JPH0651139A - Production of optical fiber preform - Google Patents
Production of optical fiber preformInfo
- Publication number
- JPH0651139A JPH0651139A JP20565492A JP20565492A JPH0651139A JP H0651139 A JPH0651139 A JP H0651139A JP 20565492 A JP20565492 A JP 20565492A JP 20565492 A JP20565492 A JP 20565492A JP H0651139 A JPH0651139 A JP H0651139A
- Authority
- JP
- Japan
- Prior art keywords
- rod
- shaped body
- optical fiber
- molding
- powder
- 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
Landscapes
- Glass Melting And Manufacturing (AREA)
- Manufacture, Treatment Of Glass Fibers (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は光ファイバプリフォーム
の製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an optical fiber preform.
【０００２】[0002]
【従来の技術】従来、光ファイバコア用ロッドの製造方
法としては、光学物質の粉末をプラスチック製容器内に
充填かつ密閉し、これを液圧により加圧成形して成形体
を作製した後、プラス容器より取り出された成型体を透
明ガラス化することにより、光ファイバコア用ロッドを
製造する方法が知られている（特開昭５９−１９８９１
号）。2. Description of the Related Art Conventionally, as a method of manufacturing a rod for an optical fiber core, a powder of an optical substance is filled and sealed in a plastic container, and this is pressure-molded by liquid pressure to prepare a molded body, A method for producing a rod for an optical fiber core by making a molded body taken out from a plus container into transparent glass is known (Japanese Patent Laid-Open No. 59-19891).
issue).
【０００３】また、光ファイバプリフォームの製造方法
としては、伸縮性のあるプラスチック型内に所定の屈折
率を有する石英ガラス棒を配置し、この石英ガラス棒の
周囲にシリカ微粒子を充填し、これを液圧により加圧成
形して成形体を作製した後、この成形体から光ファイバ
プリフォームを製造する方法が知られている（特開昭６
１−２５６９３７号）。As a method of manufacturing an optical fiber preform, a quartz glass rod having a predetermined refractive index is placed in a stretchable plastic mold, and silica particles are filled around the quartz glass rod. There is known a method in which an optical fiber preform is produced from this molded body after pressure molding is performed by hydraulic pressure to produce a molded body.
1-256937).
【０００４】[0004]
【発明が解決しようとする課題】ところで、静水圧加圧
装置の内部に設置される成形型内の中心に光ファイバの
コア用ガラス棒を設置し、この成形型内のガラス棒の周
囲に石英系ガラス粉末又はその造粒粉末を充填した後、
この粉末に液圧を加えて加圧成形し、更に得られた成形
体を焼結して光ファイバプリフォームを製造する方法で
は、加圧成形の際、コア用ガラス棒が位置ずれ（偏心）
したり、或いはコア用ガラス棒が粉末充填部の内部や境
界面（表面）に位置する部分で破断することが多い。こ
のようなことが光ファイバプリフォーム製造の歩留りを
低下させる原因となっている。By the way, a glass rod for a core of an optical fiber is installed at the center of a molding die installed inside a hydrostatic pressure device, and quartz is surrounded by the glass rod in this molding die. After filling the system glass powder or its granulated powder,
In the method for producing an optical fiber preform by applying a hydraulic pressure to this powder and press-molding it, and then sintering the obtained molded body, the glass rod for core is displaced (eccentric) during the press-molding.
Or, the glass rod for core often breaks inside the powder filling portion or at a portion located at the boundary surface (surface). This is a cause of lowering the production yield of optical fiber preforms.
【０００５】本発明は、かかる事情に鑑みてなされたも
ので、光ファイバプリフォームを高い歩留りで製造し得
る方法を提供することを目的とする。The present invention has been made in view of such circumstances, and an object of the present invention is to provide a method capable of manufacturing an optical fiber preform with a high yield.
