JP2002080238A - Base material for optical fiber and method of forming the same - Google Patents
Base material for optical fiber and method of forming the sameInfo
- Publication number
- JP2002080238A JP2002080238A JP2000269999A JP2000269999A JP2002080238A JP 2002080238 A JP2002080238 A JP 2002080238A JP 2000269999 A JP2000269999 A JP 2000269999A JP 2000269999 A JP2000269999 A JP 2000269999A JP 2002080238 A JP2002080238 A JP 2002080238A
- Authority
- JP
- Japan
- Prior art keywords
- optical fiber
- preform
- base material
- tip
- shape
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
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
- C03B37/01205—Manufacture of preforms for drawing fibres or filaments starting from tubes, rods, fibres or filaments
- C03B37/01225—Means for changing or stabilising the shape, e.g. diameter, of tubes or rods in general, e.g. collapsing
- C03B37/01251—Reshaping the ends
-
- 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
- C03B37/01205—Manufacture of preforms for drawing fibres or filaments starting from tubes, rods, fibres or filaments
- C03B37/01225—Means for changing or stabilising the shape, e.g. diameter, of tubes or rods in general, e.g. collapsing
- C03B37/0124—Means for reducing the diameter of rods or tubes by drawing, e.g. for preform draw-down
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B2205/00—Fibre drawing or extruding details
- C03B2205/47—Shaping the preform draw bulb before or during drawing
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Manufacture, Treatment Of Glass Fibers (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、線引炉にセットし
た光ファイバ用母材を紡糸して光ファイバとする際の、
光ファイバ用母材の先端形状及びその成型方法に関する
ものである。BACKGROUND OF THE INVENTION The present invention relates to a method for spinning an optical fiber preform set in a drawing furnace into an optical fiber.
The present invention relates to a tip shape of an optical fiber preform and a method of molding the same.
【０００２】[0002]
【従来の技術】従来、各種公知技術により合成したガラ
ス微粒子堆積体を加熱ガラス透明化してコア及びクラッ
ドを有するガラス母材（プリフォーム）とし、このプリ
フォームを線引炉で紡糸することにより、光ファイバを
得ている。2. Description of the Related Art Conventionally, a glass fine particle deposit synthesized by various known techniques is made transparent by heating glass to form a glass base material (preform) having a core and a clad, and this preform is spun in a drawing furnace. I have an optical fiber.
【０００３】線引炉にセットした母材をその一端から加
熱して引き出し、母材のコア／クラッド径比に対応した
コア／クラッド径比の光ファイバを得るが、大型母材の
場合はコア／クラッド径比が紡糸開始直後において所期
のものより小さい、あるいは紡糸開始から安定した紡糸
状態に至る間にかなりの不良ファイバが発生するという
問題があった。A preform set in a drawing furnace is heated and pulled out from one end to obtain an optical fiber having a core / cladding diameter ratio corresponding to the core / cladding diameter ratio of the preform. There was a problem that the / cladding diameter ratio was smaller than the expected value immediately after the start of spinning, or a considerable defective fiber was generated during the period from the start of spinning to the stable spinning state.
【０００４】これに対し、特開昭６１−２５１５３６号
公報には、線引（紡糸）後の形状に合わせて、先端形状
を先細に加熱成型した後に線引することにより、紡糸初
期からカットオフ波長（コア径に対する）の変動が少な
く安定したシングルモードファイバを得ることが提案さ
れている。また、特開平７−３３０３６２号公報には、
母材先端を平滑な円錐形状（テーパーの円錐角度が５０
〜６０°）に加工して、線引開始から線引が安定するま
でに発生する不良ファイバ長を短縮する方法が提案され
ている。さらに、特開平１１−７９７７２号公報には、
外径の異なる切削用砥石（円盤）を複数円錐状に並べ
て、母材先端に切れ目を入れ、砥石間に残る板状の部分
を折り取ることにより、母材先端をテーパー状に成型す
る方法が提案されている。On the other hand, Japanese Patent Application Laid-Open No. 61-251536 discloses a method in which the shape of a tip is tapered to form a tapered shape, and then the wire is drawn after the tip is formed. It has been proposed to obtain a stable single mode fiber with a small variation in wavelength (with respect to the core diameter). Also, JP-A-7-330362 discloses that
The tip of the base material is smooth and conical (taper cone angle is 50
(.About.60 [deg.]) To reduce the length of defective fibers that occur from the start of drawing until the drawing is stabilized. Further, JP-A-11-79772 discloses that
A method of arranging a plurality of grinding wheels (disks) with different outer diameters in a conical shape, making a cut at the tip of the base material, and cutting off the plate-shaped portion remaining between the whetstones to form the taper of the base material tip. Proposed.
