JPS5973443A - Manufacture of glass proform for optical fiber - Google Patents
Manufacture of glass proform for optical fiberInfo
- Publication number
- JPS5973443A JPS5973443A JP18124282A JP18124282A JPS5973443A JP S5973443 A JPS5973443 A JP S5973443A JP 18124282 A JP18124282 A JP 18124282A JP 18124282 A JP18124282 A JP 18124282A JP S5973443 A JPS5973443 A JP S5973443A
- Authority
- JP
- Japan
- Prior art keywords
- furnace
- base material
- gas
- preform
- optical fiber
- 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
-
- 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
- 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
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
Description
【発明の詳細な説明】
本発明は光通信用ファイバの母材の製造法に関し、特に
母材中の残留水分量を極力少なくしながら、かつ最適な
屈折率分布に制御しつつ、連続的に母材を製造する方法
に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a base material for optical communication fibers, and in particular to a method for manufacturing a base material for optical communication fibers, in particular, while minimizing the amount of residual moisture in the base material and controlling the refractive index distribution to an optimal value. The present invention relates to a method of manufacturing a base material.
光伝送用ガラス母材を造る方法の一つに特公昭４９〜１
ａ５５５８号公報等に開示されている気相軸付は法（Ｖ
ＡＤ法）がある。ここで従来、実施されているＶＡＤ法
の概略を説明すると、第１図（、ａ）に示すように、容
器１の下部に設けたバーナ２にガラス微粒子の原料ガス
や燃焼用ガスおよびドーパントガスを供給し、バーナか
ら出発物質６に向けて火炎を吹き付け、ガラス微粒子の
ススをこの出発物質３の下面に付着、堆積させ、出発物
質３を回転して引き上げながらこのガラス微粒子スス体
を成長させ、集合体４を造り、母材とするものである。One of the methods of making glass base material for optical transmission was
The gas phase shaft type disclosed in the A5558 publication etc. is based on the method (V
AD method). Here, to explain the outline of the conventional VAD method, as shown in FIG. is supplied and a flame is blown from the burner toward the starting material 6, so that the soot of glass fine particles is attached and deposited on the lower surface of the starting material 3, and the soot body of glass fine particles is grown while rotating and pulling up the starting material 3. , an aggregate 4 is made and used as a base material.
このＶＡＤ法では低損失で半径方向に任意の屈折率分布
を有し、円周および長手方向に均一な組成を有し安価な
光伝送用ファイバーを得ることができると共に、この方
法は原料収率が良く高純度製品が得られ、最大の不純物
である水分の除去もＶＡＤ多孔質母材が均一＝微粒子集
合体であるがゆえに焼結時、脱水が容易であることや、
工程数が少ないことなどの特徴があシ、実用上大きな利
点を有する。With this VAD method, it is possible to obtain an inexpensive optical transmission fiber having a low loss, an arbitrary refractive index distribution in the radial direction, and a uniform composition in the circumferential and longitudinal directions. A high-purity product can be obtained, and water, which is the largest impurity, can be removed because the VAD porous base material is uniform and is an aggregate of fine particles, so it is easy to dehydrate during sintering.
It has features such as a small number of steps, and has great practical advantages.
その際、ＧｅＯ２などのドーパントは中央部に多く堆積
し周辺部へ向うにしたがって少なく堆積させ、これによ
シト−パント濃度を所望の分布に形成させ、第１図（ｂ
）に示すような屈折率分布のガラス母材が得られる。図
中、ｎｏ は石英ガラスの屈折率レベル、△ｎ （ｄ、
ＧｅＯ２によシ増大した屈折率レベルであシ、αは△
ｎ＝ｎ〔１−（−）） で示される屈折率分布曲線の
０
指数である。このαは光ファイバにとって重要な帯域特
性に大きな影響を与える要素であシ、α２２．０前後が
最適とされておシ、使用波長域で、その値は微妙に変化
する。例えば０．８５μｍではα＝２．０．１．３０μ
ｍではα＝１，８Ｑとされている。更に近年、広帯域特
性を有した低損失の光ノア１バーの需要が２０Ｋｍ以上
の無中継伝送方式を軸に急増している。特に１，３０μ
ｍ帯で０．８ｄＢ／ＫＩｎ 以下でかつ帯域特性が８
００ＭＨ８Ｋｍ以上の特性を有するファイバが望ましい
とされている。このような特性、低損失を確保するため
には、ファイバ中の残留水分量を０． ｌｐｐｍ以下、
また帯域特性を確保するためにはαを α。１０．０５
以内に制御する必要がある。At this time, a large amount of dopant such as GeO2 is deposited in the center and less toward the periphery, thereby forming a desired distribution of the cytopant concentration, as shown in Fig. 1 (b).
