JPH0781964A - Production of core preform of dispersion shift optical fiber - Google Patents
Production of core preform of dispersion shift optical fiberInfo
- Publication number
- JPH0781964A JPH0781964A JP5230178A JP23017893A JPH0781964A JP H0781964 A JPH0781964 A JP H0781964A JP 5230178 A JP5230178 A JP 5230178A JP 23017893 A JP23017893 A JP 23017893A JP H0781964 A JPH0781964 A JP H0781964A
- Authority
- JP
- Japan
- Prior art keywords
- core
- burner
- refractive index
- soot
- 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
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/02—Optical fibres with cladding with or without a coating
- G02B6/036—Optical fibres with cladding with or without a coating core or cladding comprising multiple layers
- G02B6/03616—Optical fibres characterised both by the number of different refractive index layers around the central core segment, i.e. around the innermost high index core layer, and their relative refractive index difference
- G02B6/03622—Optical fibres characterised both by the number of different refractive index layers around the central core segment, i.e. around the innermost high index core layer, and their relative refractive index difference having 2 layers only
- G02B6/03633—Optical fibres characterised both by the number of different refractive index layers around the central core segment, i.e. around the innermost high index core layer, and their relative refractive index difference having 2 layers only arranged - -
-
- 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]
- C03B37/01413—Reactant delivery systems
- C03B37/0142—Reactant deposition burners
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/02—Optical fibres with cladding with or without a coating
- G02B6/036—Optical fibres with cladding with or without a coating core or cladding comprising multiple layers
- G02B6/03616—Optical fibres characterised both by the number of different refractive index layers around the central core segment, i.e. around the innermost high index core layer, and their relative refractive index difference
- G02B6/03638—Optical fibres characterised both by the number of different refractive index layers around the central core segment, i.e. around the innermost high index core layer, and their relative refractive index difference having 3 layers only
- G02B6/03644—Optical fibres characterised both by the number of different refractive index layers around the central core segment, i.e. around the innermost high index core layer, and their relative refractive index difference having 3 layers only arranged - + -
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B2203/00—Fibre product details, e.g. structure, shape
- C03B2203/10—Internal structure or shape details
- C03B2203/22—Radial profile of refractive index, composition or softening point
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B2207/00—Glass deposition burners
- C03B2207/50—Multiple burner arrangements
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/02—Optical fibres with cladding with or without a coating
- G02B6/02214—Optical fibres with cladding with or without a coating tailored to obtain the desired dispersion, e.g. dispersion shifted, dispersion flattened
- G02B6/02219—Characterised by the wavelength dispersion properties in the silica low loss window around 1550 nm, i.e. S, C, L and U bands from 1460-1675 nm
- G02B6/02276—Dispersion shifted fibres, i.e. zero dispersion at 1550 nm
Landscapes
- Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (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)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、センタコアの外側に、
これよりも屈折率の低いサイドコアが階段状に形成され
てなる分散シフト光ファイバのコア母材を製造するため
の方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a method for manufacturing a core base material of a dispersion-shifted optical fiber in which side cores having a lower refractive index than this are formed in a step shape.
【０００２】[0002]
【従来の技術】一般に、１.３μm用の単一モードの石英
系光ファイバにおいては、伝送損失が小さい波長域は
１.５５μm帯にあるのに対して、零分散波長は１.３μm
帯にある。したがって、デジタル化された信号光を確実
に長距離伝送するためには、光ファイバの構造と特性を
改善し、１.５５μm帯の信号光を用いつつ、波長分散が
１.５５μm帯で小さくなるような構成にすることが必要
となる。2. Description of the Related Art Generally, in a single-mode silica optical fiber for 1.3 μm, the wavelength band in which the transmission loss is small is in the 1.55 μm band, while the zero-dispersion wavelength is 1.3 μm.
It is in the obi. Therefore, in order to reliably transmit the digitized signal light over a long distance, the structure and characteristics of the optical fiber are improved, and while the signal light in the 1.55 μm band is used, the chromatic dispersion is reduced in the 1.55 μm band. It is necessary to have such a configuration.
【０００３】このため、光ファイバのコアの屈折率分布
を調整することにより、波長分散特性を１.５５μm帯に
シフトさせた分散シフト光ファイバが提案されている。Therefore, there has been proposed a dispersion-shifted optical fiber in which the wavelength dispersion characteristic is shifted to the 1.55 μm band by adjusting the refractive index distribution of the core of the optical fiber.