【０００６】[0006]
【課題を解決するための手段】本発明は、静水圧加圧装
置の内部に設置される成形型内の中心に、少なくともそ
の中央部が光ファイバのコア用ガラスとなる棒状体を設
置する工程と、前記成形型内の前記棒状体の周囲に石英
系ガラス粉末又はその造粒粉末を充填する工程と、静水
圧加圧装置の内部において前記成形型内の前記粉末に液
圧を加えて成形体とする成形工程と、前記成形体を焼結
する工程とを具備する光ファイバプリフォームの製造方
法であって、前記棒状体はその両端が前記成形型内の粉
末充填部から突出するように前記成形型内に設置され、
かつ前記成形工程はその棒状体突出部の端面及び側面に
液圧が加わるように行なわれることを特徴とする光ファ
イバプリフォームの製造方法である。According to the present invention, a step of disposing a rod-shaped body having at least a central portion thereof as a glass for a core of an optical fiber is provided at the center of a molding die installed inside a hydrostatic pressure device. And a step of filling a silica-based glass powder or a granulated powder thereof around the rod-shaped body in the molding die, and molding by applying hydraulic pressure to the powder in the molding die inside a hydrostatic pressure device. A method of manufacturing an optical fiber preform, comprising a forming step of forming a body and a step of sintering the forming body, wherein both ends of the rod-shaped body protrude from a powder filling portion in the forming die. Installed in the mold,
Further, the molding step is a method for manufacturing an optical fiber preform, characterized in that a liquid pressure is applied to the end surface and the side surface of the rod-shaped protruding portion.
【０００７】前記成形型としては、冷間静水圧加圧装置
（ＣＩＰ装置）に設置する成形型を好適に用いることが
でき、具体的には、弾性体からなる上下蓋（棒状体の支
持部材を含む）と外側に金属製支持管が配置された円筒
状の成形ゴム型との組み合わせからなる湿式タイプのＣ
ＩＰ成形型、或いは弾性体からなる上下蓋（棒状体の支
持部材を含む）と円筒状の成形ゴム型との組み合わせか
らなる湿式タイプの成形型を挙げることができる。As the molding die, a molding die installed in a cold isostatic press (CIP device) can be preferably used. Specifically, the upper and lower lids (bar-shaped support members) made of an elastic body can be used. Type) and a cylindrical molded rubber die having a metal support tube arranged on the outside thereof, a wet type C
An IP molding die or a wet type molding die formed by combining an upper and lower lids (including a rod-shaped support member) made of an elastic body and a cylindrical molding rubber die can be mentioned.
【０００８】前記成形型の上下蓋及び円筒状成形ゴム型
を形成する材料としては、高い弾性率を有するプラスチ
ックスやゴムが望ましい。As a material for forming the upper and lower lids of the molding die and the cylindrical molding rubber die, plastics or rubber having a high elastic modulus is desirable.
【０００９】前記石英系ガラス粉末又はその造粒粉末と
しては、四塩化珪素等の火炎加水分解法や金属珪素の直
接酸化法によって得られる粉末、又はこの粉末を造粒し
た粒子を用いることが望ましく、また、アルコキシ珪素
化合物の加水分解法や水ガラス法によって得られる粉末
を用いることもできる。As the quartz glass powder or the granulated powder thereof, it is desirable to use a powder obtained by a flame hydrolysis method of silicon tetrachloride or the like or a direct oxidation method of metallic silicon, or a particle obtained by granulating this powder. Alternatively, powder obtained by a hydrolysis method of an alkoxy silicon compound or a water glass method can be used.
【００１０】前記石英系ガラス粉末又はその造粒粉末と
しては、純石英ガラスを用いてもよいし、光ファイバ用
のドープ剤が配合された石英系ガラスを用いてもよい。As the silica glass powder or the granulated powder thereof, pure silica glass may be used, or silica glass containing a doping agent for optical fibers may be used.
【００１１】[0011]
【作用】本発明の製造方法によれば、棒状体をその両端
が成形型内の粉末充填部から突出するように成形型内に
設置し、かつ成形型内の粉末に液圧を加えて成形体とす
る成形工程をその棒状体突出部の端面及び側面にも液圧
が加わるように行なう。これにより、成形工程中、予め
位置決めされている棒状体には等方向の均一な圧力が加
わるため、該棒状体と粉末充填部との同心軸上のズレ
（棒状体の偏心）が抑えられると共に該棒状体への不均
一な応力も抑えられる。その結果、棒状体が偏心（位置
ずれ）したり、破断するのを防止でき、更に棒状体の位
置ずれ，破断等に伴って成形体の粉末部分に破損が生じ
るのも防止できる。従って、光ファイバプリフォームを
高い歩留りで製造することができる。According to the manufacturing method of the present invention, the rod-shaped body is placed in the molding die so that both ends thereof protrude from the powder filling portion in the molding die, and the powder in the molding die is hydraulically molded. The forming process for forming the body is performed so that the liquid pressure is also applied to the end surface and the side surface of the rod-shaped protruding portion. As a result, during the molding process, uniform pressure is applied to the pre-positioned rod-shaped body in the same direction, so that a deviation (eccentricity of the rod-shaped body) on the concentric axis between the rod-shaped body and the powder filling portion is suppressed. Non-uniform stress on the rod is also suppressed. As a result, it is possible to prevent the rod-shaped body from being eccentric (displaced) or broken, and also to prevent the powder portion of the molded body from being damaged due to the positional displacement or breakage of the rod-shaped body. Therefore, the optical fiber preform can be manufactured with a high yield.