) A glass base material with a refractive index distribution as shown in FIG. In the figure, no is the refractive index level of silica glass, △n (d,
With increased refractive index level due to GeO2, α is △
It is the 0 index of the refractive index distribution curve expressed as n=n[1-(-)). This α is a factor that has a great influence on the important band characteristics of optical fibers, and α around 22.0 is said to be optimal, but its value changes slightly depending on the wavelength range used. For example, at 0.85μm, α=2.0.1.30μ
In m, α=1.8Q. Furthermore, in recent years, the demand for low-loss optical NOR 1 bar with broadband characteristics has rapidly increased, centering on non-repeater transmission systems for distances of 20 km or more. Especially 1,30μ
0.8dB/KIn or less in m band and band characteristic is 8
It is said that a fiber having a characteristic of 00MH8Km or more is desirable. In order to ensure these characteristics and low loss, the residual water content in the fiber must be reduced to 0. lppm or less,
Also, in order to ensure the band characteristics, α is set to α. 10.05
need to be controlled within.
しかしながら従来の公知方法では屈折率分布の係数αを
変化させる場合、原料ガス、ドーパントガス、燃焼用ガ
スの量比を微妙に変える必要があり、例えば１．３０μ
ｍ帯用のα値１．８゜±０，０５よシ０．８５μｍ帯用
のα値２．００±０．０５に変更することは非常に困難
である。However, in the conventional known method, when changing the coefficient α of the refractive index distribution, it is necessary to slightly change the ratio of the raw material gas, dopant gas, and combustion gas, for example, by 1.30μ.
It is very difficult to change the α value from 1.8°±0.05 for the m band to 2.00±0.05 for the 0.85 μm band.
本発明者等は先に、最適な屈折率分布を任意に得られる
光伝送用ガラス母材の製法として、ガラス微粒子集合体
を焼結して透明ガラス体とするに際し、第２図に示すよ
うに ｃｔ２／ Ｈｅの雰囲気の１つの炉２１を用い、
そこで焼結と同時に脱水ならびにプロファイル制御を行
なう方法を提案した（特願昭５７−４９０１号）。図中
、２１が焼結炉、２２ガスバーナー、２３出発物質、２
４集合体、２５排気口、２６ヒーター、２７ ｃｔ２
／Ｈｅ 供給口である。The present inventors previously developed a method for producing a glass base material for optical transmission that can arbitrarily obtain an optimal refractive index distribution, as shown in FIG. Using one furnace 21 with ct2/He atmosphere,
Therefore, we proposed a method of performing dehydration and profile control simultaneously with sintering (Japanese Patent Application No. 57-4901). In the figure, 21 is a sintering furnace, 22 is a gas burner, 23 is a starting material, and 2 is a sintering furnace.
4 aggregates, 25 exhaust ports, 26 heaters, 27 ct2
/He is a supply port.
このたび、本発明者等は脱水反応と揮散反応の活性な領
域を鋭意、研究の結果、次のようなことを見出した。ス
ス体のカサ密度が０，１５〜０、４０１７ｃｍ３の範囲
のものでは、脱水反応は１０００〜１５００℃ で活性
であシ、この下限は脱水反応の活性化に由来し、上限は
スス体の収縮速度が脱水反応よシ上回ることに由来する
。The present inventors have made the following findings as a result of intensive research into the active regions of dehydration reactions and volatilization reactions. When the bulk density of the soot body is in the range of 0.15 to 0.4017 cm3, the dehydration reaction is active at 1000 to 1500°C; this lower limit is derived from the activation of the dehydration reaction, and the upper limit is the shrinkage of the soot body. This is because the rate is faster than the dehydration reaction.
一方、揮散反応は １２００〜１４００℃で活性であシ
、下限は、
Ｇｅ ０２ ＋２ Ｃ１２→Ｇｅ Ｃ１０＋ ０２の反
応の活性化に由来し、上限はスス体の収縮速度が非常に
速（ＧｅＯ２の揮散反応を阻害するためである。以上の
理由から、脱水反応とＧｅ ０２の揮散反応が共に活性
な温度領域は１２００〜１４００℃であることが判る。On the other hand, the volatilization reaction is active at 1200-1400°C, the lower limit is due to the activation of the Ge 02 +2 C12 → Ge C10+ 02 reaction, and the upper limit is due to the extremely rapid contraction rate of the soot body (Volatilization of GeO2). This is to inhibit the reaction.For the above reasons, it can be seen that the temperature range in which both the dehydration reaction and the Ge 02 volatilization reaction are active is 1200 to 1400°C.