【０００４】このような分散シフト光ファイバのコアの
屈折率分布としては、図４に示すように、単峰形(同図
(a))、マルチコア形(同図(b))、階段形(同図(c))の３種
のものが考えられている。The refractive index distribution of the core of such a dispersion-shifted optical fiber is, as shown in FIG.
(a)), multi-core type (Fig. (b)), and staircase type (Fig. (c)) are considered.
【０００５】しかしながら、単峰形のものは、モードフ
ィールド径が小さいために接続損失が大きく、しかも、
コア径の変化に対して分散特性が変動し易い。また、マ
ルチコア形のものは、屈折率分布が複雑な形状をしてい
るために、ＶＡＤ法を適用する上で、屈折率分布の制御
が困難で量産性に欠けるという問題がある。However, the unimodal type has a large connection loss due to a small mode field diameter, and
Dispersion characteristics easily fluctuate with changes in core diameter. Further, since the multi-core type has a complicated refractive index distribution, when the VAD method is applied, it is difficult to control the refractive index distribution, and there is a problem that mass productivity is poor.
【０００６】これに対して、階段形の屈折率分布をもつ
ものは、モードフィールド径も比較的大きくとれて接続
損失を小さくでき、また、曲げ特性もよく、さらに、Ｖ
ＡＤ法での屈折率分布の制御も容易であるために量産性
に優れている。On the other hand, the one having a stepwise refractive index distribution has a relatively large mode field diameter, which can reduce the connection loss, and has a good bending characteristic.
Since it is easy to control the refractive index distribution by the AD method, mass productivity is excellent.
【０００７】そのため、近年は、分散シフト光ファイバ
として、階段形のコア屈折率分布をもつものが主流とな
りつつある。Therefore, in recent years, as a dispersion-shifted optical fiber, a fiber having a stepwise core refractive index distribution is becoming mainstream.
【０００８】ところで、従来、このような階段形の屈折
率分布を有する分散シフト光ファイバは、次のようにし
て製造されている。By the way, conventionally, a dispersion shifted optical fiber having such a stepwise refractive index distribution is manufactured as follows.
【０００９】まず、図５に示すように、単一のセンタコ
ア用バーナＢcと、複数(この例では２本)のサイドコア
用バーナＢs1，Ｂs2とを用いる。サイドコア用バーナＢ
s1，Ｂs2を複数設けているのは、単一のバーナではサイ
ドコアを十分な厚さに堆積できないからである。First, as shown in FIG. 5, a single center core burner Bc and a plurality (two in this example) of side core burners Bs 1 and Bs 2 are used. Burner B for side core
The plurality of s 1 and Bs 2 are provided because the side core cannot be deposited to a sufficient thickness with a single burner.
【００１０】そして、従来技術では、センタコア用バー
ナＢc、およびサイドコア用バーナＢs1，Ｂs2のいずれ
にも、ＳiＣl4，ＧeＣl4，Ｈ2，Ａr，Ｏ2の各成分を含
む原料ガスを導入してコアスートＸ'を堆積する。その
際、屈折率分布が所期の階段形になるように、サイドコ
ア用バーナＢs1，Ｂs2に導入される原料ガスに含まれる
ＧeＣl4の成分比率を、各センタコア用バーナＢcに導入
する原料ガスに含まれるＧeＣl4の成分比率よりも小さ
く設定する。In the prior art, the raw material gas containing the components of SiCl 4 , GeCl 4 , H 2 , Ar and O 2 is introduced into both the center core burner Bc and the side core burners Bs 1 and Bs 2. Then, the core soot X'is deposited. At that time, in order to make the refractive index distribution have a desired step shape, the ratio of GeCl 4 contained in the raw material gas introduced into the side core burners Bs 1 and Bs 2 is changed to the raw material introduced into each center core burner Bc. It is set smaller than the ratio of GeCl 4 contained in the gas.
【００１１】こうして、コアスートＸ'が得られたなら
ば、このコアスートＸ'をＣl等のハロゲンガスを含む雰
囲気中で焼結することにより、透明ガラス化されたコア
母材が作製される。After the core soot X'is obtained in this way, the core soot X'is sintered in an atmosphere containing a halogen gas such as Cl to prepare a transparent vitrified core base material.