【００１２】[0012]
【実施例】以下、本発明の実施例を図面を参照して詳細
に説明する。Embodiments of the present invention will now be described in detail with reference to the drawings.
【００１３】実施例１ まず、図１（ａ）に示すように直径１４ｍｍ、長さ５０
０ｍｍの光ファイバのコア用ガラス棒１の両端に該ガラ
ス棒１よりも太径の支持用ガラス棒２を取り付けた棒状
体３を作製した。コア用ガラス棒１は、気相法の一つで
あるＶＡＤ法により作製されたものであり、断面積比が
コア：クラッド＝１：３で、かつ屈折率差（（コア−ク
ラッド）／コア）が０．３５％である。Example 1 First, as shown in FIG. 1A, a diameter of 14 mm and a length of 50
A rod-shaped body 3 in which a supporting glass rod 2 having a diameter larger than that of the glass rod 1 was attached to both ends of a glass rod 1 for core of 0 mm optical fiber was produced. The glass rod for core 1 is manufactured by a VAD method which is one of vapor phase methods, and has a cross-sectional area ratio of core: clad = 1: 3 and a refractive index difference ((core-clad) / core. ) Is 0.35%.
【００１４】次いで、図１（ｂ）に示すように内径１１
０ｍｍの円筒状の成形ゴム型４の下方開口端に中心部に
穴を有する下ゴム蓋５ａを嵌合し、この下ゴム蓋５ａの
穴に中心部に穴を有する防水用の下ゴム蓋５ｂを嵌合
し、更にこの下ゴム蓋５ｂの穴に棒状体３の一端部であ
る支持用ガラス棒２を挿入した。これにより、成形ゴム
型４内の中心軸上に棒状体３を設置した。Then, as shown in FIG. 1 (b), the inner diameter 11
A lower rubber lid 5a having a hole in the center is fitted to the lower opening end of a 0 mm cylindrical molded rubber mold 4, and a lower rubber lid 5b for waterproof having a hole in the center of the hole of the lower rubber lid 5a. Then, the supporting glass rod 2 which is one end of the rod-shaped body 3 was inserted into the hole of the lower rubber lid 5b. As a result, the rod-shaped body 3 was installed on the central axis of the molded rubber die 4.
【００１５】次いで、図１（ｃ）に示すように成形ゴム
型４内に平均粒径約８０μｍのシリカ造粒粉末６を投入
し、振動を加えながら充填した後、成形ゴム型４の上方
開口端に中心部に穴を有する上ゴム蓋７ａを嵌合し、こ
の上ゴム蓋７ａの穴に中心部に穴を有する防水用の上ゴ
ム蓋７ｂを嵌合し、更にこの上ゴム蓋７ｂの穴に棒状体
３の他端部である支持用ガラス棒２を挿入した。これに
より、棒状体３を、その両端が成形ゴム型４、下ゴム蓋
５ａ，５ｂ及び上ゴム蓋７ａ，７ｂからなる成形型内に
充填されたシリカ造粒粉末６から突出するように設置し
た。この場合、棒状体３の両端面を、それぞれ下ゴム蓋
５ａ，５ｂの下面及び上ゴム蓋７ａ，７ｂの上面と一致
させた。Next, as shown in FIG. 1 (c), a silica granulated powder 6 having an average particle size of about 80 μm is charged into the molding rubber mold 4 and filled while vibrating, and then the upper opening of the molding rubber mold 4 is opened. An upper rubber lid 7a having a hole at the center is fitted to the end, a waterproof upper rubber lid 7b having a hole at the center is fitted to the hole of the upper rubber lid 7a, and further the upper rubber lid 7b The supporting glass rod 2, which is the other end of the rod-shaped body 3, was inserted into the hole. Thereby, the rod-shaped body 3 was installed so that both ends thereof protruded from the silica granulated powder 6 filled in the molding die including the molding rubber die 4, the lower rubber lids 5a and 5b and the upper rubber lids 7a and 7b. . In this case, both end surfaces of the rod-shaped body 3 were made to coincide with the lower surfaces of the lower rubber lids 5a and 5b and the upper surfaces of the upper rubber lids 7a and 7b, respectively.
