JPS61270232A - Method for treating optical fiber base material - Google Patents
Method for treating optical fiber base materialInfo
- Publication number
- JPS61270232A JPS61270232A JP389586A JP389586A JPS61270232A JP S61270232 A JPS61270232 A JP S61270232A JP 389586 A JP389586 A JP 389586A JP 389586 A JP389586 A JP 389586A JP S61270232 A JPS61270232 A JP S61270232A
- Authority
- JP
- Japan
- Prior art keywords
- base material
- dehydration
- temperature
- optical fiber
- treatment
- 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.)
- Granted
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]
- C03B37/01446—Thermal after-treatment of preforms, e.g. dehydrating, consolidating, sintering
Abstract
Description
【発明の詳細な説明】
「産業上の利用分野Ｊ
本発明は光ファイバ用の多孔質母材を脱水ならびに透明
ガラス化するための処理方法に関し、さらに詳しくは水
素に起因したロス増のない光ファイバを得るための母材
処理方法に関する。Detailed Description of the Invention "Industrial Field of Application J The present invention relates to a treatment method for dehydrating and transparent vitrifying a porous base material for optical fibers, and more specifically to a method for dehydrating and transparently vitrifying a porous base material for optical fibers. The present invention relates to a method of treating a base material to obtain a fiber.
ｒ従来の技術１
一般に、石英系からなる光ファイバ用の多孔質母材は、
ＶＡＤ法（Ｖａｐｅｒ Ｐｈａｓｅ Ａｘｉａｌ Ｄｅ
ｐｏｓｉｔｉ−０１１Ｍｅｔｈｏｄ）、 ＯＶＤ法（Ｏ
ｕｔｅｒ ＶａｐｅｒＰｈａｓｅ ０ｘｉｄａ−ｔｉｏ
ｎ Ｍｅｔｈｏｄ）を介してつくられ、その後、多孔質
母材は脱水ならびに透明ガラス化され、透明な光ファイ
バ母材となる。rPrior art 1 In general, a porous base material for optical fibers made of quartz is
VAD method (Vapor Phase Axial De
position-011Method), OVD method (O
uter VaperPhase Oxida-tio
After that, the porous preform is dehydrated and vitrified to obtain a transparent optical fiber preform.
多孔質母材を脱水し、透明ガラス化する一手段に米国特
許第３，９３３，４５４号の発明（以下、先行技術２と
いう）があり、それよりも古い当該手段として米国特許
第３，４５９，５２２号の発明（以下、先行技術１とい
う）がある。One means of dehydrating a porous base material and turning it into transparent vitrification is the invention of U.S. Patent No. 3,933,454 (hereinafter referred to as Prior Art 2), and an older method is U.S. Patent No. 3,459. , No. 522 (hereinafter referred to as prior art 1).
先行技術２において処理対象となる多孔質母材は、火炎
加水分解反応を介して生成されたガラススートを堆積さ
せることにより形成されたものであり、かかる多孔質母
材を、塩素ガスを含む雰囲気中で同時に脱水、透明ガラ
ス化している。The porous base material to be treated in Prior Art 2 is formed by depositing glass soot generated through a flame hydrolysis reaction, and the porous base material is placed in an atmosphere containing chlorine gas. Inside, it is simultaneously dehydrated and transformed into transparent glass.
先行技術２の処理母材から得られる光ファイバの場合、
波長は８５０〜１ｔ００ｎｍ帯における伝送特性が１０
ｄＢ／に＠前後であるが、波長９５０１に吸収ピークが
みられる。In the case of the optical fiber obtained from the treated base material of Prior Art 2,
The transmission characteristic in the wavelength band of 850 to 1t00nm is 10
Although it is around dB/@, an absorption peak is seen at wavelength 9501.
一方、先行技術ｌでは、火炎加水分解以外の手段で多孔
質母材をつくり、その多孔質母材の脱水を塩素含有雰囲
気中で行ない、脱水済み母材の透明ガラス化を非塩素含
有雰囲気中で行なう、いわゆる二工程化を特徴としてい
る。On the other hand, in prior art I, a porous base material is created by a method other than flame hydrolysis, the porous base material is dehydrated in a chlorine-containing atmosphere, and the dehydrated base material is transformed into transparent vitrification in a non-chlorine-containing atmosphere. It is characterized by a so-called two-step process.
先行技術ｌにおいて、脱水処理工程と透明ガラス化工程
とを二工程化する理由の一つは、経済的な考えに基づく
ものであり、他の理由の一つは、塩素含有雰囲気中に長
く母材を曝したとき、その母材中に多量の塩素が停滞し
、それによってガラス中に割れの発生する虞れが生じる
からである。In the prior art, one of the reasons why the dehydration treatment process and the transparent vitrification process are made into two steps is based on economic considerations, and one of the other reasons is that the mother remains in a chlorine-containing atmosphere for a long time. This is because when the glass is exposed, a large amount of chlorine remains in the base material, which may cause cracks in the glass.
しかし、先行技術ｌにて処理されたガラスは、前記先行
技術２よりも、伝送特性が悪い。However, the glass treated with Prior Art 1 has poorer transmission characteristics than that of Prior Art 2.
しかも先行技術１に関して、先行技術２は以下の理由に
より、火炎加水分解により得られた多孔質母材の脱水に
適しいていないと説述している。Moreover, with respect to Prior Art 1, it is explained that Prior Art 2 is not suitable for dehydrating a porous base material obtained by flame hydrolysis for the following reasons.
すなわち、先行技術ｌにおいて使用される塩素含有雰囲
気内の多量の塩素は、多孔質母材のつぎの処理において
ボイドを発生せしめ、かつ、市販純度の塩素源に含まれ
ている汚染物が、許容限度を越えてガラス中に導入され
る虞れがある。That is, the large amount of chlorine in the chlorine-containing atmosphere used in the prior art causes voids in subsequent processing of the porous matrix, and the contaminants contained in commercially pure chlorine sources are There is a risk that more than the limit will be introduced into the glass.
さらに先行技術ｌでは、塩素化室内にて多孔質母材を脱
水処理した後、その脱水済み母材を塩素化室内から透明
ガラス化用の凝固室へ移すとき。Furthermore, in prior art 1, after dehydrating a porous base material in a chlorination chamber, the dehydrated base material is transferred from the chlorination chamber to a coagulation chamber for transparent vitrification.