【００１２】なお、このコア母材は、次に延伸して所定
の外径とした後、外付け法等によってコア母材の上にク
ラッドスートを堆積し、さらに、これを焼結して分散シ
フト光ファイバ母材とする。The core base material is then stretched to have a predetermined outer diameter, and then clad soot is deposited on the core base material by an external attachment method or the like, and is further sintered and dispersed. Use as shift optical fiber base material.
【００１３】[0013]
【発明が解決しようとする課題】ところで、各バーナＢ
c，Ｂs1，Ｂs2に導入される原料ガスに含まれるＧeＣl4
は、火炎加水分解反応によりＧeＯ2に変化してスートと
して堆積するが、この堆積の際のＧeＯ2は温度依存性が
あり、温度が高いほどＧeＯ2濃度が高くなる。図５のよ
うにしてバーナＢc，Ｂs1，Ｂs2で火炎加水分解反応を
起こす場合、生成されるコアスートＸ'の温度分布は、
コア中心が高く径方向外方に向かうほど低くなる。ま
た、コアスートＸ'は透明ガラス化するために、後工程
で焼結されるが、その際、ドープされているＧeの拡散
が起こる。By the way, each burner B
GeCl 4 contained in the raw material gas introduced into c, Bs 1 and Bs 2
Is by a flame hydrolysis reaction changed to GeO 2 deposited as soot, GeO 2 during the deposition has temperature dependence, GeO 2 concentration increases as the temperature is high. When the flame hydrolysis reaction is caused by the burners Bc, Bs 1 and Bs 2 as shown in FIG. 5, the temperature distribution of the generated core soot X ′ is
The center of the core is high and becomes lower toward the outside in the radial direction. Further, the core soot X'is sintered in a later step in order to become transparent glass, but at that time, diffusion of the doped Ge occurs.
【００１４】その結果、コア母材として、図６(a)に示
すような階段形をした所期の屈折率分布をもつように、
原料ガス成分を調整したつもりでも、上述したように、
コアスートＸ'の堆積時の温度分布、およびコアスート
Ｘ'の焼結時のＧeの拡散等に起因して、透明ガラス化さ
れた後のコア母材の屈折率分布は、図６(b)に示すよう
に、いわゆる“撫で肩”の形状になってしまい、センタ
コアccの外側にあるサイドコアscの部分の屈折率が平坦
でなくなる。As a result, the core base material has a desired stepwise refractive index distribution as shown in FIG.
Even if the raw material gas components are adjusted, as described above,
The refractive index distribution of the core preform after being vitrified due to the temperature distribution during the deposition of the core soot X'and the diffusion of Ge during the sintering of the core soot X'is shown in FIG. 6 (b). As shown, the so-called "stroked shoulder" shape is formed, and the refractive index of the portion of the side core sc outside the center core cc is not flat.
【００１５】そして、図６(b)のように、サイドコアsc
の屈折率分布が平坦でないと、最終的に得られる分散シ
フト光ファイバは、分散不良が生じて所期の波長分散特
性が得られないばかりか、モードフィールド径が小さく
なるなどして接続損失の増大を招く等の不都合が起こ
る。Then, as shown in FIG. 6B, the side core sc
If the refractive index distribution of is not flat, the dispersion-shifted optical fiber that is finally obtained will not have the desired chromatic dispersion characteristics due to poor dispersion, and the mode field diameter will become smaller, resulting in splice loss. Inconvenience such as an increase occurs.
【００１６】本発明は、上記の問題点を解決するために
なされたもので、サイドコアの屈折率分布が平坦な形状
となっているコア母材が安定して得られるようにして、
所期の理想的な階段形の屈折率分布を有する分散シフト
光ファイバの製造を可能とすることを課題とする。The present invention has been made to solve the above-mentioned problems, and it is possible to stably obtain a core base material in which the side core has a flat refractive index distribution.
An object of the present invention is to make it possible to manufacture a dispersion-shifted optical fiber having a desired ideal stepwise refractive index distribution.
【００１７】[0017]
【課題を解決するための手段】本発明は、上記の課題を
解決するため、次の方法を採る。The present invention adopts the following method in order to solve the above problems.