【０００５】[0005]
【発明が解決しようとする課題】本願発明は、上記した
従来技術によるよりもさらに、線引作業開始から、良好
なファイバを線引きできるまでの時間を短縮する光ファ
イバ用母材及びその成型方法の提供を課題とするもので
ある。SUMMARY OF THE INVENTION The present invention provides a preform for an optical fiber and a molding method for the same, which can shorten the time from the start of the drawing operation until a good fiber can be drawn. Providing is an issue.
【０００６】[0006]
【課題を解決するための手段】本発明は下記の構成を採
用することにより、上記課題を解決できる。 (1) 半径ｒ0 の円柱状でありその先端は断面が略テー
パ状に縮径している光ファイバ用母材において、線引中
に良好な光ファイバが得られるときの光ファイバ用母材
の先端形状を母材の中心軸上の位置ｚに対する半径の関
数ｒ(z) として計測により予め求めておき、線引炉に入
る直前の光ファイバ用母材の先端形状を母材の中心軸上
の位置ｚに対する半径の関数Ｒ(z) とし、ｒ(z) におい
て０．３０ｒ0 となる位置をｚ1 ，０．９ｒ0 となる位
置をｚ2とし、またＲ(z) においてｋｒ0 （ここでｋｒ
0 は０．３０ｒ0 又はＲ(z) の先端半径のどちらか大き
い方である）となる位置をｚ1 とし、Ｒ(z) のｚ1 とｒ
(z) のｚ1 の位置を合わせたとき、ｒ(z) のｚ2 と合致
するＲ(z) 上の位置をｚ2 とするとき、Ｒ(z) が数３の
式Means for Solving the Problems The present invention can solve the above problems by adopting the following constitution. (1) A preform for an optical fiber in which a good optical fiber is obtained during drawing in a preform for an optical fiber having a cylindrical shape with a radius r 0 and a tip of which is reduced in diameter in a substantially tapered cross section. The tip shape of the optical fiber preform immediately before entering the drawing furnace is determined in advance as a function r (z) of the radius with respect to the position z on the center axis of the preform. and a function of radius R (z) with respect to the position z of the above, the position at which the 0.30R 0 in r (z) z 1, the 0.9R 0 a position and z 2, also kr 0 in R (z) (Where kr
0 is either greater than a) a position of the tip radius of 0.30R 0 or R (z) and z 1, z 1 and r of R (z)
when aligning the z 1 of (z), when the position on the R (z) consistent with z 2 of r (z) and z 2, R (z) is the number 3 of the formula
【数３】 を満足するものであることを特徴とする光ファイバ用母
材。 (2) 上記Ｒ(z) が数４の式(Equation 3) A preform for an optical fiber, characterized by satisfying the following. (2) where R (z) is the equation of Equation 4
【数４】 を満足するものであることを特徴とする上記(1) 記載の
光ファイバ用母材。(Equation 4) The preform for an optical fiber according to the above (1), which satisfies the following.
【０００７】(3) 光ファイバ用母材の端面を熱源で加
熱して引き伸ばすことにより、上記(1) 又は(2) に記載
のＲ(z) の形状を得ることを特徴とする光ファイバ用母
材の成型方法。 (4) 光ファイバ用母材の端面を研削して、上記(1) 又
は(2) に記載のＲ(z) の形状を得ることを特徴とする光
ファイバ用母材の成型方法。(3) The shape of R (z) described in (1) or (2) above is obtained by heating and stretching the end face of the optical fiber base material with a heat source. Base material molding method. (4) A method of molding a preform for an optical fiber, characterized in that the end face of the preform for an optical fiber is ground to obtain the shape of R (z) described in the above (1) or (2).