【００１６】次いで、図１（ｄ）に示すように成形型
４，５ａ，５ｂ，７ａ，７ｂ、棒状体３及びシリカ造粒
粉末６を、ＣＩＰ装置の圧力容器８内の圧力媒体９中に
入れた。圧力媒体９としては水を用いた。なお、圧力媒
体９としては、水以外の液体，例えば潤滑油などの油を
用いてもよい。つづいて、圧力容器８内の圧力を上昇さ
せて成形圧力１０００ｋｇ／ｃｍ2 で約１分間保持した
後、減圧を約３分間費やして除々に行なった。このよう
に減圧した理由は、２００ｋｇ／ｃｍ2 以下の低圧領域
では成形型４，５ａ，５ｂ，７ａ，７ｂとシリカ造粒粉
末６との離脱により該シリカ造粒粉末６部分に亀裂が生
じることがあるので、これを防止するためである。これ
により、棒状体３のコア用ガラス棒１の周囲に加圧成形
されたシリカ造粒粉末６が配置された直径約９０ｍｍの
成形体を形成した。Then, as shown in FIG. 1 (d), the molds 4, 5a, 5b, 7a, 7b, the rod-shaped body 3 and the silica granulated powder 6 are placed in the pressure medium 9 in the pressure vessel 8 of the CIP apparatus. I put it in. Water was used as the pressure medium 9. As the pressure medium 9, a liquid other than water, for example, oil such as lubricating oil may be used. Subsequently, the pressure in the pressure vessel 8 was increased and the molding pressure was maintained at 1000 kg / cm 2 for about 1 minute, and then the pressure was gradually reduced by spending about 3 minutes. The reason for reducing the pressure in this way is that in the low pressure region of 200 kg / cm 2 or less, the silica granulation powder 6 is cracked due to the separation of the molding dies 4,5a, 5b, 7a, 7b and the silica granulation powder 6. This is to prevent this. As a result, a compact having a diameter of about 90 mm in which the pressure-formed silica granulated powder 6 was arranged around the core glass rod 1 of the rod-shaped body 3 was formed.
【００１７】こうして得られた成形体は、棒状体３のコ
ア用ガラス棒１の折れやシリカ造粒粉末６部分の破損，
クラック等が皆無であり、また、棒状体３のコア用ガラ
ス棒１の偏心率が０．５％以内であった。これは、成形
体を形成する際、棒状体３には等方向の均一な圧力が加
わるため、該棒状体１と粉末６充填部との同心軸上のズ
レが抑えられていると共に該棒状体１への不均一な応力
も抑えられていることによるものである。The molded body obtained in this manner was broken in the core glass rod 1 of the rod-shaped body 3 or the silica granulated powder 6 portion was damaged,
There were no cracks, and the eccentricity of the core glass rod 1 of the rod-shaped body 3 was within 0.5%. This is because a uniform pressure in the same direction is applied to the rod-shaped body 3 when forming the molded body, so that the concentric axis deviation between the rod-shaped body 1 and the powder 6 filling portion is suppressed and the rod-shaped body is also suppressed. This is because the non-uniform stress on 1 is also suppressed.