脱水反応に比べ上限温度が１００℃低くなるのは、スス
体内でのＧｅＣ／！４ ＝スの拡散が脱水反応で生ず
るＨＣｔガスに比べ遅いためである。The reason why the upper limit temperature is 100℃ lower than that of the dehydration reaction is that GeC/! This is because the diffusion of 4 = gas is slower than that of HCt gas generated in the dehydration reaction.
一方、透明ガラス化するには１５００℃以上の温度が必
要である。このため先に挙げた先願発明のように単一の
炉を使用し、脱水と同時に揮散反応を利用しプロファイ
ル制御を行ないながら透明ガラス化することは非常に困
難であシ、特にプロファイル制御の自由度が著しく阻害
される。On the other hand, a temperature of 1500° C. or higher is required for transparent vitrification. For this reason, it is extremely difficult to use a single furnace and simultaneously perform dehydration and vaporization reaction to achieve transparent vitrification while controlling the profile, as in the prior invention mentioned above. Freedom is significantly inhibited.
本発明は上記先願方法における、プロファイルの制御を
更に容易にすると共に、ガラス母材のｃｔ２による泡の
発生を抑えることを目的として開発されたもので、２つ
の炉を用いて、まず脱水とプロファイル制御ケ行ない、
次の炉で付加的な脱水と焼結を行なうことを特徴とする
ものである。The present invention was developed with the aim of making it easier to control the profile in the method of the prior application and suppressing the generation of bubbles due to ct2 of the glass base material. Perform profile control,
It is characterized by additional dehydration and sintering in a subsequent furnace.
すなわち、本発明は光フアイバ用多孔質母材を軸方向へ
成長させながら、これを同軸上に置かれた透明ガラス化
炉を用いて連続的に透明ガラ、ス化する方法において、
多孔質母材の成長点と透明ガラス化炉の間に、多孔質母
材を完全に収縮させない温度範囲に調整した予備加熱炉
を設け、この炉内で不活性ガス、とドーパントを還元揮
散させる作用を有する脱水剤を含む雰囲気下、上記母材
の脱水を行・ないながら、ドーパントの揮散による屈折
率分布の制御を行ない、更に透明ガラス化炉で不活性ガ
・スと脱水剤を含む雰囲気下、母材の透明ガラス化を行
なうことを特徴とする方法、に関するものである。That is, the present invention provides a method for continuously growing a porous preform for optical fiber in the axial direction and converting it into transparent glass using a coaxially placed transparent vitrification furnace.
A preheating furnace adjusted to a temperature range that does not completely shrink the porous base material is installed between the growth point of the porous base material and the transparent vitrification furnace, and the inert gas and dopant are reduced and volatilized in this furnace. While dehydrating the base material in an atmosphere containing an effective dehydrating agent, the refractive index distribution is controlled by volatilization of the dopant, and then in an atmosphere containing an inert gas and a dehydrating agent in a transparent vitrification furnace. The present invention relates to a method characterized in that the base material is transparently vitrified.
本発明で用いられる脱水剤としてはＣｔａガス等のハロ
ゲン、ＣＣｌ４．５ＯＣ１ｚ 等のハロゲン化物、−
酸化炭素、ＣＯＣｌ２ 等のカルボニル化・金物等が
挙げられる。不活性ガスとしてはＨｅ、Ａｒ。The dehydrating agent used in the present invention includes halogens such as Cta gas, halides such as CCl4.5OC1z, -
Examples include carbon oxide, carbonylation such as COCl2, metal materials, and the like. Examples of inert gas include He and Ar.
Ｎ２ 等が用いられる。N2 etc. are used.