【０００８】(5) 線引炉に入る直前の光ファイバ用母
材であって、テーパ状の半径ｒ0 の円柱状であり先端部
は断面が略テーパ状に縮径しており、該母材の先端角度
が、半径０．６ｒ0 〜０．９ｒ0 の部分において３５°
以上５０°未満であることを特徴とする光ファイバ用母
材。(5) A preform for an optical fiber immediately before entering a drawing furnace, wherein the preform has a tapered cylindrical shape with a radius of r 0 , and has a tapered cross-section at the tip end. The tip angle of the material is 35 ° at a radius of 0.6 r 0 to 0.9 r 0 .
A preform for an optical fiber, which is at least 50 ° or less.
【０００９】[0009]
【発明の実施の形態】上記した従来法では線引開始時の
母材の先端形状として、設計値のコア／クラッド径比で
安定して線引できている時の母材先端形状（線引が安定
した理想の形状が最も好ましいと考えて、この安定した
線引状態にある母材形状（以下「理想形状」という）に
予め加工しておくことを目指していた。光ファイバ用母
材の長手方向の軸をｚとするとき、光ファイバ用母材の
形状は長手方向軸ｚを中心軸としてこのｚに沿って外径
（半径ｒ）が変化する回転体と考えると、関数ｒ（ｚ）
として表すことができる。上記理想形状を図１の
（Ａ），（Ｂ）において関数ｒ（ｚ）として二点破線で
示す。本発明は従来技術とは異なって、図１の（Ａ），
（Ｂ）に半径分布関数Ｒ（ｚ）として実線で示すよう
に、中心軸（ｚ）の特定範囲ｚ1 〜 ｚ2 においてはこ
の理想形状ｒ（ｚ）よりも大きな容積を有し、断面が直
線または凸状曲線のテーパを持つような形状に、母材の
線引開始端部を加工しておいて線引を開始する。これに
より不良ファイバ長の短縮、安定した線引状態にいたる
時間の短縮に非常に有効であることを見いだした。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the above-mentioned conventional method, the shape of the base material at the start of drawing is defined as the shape of the base material at the time of drawing stably at the designed core / cladding diameter ratio (drawing). Considering that a stable ideal shape is the most preferable, it was aimed to pre-process the preform in a stable drawing state (hereinafter referred to as an “ideal shape”). Assuming that the axis of the longitudinal direction is z, the shape of the optical fiber preform is a rotating body whose outer diameter (radius r) changes along the longitudinal axis z as the center axis and the function r (z )
Can be expressed as The ideal shape is indicated by a two-dot broken line as a function r (z) in FIGS. 1 (A) and 1 (B). The present invention differs from the prior art in that FIG.
As shown by the solid line as the radius distribution function R (z) in (B), the specific range z 1 to z 2 of the central axis (z) has a larger volume than the ideal shape r (z), and the cross section is The drawing start end of the base material is processed into a shape having a straight or convex curved taper, and drawing is started. It has been found that this is very effective in shortening the length of a defective fiber and shortening the time required for a stable drawing state.
【００１０】すなわち本発明は、有効定常部半径がr0の
光ファイバ用母材を線引きするにあたり、安定した線引
状態における有効定常部半径がr0の光ファイバ用母材の
線引方向中心軸z において光ファイバ用母材の半径が0.
9 r0となる位置をz2、0.3 r0となる位置をz1、z2からz1
にいたる光ファイバ用母材の体積をＶN 、半径がr0で高
さが(z2 −z1) の円柱の体積をＶ0 として予め求めてお
き、線引しようとする有効定常部r0の光ファイバ用母材
の先端形状を、先端部の半径が0.3r0 より大きい場合に
は先端から中心軸でz2長さにいたる部分の母材体積又
は、先端部半径が0.3r0 以下の場合には半径が0.3r0 に
等しくなる位置から中心軸方向に(z2 −z1) 長さに相当
する部分の母材体積をＶB とするとき、ＶB はＶ0 より
大きく且つＶB とＶ0 の差がＶN とＶ0 の差の0.8 倍以
下となるようにされたことを特徴とする光ファイバ用母
材である。[0010] The present invention, when the effective constant radii are drawn optical fiber preform of r 0, stable effective constant radii of drawing state of the optical fiber preform of r 0 drawing direction center The radius of the optical fiber preform is 0 at the axis z.