当該脱水済み母材中に再度水分の侵入する場合がある。Water may enter the dehydrated base material again.
その他、先行技術１のように二工程化するよりも、脱水
と透明ガラス化とを同時に行なうことができれば、経済
的効果が高まる。In addition, if dehydration and transparent vitrification can be performed at the same time, the economical effect will be increased, rather than performing two steps as in Prior Art 1.
こうした背景が、先行技術２において脱水と透明ガラス
化とを同時に行なわせる動機と、なっている。This background is the motivation for performing dehydration and transparent vitrification at the same time in Prior Art 2.
ｒ発明が解決しようとする問題点１
周知の通り、光ファイバへ水素（Ｈ２）が拡散混入した
場合、その伝送特性が経時的に劣化するが。Problem 1 to be Solved by the Invention As is well known, when hydrogen (H2) is diffused and mixed into an optical fiber, its transmission characteristics deteriorate over time.
これの対策に関する技術的経緯は“日経エレクトロニク
ス” 「解決した光ファイバの水素による損失増加問題
１．２Ｊ （１９８４年１２月３日号）に詳述されてい
るが、水素ロス増ピークとして従来注目されていたのは
波長１．３θルｍ 、 １．４１ｇ薦における５ｉＯＨ
およびＧｅＯＨの吸収ピーク、水素分子による波長１．
２４１Ｌ厘による吸収ピークなどであり、これ以外の重
要な水素ロス増ピークに関する研究報告はまだ見られな
い。The technical history of countermeasures for this problem is detailed in "Nikkei Electronics""Solved problem of increased loss due to hydrogen in optical fibers 1.2J" (December 3, 1984 issue), but it has been attracting attention as a peak of increased hydrogen loss. The wavelength was 1.3θ lm, 5iOH at 1.41g recommendation.
and absorption peak of GeOH, wavelength 1 due to hydrogen molecules.
This is the absorption peak due to 241L, and no research reports regarding other important hydrogen loss increase peaks have yet been found.
ところが、光ファイバの伝送特性に関する本発明者らの
研究において、従来知られていない重要なロス増ピーク
、すなわち上記以外のロス増ピークとして、波長１．５
２％會における吸収ピークのあることが発見された。However, in the research conducted by the present inventors regarding the transmission characteristics of optical fibers, a previously unknown important loss increase peak, that is, a loss increase peak other than the above, was found at a wavelength of 1.5.
It was discovered that there is an absorption peak at 2%.
この１．５２％厘の吸収ピークについては、５ｉ−Ｈ振
動吸収に起因すると考えられる。This absorption peak at 1.52% is considered to be due to 5i-H vibrational absorption.
上記吸収ピークの挙動の特徴として、本発明者らの知見
では、光ファイバケーブル製造工程中の、 光ファイ
バが８０〜１００℃の高温を経験したとき当該ピークが
生じやすいこと、−たん出現した当該ピークがその後ゆ
るやかに減少する傾向を有すること等が判明している。According to the findings of the present inventors, the characteristics of the behavior of the above absorption peak are that the peak is likely to occur when the optical fiber experiences high temperatures of 80 to 100°C during the optical fiber cable manufacturing process; It has been found that the peak tends to gradually decrease thereafter.
第３図には、実際に波長１．５２ＪＬＩＩでの吸収ロス
増を起こした光ファイバのロススペクトルを示した。FIG. 3 shows a loss spectrum of an optical fiber in which an increase in absorption loss actually occurred at a wavelength of 1.52 JLII.
同図で明らかなように、この吸収ピークが出現する際の
特徴として、１．５５ｐ厘奇に吸収ピークが現われると
同時に１．３９ル履帯および１．２す１帯のロス増加を
も惹き起こすこととなり、したがって１．２〜１．６ル
■帯の伝送特性劣化を惹き起こす性質のものであること
が理解できる。As is clear from the figure, the characteristic when this absorption peak appears is that an absorption peak appears at 1.55p and at the same time, it also causes an increase in the loss of the 1.39l track and 1.2sl track. Therefore, it can be understood that this has the property of causing deterioration of transmission characteristics in the 1.2 to 1.6 L band.
このような吸収ピークは、波長１．２〜１．８ル■帯で
の伝送特性が５ｄＢ／に層以下となる光ファイバにおい
て認識できる問題であるから、先行技術２のごとき波長
域、伝送特性では発見できず、先行技術２よりも伝送特
性の悪い先行技術１では全く予測もつかない事項である
。Such an absorption peak is a problem that can be recognized in optical fibers whose transmission characteristics in the wavelength band of 1.2 to 1.8 nm are below 5 dB/layer. This is a matter that cannot be discovered in the prior art 1, which has worse transmission characteristics than the prior art 2, and cannot be predicted at all in the prior art 1.
「発明の目的１
本発明は上記の問題点に鑑み、波長１．５２終菖に出現
の水素ロス増ピークを発生させない光ファイバが得られ
る光ファイバ母材の処理方法を提供しようとするもので
ある。``Object of the Invention 1 In view of the above-mentioned problems, the present invention seeks to provide a method for processing an optical fiber base material that can obtain an optical fiber that does not generate the hydrogen loss increase peak that appears at the wavelength of 1.52. be.
ｒ問題点を解決するための手段１
本発明は、波長１．２〜１．６μ篇帯での伝送特性が５
ｄＢ八層以下となる光ファイバの母材を得るため、石英
系の多孔質母材を脱水ならびに透明ガラス化する光ファ
イバ母材の処理方法において、脱水処理工程が先行し、
透明ガラス化工程が後行するよう、これらの工程を別々
に行ない、先行する脱水処理工程では、 Ｈｅと０２と
脱水ガスとにより脱水雰囲気を形成するとともに、処理
温度を上記多孔質母材の実質的脱水反応開始温度以上か
つ独立閉孔形成温度未満に設定し、かかる脱水雰囲気中
の処理温度域を多孔質母材が通過し、後行する透明ガラ
ス化工程では、 Ｈｅと０２またはＨｅのみで透明ガラ
ス化雰囲気を形成するとともに、処理温度を最低透明ガ
ラス化温度以上に設定し、かかる透明カラス化雰囲気中
の処理温度域を上記脱水処理後の母材が通過することを
特徴とする。Means 1 for solving the r problem The present invention has transmission characteristics in the wavelength range of 1.2 to 1.6μ.