本発明では、脱水剤としてｃｔ２ガスを使用し、予備加
熱炉の炉温は １２００〜１３０ｏ℃ で、ｃｔ２ガス
濃度が０．５〜５容量チである不活性ガス（Ｈｅ等）雰
囲気であシ、透明ガラス化炉の炉温は １５００〜１７
００℃で、ｃｔ２ガス濃度が０．１〜０．２容量チであ
るＨｅガス雰囲気で、光フアイバ母材をＶＡＤ法で製造
することによって、特゛性のよいものを効率よく製造す
ることができるＯ
他方、光フアイバ母材の製造に当シ２つの加熱部あるい
は炉を用い第１の加熱部で脱水、第２の加熱部で透明化
を行う方法も特開昭５４−１３４７２２号、同５４−ｆ
３４１２８号、同５４−９４０５０号、同５５−１０４
１２号公報に記載されているが、第１の加熱部でプロフ
ァイル制御が行なわれていない点、第２の加熱部に脱水
剤が存在せず単に焼結のみが行なわれている点で本発明
と異なり、本発明ではこの相違する構成によって、光フ
アイバ中の残留水分を取シ除き、更に帯域特性にとシ重
要なα値を連続的に変化させ、しかもその制御範囲をα
ｂ±０．０５以内にすることを可能にし、これによシ任
意の屈折率分布を有する光ファイバが連続的に製造でき
、光ファイバを安価に提供することを可能ならしめたも
のである。In the present invention, CT2 gas is used as a dehydrating agent, the furnace temperature of the preheating furnace is 1200 to 130oC, and the dehydration is carried out in an inert gas (such as He) atmosphere with a CT2 gas concentration of 0.5 to 5% by volume. , the furnace temperature of the transparent vitrification furnace is 1500~17
By manufacturing the optical fiber base material using the VAD method in a He gas atmosphere with a ct2 gas concentration of 0.1 to 0.2 volume at 00°C, it is possible to efficiently manufacture products with good properties. On the other hand, a method of manufacturing optical fiber base material using two heating sections or furnaces, dehydrating in the first heating section and making transparent in the second heating section, is also disclosed in JP-A-54-134722 and the same. 54-f
No. 34128, No. 54-94050, No. 55-104
Although it is described in Japanese Patent No. 12, the present invention differs in that profile control is not performed in the first heating section, and that only sintering is performed without a dehydrating agent in the second heating section. However, in the present invention, with this different configuration, the residual moisture in the optical fiber is removed, and the α value, which is important for the band characteristics, is continuously changed, and the control range is
This makes it possible to keep b within ±0.05, thereby making it possible to continuously manufacture optical fibers having arbitrary refractive index distributions and to provide optical fibers at low cost.
１つの炉を用いて脱水と焼結を行なう先願方法（特願昭
５７−４９０１号）と本願発明の差を図を用いて説明す
る。The difference between the method of the prior application (Japanese Patent Application No. 57-4901), which performs dehydration and sintering using one furnace, and the present invention will be explained with reference to the drawings.
１５００℃とした場合（先願方法）のヒータの炉温分布
とスス体の収縮は第３図（ａ）、１１００〜１３００℃
とした場合（本発明方法）のヒータの炉温分布とスス体
の収縮は第３図（ｂ）に示される通シである。図中、斜
線部ｔで示されるのが反応領域で、ここでドーパント揮
散、続いて脱水が行なわれるが、この領域はｔｌ（先願
） ＜＜ ｔ２ （本発明）で、本発明のものが非常に
長いことが判る。Figure 3 (a) shows the furnace temperature distribution of the heater and the shrinkage of the soot body when the temperature is set at 1500°C (first application method), 1100 to 1300°C.
In this case (method of the present invention), the furnace temperature distribution of the heater and the contraction of the soot body are as shown in FIG. 3(b). In the figure, the hatched area t is the reaction region, where dopant volatilization and subsequent dehydration take place. It turns out to be very long.
一方、ブロンアイル制御（ドーパント揮散、）のパラメ
ータは温度Ｔ１反応時間ｔ１塩素濃度Ｃの６つで、これ
によシプロファイルｆが決定される。On the other hand, there are six parameters for blow-aisle control (dopant volatilization): temperature T1 reaction time t1 chlorine concentration C, which determines the shading profile f.
ゾｉン焼結の場合、ｔは反応領域ｔを下降ｒａｔｅ
Ｒで割った値
ｔ、 ＝ ｔｌＲ（２）
で表示され、ズ２）より（１）は
ｆｔ （Ｔ、 ｔ／Ｒ％ ｃ ） となる。 （
３）またＴは反応の活性度を示し、
で表示できる。In the case of zone sintering, t is the rate at which the reaction region t descends.
The value t divided by R is expressed as = tlR(2), and from step 2), (1) becomes ft (T, t/R% c). (
3) Also, T indicates the activity of the reaction and can be expressed as:
■ 先願の場合（第３図（ａ） ） ｔが小さく、ｆｌ
を大きくするためにはＲを小さくするがＣを大きくする
必要がある。■ In the case of a prior application (Figure 3 (a)) t is small and fl
In order to increase , it is necessary to decrease R and increase C.