9 r 0 and a position of z 2, z 1 a position at which the 0.3 r 0 from z 1, z 2
The volume of the optical fiber preform reaching V N , the volume of a cylinder having a radius of r 0 and a height of (z 2 −z 1 ) is determined in advance as V 0 , and the effective stationary portion r to be drawn is determined. 0 of the optical fiber preform of the tip shape, preform volume radius leads to z 2 lengths in the center axis from the tip if 0.3 r 0 larger portion of the tip or the tip radius 0.3 r 0 In the following case, when the base material volume of the portion corresponding to the length (z 2 −z 1 ) in the central axis direction from the position where the radius is equal to 0.3r 0 is V B , V B is larger than V 0 and a preform for optical fibers, wherein a difference between V B and V 0 are to be more than 0.8 times the difference between V N and V 0.
【００１１】本願発明が上記の効果を奏する理由として
次のように考えられる。図２に示すように、線引を開始
するには母材先端部を線引炉に挿入し、ある程度の重量
を持った部分を「落し種」として落下させて口出しを行
っている。線引炉に挿入する母材の先端形状を理想形状
と同じにしておくと、この口出し時に形状が崩れてしま
う。そこで、理想形状を基に、それよりも落し種分に対
応させたガラス量の多い母材先端形状を形成することに
より、より短時間で落し種を作ることができて、線引開
始迄の時間が短縮できる。また、理想形状よりも特定容
積量だけガラス量を多くすることにより、落し種形成後
には直ちに理想形状に近づくので、安定した線引に至る
迄の時間を短縮できる。The following is considered as a reason why the present invention exhibits the above effects. As shown in FIG. 2, in order to start drawing, the leading end of the base material is inserted into a drawing furnace, and a portion having a certain weight is dropped as a "dropping seed" to perform tapping. If the shape of the tip of the base material to be inserted into the drawing furnace is set to be the same as the ideal shape, the shape will collapse at the time of tapping. Therefore, based on the ideal shape, by forming a base material tip shape with a large amount of glass corresponding to the dropped seed, it is possible to make the dropped seed in a shorter time, and until the drawing starts. Time can be reduced. In addition, by increasing the amount of glass by a specific volume than the ideal shape, the shape immediately approaches the ideal shape after dropping seeds are formed, so that the time required for stable drawing can be reduced.
【００１２】さらに詳細に本発明の光ファイバ用母材先
端形状について説明する。図１の（Ａ），（Ｂ）におい
て、ｒ0 は母材外径がほぼ均一な領域での半径で、いわ
ゆる良好部分（定常有効部）の母材半径である。ｒ
（ｚ）は良好部分を安定して線引しているときの母材先
端形状を中心軸ｚに対する半径分布で表した関数であ
り、線引終了時には引き残された母材先端がこのｒ
（ｚ）の形状を有している。従来法では母材先端をこの
ｒ（ｚ）に加工して線引するようにしていた。The tip shape of the optical fiber preform according to the present invention will be described in more detail. In FIGS. 1A and 1B, r 0 is a radius in a region where the outer diameter of the base material is substantially uniform, and is a base material radius of a so-called good portion (steady effective portion). r
(Z) is a function that represents the shape of the base metal tip when the good portion is stably drawn by a radius distribution with respect to the central axis z.
It has the shape of (z). In the conventional method, the base material tip is processed into this r (z) and drawn.