In order to obtain an optical fiber base material with a dB of 8 layers or less, a method for processing an optical fiber base material in which a quartz-based porous base material is dehydrated and made into transparent vitrification, a dehydration treatment step is preceded,
These steps are performed separately so that the transparent vitrification step follows, and in the preceding dehydration treatment step, a dehydration atmosphere is formed with He, 02, and dehydration gas, and the treatment temperature is adjusted to match the substance of the porous base material. The porous base material passes through the treatment temperature range in the dehydration atmosphere, which is set at a temperature higher than the dehydration reaction initiation temperature and lower than the independent closed pore formation temperature, and in the subsequent transparent vitrification step, only He and 02 or He are used. The present invention is characterized in that a transparent vitrification atmosphere is formed, the treatment temperature is set at a minimum transparent vitrification temperature or higher, and the base material after the dehydration treatment passes through the treatment temperature range in the transparent vitrification atmosphere.
１作用」
本発明方法では、ＭＡＤ法、ＯＶＤ法等により作製され
た多孔質母材を、それぞれ所定の雰囲気中に入れて脱水
ならびに透明ガラス化するとき、脱水処理工程と透明ガ
ラス化工程とを別工程で行なうため、透明ガラス化後の
母材の残留塩素量がごく微量となり、その母材からは伝
送特性の良好な光ファイバが得られるようになる。1. In the method of the present invention, when a porous base material produced by the MAD method, OVD method, etc. is placed in a predetermined atmosphere and dehydrated and made transparent vitrified, the dehydration treatment step and the transparent vitrification step are performed. Since this is done in a separate process, the amount of residual chlorine in the base material after transparent vitrification is extremely small, and an optical fiber with good transmission characteristics can be obtained from the base material.
つまり、多孔質母材を脱水処理工程と透明ガラス化工程
とを同一工程で実施する方法の場合、その母材が塩素含
有雰囲気中で透明ガラス化されることになるため、透明
ガラス化母材の残留塩素が多くなり、これが原因でガラ
ス中に構造欠陥が生じ、水素を固着させるといったメカ
ニズムにより水素ロス増を惹き起こすことになるが、本
発明のごとく両工程を別々に行なう場合、こうした問題
が生じない。In other words, in the case of a method in which the dehydration treatment process and the transparent vitrification process are carried out on a porous base material in the same process, the base material will be transparently vitrified in a chlorine-containing atmosphere, so the transparent vitrified base material This increases the amount of residual chlorine in the glass, which causes structural defects in the glass, causing hydrogen loss through a mechanism such as fixation of hydrogen. However, when both processes are performed separately as in the present invention, these problems can be avoided. does not occur.
本発明での脱水工程では、その雰囲気をＨｅと０２と脱
水ガス（塩素ガス、塩化チオニル、フルオル系シランな
ど）とで形成し、その処理温度を実質的脱水反応開始温
度以上かつ独立閉孔形成温度未満とする。In the dehydration process of the present invention, the atmosphere is formed with He, 02, and dehydration gas (chlorine gas, thionyl chloride, fluoro-silane, etc.), and the treatment temperature is set to a temperature higher than the actual dehydration reaction initiation temperature to form independent closed pores. below the temperature.
ここで脱水処理温度を実質的脱水反応開始温度以上かつ
独立閉孔形成温度未満としたのはつぎの理由による。The reason why the dehydration treatment temperature is set to be equal to or higher than the substantial dehydration reaction initiation temperature and lower than the independent closed pore formation temperature is as follows.
すなわち脱水処理温度の下限を実質的脱水反応開始温度
以上に設定したのは、当該処理温度がその下限値を下回
る処理温度のとき、効果のある脱水処理ができない自明
の理由があり、一方、脱水処理温度の上限を独立閉孔形
成温度未満に設定したのは、これ以上の温度のとき、多
孔質母材の焼結が過度に進むことにより５該母材の独立
閉孔（Ｃ１ｏｓｅｄ ｐａｒｅ）が生じ、その気孔内に
塩素が閉じこめられて水素ロス増の問題を惹き起こすか
らである。In other words, the reason why the lower limit of the dehydration treatment temperature was set above the actual dehydration reaction starting temperature is that there is an obvious reason why an effective dehydration treatment cannot be performed when the treatment temperature is lower than the lower limit. The reason why the upper limit of the processing temperature was set below the independent closed pore formation temperature is that at temperatures higher than this temperature, the sintering of the porous base material progresses excessively, resulting in independent closed pores (C1osed pare) of the base material. This is because chlorine is trapped in the pores and causes the problem of increased hydrogen loss.
本発明の透明ガラス化工程では、その雰囲気をＨｅと０
２またはＨｅのみで形成し、その処理温度を最低透明ガ
ラス化温度以上とする。In the transparent vitrification process of the present invention, the atmosphere is He and 0
2 or only He, and the treatment temperature is set to be equal to or higher than the lowest transparent vitrification temperature.
この雰囲気が塩素を含まないことにより、当該透明ガラ
ス化に際してのガラス欠陥が生ぜず、また、その処理温
度が透明ガラス化温度以上であることにより、ガラス組
成の均一度が高まり、ひいては光ファイバの伝送特性を
良好にする。Since this atmosphere does not contain chlorine, no glass defects occur during the transparent vitrification process, and since the processing temperature is higher than the transparent vitrification temperature, the uniformity of the glass composition increases, which in turn leads to the formation of optical fibers. Improve transmission characteristics.
かくて、本発明方法により処理された母材からは、伝送
特性の良好な光ファイバが得られることとなり、しかも
その母材処理条件が適切であることにより、後述の実験
例等で明らかなように波長１．５２１Ｌ璽に出現の水素
ロス増ピークを発生させない光ファイバが得られる。Thus, an optical fiber with good transmission characteristics can be obtained from the base material treated by the method of the present invention, and if the base material treatment conditions are appropriate, as will be clear from the experimental examples described later, etc. An optical fiber that does not generate the hydrogen loss increase peak that appears at a wavelength of 1.521L can be obtained.
ｒ実 施 例１
以下本発明方法の実施例につき、図面を参照して説明す
る。rExample 1 Examples of the method of the present invention will be described below with reference to the drawings.