一方、では透明ガラス化するため姉は
１５００℃以上である必要がある。このような温度領域
では気泡が発生し易く、ｃ（ｃｔ２濃度）を小さく抑え
る必要があシ、事実０．６〜１ ｍａｔチが限界（スス
体にょシ差あシ）−′Ｃ−１それ以下に抑えねばならず
、このためＣの量を変化させてｆｌ の制御をはかる
ことは困難でおる。On the other hand, the temperature for the older sister needs to be 1500°C or higher in order to make it transparent. In such a temperature range, air bubbles are likely to occur, and it is necessary to keep c (ct2 concentration) low, and in fact, the limit is 0.6 to 1% (there is a difference in the soot body). Therefore, it is difficult to control fl by changing the amount of C.
またＲについても透明ガラス化に要する加熱時間より４
簡／分以下が必要であり、これが上限となる。下降は効
率の問題より１籟／分が限度（５６０ｔのススで６時間
要する）でおる。Also, regarding R, 4
It needs to be less than 1 minute per minute, and this is the upper limit. Due to efficiency issues, the rate of descent is limited to 1 lint/minute (6 hours required with 560 tons of soot).
以上より先願の単一炉を・用いる方法ではフ。Based on the above, the method using a single reactor in the earlier application is futile.
ロファイル制御の自由度は非常に狭く、プロファイル制
御は困難である。The degree of freedom in profile control is very narrow, making profile control difficult.
■ 一方、本発明の方式（第３図（ｂ））では、反応領
域ｔが長くまたＣも５モルチとしても気泡の発生もなく
、Ｔも透明ガラス化する必要がないため可変領域が大き
い。(2) On the other hand, in the method of the present invention (FIG. 3(b)), the reaction region t is long, no air bubbles are generated even if C is 5 ml, and T does not need to be made into transparent glass, so the variable region is large.
ｆｌが効率的な領域は １０００＜Ｔ＜ （１５００℃）＠ ０．５＜Ｃ＜５モルチ Ｒ〈 １０ ■は他の要因で決まる。The area where fl is efficient is 1000<T< (1500℃)@ 0.5<C<5molti R〈 10 ■ is determined by other factors.
Ｔ＜１３００℃は１３００℃以上だとスス体が収縮し、
スス体のわずかの変化（Ｐ童女ど）で収縮速度が変化し
、負 が同一条件でもリン量（例えばｐｏｃｔ、 ガ
スの形で導入する）によシ変動する。If T<1300℃ is 1300℃ or higher, the soot body will shrink.
The contraction speed changes due to a slight change in the soot body (such as P girls), and even under the same negative conditions, it changes depending on the amount of phosphorus (for example, poct, introduced in the form of gas).
以上の点からＴ、 Ｃ，Ｈのいずれか１つを固定しても
ｆｌ を一定の値にできる（Ｔ−Ｃの選択領域が広い
）という広い自由度をもった方式本発明ではＲを選択し
てもｆ、はＴ−Ｃで調整でき、スス付はタンデムにとり
非常に有利である。この方法で大力の水分の除去も可能
でｓｂ、また脱水の不足分は更に上記の透明化炉で若干
のｃｔ２を添加することによシ補うことである。From the above points, R is selected in the present invention as a method with a wide degree of freedom in that even if any one of T, C, and H is fixed, fl can be kept at a constant value (the selection range of T-C is wide). Even if f, can be adjusted by T-C, sooting is very advantageous for tandem. A large amount of water can be removed by this method, and the lack of dehydration can be made up by adding some ct2 in the above-mentioned clarifying furnace.
以上述べたように、引上げスピード（下降に対応）がス
ス付けｒａｔθ で決まることから、第６図（ａ）の先
願の方式では高速化した場合限度があるが、第６図（ｂ
）の本発明方式では高速化の場合にも対応でき、非常に
有利な方法といえる。As mentioned above, since the pulling speed (corresponding to the descent) is determined by the sooting rate ratθ, there is a limit to how high the speed can be increased in the method of the prior application shown in Fig. 6(a), but as shown in Fig. 6(b)
) The method of the present invention can also be applied to cases of high speed, and can be said to be a very advantageous method.