【００１８】得られた成形体を大気中の温度６００℃下
で脱脂した後、ヘリウムに対して塩素が約１０体積％含
まれる雰囲気中の温度１２５０℃下で精製，脱水し、更
にヘリウム雰囲気中の温度１６００℃下で焼結してシリ
カ造粒粉末６部分を透明ガラス化することにより、光フ
ァイバプリフォームを製造した。この光ファイバプリフ
ォームのコア用ガラス棒１部分の界面付近には気泡等の
欠陥が皆無であった。その後、この光ファイバプリフォ
ームを通常の方法により線引きして光ファイバを製造し
たところ、得られた光ファイバは気相法により製造した
シングルモードの光ファイバと同等の特性を有してい
た。The obtained molded body is degreased at a temperature of 600 ° C. in the atmosphere, then purified and dehydrated at a temperature of 1250 ° C. in an atmosphere containing about 10% by volume of chlorine with respect to helium, and further in a helium atmosphere. An optical fiber preform was manufactured by sintering at a temperature of 1600 ° C. to make 6 parts of the silica granulated powder into transparent glass. There were no defects such as bubbles in the vicinity of the interface of the glass rod for core 1 portion of this optical fiber preform. Then, when this optical fiber preform was drawn by a usual method to manufacture an optical fiber, the obtained optical fiber had the same characteristics as a single mode optical fiber manufactured by a vapor phase method.
【００１９】実施例２ 図２（ａ）に示すように円筒状の成形ゴム型４と、成形
ゴム型４の下方開口端に嵌合され、かつ棒状体３の一端
部である支持用ガラス棒２を挿入する穴を中心部に有す
る下ゴム蓋１１と、成形ゴム型４の上方開口端に嵌合さ
れ、かつ棒状体３の他端部である支持用ガラス棒２を挿
入する穴を中心部に有する上ゴム蓋１２とからなる成形
型を用いた。この場合、棒状体３の両端面をそれぞれ下
ゴム蓋１１及び上ゴム蓋１２の穴の途中に位置させ、こ
の下ゴム蓋１１及び上ゴム蓋１２の穴をそれぞれ埋める
ためのゴム栓１３を用いた。これ以外は、実施例１と同
様に行なったところ、この場合もゴム栓１３、下ゴム蓋
１１、上ゴム蓋１２等を介して棒状体３の端面及び側面
に等方向の均一な圧力が加わり、実施例１と同様な結果
が得られた。Embodiment 2 As shown in FIG. 2A, a cylindrical molding rubber die 4 and a supporting glass rod which is fitted to the lower open end of the molding rubber die 4 and which is one end of the rod-shaped body 3. A lower rubber lid 11 having a hole for inserting 2 in the center, and a hole for inserting the supporting glass rod 2 which is the other end of the rod-shaped body 3 and is fitted into the upper open end of the molding rubber mold 4 A molding die including the upper rubber lid 12 provided in the part was used. In this case, both end surfaces of the rod-shaped body 3 are located in the middle of the holes of the lower rubber lid 11 and the upper rubber lid 12, respectively, and the rubber plugs 13 for filling the holes of the lower rubber lid 11 and the upper rubber lid 12 are used. I was there. Except for this, the same procedure as in Example 1 was performed, and in this case as well, uniform pressure in the same direction was applied to the end surface and the side surface of the rod-shaped body 3 via the rubber plug 13, the lower rubber lid 11, the upper rubber lid 12, and the like. The same results as in Example 1 were obtained.
【００２０】実施例３ 図２（ｂ）に示すように円筒状の成形ゴム型４と、成形
ゴム型４の下方開口端に嵌合され、かつ棒状体３の一端
部である支持用ガラス棒２を挿入する穴を中心部に有す
る下ゴム蓋１４と、成形ゴム型４の上方開口端に嵌合さ
れ、かつ棒状体３の他端部である支持用ガラス棒２を挿
入する穴を中心部に有する上ゴム蓋１５とからなる成形
型を用いた。この場合、棒状体３の両端面をそれぞれ下
ゴム蓋１４の下面及び上ゴム蓋１５の上面より突出さ
せ、この棒状体３の両突出部をそれぞれ覆うように防水
用のゴムシート１６を用いた。これ以外は、実施例１と
同様に行なったところ、やはり棒状体３の端面及び側面
に等方向の均一な圧力が加わり、実施例１と同様な結果
が得られた。Example 3 As shown in FIG. 2B, a cylindrical molding rubber die 4 and a supporting glass rod which is fitted to the lower open end of the molding rubber die 4 and which is one end of the rod-shaped body 3. A lower rubber lid 14 having a hole for inserting 2 in the center and a hole for inserting the supporting glass rod 2 which is the other end of the rod-shaped body 3 and which is fitted to the upper open end of the molding rubber mold 4 A molding die including the upper rubber lid 15 provided in the part was used. In this case, both end surfaces of the rod-shaped body 3 are projected from the lower surface of the lower rubber lid 14 and the upper surface of the upper rubber lid 15, respectively, and a waterproof rubber sheet 16 is used to cover both protruding portions of the rod-shaped body 3. . Except for this, the same procedure as in Example 1 was carried out. As a result, uniform pressure was applied to the end faces and side faces of the rod-shaped body 3 in the same direction, and the same results as in Example 1 were obtained.