【００１３】本発明の母材先端形状の特徴は、理想形状
よりも落し種分を考慮してより多量のガラス分が先端に
存在するように加工しておく点にある。すなわち、本発
明では、まずｒ（ｚ）の関数を予め計測により求めてお
く。ｒ（ｚ）＝０．３ｒ0 となる位置をｚ1 、ｒ（ｚ）
＝０．９ｒ0 となる位置をｚ 2 とする。次に線引しよう
とする母材（有効定常部は半径ｒ0 の円筒）の、先端形
状を断面直線状または凸状曲線であるテーパを有する関
数Ｒ（ｚ）として、図１の（Ａ）に示すように先端にお
いてＲ（ｚ）≦０．３ｒ0 の場合には、Ｒ（ｚ）＝０．
３ｒ0 となる中心軸Ｚ上の位置をｚ1 とする また、先端においてＲ（ｚ）＞０．３ｒ0 の場合には、
図１の（Ｂ）に示すように先端位置をｚ1 とする。次
に、ｒ（ｚ）におけるｚ1 とＲ（ｚ）におけるｚ 1 をｚ
軸上で重ねたときに、ｒ（ｚ）におけるｚ2 となる位置
をＲ（ｚ）におけるｚ2 とする。以上のようにｚ1 とｚ
2 を決め、Ｒ（ｚ）が数５の式を満足する母材形状とし
て線引する。The feature of the base material tip shape of the present invention is that it is an ideal shape.
More glass at the tip to account for dropped seeds
The point is that it is processed to exist. That is,
In the following, the function of r (z) is first determined by measurement in advance.
Good. r (z) = 0.3r0Where z is1, R (z)
= 0.9r0Where z is TwoAnd Next, draw a line
Base material (effective stationary part is radius r0Cylinder), tip type
A section having a taper whose cross section is linear or convex
As a number R (z), as shown in FIG.
And R (z) ≦ 0.3r0In the case of R (z) = 0.
3r0The position on the central axis Z1Also, at the tip, R (z)> 0.3r0In Case of,
As shown in FIG. 1B, the tip position is z1And Next
Where z in r (z)1And z in R (z) 1To z
When superimposed on the axis, z in r (z)TwoPosition
With z in R (z)TwoAnd As described above, z1And z
TwoIs determined, and R (z) is a base material shape satisfying the equation (5).
Draw a line.
【数５】 (Equation 5)
【００１４】すなわち、理想形状でのｚ1 からｚ2 の母
材部分をネックダウン部とするとき、該ネックダウン部
の体積をＶN 、半径ｒ0 で高さが（ｚ2 −ｚ1 ）の仮想
円柱を考えるときこの体積をＶ0 とすると、従来法では
Ｖ0 −ＶN に相当する部分がカットされた形状に加工し
ていたわけであるが、本発明では（Ｖ0 −ＶN ）の０．
８倍までをカットする。That is, when the base material portion from z 1 to z 2 in the ideal shape is used as the neck down portion, the volume of the neck down portion is V N , the radius is r 0 , and the height is (z 2 −z 1 ). When this volume is assumed to be V 0 when considering the virtual cylinder of the above, the portion corresponding to V 0 −V N was processed into a cut shape in the conventional method, but in the present invention, (V 0 −V N ) 0.
Cut up to 8 times.
【００１５】さらに、好ましくはFurther, preferably
【数６】 であり、より更に好ましくは、(Equation 6) And even more preferably,
【数７】 であり、格別好ましくは、(Equation 7) And particularly preferably,
【数８】 とする。(Equation 8) And
【００１６】本発明は線引開始時のｚ1 からｚ2 にいた
る母材形状を上記のように限定するものであるので、図
３に示すように先端形状が断面凸状のテーパを有する
（Ａ）のようなものでもよい〔この場合にテーパ開始位
置はｚ2 より先端側（ｚ1 側）であって、後端側であっ
てもよい〕し、また断面が直線状の全体的には断面Ｖ字
状の（Ｂ）のようなものでもよい。さらに（Ａ）や
（Ｂ）の先端部分をカットした断面が（Ｃ）や（Ｄ）の
ものでもよい。Since the present invention limits the shape of the base material from z 1 to z 2 at the start of drawing as described above, the tip has a taper having a convex cross section as shown in FIG. 3 ( which may [taper start position in this case is a tip side than z 2 (z 1 side), may also be a rear end] like a a), and also the overall cross section linear May have a V-shaped cross section as shown in FIG. Further, the cross section obtained by cutting the tip portion of (A) or (B) may be (C) or (D).