以下に本発明をＶＡＤ法を例にとった第４図を用いて詳
細に説明する。第４図は本発明を実施する装置構成の一
例である。ここでは、反応容器３１の下部にバーナ５２
が設けられておシ、バーナ５２に対向して出発物質３３
が容器内部に回転自在に吊下され、更に各盤３１の内周
にヒータ３６．３８が設けられている。また容器３１上
部や側面に容器内に所定のガスを送シ込むガス供給口３
７．５９が段付られていると共に、反応容器３１の下部
には容器内のガスを排出する排気口３５が設けられてい
る。The present invention will be explained in detail below using FIG. 4, taking the VAD method as an example. FIG. 4 shows an example of an apparatus configuration for implementing the present invention. Here, a burner 52 is installed at the bottom of the reaction vessel 31.
is provided opposite the burner 52 to feed the starting material 33.
is rotatably suspended inside the container, and furthermore, heaters 36 and 38 are provided on the inner periphery of each panel 31. Also, a gas supply port 3 at the top or side of the container 31 for supplying a predetermined gas into the container.
7.59 is stepped, and an exhaust port 35 is provided at the bottom of the reaction container 31 to discharge the gas inside the container.
上記装置を用いてバーナ３２から原料ガスを燃焼させて
生じたガラス微粒子のススを出発物質３３の下面に堆積
させ、ガラス微粒子集合体３４を形成する。この場合ガ
ス供給口５７．５９を通し不活性ガスに希釈されたハロ
ゲン、ハロゲン化物やカルボニルガス（ＣＯを含む）な
どの脱水作用と共にドーパント揮散作用を有するガスを
供給して炉３６内を不活性ガス芽囲気、炉３８内を脱水
作用やドーパント揮散可能な雰囲気とし、これらの雰囲
気で上記ガラス微粒子集合体３４を形成すると共に、該
ガラス微粒子体４０を′上方へ引上け、ヒータ３゛８で
脱水を行ないつつプロファイル制御（ドーパントを揮散
）させながら、ヒータ３６で脱水と透明ガラス化を行な
う。ヒータ３８は当該母材の脱水とプロファイル制御を
行々う目的で設置されておシ、この場合、ヒータは１台
となっているが２台であっても差し支えない。またヒー
タ３６は微粒子体３４を透明ガラス化に使用する目的で
設置されている。ヒータ３６．３８の加熱温度や雰囲気
ガスを変化させることによシ、“帯域特性にとって重要
な係数αを容易に変化させることが可能である。Using the above-mentioned apparatus, the soot of glass particles produced by burning the raw material gas from the burner 32 is deposited on the lower surface of the starting material 33 to form a glass particle aggregate 34. In this case, a gas having a dehydrating effect and a dopant volatilization effect such as halogen, halide, or carbonyl gas (including CO) diluted with an inert gas is supplied through the gas supply ports 57 and 59 to inert the inside of the furnace 36. The atmosphere surrounding the gas buds and the inside of the furnace 38 are made to be capable of dehydration and dopant volatilization, and in these atmospheres, the above-mentioned glass fine particle aggregate 34 is formed, and the glass fine particle body 40 is pulled upward and heated to the heater 3'8. The heater 36 performs dehydration and transparent vitrification while performing dehydration and controlling the profile (vaporizing the dopant). The heater 38 is installed for the purpose of dehydrating the base material and controlling the profile. In this case, there is one heater, but two heaters may be used. Further, the heater 36 is installed for the purpose of using the fine particles 34 for transparent vitrification. By changing the heating temperature of the heaters 36 and 38 and the atmospheric gas, it is possible to easily change the coefficient α, which is important for the band characteristics.
なお、３７よ、り Ｃ１ｚガスを添加するのは、上部外
気の浸入水分を塩酸にするもので積極的に母材を脱水す
るものではない。Ｃ１２０，１容量チで充分で、０．２
容量−以上とした場合、透明化母材に泡の発生が見られ
ることがあった。またＣｌ２Ｏ，２容量チ以下の場合プ
ロファイルが段状となってしまうし、５容量チ以上の場
合、周辺部がすそ引きを起こし、共に帯域特性に悪影響
を及ばず。In addition, according to No. 37, the addition of C1z gas is to convert the moisture infiltrating the upper outside air into hydrochloric acid, and is not to actively dehydrate the base material. C120, 1 capacity is enough, 0.2
When the capacity was - or more, bubbles were sometimes observed in the transparent base material. Further, when Cl2O is less than 2 capacitances, the profile becomes step-like, and when it is more than 5 capacitances, the peripheral part causes a skirt, but neither of them has any adverse effect on the band characteristics.
第４図の装置を用いてファイバ母材を製造した例を次に
示す。An example of manufacturing a fiber preform using the apparatus shown in FIG. 4 is shown below.