【００１８】すなわち、本発明に係る分散シフト光ファ
イバのコア母材の製造方法では、単一のセンタコア用バ
ーナと、複数のサイドコア用バーナとを用い、センタコ
ア用バーナにはＳiＣl4とＧeＣl4とを共に含む原料ガス
を、このセンタコア用バーナに隣接するサイドコア用バ
ーナにはＳiＣl4は含むがＧeＣl4は含まない原料ガス
を、残りのサイドコア用バーナの内の少なくとも一つは
ＳiＣl4とＧeＣl4とを共に含む原料ガスを、それぞれ導
入してコアスートを堆積した後、このコアスートをＣl
等のハロゲンガスを含む雰囲気中で焼結することによ
り、透明ガラス化されたコア母材を得るようにしてい
る。That is, in the method for manufacturing the core preform of the dispersion-shifted optical fiber according to the present invention, a single center core burner and a plurality of side core burners are used, and the center core burners include SiCl 4 and GeCl 4 . Of the source gas containing SiCl 4 but not GeCl 4 in the side core burner adjacent to the center core burner, and at least one of the remaining side core burners is SiCl 4 and GeCl 4 Introducing a source gas containing both of and, to deposit core soot,
A transparent vitrified core base material is obtained by sintering in an atmosphere containing a halogen gas such as.
【００１９】[0019]
【作用】上記方法において、複数のサイドコア用バーナ
の内、センタコア用バーナに隣接するサイドコア用バー
ナには、ＳiＣl4は含むがＧeＣl4は含まない原料ガスを
導入してコアスートを作製するから、サイドコアスート
の内のセンタコアスートに隣接する箇所には、Ｇeがド
ープされていない領域が形成される。そして、このコア
スートを焼結する際に、Ｇeがドープされているセンタ
コアスートおよびサイドコアスートの部分から、両者に
挟まれたＧeがドープされていない部分にＧeが拡散する
ため、結果的にサイドコアの部分のＧe濃度が全体的に
平均化されて、サイドコア部分が平坦な屈折率分布をも
つようになる。In the above method, the raw material gas containing SiCl 4 but not GeCl 4 is introduced into the side core burner adjacent to the center core burner among the plurality of side core burners to produce the core soot. A region that is not doped with Ge is formed in a portion of the core soot adjacent to the center core soot. When this core soot is sintered, Ge diffuses from the Ge-doped center core soot and side core soot to the non-Ge-doped portions sandwiched between the two, resulting in The Ge concentration in the side core portion is averaged as a whole, so that the side core portion has a flat refractive index distribution.
【００２０】[0020]
【実施例】本発明に係る分散シフト光ファイバのコア母
材の製造方法について、以下に説明する。EXAMPLES A method of manufacturing a core preform of a dispersion shifted optical fiber according to the present invention will be described below.
【００２１】ＶＡＤ法を適用してコアスートを作製する
ために、図１に示すように、単一のセンタコア用バーナ
Ｂcと、複数(この例では２本)のサイドコア用バーナＢs
1，Ｂs2とを用いる。In order to manufacture the core soot by applying the VAD method, as shown in FIG. 1, a single center core burner Bc and a plurality of (two in this example) side core burners Bs are used.
1 and Bs 2 are used.
【００２２】そして、本例では、堆積して得られるコア
スートが、図２(a)に示すような所期の屈折率分布をも
つように、予め、原料ガス成分を調整する。In this example, the raw material gas components are adjusted in advance so that the core soot obtained by the deposition has the desired refractive index distribution as shown in FIG. 2 (a).
【００２３】すなわち、センタコア用バーナＢcと、２
つのサイドコア用バーナＢs1，Ｂs2の内の外側のバーナ
Ｂs2には、ＳiＣl4，ＧeＣl4，Ｈ2，Ａr，Ｏ2の各成分
を含む原料ガスを導入する。ただし、サイドコア用バー
ナＢs2に導入される原料ガスに含まれるＧeＣl4の成分
比率は、各センタコア用バーナＢcに導入する原料ガス
に含まれるＧeＣl4の成分比率よりも小さくする。ま
た、両バーナＢc，Ｂs2の間にあるサイドコア用バーナ
Ｂs1には、ＳiＣl4，Ｈ2，Ａr，Ｏ2の各成分を含むが、
ＧeＣl4は含まない原料ガスを導入する。That is, the center core burners Bc and 2
A raw material gas containing components of SiCl 4 , GeCl 4 , H 2 , Ar and O 2 is introduced into the outer burner Bs 2 of the two side core burners Bs 1 and Bs 2 . However, the component ratio of GeCl 4 contained in the source gas introduced into the side core burner Bs 2 is made smaller than the component ratio of GeCl 4 contained in the source gas introduced into each center core burner Bc. The side core burner Bs 1 between the burners Bc and Bs 2 contains components of SiCl 4 , H 2 , Ar and O 2 , respectively.