第１図は本発明方法に用いる装置を例示したものであり
、同図の１は電気炉、２は七の電気炉１の炉心管、３は
その電気炉１のカーボン製ヒータである。FIG. 1 shows an example of the apparatus used in the method of the present invention, in which 1 is an electric furnace, 2 is a furnace tube of the 7 electric furnace 1, and 3 is a carbon heater of the electric furnace 1.
上記炉心管２はその下部にガス入口４を有し、その上部
にガス出口５を有している。The core tube 2 has a gas inlet 4 at its lower part and a gas outlet 5 at its upper part.
６はＶＡＤ法またはＯＶＤ法等により作製された石英系
の多孔質母材であり、この多孔質母材Ｂは石英系の支持
棒７により担持されている。Reference numeral 6 denotes a quartz-based porous base material produced by a VAD method, an OVD method, or the like, and this porous base material B is supported by a quartz-based support rod 7 .
第１図において多孔質母材８を脱水処理するとき、ガス
入口痙から炉心管２内にＨｅ、０２、脱水ガス（例えば
Ｃ１２）等を供給してその炉心管２内を所定の雰囲気と
し、さらに炉心管２内における処理温度を実質的脱水反
応開始温度以上かつ独立閉孔形成温度未満とすべく、当
該処理温度（実温）をヒータ３により約９００℃ないし
１３００℃程度に設定する。When dehydrating the porous base material 8 in FIG. 1, He, 02, dehydrated gas (for example, C12), etc. are supplied into the reactor core tube 2 from the gas inlet to create a predetermined atmosphere inside the reactor core tube 2. Further, in order to keep the processing temperature in the reactor core tube 2 above the substantial dehydration reaction start temperature and below the independent closed pore formation temperature, the processing temperature (actual temperature) is set at about 900° C. to about 1300° C. by the heater 3.
こうした上記炉心管２内には、その上部から多孔質母材
８を挿入し、該多孔質母材８を脱水処理温度域に向けて
適当な移動速度で降下させ、該多孔質母材６をその下端
から順次脱水処理する。A porous base material 8 is inserted into the reactor core tube 2 from above, and the porous base material 8 is lowered at an appropriate speed toward the dehydration treatment temperature range. Dehydration is performed sequentially starting from the bottom end.
かかる脱水処理により多孔質母材Ｂは焼結状態となるが
、この際の処理温度が前記のごとく独立閉孔形成温度未
満であるため、その母材Ｂの気孔が閉じられることがな
く、シたがって母材６はその各気孔内に侵入した脱水ガ
ス成分（Ｇｌｚ）をそのまま取りこんでしまうことがな
い。This dehydration treatment brings the porous base material B into a sintered state, but since the treatment temperature at this time is below the independent closed pore formation temperature as described above, the pores of the base material B are not closed and the sintered state is maintained. Therefore, the base material 6 does not directly take in the dehydration gas component (Glz) that has entered its respective pores.
脱水処理後の母材６はこれを透明ガラス化するが、この
透明ガラス化は第１図の電気炉ｌまたは別途に用意され
た第１図と同様の電気炉１により行なう。After the dehydration treatment, the base material 6 is turned into transparent glass, and this transparent vitrification is carried out using the electric furnace 1 shown in FIG. 1 or the separately prepared electric furnace 1 similar to that shown in FIG.
脱水処理後の上記電気炉１を透明ガラス化のため引きつ
づき使用するときは、あらかじめ炉心管２内にパージガ
スを流してその内部から脱水雰囲気ガスを完全に排除す
るほか、−たん脱水済み母材を炉心管２内の上部に引き
上げる。When the electric furnace 1 after the dehydration treatment is to be used for transparent vitrification, purge gas is flowed into the furnace tube 2 in advance to completely eliminate the dehydration atmosphere gas from inside the furnace tube 2. is pulled up to the upper part of the furnace core tube 2.
透明ガラス化のため別途の電気炉を使用するとき、脱水
用電気炉、透明ガラス化用電気炉を所定値以上のクリー
ン度に保持されたケーシング内にあらかじめ配置してお
き、脱水用電気炉内の脱水済み母材を透明ガラス化用電
気炉内へ移し、その炉心管の上部に脱水済み母材を位置
せしめる。When using a separate electric furnace for transparent vitrification, place the electric furnace for dehydration and the electric furnace for transparent vitrification in a casing maintained at a cleanliness level higher than a specified value in advance, and The dehydrated base material is transferred to an electric furnace for transparent vitrification, and the dehydrated base material is positioned above the furnace tube.
しかる後、ガス入口４から炉心管２内にＨｅと０２また
はＨｅのみを供給してその炉心管２内を所定の雰囲気に
保持するとともに、炉心管２内における処理温度を最低
透明ガラス化温度以上とすべく、当該処理温度（実温）
をヒータ３により１３５０〜１８５０℃程度に設定し、
こうした炉心管２内に脱水処理後の母材Ｂを入れ、かつ
、これを透明ガラス化温度域に向けて適当な速度で移動
（降下）させることにより、当該脱水済み母材８をその
下端から順次透明ガラス化する。Thereafter, He and 02 or only He are supplied into the furnace tube 2 from the gas inlet 4 to maintain the inside of the furnace tube 2 at a predetermined atmosphere, and the processing temperature inside the furnace tube 2 is set to be higher than the minimum transparent vitrification temperature. In order to achieve this, the processing temperature (actual temperature)
is set to about 1350-1850℃ by heater 3,
By putting the dehydrated base material B into the reactor core tube 2 and moving (descending) it at an appropriate speed toward the transparent vitrification temperature range, the dehydrated base material 8 is moved from the lower end thereof. Gradually convert to transparent glass.
かくて多孔質母材８の脱水処理ならびに透明ガラス化処
理が完了する。In this way, the dehydration treatment and transparent vitrification treatment of the porous base material 8 are completed.
なお、上記において脱水処理後の母材６を透明ガラス化
するとき、炉心管２内における母材処理速度（移動速度
）は、伝送特性のよいものを得る点で低速とするのが望
ましく、その速度の具体的１例として１００ｍｍ／時が
あげられる。In addition, when converting the base material 6 after the dehydration treatment into transparent vitrification in the above, it is desirable that the base material processing speed (moving speed) in the furnace tube 2 be low in order to obtain good transmission characteristics. A specific example of the speed is 100 mm/hour.