実施例１
多孔質母材の生成条件を一定とし炉３８での加熱温度＞
１２０ ｏ℃とし、ガス供給口３９よりＣｔ２２容量係
を含むＨｅ ガ、＜ｓｔ１分を流し、炉３６での加熱温
度１６０ｏ℃とし、ガス供給１コ３７よシＣ４２０，１
容量係を含む５ｔ／分のＨｅ ガスを流したところ、
残留水分量０．０１ ｐｐｍ。Example 1 Heating temperature in furnace 38 with constant generation conditions of porous base material>
The temperature was set at 120oC, He gas containing Ct22 capacity factor <st1 min was flowed from the gas supply port 39, the heating temperature in the furnace 36 was set at 160oC, and the gas supply 1 port 37 was heated to C420,1.
When 5 t/min of He gas including the capacity factor was flowed,
Residual moisture content 0.01 ppm.
屈折率分布α−１，９５のファイバーが得られた。A fiber with a refractive index distribution α-1.95 was obtained.
実施例２
ガス供給口３９よｐｃｔ２１容量チを含むＨｅガス５ｔ
を流し、他は実施例１と同様にした場合、残留水分０．
Ｏ５ｐｐｍ、 α＝２．００のファイバが得られた。Example 2 5 tons of He gas including pct21 capacity from gas supply port 39
When the other conditions were the same as in Example 1, the residual moisture was 0.
A fiber with O5ppm and α=2.00 was obtained.
実施例６
炉３８を１１００℃とし他は実施例１と同様とした場合
、残留水分量０５ ｐｐｍ 、 α−１，８５のファ
イバが得られた。Example 6 When the furnace 38 was set at 1100° C. and the other conditions were the same as in Example 1, a fiber with a residual moisture content of 05 ppm and α-1.85 was obtained.
実施例４
炉３８を１１００℃としガス供給口３９よシＣ１２１容
量チを含むＨｅガス５１−７分を流し７、他は実施例１
と同様とした場合、残留水分は０、Ｏ４ｐｐｍ、 α
＝１．８０のファイバが得られた。Example 4 The furnace 38 was set to 1100° C., and He gas containing C121 capacity Q was flowed through the gas supply port 39 for 51-7 minutes, and the rest was Example 1.
In the same case, the residual moisture is 0, O4ppm, α
=1.80 fiber was obtained.
実施例５
実施例１においてガス供給口３７よりのＣｔ２添加を止
めた場合、残留水分量は０．０３ ｐｐｍとなり屈折率
分布はα＝ｊ、９５となった。Example 5 In Example 1, when the addition of Ct2 from the gas supply port 37 was stopped, the residual moisture content was 0.03 ppm and the refractive index distribution was α=j, 95.
第１図（ａ）はＶＡＤ法の概略を示す図であり、第１図
（ｂ）はＶＡＤ法における屈折率分布を示す図であシ、
第２図ｉｄ ＶＡＤ法において１つの炉を用いる先行発
明の方法を示す図であり、第６図（ａ）は第２図の先行
発明の法におけるヒータの炉温分布とスス体の収縮を示
す図であり、第６図（ｂ）は゛本発明方法におけるヒー
タの炉温分布とスス体の収縮を示す図であシ、第４図は
本発明方法の概略を示す図である。
代理人 内 １） 明
代理人 萩 原 亮 −FIG. 1(a) is a diagram showing an outline of the VAD method, and FIG. 1(b) is a diagram showing the refractive index distribution in the VAD method.
Fig. 2 id is a diagram showing the method of the prior invention using one furnace in the VAD method, and Fig. 6 (a) shows the furnace temperature distribution of the heater and the contraction of the soot body in the method of the prior invention of Fig. 2. 6(b) is a diagram showing the furnace temperature distribution of the heater and the contraction of the soot body in the method of the present invention, and FIG. 4 is a diagram schematically showing the method of the present invention. Agents 1) Akira’s agent Ryo Hagiwara −
Claims (2)
ら、これを同軸上に置かれた透明ガラス化炉を用いて連
続的に透明ガラス化する方法において、多孔質母材の成
長源と透明ガラス化炉の間に、多孔質母材な完全に収縮
させない温度範囲に調整した予備加熱炉を設け、この炉
内で不活性ガス′とドーパントを還元揮散させる１作用
を有する脱水剤を含む雰囲気下、上記母材の脱水を行な
いながち、ドーパントの揮散による屈折率分布の制御を
行ない、更に透明ガラス化炉で不活性ガスと脱水剤を含
む雰囲気下、母材の透明ガラス化を行なうことを特徴と
する光フアイバ用ガラス母材の製造方法。(1) In a method of growing a porous base material for optical fiber in the axial direction and continuously converting it into transparent vitrification using a transparent vitrification furnace placed on the same axis, the growth source of the porous base material is A preheating furnace adjusted to a temperature range that does not completely shrink the porous base material is installed between the transparent vitrification furnace and the porous base material, and a dehydrating agent having the function of reducing and volatilizing the inert gas' and the dopant is installed in this furnace. The above-mentioned base material is often dehydrated in an atmosphere containing an inert gas and a dehydrating agent, and the refractive index distribution is controlled by volatilization of the dopant.Furthermore, the base material is made into transparent vitrification in an atmosphere containing an inert gas and a dehydrating agent in a transparent vitrification furnace. A method for producing a glass base material for optical fiber, characterized by carrying out the following steps.