【００１７】さらに具体的には、本発明の先端形状とし
て特に好ましい実施態様として、図４に示すように先端
部の半径が０．６ｒ0 〜０．９ｒ0 の部分において（先
端半径が０．６ｒ0 以上であれば先端から０．９ｒ0 に
おいて）テーパ角度をθとするとき、θが３５°以上５
０°未満のものを挙げることができる。More specifically, as a particularly preferred embodiment of the tip shape of the present invention, as shown in FIG. 4, the tip portion has a radius of 0.6 r 0 to 0.9 r 0 (the tip radius is 0. 6r 0 when the a) taper angle at 0.9R 0 from tip if more than theta, theta is 35 ° or more 5
Those having an angle of less than 0 ° can be mentioned.
【００１８】本発明の光ファイバ用母材の線引開始端の
先端形状を成形するには、光ファイバ用母材の端面を熱
源で加熱して引き延ばす、あるいは端面を研削すること
によればよい。In order to shape the leading end of the drawing start end of the optical fiber preform of the present invention, the end face of the optical fiber preform may be stretched by heating with a heat source, or the end face may be ground. .
【００１９】[0019]
【実施例】以下、実施例により本発明を具体的に説明す
るが、本発明はこれに限定されるものではない。 〔実施例１〕有効定常部が直径５０ｍｍφの円柱状光フ
ァイバ用母材を準備した。この先端部を本発明に従い前
記数１の式を満足するように切削工具で加工し、図５に
示す先端形状とした。得られた先端形状を持つ母材を線
引炉に挿入したところ、従来の予め理想形状の先端形状
にした場合（比較例１）に１時間以上要していた落し種
形成時間が、４０分に短縮された。EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. [Example 1] A preform for a columnar optical fiber having an effective stationary portion having a diameter of 50 mmφ was prepared. According to the present invention, this tip portion was machined with a cutting tool so as to satisfy the above equation (1) to obtain a tip shape shown in FIG. When the obtained base material having a tip shape was inserted into a drawing furnace, the time required for removing seeds, which was one hour or more in the case of a conventional tip shape having an ideal shape (Comparative Example 1), was 40 minutes. Was shortened to
【００２０】〔実施例２〕有効定常部が直径７０ｍｍφ
の円柱状光ファイバ用母材の先端部を酸水素火炎で熱
し、本発明の前記数１の式を満足するように加工し、図
６に示す先端形状とした。得られた先端形状を持つ母材
を線引炉に挿入したところ、従来の予め理想形状の先端
形状にした場合（比較例２）に５０分以上要していた落
し種形成時間が３０分に短縮された。[Embodiment 2] The effective stationary part has a diameter of 70 mmφ.
The tip of the preform for a cylindrical optical fiber was heated by an oxyhydrogen flame and worked so as to satisfy the above-mentioned formula (1) of the present invention to obtain a tip shape shown in FIG. When the base material having the obtained tip shape was inserted into the drawing furnace, the dropping seed formation time required for more than 50 minutes in the case where the conventional tip shape had been previously idealized (Comparative Example 2) was reduced to 30 minutes. Shortened.
【００２１】[0021]
【発明の効果】本発明は、母材先端形状を理想形状より
ガラス量が特定範囲の量で多い形状とすることにより、
落し種形成時間が短縮され、これに続く線引時間が短縮
できるという、大きな効果を奏することができる。According to the present invention, the shape of the base metal tip is set to a shape in which the amount of glass is larger than the ideal shape by a specific amount.
There is a great effect that the time for forming the seeds is shortened, and the subsequent drawing time can be shortened.
【図１】本発明の先端形状を模式的に説明する概略説明
図である。FIG. 1 is a schematic explanatory view schematically illustrating a tip shape of the present invention.
【図２】光ファイバ用母材の線引開始時を説明する概略
断面図である。FIG. 2 is a schematic cross-sectional view illustrating when starting drawing of an optical fiber preform.
【図３】本発明の先端形状を模式的に説明する概略断面
図である。FIG. 3 is a schematic sectional view schematically illustrating a tip shape of the present invention.
【図４】本発明の先端形状のテーパ角度を説明する概略
断面図である。FIG. 4 is a schematic sectional view illustrating a taper angle of a tip shape according to the present invention.
【図５】本発明の実施例１で作成した母材先端形状を説
明する概略断面図である。FIG. 5 is a schematic cross-sectional view for explaining a base material tip shape created in Example 1 of the present invention.