また、透明ガラス化時の処理温度は特に上限はないが、
１７００℃程度で炉心管２が融けるので実用上、その
上限温度は１８５０℃程度がよい。In addition, there is no particular upper limit for the processing temperature during transparent vitrification, but
Since the furnace core tube 2 melts at about 1700°C, in practical terms, the upper limit temperature is preferably about 1850°C.
つぎに本発明方法に関する実験例について説明する。Next, experimental examples related to the method of the present invention will be explained.
以下に述べる実験例では、ＶＡＤ法により作製した各母
材からコア直径８μ腸、純石英クラッド直径１２５絡■
、Δ＝ ０．３Ｘのシングルモード光ファイバをつくり
、試験方法の１例として、これら光ファイバを１００℃
の１０ｏｚ水素雰囲気内に入れて１５分間保持し、その
後、各光ファイバを取り出してそれぞれのロススペクト
ルを測定し、これらの水素ロス増特性を初期ロス特性と
の比較において評価した。In the experimental examples described below, each base material produced by the VAD method has a core diameter of 8 μm and a pure quartz cladding diameter of 125 μm.
, Δ=0.3X single mode optical fibers were made, and as an example of the test method, these optical fibers were
The optical fibers were placed in a 10 oz hydrogen atmosphere and held for 15 minutes, and then each optical fiber was taken out and its loss spectrum was measured, and the hydrogen loss increase characteristics were evaluated in comparison with the initial loss characteristics.
この評価で用いた波長は１．５２ｘ腸である。The wavelength used in this evaluation is 1.52x intestine.
実験は表１．２の通り多孔質母材の脱水処理条件、透明
ガラス化条件を種々変更し、これら母材かち得られたシ
ングルモード光ファイバにつき、上述の評価を行ない、
各処理の最適条件を検討した。In the experiment, the dehydration treatment conditions and transparent vitrification conditions of the porous base material were variously changed as shown in Table 1.2, and the single mode optical fibers obtained from these base materials were evaluated as described above.
The optimal conditions for each treatment were investigated.
表１
表２
なお、表１での処理方法工は脱水処理と透明ガラス化と
を同時に行ない、表２での処理方法■は脱水処理と透明
ガラス化とを別工程で行なった。Table 1 Table 2 Note that in the treatment method shown in Table 1, dehydration treatment and transparent vitrification were performed simultaneously, and in treatment method (2) in Table 2, dehydration treatment and transparent vitrification were performed in separate steps.
各処理はそれぞれ第１図の電気炉を用いて実施した。Each treatment was carried out using the electric furnace shown in FIG. 1, respectively.
表２中、ＴＩは脱水処理時における処理温度を示し、Ｔ
２は透明ガラス化時における処理温度を示す。In Table 2, TI indicates the treatment temperature during dehydration treatment, and T
2 indicates the processing temperature during transparent vitrification.
表１１表２の結果で明らかなように、処理方法工の場合
は処理方法■と比べ、水素によるロス増が大きい。As is clear from the results in Table 11 and Table 2, in the case of treatment method engineering, the increase in loss due to hydrogen is greater than in treatment method (2).
処理方法■においてロス増が大きくなる理由として、塩
素含有雰囲気中で多孔質母材が透明ガラス化されたため
、ガラス中への塩素残留、その塩素残留によるガラス構
造欠陥の形成、そのガラス構造欠陥への水素の固着とい
ったメカニズムが考えられるのに対し、処理方法■の場
合は、脱水処理と透明ガラス化とが別工程であるため、
処理方法工のような問題が生じなかったと推測できる。The reason for the large increase in loss in treatment method ① is that because the porous base material is made into transparent glass in a chlorine-containing atmosphere, chlorine remains in the glass, the formation of glass structural defects due to the chlorine residue, and the formation of glass structural defects. In contrast, in the case of treatment method ①, dehydration treatment and transparent vitrification are separate processes, so
It can be assumed that there were no problems with the processing method.
一方、処理方法■においても、この際のサンプルである
各党ファイバ（イ）（ロ）に特性上の差がみられた。On the other hand, in processing method (2), differences in characteristics were observed in the fibers of each party (A) and (B), which were the samples at this time.
これは、処理方法■において処理温度（処理時間も関与
）をさらに探索すれば、より適切な処理条件のあること
を示唆している。This suggests that if the processing temperature (processing time is also involved) is further investigated in processing method (2), more appropriate processing conditions may be found.
かかる観点から、処理方法■における最適化のため、つ
ざの実験を行なった。From this point of view, we conducted a series of experiments to optimize treatment method (2).
この実験を実施した各パラメータの範囲は表３の通りで
あり、当該実験では各パラメータを数値的に種々組み合
わせて、前記多孔質母材の脱水処理ならびに透明ガラス
化処理を行ない、その処理後の母材を紡糸して得た光フ
ァイバにつき、水素添加による損失増加のテストを実施
した。The range of each parameter in which this experiment was conducted is shown in Table 3. In this experiment, each parameter was numerically combined in various ways to perform dehydration treatment and transparent vitrification treatment of the porous base material. Optical fibers obtained by spinning the base material were tested for loss increase due to hydrogen addition.
なお、表３中の各温度は実温でり、同表中における各ガ
スの供給量はＨｅ＝ ８５４１ ／ｓ＋ｉｎ、Ｃｌ２＝
８．５Ｊｌ ／ｓｉｎ、０２＝０．８５ ｊＬ／ｗｉｎ
である。In addition, each temperature in Table 3 is the actual temperature, and the supply amount of each gas in the same table is He = 8541 /s + in, Cl2 =
8.5Jl/sin, 02=0.85jL/win
It is.
まず、雰囲気ガスについて、ＨｅおよびＣ１２の組み合
わせと、Ｈｅ、Ｇ１２および０２の組み合わせとを比較
したところ、前者の雰囲気で処理された母材から得られ
た光ファイバの場合、すべて水素添加ロス増を示したの
に対し、後者の雰囲気で処理された母材から得られた光
ファイバは、水素添加ロス増が軽微であった。First, we compared the combination of He and C12 with the combination of He, G12 and 02 regarding atmospheric gases, and found that in the case of optical fibers obtained from base materials treated in the former atmosphere, all cases showed an increase in hydrogenation loss. In contrast, the optical fiber obtained from the base material treated in the latter atmosphere showed a slight increase in hydrogenation loss.
