JPH024540B2 - - Google Patents

Info

Publication number
JPH024540B2
JPH024540B2 JP57090997A JP9099782A JPH024540B2 JP H024540 B2 JPH024540 B2 JP H024540B2 JP 57090997 A JP57090997 A JP 57090997A JP 9099782 A JP9099782 A JP 9099782A JP H024540 B2 JPH024540 B2 JP H024540B2
Authority
JP
Japan
Prior art keywords
jacket
base material
cladding
cladding portion
glass
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.)
Expired - Lifetime
Application number
JP57090997A
Other languages
Japanese (ja)
Other versions
JPS58208148A (en
Inventor
Suehiro Myamoto
Takao Shioda
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fujikura Ltd
Original Assignee
Fujikura Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Fujikura Ltd filed Critical Fujikura Ltd
Priority to JP57090997A priority Critical patent/JPS58208148A/en
Publication of JPS58208148A publication Critical patent/JPS58208148A/en
Publication of JPH024540B2 publication Critical patent/JPH024540B2/ja
Granted legal-status Critical Current

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]
    • C03B37/01486—Means for supporting, rotating or translating the preforms being formed, e.g. lathes
    • 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]
    • C03B37/018—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] by glass deposition on a glass substrate, e.g. by inside-, modified-, plasma-, or plasma modified- chemical vapour deposition [ICVD, MCVD, PCVD, PMCVD], i.e. by thin layer coating on the inside or outside of a glass tube or on a glass rod
    • C03B37/01861—Means for changing or stabilising the diameter or form of tubes or rods
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B2203/00—Fibre product details, e.g. structure, shape
    • C03B2203/30—Polarisation maintaining [PM], i.e. birefringent products, e.g. with elliptical core, by use of stress rods, "PANDA" type fibres

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General 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)
  • Optical Fibers, Optical Fiber Cores, And Optical Fiber Bundles (AREA)
  • Manufacture, Treatment Of Glass Fibers (AREA)

Description

【発明の詳細な説明】[Detailed description of the invention]