A source gas containing no GeCl 4 is introduced.
【００２４】そして、各バーナＢc，Ｂs1，Ｂs2に導入
される原料ガスの火炎加水分解反応によってコアスート
Ｘが堆積される。Then, the core soot X is deposited by the flame hydrolysis reaction of the raw material gas introduced into each of the burners Bc, Bs 1 and Bs 2 .
【００２５】これにより、サイドコアスートの内のセン
タコアスートに隣接する箇所には、Ｇeがドープされて
いない領域が形成されることになる。As a result, a region which is not doped with Ge is formed in a portion of the side core soot adjacent to the center core soot.
【００２６】こうして、コアスートＸが得られたなら
ば、このコアスートＸをＣl等のハロゲンガスを含む雰
囲気中で焼結して透明ガラス化し、コア母材とする。When the core soot X is obtained in this manner, the core soot X is sintered in an atmosphere containing a halogen gas such as Cl to be transparent vitrified and used as a core base material.
【００２７】この焼結の際に、Ｇeがドープされている
センタコアおよび同じくＧeがドープされているサイド
コアの部分から、両者に挟まれたＧeがドープされてい
ないサイドコアの部分にＧeが拡散するために、サイド
コアの部分のＧe濃度が全体的に平均化される。その結
果、図２(b)に示すように、センタコアccの周りにある
サイドコアscの部分が平坦な屈折率分布をもつようにな
る。During this sintering, Ge diffuses from the Ge-doped center core and the Ge-doped side core portion to the Ge-undoped side core portion sandwiched therebetween. In addition, the Ge concentration in the side core portion is averaged as a whole. As a result, as shown in FIG. 2B, the side core sc around the center core cc has a flat refractive index distribution.
【００２８】なお、このコア母材は、次に延伸して所定
の外径とした後、外付け法等によってコア母材の上にク
ラッドスートを堆積し、さらに、これを焼結して分散シ
フト光ファイバ母材とする。The core base material is then stretched to have a predetermined outer diameter, and then clad soot is deposited on the core base material by an external attachment method or the like, and is further sintered and dispersed. Use as shift optical fiber base material.
【００２９】図３は、本発明方法と従来方法とに基づい
てそれぞれ作製したコア母材の屈折率分布を測定し、両
者を比較したものである。同図中、実線が本発明方法に
基づくコア母材の屈折率分布を、破線が従来方法に基づ
くコア母材の屈折率分布を示す。FIG. 3 shows a comparison of the refractive index distributions of the core preforms produced by the method of the present invention and the conventional method, respectively. In the figure, the solid line shows the refractive index distribution of the core base material based on the method of the present invention, and the broken line shows the refractive index distribution of the core base material based on the conventional method.
【００３０】図から明らかなように、従来方法に係るコ
ア母材は、そのサイドコアscの屈折率分布が平坦でなく
撫で肩の形状となっているのに対して、本発明方法に係
るコア母材では、そのサイドコアscの屈折率分布が比較
的平坦な形状となっていることが理解される。As can be seen from the figure, in the core base material according to the conventional method, the side core sc does not have a flat refractive index distribution but has a shoulder shape by stroking, whereas the core base material according to the method of the present invention has Then, it is understood that the refractive index distribution of the side core sc has a relatively flat shape.
【００３１】[0031]
【発明の効果】本発明によれば、サイドコアの屈折率分
布が平坦な形状となっているコア母材が安定して得られ
るようになる。このため、分散不良やモードフィールド
径不良のない所期の理想的な階段形の屈折率分布を有す
る分散シフト光ファイバの製造が可能となる。According to the present invention, it is possible to stably obtain a core base material in which the side core has a flat refractive index distribution. For this reason, it is possible to manufacture a dispersion-shifted optical fiber having a desired ideal stepwise refractive index distribution without dispersion defects or mode field diameter defects.