【００２１】実施例４ 図２（ｃ）に示すように実施例１と同様なコア用ガラス
棒１の両端に該ガラス棒１と同径の支持用ガラス棒１７
を溶接により取り付けた棒状体１８を用いた。Example 4 As shown in FIG. 2 (c), a glass rod for core 1 similar to that of Example 1 is provided on both ends with a supporting glass rod 17 having the same diameter as the glass rod 1.
The rod-shaped body 18 attached by welding was used.
【００２２】また、同図２（ｃ）に示すように円筒状の
成形ゴム型４と、成形ゴム型４の下方開口端に嵌合さ
れ、かつ棒状体１８の一端部である支持用ガラス棒１７
を挿入する穴を中心部に有する下ゴム蓋１９と、成形ゴ
ム型４の上方開口端に嵌合され、かつ棒状体１８の他端
部である支持用ガラス棒１７を挿入する穴を中心部に有
する上ゴム蓋２０とからなる成形型を用いた。この場
合、棒状体１８の両端面を、それぞれ下ゴム蓋１９の下
面及び上ゴム蓋２０の上面と一致させた。Further, as shown in FIG. 2C, a cylindrical molding rubber die 4 and a supporting glass rod which is fitted to the lower open end of the molding rubber die 4 and which is one end of the rod-shaped body 18. 17
And a lower rubber lid 19 having a hole for inserting the center portion, and a hole for inserting the supporting glass rod 17 which is the other end portion of the rod-shaped body 18 and which is fitted into the upper opening end of the molding rubber mold 4. A molding die including the upper rubber lid 20 included in 1. In this case, both end surfaces of the rod-shaped body 18 were made to coincide with the lower surface of the lower rubber lid 19 and the upper surface of the upper rubber lid 20, respectively.
【００２３】これ以外は、実施例１と同様に行なったと
ころ、実施例１と同様な結果が得られた。Except for this, the same procedure as in Example 1 was carried out, and the same results as in Example 1 were obtained.
【００２４】比較例１ 図３に示すように実施例１と同様なコア用ガラス棒１の
両端に該ガラス棒１と同径の支持用ガラス棒１７を溶接
により取り付けた棒状体１８を用いた。Comparative Example 1 As shown in FIG. 3, a rod-shaped body 18 was used, in which a glass rod for core 1 similar to that of Example 1 was attached to both ends of a glass rod for support 17 having the same diameter as the glass rod 1 by welding. .
【００２５】また、同図３に示すように円筒状の成形ゴ
ム型４と、成形ゴム型４の外側に配置され、かつ圧力媒
体を通す穴を有する補助用の円筒状の金属製管２１と、
成形ゴム型４及び金属製管２１の下方開口端に嵌合さ
れ、かつ棒状体１８の一端部である支持用ガラス棒１７
を挿入する窪みを中心部に有する金属製の下蓋２２と、
成形ゴム型４及び金属製管２１の上方開口端に嵌合さ
れ、かつ棒状体１８の他端部である支持用ガラス棒１７
を挿入する窪みを中心部に有する金属製の上蓋２３とか
らなる成形型を用いた。Further, as shown in FIG. 3, a cylindrical molding rubber mold 4 and an auxiliary cylindrical metal pipe 21 arranged outside the molding rubber mold 4 and having a hole through which a pressure medium passes. ,
The supporting glass rod 17 that is fitted to the lower open ends of the molded rubber mold 4 and the metal pipe 21 and is one end of the rod-shaped body 18.
A metal lower lid 22 having a recess at the center for inserting
The supporting glass rod 17 that is fitted to the upper open ends of the molding rubber mold 4 and the metal tube 21 and is the other end of the rod-shaped body 18.
A mold made of a metal upper lid 23 having a recess at the center thereof was used.