つぎに脱水処理雰囲気を上記後者と同じ、透明ガラス化
雰囲気を前述したものと同じにしくＨｅと０２またはＨ
ｅのみ）、脱水時の処理温度ＴＩおよび透明ガラス化温
度Ｔ２をそれぞれ変化させて所定の母材をつくり、当該
母材を紡糸して各種サンプル用の光ファイバを得た。Next, the dehydration treatment atmosphere should be the same as the latter, and the transparent vitrification atmosphere should be the same as the one described above.
e only), the treatment temperature TI during dehydration and the transparent vitrification temperature T2 were varied to produce predetermined base materials, and the base materials were spun to obtain optical fibers for various samples.
これら光ファイバにつき、既述の水素添加ロス増テスト
を実施し、その結果を第２図に示した。The aforementioned hydrogen addition loss increase test was carried out on these optical fibers, and the results are shown in FIG.
第２図において、ｘ印は水素ロス増あり、０印は水素ロ
ス増なし、・印は水素ロス増なしであるが初期ロスが大
きいもの、ム印はＯＲ吸収ロスが大きいものを示す。In FIG. 2, the x mark indicates an increase in hydrogen loss, the 0 mark indicates no increase in hydrogen loss, the * mark indicates no increase in hydrogen loss but the initial loss is large, and the mu mark indicates a large OR absorption loss.
第２図においてＴ Ｉ ＝ ９００℃のとき、その温度
の低さにより化学的脱水反応、ひいては光ファイバ母材
の脱水が不十分となり、そのため初期のＯＨ吸収ロスが
大きいと考えられ、φ印については。In Fig. 2, when T I = 900°C, the chemical dehydration reaction and eventually the dehydration of the optical fiber base material are insufficient due to the low temperature, so it is thought that the initial OH absorption loss is large, and the teeth.
ガラス化温度が低すぎたため、既述のガラス組成不均一
が生じたと考えられる。It is thought that the glass composition non-uniformity described above occurred because the vitrification temperature was too low.
一方、Ｘ印の領域については、脱水処理温度が高すぎる
ことにより、既述の独立閉孔（塩素取りこみ原因）が生
じたと考えられる。On the other hand, in the region marked with X, it is considered that the above-mentioned independent closed pores (cause of chlorine uptake) occurred due to the dehydration treatment temperature being too high.
それに対し、０印が点在する領域には脱水不十分、ガラ
ス組成不均一、独立閉孔なと、上述した種々の問題が発
生せず、それゆえ初期ロス、水素ロス増についていずれ
も良好な結果を示したと考えられる。On the other hand, in the area where the 0 marks are scattered, the various problems mentioned above do not occur, such as insufficient dehydration, non-uniform glass composition, and closed pores, and therefore there is no problem in terms of initial loss and increase in hydrogen loss. It is considered that the results were shown.
かかる結果からすると、脱水ガスとして０１２ を用い
る場合のＴ１．Ｔ２については、第２図の点線で囲う領
域内で設定するのがよいといえる。From these results, T1.0 when using 012 as the dehydration gas. Regarding T2, it can be said that it is best to set it within the area surrounded by the dotted line in FIG.
つぎに、本発明において脱水ガスとしてＣＩ２に代え、
５ＯＩＩＩ：１２を用いた場合の実験例について説明す
る。Next, in the present invention, instead of CI2 as the dehydration gas,
An experimental example using 5OIII:12 will be described.
前記表１．２を参照して述べたと同様の実験を行なうと
き、脱水ガスとしてＣ１２に代わる５ＯＣＩ２を用い、
脱水処理と透明ガラス化を表４、表５に示す条件で実施
した。When conducting an experiment similar to that described with reference to Table 1.2 above, using 5OCI2 instead of C12 as the dehydration gas,
Dehydration treatment and transparent vitrification were carried out under the conditions shown in Tables 4 and 5.
表４
表５
なお、表４での処理方法■は脱水処理と透明ガラス化と
を同時に行ない、表５での処理方法■は脱水処理と透明
ガラス化とを別工程で行ない、各処理とも第１図の電気
炉を用いて実施した。Table 4 Table 5 In addition, the treatment method ■ in Table 4 performs dehydration treatment and transparent vitrification at the same time, and the treatment method ■ in Table 5 performs dehydration treatment and transparent vitrification in separate steps, and each treatment is performed at the same time. The experiment was carried out using the electric furnace shown in Figure 1.
表５中、Ｔ１は脱水処理時における処理温度を示し、Ｔ
２は透明ガラス化時における処理温度を示す。In Table 5, T1 indicates the treatment temperature during dehydration treatment;
2 indicates the processing temperature during transparent vitrification.
これら表４、表５の結果で明らかなように、処理方法■
の場合は処理方法■と比べ、水素によるロス増が大きく
、前記の結果と同様の傾向を示している。As is clear from the results in Tables 4 and 5, treatment method ■
In case of 2, the increase in loss due to hydrogen is greater than in treatment method 2, showing the same tendency as the above results.
これは本発明において、脱水ガスとして５ＯＧ１７を用
いた場合でも０１２ と同様の効果が期待できることを
示している。This shows that in the present invention, even when 5OG17 is used as the dehydration gas, the same effects as 012 can be expected.
つぎに、脱水ガスとしてフルオル系シランを用いた場合
の実験例について説明する。Next, an experimental example in which fluorosilane is used as the dehydration gas will be explained.
前記表１．２を参照して述べたと同様の実験を行なうと
き、脱水ガスとして０１２に代わる５ｉＦａを用い、脱
水処理と透明ガラス化を表６、表７に示す条件で実施し
た。When conducting the same experiment as described with reference to Table 1.2 above, 5iFa was used instead of 012 as the dehydration gas, and the dehydration treatment and transparent vitrification were performed under the conditions shown in Tables 6 and 7.
表６
表７
なお、前記と同様１表６での処理方法Ｖは脱水処理と透
明ガラス化とを同時に行ない１表７での処理方法■は脱
水処理と透明ガラス化とを別工程で行ない、各処理とも
第１図の電気炉を用いて実施した。Table 6 Table 7 As mentioned above, treatment method V in Table 1 performs dehydration and transparent vitrification at the same time, and treatment method ■ in Table 1 performs dehydration and transparent vitrification in separate steps. Each treatment was carried out using the electric furnace shown in FIG.
