas are supplied to the burner on the surface in the same manner as in the VAD method, and a glass fine powder produced in the flame of the burner is produced. The powder is sprayed and deposited, and then heated to about 1600 ° C. to form a transparent glass in an atmosphere of He gas and CL 2 gas to obtain an optical fiber preform. After that, the surfaces of both ends of the rod-shaped optical fiber preform transparentized with an oxyhydrogen burner are cleaned and placed in a furnace at about 2000 ° C. to soften the tip of the preform to draw an optical fiber having an outer diameter of 125 μm.
【０００３】[0003]
【発明が解決しようとする課題】前記方法でつくられた
光ファイバ母材をそのまま、線引きすると光ファイバの
中に気泡が発生し特に外付ＶＡＤ法で作られた部分とＶ
ＡＤ法で作られたガラスロッドの表面部分との境界に多
く見られ光ファイバの光学的機械的特性を著しく低下さ
せるとともに良品の歩留りが低下する。When the optical fiber preform produced by the above method is drawn as it is, air bubbles are generated in the optical fiber, and in particular, the portion formed by the external VAD method and the V
It is often found at the boundary with the surface portion of the glass rod manufactured by the AD method, which significantly deteriorates the optical mechanical properties of the optical fiber and also reduces the yield of non-defective products.
【０００４】この原因は前記方法で製造した光ファイバ
の気泡部のガス分析をすると、Ｈｅガスであることか
ら、光ファイバ母材の段階では肉眼では見ることのでき
ないわずかな外付ＶＡＤ部とＶＡＤ法で作られたガラス
ロッド間の空隙や気泡部に透明ガラス化時の雰囲気であ
るＨｅガスが含まれあるいは溶け込んでおり、この部分
が線引時の加熱により膨脹して、大きな気泡になるもの
と思われる。The cause of this is that when gas analysis of the bubble portion of the optical fiber manufactured by the above method is He gas, a slight external VAD portion and VAD which cannot be seen with the naked eye at the stage of the optical fiber base material. He gas, which is the atmosphere at the time of transparent vitrification, is contained or melted in the voids and bubble portions between the glass rods produced by the method, and this portion expands due to the heating during drawing and becomes large bubbles I think that the.
【０００５】本発明は前記した従来技術の欠点を解消
し、線引きした光ファイバ中に気泡が発生しない光ファ
イバ母材の製造方法を提供することにある。SUMMARY OF THE INVENTION The present invention solves the above-mentioned drawbacks of the prior art and provides a method of manufacturing an optical fiber preform in which bubbles are not generated in the drawn optical fiber.
【０００６】[0006]
【課題を解決するための手段】本発明の要旨は透明ガラ
ス化した光ファイバ母材を真空雰囲気下５００℃〜１２
００℃に加熱処理しそれによって、光ファイバ中に発生
する気泡を低減させることにある。The gist of the present invention is to provide a transparent vitrified optical fiber preform in a vacuum atmosphere at 500 ° C to 12 ° C.
The purpose is to heat-treat to 00 ° C. and thereby reduce the bubbles generated in the optical fiber.
【０００７】[0007]
【実施例】コア用ガラスロッドの外周にクラッド用のガ
ラス微粉末を外付した長さ１１００ｍｍ外径８０φの光
ファイバ母材を１６００℃に加熱しＨｅガス流量６■／
ｍｉｎ、Ｃ■2 ガス流量２５０ｃｃ／ｍｉｎを流しなが
ら石英ガラスからなる炉芯管内で２４０ｍｍ／ｈｒの速
度で移動させながら透明ガラス化し長さ９００ｍｍ外径
φ４０の光ファイバ母材を得た。[Example] An optical fiber preform having a length of 1100 mm and an outer diameter of 80φ with glass fine powder for cladding attached to the outer periphery of a glass rod for core was heated to 1600 ° C. and a He gas flow rate of 6
min, C. 2 Gas was flowed at a flow rate of 250 cc / min and moved into a furnace core tube made of quartz glass at a speed of 240 mm / hr to be transparent vitrified to obtain an optical fiber preform having a length of 900 mm and an outer diameter of φ40.
【０００８】次に、この母材を１０００℃の均熱部が長
さ１０００ｍｍの石英炉芯管からなる炉内に入れ、１０
００℃に加熱しながら炉内を油回転真空ポンプで真空引
きし０．１３３ｐａ（１×１０-3Ｔｏｒｎ）の真空度で
２時間処理した。Next, this base material was placed in a furnace composed of a quartz furnace core tube having a length of 1000 mm at a soaking temperature of 1000 ° C.