【００２６】これ以外は、実施例１と同様にして成型体
の形成を試みたところ、棒状体３のコア用ガラス棒１の
折れ、及びそれに伴うシリカ造粒粉末６部分の破損を生
じた成形体の割合は７０％以上と高かった。その理由
は、下蓋２２と上蓋２３とが金属製のため棒状体１８の
両端面及び両端面近傍の側面に等方向の均一な圧力が加
わらなかったためと推定される。この内の得られた成形
体を用いて実施例１と同様に光ファイバプリフォームを
製造したところ、コア用ガラス棒１部分の界面には気泡
が多数発生していた。更に、この光ファイバプリフォー
ムを通常の方法により線引きして光ファイバを製造した
ところ、得られた光ファイバは気相法により製造したシ
ングルモードの光ファイバよりも特性が劣っていた。Except for this, when a molded body was tried to be formed in the same manner as in Example 1, the molding resulted in breakage of the glass rod 1 for core of the rod-shaped body 3 and accompanying breakage of the silica granulated powder 6 portion. The body proportion was as high as 70% or more. It is presumed that the reason is that since the lower lid 22 and the upper lid 23 are made of metal, uniform pressure in the same direction was not applied to both end faces of the rod-shaped body 18 and side faces near both end faces. When an optical fiber preform was manufactured in the same manner as in Example 1 using the obtained molded body, a large number of bubbles were generated at the interface of the glass rod for core 1 portion. Furthermore, when an optical fiber was manufactured by drawing this optical fiber preform by a usual method, the obtained optical fiber was inferior in characteristics to the single mode optical fiber manufactured by the vapor phase method.
【００２７】[0027]
【発明の効果】以上詳述した如く、本発明によれば光フ
ァイバプリフォームを高い歩留りで製造し得る方法が提
供される。かかる方法は、高品質で大型の光ファイバプ
リフォームを製造する場合に特に有効である。As described in detail above, according to the present invention, there is provided a method capable of manufacturing an optical fiber preform with a high yield. Such a method is particularly effective for manufacturing a high quality and large-sized optical fiber preform.
【図１】実施例１の光ファイバプリフォームの製造工程
を示す説明図。FIG. 1 is an explanatory view showing a manufacturing process of an optical fiber preform of Example 1.
【図２】実施例２〜４で用いた成形型及び棒状体の状態
を示す説明図。FIG. 2 is an explanatory view showing a state of a molding die and a rod-shaped body used in Examples 2 to 4.
【図３】比較例１で用いた成形型及び棒状体の状態を示
す説明図。FIG. 3 is an explanatory view showing a state of a molding die and a rod-shaped body used in Comparative Example 1.
１…光ファイバのコア用ガラス棒、２，１７…支持用ガ
ラス棒、３，１８…棒状体、４…成形型（円筒状の成形
ゴム型）、５ａ，５ｂ，１１，１４，１９…成形型（下
ゴム蓋）、６…石英系ガラス粉末の造粒粉末（シリカ造
粒粉末）、７ａ，７ｂ，１２，１５，２０…成形型（上
ゴム蓋）、８…圧力容器、９…圧力媒体、１３…ゴム
栓、１６…ゴムシート。1 ... Optical fiber core glass rod, 2, 17 ... Supporting glass rod, 3, 18 ... Rod-shaped body, 4 ... Mold (cylindrical molded rubber mold), 5a, 5b, 11, 14, 19 ... Molded Mold (lower rubber lid), 6 ... Granulated powder of silica glass powder (silica granulated powder), 7a, 7b, 12, 15, 20 ... Mold (upper rubber lid), 8 ... Pressure vessel, 9 ... Pressure Medium, 13 ... Rubber stopper, 16 ... Rubber sheet.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 佐藤 継男 東京都千代田区丸の内２丁目６番１号 古 河電気工業株式会社内 (72)発明者 吉田 和昭 東京都千代田区丸の内２丁目６番１号 古 河電気工業株式会社内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tsuneo Sato 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. (72) Inventor Kazuaki Yoshida 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd.