表７中、ＴＩは脱水処理時における処理温度を示し、Ｔ
２は透明ガラス化時における処理温度を示す。In Table 7, TI indicates the treatment temperature during dehydration treatment, and T
2 indicates the processing temperature during transparent vitrification.
これら表６、表７の結果でも、処理方法Ｖの場合は処理
方法■と比べ、水素によるロス増が大きく、前記の結果
と同様の傾向を示している。The results in Tables 6 and 7 also show that in the case of treatment method V, the increase in loss due to hydrogen is greater than in treatment method (2), showing the same tendency as the above results.
したがって１本発明での脱水ガスとしてＳｉＦ４も有効
であることが理解できるが、脱水ガスとしてかかる５ｉ
Ｆｉを用いた場合、処理ガラス中にフッ素がドープされ
るため、脱水処理温度Ｔｌ、透明ガラス化温度Ｔ２が前
記各側よりも約１００℃程度低温化する傾向がみられる
。Therefore, it can be understood that SiF4 is also effective as a dehydrating gas in the present invention, but
When Fi is used, since fluorine is doped into the treated glass, there is a tendency for the dehydration treatment temperature Tl and the transparent vitrification temperature T2 to be about 100° C. lower than those on each side.
実験の結果からすると、ＳｉＦ４を脱水ガスとして用い
る場合、Ｔ１．Ｔ２については、前記第４図の一点鎖線
で囲う領域内で設定するのがよいといえる。According to the experimental results, when SiF4 is used as the dehydration gas, T1. Regarding T2, it can be said that it is best to set it within the area surrounded by the dashed line in FIG. 4.
第４図におけるｘ印、０印、φ印、ム印は前記第２図と
同様の意味をあられす。The x, 0, φ, and mu marks in Figure 4 have the same meanings as in Figure 2 above.
なお、実験例ではフルオル系シランを代表する脱水ガス
としてＳｉＦ４をあげたが、Ｓｉ２Ｆ６． ＳｉＨＦ３
゜ＳｉＨ２Ｆ２． ＳｉＨ３Ｆなども有効であり、ＣＦ
ｂも有効である。In the experimental example, SiF4 was used as a dehydration gas representative of fluoric silane, but Si2F6. SiHF3
゜SiH2F2. SiH3F etc. are also effective, and CF
b is also valid.
ただし、石英炉心管をエツチングしてしまう脱水ガスを
用いる場合は、その炉心管に耐蝕性の処理を施しておく
必要がある。However, if a dehydrated gas that etches the quartz core tube is used, the core tube must be treated to resist corrosion.
ｒ発明の効果１
以上説明した通り１本発明方法によるときは、初期ロス
が小さいだけでなく、波長１．５２ｐｍに出現の水素ロ
ス増ピークを発生させない光ファイバの母材が得られる
。Effects of the Invention 1 As explained above, when the method of the present invention is used, it is possible to obtain an optical fiber base material that not only has a small initial loss but also does not generate the hydrogen loss increase peak that appears at a wavelength of 1.52 pm.
第１図は本発明方法をこれに用いる装置とともに略示し
た説明図、第２図は本発明方法において脱水ガスとして
Ｃ１２を用いた場合の適性処理温度の範囲を示した説明
図、第３図は波長１．５５ｐｍ帯のロススペクトルを示
した説明図、第４図は本発明方法において脱水ガスとし
てＳｉＦ４を用いた場合の適性処理温度の範囲を示した
説明図である。
１・・・電気炉
２・・・電気炉の炉心管（処理雰囲気）Ｂ−・・多孔質
母材
代理人 弁理士 斎 藤 義 雄
第１図
古
今
第２図
ＴＩ （ｔ Ａ ’Ｃ）
第４図
ＴＩ（貧 ｌ τ）Fig. 1 is an explanatory diagram schematically showing the method of the present invention together with the equipment used therein, Fig. 2 is an explanatory diagram showing the range of suitable treatment temperatures when C12 is used as the dehydration gas in the method of the present invention, and Fig. 3 FIG. 4 is an explanatory diagram showing a loss spectrum in the wavelength band of 1.55 pm, and FIG. 4 is an explanatory diagram showing an appropriate treatment temperature range when SiF4 is used as the dehydration gas in the method of the present invention. 1... Electric furnace 2... Furnace tube of electric furnace (processing atmosphere) B-... Porous base material agent Patent attorney Yoshio Saito Figure 1 Ancient and modern Figure 2 TI (t A 'C) Figure 4 TI (poor l τ)
Claims (8)
／ｋｍ以下となる光ファイバの母材を得るため、石英系
の多孔質母材を脱水ならびに透明ガラス化する光ファイ
バ母材の処理方法において、脱水処理工程が先行し、透
明ガラス化工程が後行するよう、これらの工程を別々に
行ない、先行する脱水処理工程では、ＨｅとＯ＿２と脱
水ガスとにより脱水雰囲気を形成するとともに、処理温
度を上記多孔質母材の実質的脱水反応開始温度以上かつ
独立閉孔形成温度未満に設定し、かかる脱水雰囲気中の
処理温度域を多孔質母材が通過し、後行する透明ガラス
化工程では、ＨｅとＯ＿２またはＨｅのみで透明ガラス
化雰囲気を形成するとともに、処理温度を最低透明ガラ
ス化温度以上に設定し、かかる透明ガラス化雰囲気中の
処理温度域を上記脱水処理後の母材が通過することを特
徴とする光ファイバ母材の処理方法。(1) Transmission characteristics in the wavelength band of 1.2 to 1.6 μm are 5 dB
In order to obtain an optical fiber base material with a thickness of less than In the preceding dehydration treatment step, a dehydration atmosphere is formed with He, O_2, and dehydration gas, and the treatment temperature is set to a temperature higher than the actual dehydration reaction initiation temperature of the porous base material. The porous base material passes through the treatment temperature range in such a dehydrated atmosphere, and in the subsequent transparent vitrification step, a transparent vitrification atmosphere is formed only with He and O_2 or He. A method for processing an optical fiber preform, characterized in that the processing temperature is set at a minimum transparent vitrification temperature or higher, and the preform after the dehydration treatment passes through a processing temperature range in such a transparent vitrification atmosphere.