この発明は、だ円クラツド型の、単偏波シング
ルモード光フアイバの製造方法に関するものであ
る。 発明の背景 「第１図」は従来のだ円クラツド型の単偏波光
フアイバの母材の断面図で、50はコア部分、５２
はクラツド部分である。５４はジヤケツト（第２
クラツド）で、クラツド部分５２とは熱膨張係数
が非常に異なつたガラスからなり、外形はだ円で
ある。５６は通常のガラスで、外形は円形であ
る。 この母材を線引きするとき、熱膨張係数の違い
に基づいて応力が発生して残留し、それによつて
コア部分５０に複屈折率効果が生じ、単偏波光フ
アイバになる。 このだ円クラツド型単偏波光フアイバは、だ円
コア型に比べて十分な定偏波特性が得られる。し
かし、次の点に問題があつた。 すなわち、従来のだ円クラツド型単偏波光フア
イバは、MCVD法によつて、次のように作つて
いた。はじめ内付け管内を陰圧にして、管の断面
をだ円形にする。その内面にガラス５６、ジヤケ
ツト５４、クラツド部分５２、コア部分５０の各
層のガラスを付け、中実化する。その中実化のと
きに、表面張力によつて、管の断面はだ円から円
形になり、第１図のような母材になる。 しかし、この方法では、圧力差によつて管を変
形させるという方法でだ円形のジヤケツト５４を
作つているため、だ円率を設定どおりに実現する
ことが難しい。 この発明の目的は、だ円率を精密にコントロー
ルすることができ、したがつて定偏波の設計が容
易にできる、だ円クラツド型単偏波光フアイバの
製造方法を提供することである。 発明の構成（第２〜４図） (1) コア部分２０とクラツド部分３０とからな
り、かつ全体が透明ガラス化しているととも
に、「第３図」のように、コア部分２０は断面
が円形で、クラツド部分３０は断面の外形がだ
円であるような、いわば母材の中心部分１１と
もいうべきものを作る工程と、 (2) 前記クラツド部分３０とは熱膨張係数が異な
り、かつ前記クラツド部分３０より軟化温度が
低いジヤケツト４０を、多孔質ガラスの状態
で、前記母材の中心部分１１の周りに、ほぼ同
じ厚さに付ける工程（第４図）と、 (3) 前記多孔質ガラスからなるジヤケツト４０を
加熱して、断面の形状が円形の、透明ガラスか
らなるジヤケツト４０を形成する工程 とを有することを特徴とする。 そのより詳しい説明 (1) 上記の母材の中心部分１１（第３図）は、次
のようにして作る。すなわち、VAD法または
CVD法によつて、「第２図」のように、コア部
分２０、クラツド部分３０とも円形の透明ガラ
スからなる、シングルモードフアイバの母材の
中心部分を作る。 それからクラツド部分３０の相対する両側面
を、軸に沿つて研摩し、断面をだ円にする（第
３図）。 なお、この明細書における「だ円」という用
語は、直交する直径の長さが異なる、細長い円
の全てを含む意味（幾何学的なだ円だけでな
い）で使用している。 なお、断面が両方とも円形のコア部分２０と
クラツド部分３０とからなる多孔質ガラスの母
材ができた段階で、クラツド部分３０の両側面
を切削し、その後透明ガラス化して「第３図」
のようにしてもよい。 (2) ジヤケツト４０の形成は、外付け法による。
はじめジヤケツト４０を多孔質ガラスの状態
で、中心部分１１の回りに、ほぼ同じ厚さに付
ける（第４図）。したがつてその断面はだ円形
である。その後加熱して透明ガラス化すると
き、表面張力によつてジヤケツト４０は円形に
なる（第５図）。 ジヤケツト４０のガラスにはクラツド部分３
０よりも軟化温度の低いものを使用する。そう
すると、加熱した際、クラツド部分３０は正し
いだ円の形を保つたまま、ジヤケツト４０だけ
が円形になる。 またジヤケツト４０には、上記のようにクラ
ツド部分３０と熱膨張係数の違うものを使用す
る。この熱膨張係数の違いによつて、線引する
とき、フアイバ内部に応力が発生する。したが
つて必要な応力が得られる程度の熱膨張係数の
違いを持たせるようにする。 また、ジヤケツト４０はクラツドの一部にな
る。したがつてその屈折率はクラツド部分３０
と等しいか、またほぼ等しくなるようにする。 (3) ジヤケツト４０の上に通常の石英管を、ロツ
ドインチユーブ法で被覆し、最終的な母材にす
る。 その母材を線引すると、クラツド部分３０と
ジヤケツト４０との間の熱膨張係数の違い、お
よびクラツド部分３０がだ円形であることによ
つて、コアの直交する２直径の方向（クラツド
部分３０の短軸と長軸の方向）に異なつた大き
さの応力が作用し、単偏波光フアイバになる。 実施例 はじめ、VAD法によつて、第２図のような、
シングルモードフアイバの、透明ガラスからなる
母材の中心部分１０を作つた。直径は、コア部分
２０（SiO2＋GeO2）が３mm、クラツド部分３０
（SiO2）は18mmで、径比は６。 クラツド部分３０の両側面を研摩して、短軸を
10mmとした（短軸方向のコアクラツドの径比は
３）。 その表面を火炎で清浄にした後、次の流量で、
通常の外付け法によつて多孔質ガラスのジヤケツ
ト４０を付着させた。 SiCl4 600c.c.／min GeCl4 40c.c.／min BF3 300c.c.／min H2 ４／min O2 ８／min なおこのガラスの屈折率はクラツド部分３０の
屈折率、すなわち石英に等しい。また熱膨張係数
はクラツド部分３０に比べて非常に高い。 これを透明ガラス化して、長径25mm、短径18mm
の母材を得、さらに酸水素炎で加熱軟化させて、
外径が22mmの円形母材を得た。 それにさらに内外径24／26mmの石英管を、通常
のロツドインチユーブ法によつて被覆し、目的の
単偏波光フアイバの母材を得た。 それを紡糸して得たフアイバの寸法、特性を次
の「第１表」に示す。 The present invention relates to a method for manufacturing an elliptical cladding type single-polarization single-mode optical fiber. Background of the Invention "Figure 1" is a cross-sectional view of the base material of a conventional elliptical clad single-polarized optical fiber, where 50 is the core part, 52
is the clad part. 54 is the jacket (second
The cladding portion 52 is made of glass having a very different thermal expansion coefficient from that of the cladding portion 52, and has an oval outer shape. 56 is ordinary glass and has a circular outer shape. When this base material is drawn, stress is generated and remains due to the difference in thermal expansion coefficients, thereby creating a birefringence effect in the core portion 50, resulting in a single polarization optical fiber. This elliptical clad single-polarized optical fiber can provide sufficient constant polarization characteristics compared to the elliptical core type. However, the following problems arose. That is, the conventional elliptic clad single-polarized optical fiber was manufactured using the MCVD method as follows. First, create a negative pressure inside the internal tube and make the cross section of the tube oval. Each layer of glass, ie, glass 56, jacket 54, cladding portion 52, and core portion 50, is attached to the inner surface and solidified. At the time of solidification, the cross section of the tube changes from an oval to a circle due to surface tension, resulting in a base material as shown in Figure 1. However, in this method, since the elliptical jacket 54 is made by deforming the tube due to a pressure difference, it is difficult to achieve the ellipticity as set. An object of the present invention is to provide a method for manufacturing an elliptical clad single-polarization optical fiber, which allows precise control of ellipticity and therefore facilitates the design of constant polarization. Structure of the invention (Figs. 2 to 4) (1) It consists of a core part 20 and a clad part 30, and the whole is made of