Claims (1)
型内の中心に、少なくともその中央部が光ファイバのコ
ア用ガラスとなる棒状体を設置する工程と、前記成形型
内の前記棒状体の周囲に石英系ガラス粉末又はその造粒
粉末を充填する工程と、静水圧加圧装置の内部において
前記成形型内の前記粉末に液圧を加えて成形体とする成
形工程と、前記成形体を焼結する工程とを具備する光フ
ァイバプリフォームの製造方法であって、 前記棒状体はその両端が前記成形型内の粉末充填部から
突出するように前記成形型内に設置され、かつ前記成形
工程はその棒状体突出部の端面及び側面に液圧が加わる
ように行なわれることを特徴とする光ファイバプリフォ
ームの製造方法。1. A step of installing a rod-shaped body, at least a central portion of which is a glass for a core of an optical fiber, at the center of a molding die installed inside a hydrostatic pressure device, and in the molding die. A step of filling a quartz glass powder or a granulated powder thereof around the rod-shaped body, a molding step of applying a hydraulic pressure to the powder in the molding die inside the hydrostatic pressure device to form a molded body, A method of manufacturing an optical fiber preform comprising a step of sintering a molded body, wherein the rod-shaped body is installed in the molding die so that both ends thereof protrude from a powder filling portion in the molding die, The method of manufacturing an optical fiber preform is characterized in that the molding step is performed so that liquid pressure is applied to the end surface and the side surface of the rod-shaped protruding portion.
Priority Applications (8)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20565492A JP3177308B2 (en) | 1992-07-31 | 1992-07-31 | Manufacturing method of optical fiber preform |
| CA002088238A CA2088238C (en) | 1992-01-30 | 1993-01-27 | Method of manufacturing optical fiber preform |
| MYPI93000123A MY107768A (en) | 1992-01-30 | 1993-01-28 | Method of manufacturing optical fiber preform |
| US08/010,670 US5352259A (en) | 1992-01-30 | 1993-01-28 | Method of manufacturing optical fiber preform |
| DE69312104T DE69312104T2 (en) | 1992-01-30 | 1993-01-29 | Process for making an optical fiber preform |
| BR9300385A BR9300385A (en) | 1992-01-30 | 1993-01-29 | METHOD OF MANUFACTURING A PRE-FORM OF FIBER OPTICS |
| EP93101433A EP0553868B1 (en) | 1992-01-30 | 1993-01-29 | Method of manufacturing optical fiber preform |
| CN93102370A CN1078309A (en) | 1992-01-30 | 1993-01-29 | The manufacture method of fibre-optical preform |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20565492A JP3177308B2 (en) | 1992-07-31 | 1992-07-31 | Manufacturing method of optical fiber preform |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0651139A true JPH0651139A (en) | 1994-02-25 |
| JP3177308B2 JP3177308B2 (en) | 2001-06-18 |
Family
ID=16510476
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP20565492A Expired - Fee Related JP3177308B2 (en) | 1992-01-30 | 1992-07-31 | Manufacturing method of optical fiber preform |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3177308B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100378595B1 (en) * | 2000-08-22 | 2003-03-31 | 한국전자통신연구원 | Fabrication Method Of Fiber Preform via Melting Process |
| KR100390329B1 (en) * | 2001-08-06 | 2003-07-04 | 한국전자통신연구원 | Method of manufacturing an optical fiber |
| JP2019172492A (en) * | 2018-03-28 | 2019-10-10 | 住友電気工業株式会社 | Production method of optical fiber |
| US11292649B2 (en) | 2015-12-11 | 2022-04-05 | Toppan Printing Co., Ltd. | Packaging bag |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP7448737B1 (en) | 2022-08-30 | 2024-03-12 | 株式会社トクヤマ | Aluminum nitride powder and resin composition |
-
1992
- 1992-07-31 JP JP20565492A patent/JP3177308B2/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100378595B1 (en) * | 2000-08-22 | 2003-03-31 | 한국전자통신연구원 | Fabrication Method Of Fiber Preform via Melting Process |
| KR100390329B1 (en) * | 2001-08-06 | 2003-07-04 | 한국전자통신연구원 | Method of manufacturing an optical fiber |
| US11292649B2 (en) | 2015-12-11 | 2022-04-05 | Toppan Printing Co., Ltd. | Packaging bag |
| JP2019172492A (en) * | 2018-03-28 | 2019-10-10 | 住友電気工業株式会社 | Production method of optical fiber |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3177308B2 (en) | 2001-06-18 |
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