【図６】本発明の実施例２で作成した母材先端形状を説
明する概略断面図である。FIG. 6 is a schematic cross-sectional view for explaining a base material tip shape created in Example 2 of the present invention.
Claims (5)
面が略テーパ状に縮径している光ファイバ用母材におい
て、 線引中に良好な光ファイバが得られるときの光ファイバ
用母材の先端形状を母材の中心軸上の位置ｚに対する半
径の関数ｒ(z) として計測により予め求めておき、線引
炉に入る直前の光ファイバ用母材の先端形状を母材の中
心軸上の位置ｚに対する半径の関数Ｒ(z) とし、 ｒ(z) において０．３０ｒ0 となる位置をｚ1 ，０．９
ｒ0 となる位置をｚ2とし、 またＲ(z) においてｋｒ0 （ここでｋｒ0 は０．３０ｒ
0 又はＲ(z) の先端半径のどちらか大きい方である）と
なる位置をｚ1 とし、Ｒ(z) のｚ1 とｒ(z) のｚ1 の位
置を合わせたとき、ｒ(z) のｚ2 と合致するＲ(z) 上の
位置をｚ2 とするとき、 Ｒ(z) が数１の式 【数１】 を満足するようにしたことを特徴とする光ファイバ用母
材。1. An optical fiber preform having a cylindrical shape with a radius of r 0 and a tip portion whose diameter is reduced in a substantially tapered cross-section when a good optical fiber is obtained during drawing. The tip shape of the optical fiber preform is determined in advance as a function r (z) of the radius with respect to the position z on the center axis of the preform, and the tip shape of the optical fiber preform immediately before entering the drawing furnace is determined by the preform. of a function of radius R (z) with respect to the position z on the center axis, z 1 a 0.30R 0 a position in r (z), 0.9
The position that becomes r 0 is z 2, and kr 0 in R (z) (where kr 0 is 0.30r
0 or R a position towards the is either tip radius larger (z)) and z 1, when aligning the z 1 of R (z 1 and r of z) (z), r ( z )) Is z 2 , where R 2 is a position on R (z) that matches z 2. A preform for an optical fiber, characterized by satisfying the following.
光ファイバ用母材。2. The above R (z) is expressed by the following equation (2). 2. The preform for an optical fiber according to claim 1, wherein the following condition is satisfied.
て引き伸ばすことにより、請求項１又は請求項２記載の
Ｒ(z) の形状を得ることを特徴とする光ファイバ用母材
の成型方法。3. An optical fiber preform according to claim 1 or 2, wherein the end face of the optical fiber preform is heated and stretched by a heat source to obtain the shape of R (z) according to claim 1 or 2. Molding method.
求項１又は請求項２に記載のＲ(z) の形状を得ることを
特徴とする光ファイバ用母材の成型方法。4. A method for molding an optical fiber preform according to claim 1 or 2, wherein the end face of the optical fiber preform is ground to obtain the shape of R (z) according to claim 1 or 2.