transparent glass, and as shown in "Fig. 3", the core part 20 has a circular cross section. (2) The cladding part 30 has an oval cross-sectional outline, which can be called the center part 11 of the base material. (2) The cladding part 30 has a different thermal expansion coefficient from the cladding part 30 and (3) attaching a jacket 40 having a softening temperature lower than that of the cladding portion 30 around the central portion 11 of the base material in a state of porous glass to approximately the same thickness (FIG. 4); The present invention is characterized by the step of heating the jacket 40 made of glass to form the jacket 40 made of transparent glass and having a circular cross-sectional shape. More detailed explanation (1) The center portion 11 (FIG. 3) of the above base material is made as follows. i.e. VAD method or
By the CVD method, as shown in FIG. 2, the central part of the base material of a single-mode fiber is made, with both the core part 20 and the cladding part 30 made of circular transparent glass. The opposing sides of the cladding portion 30 are then ground along the axis to create an oval cross-section (FIG. 3). Note that the term "ellipse" in this specification is used to include all elongated circles (not just geometrical ellipses) whose orthogonal diameters have different lengths. When the porous glass base material consisting of the core portion 20 and the cladding portion 30, both of which have circular cross-sections, is prepared, both sides of the cladding portion 30 are cut, and then transparent glass is formed, as shown in Fig. 3.
You can do it like this. (2) The jacket 40 is formed by an external attachment method.
Initially, the jacket 40 is placed in porous glass around the central portion 11 to approximately the same thickness (FIG. 4). Therefore, its cross section is oval. When the jacket 40 is then heated to become transparent vitrified, the jacket 40 becomes circular due to surface tension (FIG. 5). The jacket 40 has a cladding part 3 on the glass.
Use a material with a softening temperature lower than 0. Then, when heated, only the jacket 40 becomes circular while the cladding portion 30 maintains its correct oval shape. Further, the jacket 40 is made of a material having a different coefficient of thermal expansion from that of the clad portion 30, as described above. This difference in coefficient of thermal expansion creates stress within the fiber when it is drawn. Therefore, the thermal expansion coefficients should be different enough to obtain the necessary stress. Also, the jacket 40 becomes part of the cladding. Therefore, its refractive index is 30
be equal to or approximately equal to . (3) A regular quartz tube is coated on top of the jacket 40 using the rod incubation method to form the final base material. When the base material is drawn, due to the difference in thermal expansion coefficient between the cladding portion 30 and the jacket 40 and the oval shape of the cladding portion 30, it is possible to Stresses of different magnitudes act on the short and long axes of the fiber, resulting in a single polarized optical fiber. Example First, by using the VAD method, as shown in Figure 2,
A central portion 10 of a single mode fiber matrix made of transparent glass was made. The diameter of the core part 20 (SiO 2 + GeO 2 ) is 3 mm, and the clad part 30 mm.
(SiO 2 ) is 18 mm and the diameter ratio is 6. Polish both sides of the cladding part 30 and
It was set to 10 mm (the diameter ratio of the core clad in the short axis direction is 3). After cleaning the surface with flame, at the following flow rate:
A porous glass jacket 40 was applied using conventional external methods. SiCl 4 600c.c./min GeCl 4 40c.c./min BF 3 300c.c./min H 2 4/min O 2 8/min The refractive index of this glass is the refractive index of the cladding portion 30, that is, quartz. be equivalent to. Also, the coefficient of thermal expansion is much higher than that of the cladding portion 30. This is made into transparent glass with a major axis of 25 mm and a minor axis of 18 mm.
The base material was obtained and further heated and softened with an oxyhydrogen flame,
A circular base material with an outer diameter of 22 mm was obtained. Furthermore, a quartz tube with an inner and outer diameter of 24/26 mm was coated by the usual rod incubation method to obtain the desired base material of a single-polarized optical fiber. The dimensions and properties of the fiber obtained by spinning it are shown in Table 1 below.