While heating to 00 ° C., the inside of the furnace was evacuated by an oil rotary vacuum pump and treated at a vacuum degree of 0.133 pa (1 × 10 −3 Torn) for 2 hours.
【０００９】処理後炉内から取り出し冷却後光ファイバ
母材両端および表面を酸水素バーナーで処理し約２００
０℃に加熱して線引し光ファイバとした。その結果、光
ファイバ中に気泡の発生は見られなくなりかつ肉眼で見
られた母材段階での気泡も線引き時に消滅してしまっ
た。After the treatment, the product is taken out of the furnace, and after cooling, both ends and the surface of the optical fiber preform are treated with an oxyhydrogen burner for about 200
An optical fiber was drawn by heating to 0 ° C. As a result, no bubbles were found in the optical fiber, and the bubbles seen by the naked eye at the base material stage disappeared during drawing.
【００１０】処理温度は、良く知られている様にガラス
中のＨｅガス透過量は温度が高ければ高いほど大きくな
ることから、高い温度にすれば良いが、１２００℃以上
では光ファイバ母材および炉芯管の変形が生じるため、
適当ではない。一方５００℃以下ではガスの透過率が小
さく処理時間が極めて長くなってしまう。As is well known, the treatment temperature is high because the He gas permeation amount in glass increases as the temperature rises. Therefore, the treatment temperature may be set to a high temperature. Because the furnace core tube is deformed,
Not suitable. On the other hand, if the temperature is 500 ° C. or lower, the gas permeability is small and the processing time becomes extremely long.
【００１１】また真空度は、減圧下であれば十分であ
る。さらに処理時間は処理前の母材の状態にも関係し数
十分から数時間の範囲で十分である。The degree of vacuum is sufficient if it is reduced. Further, the treatment time is in the range of several tens of minutes to several hours, which is related to the state of the base material before the treatment.
【００１２】[0012]
【発明の効果】本発明により線引前の光ファイバ母材段
階で肉眼で見ることのできない小さな気泡が原因とな
る。光ファイバ中の気泡発生が著しく低減され従来５ケ
／７０ｋｍの気泡発生頻度がほぼゼロになった。また、
母材段階で肉眼で見える気泡も加熱処理により気泡中の
Ｈｅガスを抜くため、線引時には消滅してしまい、気泡
のある母材でも光ファイバにすると気泡がなくなると言
う効果も見られ、気泡発生による歩留低下を著しく改善
することができた。According to the present invention, small bubbles that cannot be seen with the naked eye are caused at the stage of the optical fiber preform before drawing. The bubble generation in the optical fiber was significantly reduced, and the frequency of bubble generation of 5 cells / 70 km was almost zero. Also,
The bubbles that can be seen with the naked eye at the base material stage are also removed by the heat treatment to remove the He gas in the bubbles, so they disappear when drawing, and the effect that even if the base material with bubbles is made into an optical fiber, the bubbles disappear. It was possible to remarkably reduce the yield decrease due to the occurrence.
【手続補正書】[Procedure amendment]
【提出日】平成５年４月２６日[Submission date] April 26, 1993
【手続補正１】[Procedure Amendment 1]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】０００７[Correction target item name] 0007
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【０００７】[0007]
【実施例】コア用ガラスロッドの外周にクラッド用のガ
ラス微粉末を外付した長さ１１００ｍｍ外径８０φの光
ファイバ母材を１６００℃に加熱しＨｅガス流量６l/mi
n、Ｃｌ 2 ガス流量２５０cc/minを流しながら石英ガラ
スからなる炉芯管内で２４０mm/hr の速度で移動させな
がら透明ガラス化し長さ９００mm外径φ４０の光ファイ
バ母材を得た。[Example] An optical fiber preform having a length of 1100 mm and an outer diameter of 80φ with glass fine powder for cladding attached to the outer periphery of a glass rod for core was heated to 1600 ° C., and a He gas flow rate was 6 l / mi.
An optical fiber preform with a length of 900 mm and an outer diameter of φ40 was obtained by vitrification while moving at a speed of 240 mm / hr in a furnace tube made of quartz glass while flowing n and Cl 2 gas at a flow rate of 250 cc / min .