あって、テーパ状の半径ｒ0 の円柱状であり先端部は断
面が略テーパ状に縮径しており、該母材の先端角度が、
半径０．６ｒ0 〜０．９ｒ0 の部分において３５°以上
５０°未満であることを特徴とする光ファイバ用母材。A preform for an optical fiber immediately before entering wherein line drawing furnace, cylindrical and has the tip portion of the tapered radius r 0 is reduced in diameter in cross-section in a substantially tapered shape, the base material The tip angle of
Preform for optical fibers and less than 35 ° 50 ° or more in the portion of the radius 0.6r 0 ~0.9r 0.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000269999A JP2002080238A (en) | 2000-09-06 | 2000-09-06 | Base material for optical fiber and method of forming the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000269999A JP2002080238A (en) | 2000-09-06 | 2000-09-06 | Base material for optical fiber and method of forming the same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2002080238A true JP2002080238A (en) | 2002-03-19 |
Family
ID=18756516
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2000269999A Pending JP2002080238A (en) | 2000-09-06 | 2000-09-06 | Base material for optical fiber and method of forming the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2002080238A (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1426339A1 (en) * | 2002-12-04 | 2004-06-09 | FITEL USA CORPORATION (a Delaware Corporation) | Rod-in-tube optical fibre preform and method of drawing it |
| FR2861719A1 (en) * | 2003-11-03 | 2005-05-06 | Cit Alcatel | Fabrication of a preformer with an optimized cone for entry into a fibre optic drawing installation |
| JP2006027924A (en) * | 2004-07-13 | 2006-02-02 | Furukawa Electric Co Ltd:The | Optical fiber preform, and its manufacturing method and apparatus |
| JP2010173933A (en) * | 2010-03-26 | 2010-08-12 | Furukawa Electric Co Ltd:The | Optical fiber preform and method for encapsulating gas |
| WO2016111355A1 (en) * | 2015-01-09 | 2016-07-14 | 古河電気工業株式会社 | Optical fiber parent material and method for manufacturing optical fiber |
| CN106365434A (en) * | 2016-08-26 | 2017-02-01 | 江苏亨通光导新材料有限公司 | Method for preparing optical fiber perform conical head |
| US11618708B2 (en) | 2016-05-03 | 2023-04-04 | Heraeus Quartz North America Llc | Elongation method and preform for producing an optical glass component |
| US11649185B2 (en) | 2019-01-15 | 2023-05-16 | Heraeus Quartz North America Llc | Automated large outside diameter preform tipping process and resulting glass preforms |
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2000
- 2000-09-06 JP JP2000269999A patent/JP2002080238A/en active Pending
Cited By (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1426339A1 (en) * | 2002-12-04 | 2004-06-09 | FITEL USA CORPORATION (a Delaware Corporation) | Rod-in-tube optical fibre preform and method of drawing it |
| JP2004182595A (en) * | 2002-12-04 | 2004-07-02 | Fitel Usa Corp | Rod-in tube optical fiber preform and method of drawing the same |
| CN100497224C (en) * | 2002-12-04 | 2009-06-10 | 菲特尔美国公司 | Rod-in-tube optical fiber preform and method |
| FR2861719A1 (en) * | 2003-11-03 | 2005-05-06 | Cit Alcatel | Fabrication of a preformer with an optimized cone for entry into a fibre optic drawing installation |
| JP2006027924A (en) * | 2004-07-13 | 2006-02-02 | Furukawa Electric Co Ltd:The | Optical fiber preform, and its manufacturing method and apparatus |
| JP4728605B2 (en) * | 2004-07-13 | 2011-07-20 | 古河電気工業株式会社 | Optical fiber preform and manufacturing method thereof |
| JP2010173933A (en) * | 2010-03-26 | 2010-08-12 | Furukawa Electric Co Ltd:The | Optical fiber preform and method for encapsulating gas |
| JP5989943B1 (en) * | 2015-01-09 | 2016-09-07 | 古河電気工業株式会社 | Optical fiber preform and optical fiber manufacturing method |
| WO2016111355A1 (en) * | 2015-01-09 | 2016-07-14 | 古河電気工業株式会社 | Optical fiber parent material and method for manufacturing optical fiber |
| CN107108326A (en) * | 2015-01-09 | 2017-08-29 | 古河电气工业株式会社 | The manufacture method of fibre parent material and optical fiber |
| US9856164B2 (en) | 2015-01-09 | 2018-01-02 | Furukawa Electric Co., Ltd. | Optical fiber preform and method of manufacturing optical fiber |
| CN107108326B (en) * | 2015-01-09 | 2020-04-14 | 古河电气工业株式会社 | Optical fiber preform and method for manufacturing optical fiber |
| US11618708B2 (en) | 2016-05-03 | 2023-04-04 | Heraeus Quartz North America Llc | Elongation method and preform for producing an optical glass component |
| US11840472B2 (en) | 2016-05-03 | 2023-12-12 | Heraeus Quartz North America Llc | Elongation method and preform for producing an optical glass component |
| CN106365434A (en) * | 2016-08-26 | 2017-02-01 | 江苏亨通光导新材料有限公司 | Method for preparing optical fiber perform conical head |
| US11649185B2 (en) | 2019-01-15 | 2023-05-16 | Heraeus Quartz North America Llc | Automated large outside diameter preform tipping process and resulting glass preforms |
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