【表】 得られた単偏波光フアイバは、低損失で、十分
短いビート長を持つている。また諸特性は長さ方
向に安定であり、精度の良さを確認した。 発明の効果 コア部分２０とクラツド部分３０とからなり、
かつ全体が透明ガラス化しているとともに、前記
コア部分２０は断面が円形で、前記クラツド部分
３０は断面の外形がだ円形である母材の中心部分
１１を作り、その前記母材の中心部分１１の周り
に、前記クラツド部分３０とは熱膨張係数が異な
り、かつ前記クラツド部分３０より軟化温度が低
いジヤケツト４０を、多孔質ガラスの状態で、ほ
ぼ同じ厚さに付け、その後、前記多孔質ガラスか
らなるジヤケツト４０を加熱して、断面の形状が
円形の、透明ガラスからなるジヤケツト４０を形
成するので、 多孔質ガラスからなるジヤケツト４０を加熱し
たとき、ジヤケツト４０だけが透明ガラス化し、
かつ表面張力により円形になり、しかもクラツド
部分３０は軟化変形することなく最初に決められ
た正しいだ円の形状を保持することができる。 したがつて、設計どおりの定偏波特性を容易に
得ることができる。[Table] The obtained single-polarized optical fiber has low loss and a sufficiently short beat length. In addition, the various properties were stable in the length direction, confirming good accuracy. Effects of the invention Consisting of a core part 20 and a clad part 30,
The core portion 20 has a circular cross-section, and the clad portion 30 has an oval cross-sectional outer shape, forming a central portion 11 of the base material. A jacket 40 having a thermal expansion coefficient different from that of the cladding portion 30 and having a softening temperature lower than that of the cladding portion 30 is attached around the cladding portion 30 to approximately the same thickness in the state of porous glass. The jacket 40 made of transparent glass is heated to form the jacket 40 made of transparent glass and has a circular cross-sectional shape. When the jacket 40 made of porous glass is heated, only the jacket 40 becomes transparent glass.
Moreover, the cladding portion 30 becomes circular due to surface tension, and the cladding portion 30 can maintain the initially determined correct elliptical shape without being softened and deformed. Therefore, constant polarization characteristics as designed can be easily obtained.