【手続補正２】[Procedure Amendment 2]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】０００８[Correction target item name] 0008
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【０００８】次に、この母材を１０００℃の均熱部が長
さ１０００mmの石英炉芯管からなる炉内にいれ、１００
０℃に加熱しながら炉内を油回転真空ポンプで真空引き
し０．１３３Pa（１×１０ -3Torr）の真空度で２時間処
理した。Next, the base material was placed in a furnace having a soaking section at 1000 ° C. and made of a quartz furnace core tube having a length of 1000 mm , and 100
While heating to 0 ° C., the inside of the furnace was evacuated by an oil rotary vacuum pump and treated at a vacuum degree of 0.133 Pa (1 × 10 −3 Torr ) for 2 hours.
Claims (2)
面にＶＡＤ法と同じ方法でガラス微粉末を周方向に堆積
させその後、Ｈｅガスからなる雰囲気中で透明ガラス化
する光ファイバ母材の製造方法において透明ガラス化し
た母材を真空雰囲気下で５００〜１２００℃に加熱処理
することを特徴とする光ファイバ母材の製造方法。1. A method for producing an optical fiber preform in which glass fine powder is circumferentially deposited on the surface of a quartz transparent rod manufactured by the VAD method by the same method as in the VAD method, and then vitrified into a transparent glass in an atmosphere consisting of He gas. 2. The method for producing an optical fiber preform, wherein the transparent vitrified preform is heat-treated at 500 to 1200 ° C. in a vacuum atmosphere.
３Ｐａ以下の真空度である光ファイバ母材の製造方法。2. The vacuum atmosphere according to claim 1, wherein the vacuum atmosphere is 0.13.
A method for manufacturing an optical fiber preform having a vacuum degree of 3 Pa or less.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7928793A JPH06293530A (en) | 1993-04-06 | 1993-04-06 | Method for manufacturing optical fiber preform |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7928793A JPH06293530A (en) | 1993-04-06 | 1993-04-06 | Method for manufacturing optical fiber preform |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06293530A true JPH06293530A (en) | 1994-10-21 |
Family
ID=13685656
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7928793A Pending JPH06293530A (en) | 1993-04-06 | 1993-04-06 | Method for manufacturing optical fiber preform |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06293530A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7946135B2 (en) * | 2007-01-02 | 2011-05-24 | Draka Comteq, B.V. | Extended-baking process for glass deposition tubes |
-
1993
- 1993-04-06 JP JP7928793A patent/JPH06293530A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7946135B2 (en) * | 2007-01-02 | 2011-05-24 | Draka Comteq, B.V. | Extended-baking process for glass deposition tubes |
| US8230702B2 (en) | 2007-01-02 | 2012-07-31 | Draka Comteq, B.V. | Glass-tube extended-baking process |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7469559B2 (en) | Method for making low loss optical fiber | |
| US20040240814A1 (en) | Optical fiber having reduced viscosity mismatch | |
| JPS62176935A (en) | Method for manufacturing optical fiber preform | |
| JPH044986B2 (en) | ||
| US4648891A (en) | Optical fiber | |
| JPH10139460A (en) | Heat treatment of silica-base glass | |
| US5609665A (en) | Method of making optical fiber with low melting glass core | |
| JP4079204B2 (en) | Quartz glass tube for optical fiber preform and manufacturing method thereof | |
| JPH06293530A (en) | Method for manufacturing optical fiber preform | |
| JP2836302B2 (en) | Method for manufacturing glass articles | |
| US20040118164A1 (en) | Method for heat treating a glass article | |
| JP4565221B2 (en) | Optical fiber preform | |
| JPH07157328A (en) | Optical fiber manufacturing method | |
| JPS632900B2 (en) | ||
| JPS63147840A (en) | Production of quartz glass material | |
| JPS63151639A (en) | Manufacturing method of glass base material for optical fiber | |
| JPS62292647A (en) | Method for manufacturing dispersion-shifted single-mode optical fiber | |
| JP4057332B2 (en) | Manufacturing method of glass preform for optical fiber | |
| JP2618260B2 (en) | Method for producing intermediate for optical fiber preform | |
| JPS63236727A (en) | Manufacturing method of optical fiber base material | |
| JPS61215229A (en) | Production of parent material for optical fiber | |
| JPS5910938B2 (en) | Method of manufacturing optical transmission glass | |
| JPH03232732A (en) | Production of glass preform for hydrogen-resistant optical fiber | |
| JPS63285128A (en) | Manufacturing method of optical fiber base material | |
| JPS62143834A (en) | Method for manufacturing base material for optical fiber |