炉温は１２００〜１３００℃で、ｃｔ２ガス濃度が０．
５〜５容量チである不活性ガス（Ｈｅ等）雰囲気であシ
、透明ガラス化炉の炉温は１５００〜１７００℃ で、
ｃｔ２ガス濃度がＱ、 ｆ〜０．２容量チであるＨｅガ
ス雰囲気である、特許請求の範囲第（１）項記載の光フ
アイバ母材の製造方法。(2) Ct2 gas is used as a dehydrating agent, the furnace temperature of the preheating furnace is 1200 to 1300°C, and the ct2 gas concentration is 0.
An inert gas (He, etc.) atmosphere with a volume of 5 to 5 is used, and the temperature of the transparent vitrification furnace is 1500 to 1700°C.
The method for manufacturing an optical fiber preform according to claim 1, wherein the helium gas atmosphere has a ct2 gas concentration of Q, f~0.2 capacitance.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18124282A JPS5973443A (en) | 1982-10-18 | 1982-10-18 | Manufacture of glass proform for optical fiber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18124282A JPS5973443A (en) | 1982-10-18 | 1982-10-18 | Manufacture of glass proform for optical fiber |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5973443A true JPS5973443A (en) | 1984-04-25 |
| JPS6219367B2 JPS6219367B2 (en) | 1987-04-28 |
Family
ID=16097274
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP18124282A Granted JPS5973443A (en) | 1982-10-18 | 1982-10-18 | Manufacture of glass proform for optical fiber |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5973443A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6230636A (en) * | 1985-07-30 | 1987-02-09 | Furukawa Electric Co Ltd:The | Vitrification of optical fiber preform |
| EP0561371A2 (en) * | 1992-03-17 | 1993-09-22 | Sumitomo Electric Industries, Limited | Method and apparatus for producing glass thin film |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54134128A (en) * | 1978-04-04 | 1979-10-18 | Nippon Telegr & Teleph Corp <Ntt> | Manufacture of basic material for light transmitting fiber |
| JPS5659635A (en) * | 1979-10-17 | 1981-05-23 | Nippon Telegr & Teleph Corp <Ntt> | Manufacturing apparatus for anhydrous quartz optical fiber base material |
-
1982
- 1982-10-18 JP JP18124282A patent/JPS5973443A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54134128A (en) * | 1978-04-04 | 1979-10-18 | Nippon Telegr & Teleph Corp <Ntt> | Manufacture of basic material for light transmitting fiber |
| JPS5659635A (en) * | 1979-10-17 | 1981-05-23 | Nippon Telegr & Teleph Corp <Ntt> | Manufacturing apparatus for anhydrous quartz optical fiber base material |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6230636A (en) * | 1985-07-30 | 1987-02-09 | Furukawa Electric Co Ltd:The | Vitrification of optical fiber preform |
| EP0561371A2 (en) * | 1992-03-17 | 1993-09-22 | Sumitomo Electric Industries, Limited | Method and apparatus for producing glass thin film |
| EP0561371A3 (en) * | 1992-03-17 | 1994-09-14 | Sumitomo Electric Industries | Method and apparatus for producing glass thin film |
| US5503650A (en) * | 1992-03-17 | 1996-04-02 | Sumitomo Electric Industries, Ltd. | Method for producing a glass thin film with controlloing an oxide vapor of an additive |
| US5660611A (en) * | 1992-03-17 | 1997-08-26 | Sumitomo Electric Industries, Ltd. | Method for producing glass thin film |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6219367B2 (en) | 1987-04-28 |
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