【図面の簡単な説明】[Brief explanation of drawings]

第１図は従来技術の説明図、第２図、第３図、
第４図、第５図は、この発明の製造方法を工程順
に示した説明図。 ２０：コア部分、３０：クラツド部分、４０：
ジヤケツト。 Fig. 1 is an explanatory diagram of the prior art, Fig. 2, Fig. 3,
FIG. 4 and FIG. 5 are explanatory diagrams showing the manufacturing method of the present invention in order of steps. 20: Core part, 30: Clad part, 40:
Jacket.

Claims (1)

【特許請求の範囲】 １ コア部分とクラツド部分とからなり、かつ全
体が透明ガラス化しているとともに、前記コア部
分は断面が円形で、前記クラツド部分は断面の外
形がだ円である、母材の中心部分を作る工程と、 前記クラツド部分とは熱膨張係数が異なり、か
つ前記クラツド部分より軟化温度が低いジヤケツ
トを、多孔質ガラスの状態で、前記母材の中心部
分の周りに、ほぼ同じ厚さに付ける工程と、 多孔質ガラスからなる前記ジヤケツトを加熱し
て、断面の形状が円形の、透明ガラスからなるジ
ヤケツトを形成する工程、 とを有することを特徴とする、単偏波光フアイバ
の製造方法。[Scope of Claims] 1. A base material consisting of a core portion and a cladding portion, the entire body being made of transparent glass, the core portion having a circular cross section, and the cladding portion having an oval outer shape in cross section. a step of forming a central portion of the base material, and a step of forming a jacket having a thermal expansion coefficient different from that of the cladding portion and having a softening temperature lower than that of the cladding portion, in a state of porous glass, around the central portion of the base material in approximately the same size. and heating the jacket made of porous glass to form a jacket made of transparent glass having a circular cross-sectional shape. Production method.
JP57090997A 1982-05-28 1982-05-28 Manufacture of optical fiber causing single polarization Granted JPS58208148A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP57090997A JPS58208148A (en) 1982-05-28 1982-05-28 Manufacture of optical fiber causing single polarization

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP57090997A JPS58208148A (en) 1982-05-28 1982-05-28 Manufacture of optical fiber causing single polarization

Publications (2)

Publication Number Publication Date
JPS58208148A JPS58208148A (en) 1983-12-03
JPH024540B2 true JPH024540B2 (en) 1990-01-29

Family

ID=14014134

Family Applications (1)

Application Number Title Priority Date Filing Date
JP57090997A Granted JPS58208148A (en) 1982-05-28 1982-05-28 Manufacture of optical fiber causing single polarization

Country Status (1)

Country Link
JP (1) JPS58208148A (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0662310B2 (en) * 1987-12-07 1994-08-17 日立電線株式会社 Method of manufacturing elliptical core type polarization-maintaining optical fiber
JPH02135304A (en) * 1988-11-16 1990-05-24 Sumitomo Electric Ind Ltd Manufacturing method of polarization maintaining optical fiber

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5949438B2 (en) * 1977-06-29 1984-12-03 川崎重工業株式会社 Impeller of linear radial type mixed flow blower
US4274854A (en) * 1978-01-13 1981-06-23 Bell Telephone Laboratories, Incorporated Polarization-preserving optical fiber
JPS5727209A (en) * 1980-07-28 1982-02-13 Nippon Telegr & Teleph Corp <Ntt> Manufacture of base material for optical fiber of single polarization and single mode

Also Published As

Publication number Publication date
JPS58208148A (en) 1983-12-03

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