透明ガラス化する特許請求の範囲第１項記載の光ファイ
バ母材の処理方法。(2) Dewatering the porous base material produced by the VAD method,
A method for processing an optical fiber preform according to claim 1, which converts the preform into transparent glass.
透明ガラス化する特許請求の範囲第１項記載の光ファイ
バ母材の処理方法。(3) Dewatering the porous base material produced by the OVD method,
A method for processing an optical fiber preform according to claim 1, which converts the preform into transparent glass.
に設定する特許請求の範囲第１項ないし第３項いずれか
に記載の光ファイバ母材の処理方法。(4) The treatment temperature in the dehydration process is 900-1300℃
A method for processing an optical fiber preform according to any one of claims 1 to 3.
５０℃に設定する特許請求の範囲第１項ないし第３項い
ずれかに記載の光ファイバ母材の処理方法。(5) The treatment temperature in the transparent vitrification process is 1350-16
A method for processing an optical fiber preform according to any one of claims 1 to 3, wherein the temperature is set at 50°C.
項ないし第４項いずれかに記載の光ファイバ母材の処理
方法。(6) Claim 1 in which the dehydration gas is chlorine gas
A method for processing an optical fiber preform according to any one of items 1 to 4.
第１項ないし第４項いずれかに記載の光ファイバ母材の
処理方法。(7) The method for treating an optical fiber preform according to any one of claims 1 to 4, wherein the dehydration gas is thionyl chloride.
範囲第１項ないし第４項いずれかに記載の光ファイバ母
材の処理方法。(8) The method for treating an optical fiber preform according to any one of claims 1 to 4, wherein the dehydration gas is fluorine-based silane.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP426985 | 1985-01-14 | ||
| JP60-4269 | 1985-01-14 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61270232A true JPS61270232A (en) | 1986-11-29 |
| JPH0442340B2 JPH0442340B2 (en) | 1992-07-13 |
Family
ID=11579819
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP389586A Granted JPS61270232A (en) | 1985-01-14 | 1986-01-11 | Method for treating optical fiber base material |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JPS61270232A (en) |
| CN (1) | CN86100210A (en) |
| GB (1) | GB2171691B (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006176377A (en) * | 2004-12-24 | 2006-07-06 | Shinetsu Quartz Prod Co Ltd | Method for manufacturing synthetic silica glass having controlled oh group concentration and silica glass body |
| JP2007284302A (en) * | 2006-04-18 | 2007-11-01 | Shin Etsu Chem Co Ltd | Method for producing low-loss optical fiber preform |
| JP2010189251A (en) * | 2009-01-20 | 2010-09-02 | Furukawa Electric Co Ltd:The | Method for manufacturing optical fiber preform |
| JP2016200830A (en) * | 2011-04-15 | 2016-12-01 | 住友電気工業株式会社 | Optical fiber |
| WO2019107557A1 (en) * | 2017-12-01 | 2019-06-06 | 古河電気工業株式会社 | Device for manufacturing lass body, method for manufacturing glass body, soot conveyance mechanism, and soot heating mechanism |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004002106A (en) * | 2002-05-31 | 2004-01-08 | Shin Etsu Chem Co Ltd | Low loss optical fiber preform and its manufacturing method |
| CN105669019B (en) * | 2016-04-19 | 2018-08-07 | 江苏亨通光导新材料有限公司 | The manufacturing device and its manufacturing method of preform |
| CN106116121A (en) * | 2016-08-31 | 2016-11-16 | 中国建筑材料科学研究总院 | The preparation method of quartz glass and quartz glass |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS583981A (en) * | 1981-06-30 | 1983-01-10 | Moai:Kk | Manufacture of iron cloisonne ware |
| JPS6081033A (en) * | 1983-10-11 | 1985-05-09 | Nippon Telegr & Teleph Corp <Ntt> | Manufacture of optical fiber |
-
1986
- 1986-01-11 JP JP389586A patent/JPS61270232A/en active Granted
- 1986-01-14 CN CN198686100210A patent/CN86100210A/en active Pending
- 1986-01-14 GB GB08600792A patent/GB2171691B/en not_active Expired
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS583981A (en) * | 1981-06-30 | 1983-01-10 | Moai:Kk | Manufacture of iron cloisonne ware |
| JPS6081033A (en) * | 1983-10-11 | 1985-05-09 | Nippon Telegr & Teleph Corp <Ntt> | Manufacture of optical fiber |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006176377A (en) * | 2004-12-24 | 2006-07-06 | Shinetsu Quartz Prod Co Ltd | Method for manufacturing synthetic silica glass having controlled oh group concentration and silica glass body |
| JP2007284302A (en) * | 2006-04-18 | 2007-11-01 | Shin Etsu Chem Co Ltd | Method for producing low-loss optical fiber preform |
| WO2007123163A1 (en) * | 2006-04-18 | 2007-11-01 | Shin-Etsu Chemical Co., Ltd. | Process for producing optical fiber base |
| US8561431B2 (en) | 2006-04-18 | 2013-10-22 | Shin-Etsu Chemical Co., Ltd. | Method of manufacturing optical fiber base material |
| JP2010189251A (en) * | 2009-01-20 | 2010-09-02 | Furukawa Electric Co Ltd:The | Method for manufacturing optical fiber preform |
| JP2016200830A (en) * | 2011-04-15 | 2016-12-01 | 住友電気工業株式会社 | Optical fiber |
| WO2019107557A1 (en) * | 2017-12-01 | 2019-06-06 | 古河電気工業株式会社 | Device for manufacturing lass body, method for manufacturing glass body, soot conveyance mechanism, and soot heating mechanism |
| JPWO2019107557A1 (en) * | 2017-12-01 | 2020-11-19 | 古河電気工業株式会社 | Glass body manufacturing equipment, glass body manufacturing method, soot transfer mechanism, and soot heating mechanism |
| US11548806B2 (en) | 2017-12-01 | 2023-01-10 | Furukawa Electric Co., Ltd. | Glass body manufacturing apparatus, glass body manufacturing method, soot conveying mechanism, and soot heating mechanism |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2171691A (en) | 1986-09-03 |
| JPH0442340B2 (en) | 1992-07-13 |
| CN86100210A (en) | 1986-09-10 |
| GB2171691B (en) | 1988-06-29 |
| GB8600792D0 (en) | 1986-02-19 |
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