【図１】本発明方法に基づいて分散シフト光ファイバの
コア母材を製造する上での、コアスートの堆積状態を示
す概略説明図である。FIG. 1 is a schematic explanatory view showing a deposition state of core soot in manufacturing a core preform of a dispersion shifted optical fiber based on the method of the present invention.
【図２】本発明方法に基づくコアスートの屈折率分布の
設定、およびコアスートの焼結後に得られるコア母材の
屈折率分布を示す説明図である。FIG. 2 is an explanatory view showing the setting of the refractive index distribution of the core soot based on the method of the present invention and the refractive index distribution of the core base material obtained after sintering of the core soot.
【図３】本発明方法と従来方法に基づいて得られるコア
母材の屈折率分布を比較して示す特性図である。FIG. 3 is a characteristic diagram showing a comparison of the refractive index distributions of the core base material obtained by the method of the present invention and the conventional method.
【図４】分散シフト光ファイバのコアにおける各種の屈
折率分布を示す特性図である。FIG. 4 is a characteristic diagram showing various refractive index distributions in the core of a dispersion shifted optical fiber.
【図５】従来方法に基づいて分散シフト光ファイバのコ
ア母材を製造する上での、コアスートの堆積状態を示す
概略説明図である。FIG. 5 is a schematic explanatory view showing a deposition state of core soot in manufacturing a core preform of a dispersion shifted optical fiber based on a conventional method.
【図６】従来方法に基づくコアスートの屈折率分布の設
定、およびコアスートの焼結後に得られるコア母材の屈
折率分布を示す説明図である。FIG. 6 is an explanatory diagram showing the setting of the refractive index distribution of the core soot based on the conventional method and the refractive index distribution of the core base material obtained after sintering of the core soot.
Ｂc…センタコア用バーナ、Ｂs1，Ｂs2…サイドコア用
バーナ、Ｘ…コアスート。Bc ... center core burner, Bs 1, Bs 2 ... side core burner, X ... the core soot.
Claims (1)
の低いサイドコアが階段状に形成されてなる分散シフト
光ファイバのコア母材をＶＡＤ法によって製造するため
の方法であって、 単一のセンタコア用バーナと、複数のサイドコア用バー
ナとを用い、センタコア用バーナにはＳiＣl4とＧeＣl4
とを共に含む原料ガスを、このセンタコア用バーナに隣
接するサイドコア用バーナにはＳiＣl4は含むがＧeＣl4
は含まない原料ガスを、残りのサイドコア用バーナの内
の少なくとも一つはＳiＣl4とＧeＣl4とを共に含む原料
ガスを、それぞれ導入してコアスートを堆積した後、こ
のコアスートをＣl等のハロゲンガスを含む雰囲気中で
焼結することにより、透明ガラス化されたコア母材を得
ることを特徴とする分散シフト光ファイバのコア母材の
製造方法。1. A method for producing a core base material of a dispersion-shifted optical fiber by a VAD method, wherein a side core having a refractive index lower than that of the center core is formed stepwise on the outside of the center core. A center core burner and a plurality of side core burners are used. The center core burners are SiCl 4 and GeCl 4
A source gas containing both of the above and the side core burner adjacent to the center core burner including SiCl 4 but GeCl 4
Is not included, and at least one of the remaining side core burners is introduced with a source gas containing both SiCl 4 and GeCl 4 to deposit core soot, and the core soot is then used as a halogen gas such as Cl. A method for producing a core preform of a dispersion-shifted optical fiber, which comprises obtaining a transparent vitrified core preform by sintering in an atmosphere containing
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23017893A JP3356503B2 (en) | 1993-09-16 | 1993-09-16 | Manufacturing method of core preform of dispersion shifted optical fiber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23017893A JP3356503B2 (en) | 1993-09-16 | 1993-09-16 | Manufacturing method of core preform of dispersion shifted optical fiber |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0781964A true JPH0781964A (en) | 1995-03-28 |
| JP3356503B2 JP3356503B2 (en) | 2002-12-16 |
Family
ID=16903831
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23017893A Expired - Fee Related JP3356503B2 (en) | 1993-09-16 | 1993-09-16 | Manufacturing method of core preform of dispersion shifted optical fiber |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3356503B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100368575B1 (en) * | 1999-11-12 | 2003-01-24 | 대한전선 주식회사 | Non-zero dispersion shifted fiber manufacturing method |
-
1993
- 1993-09-16 JP JP23017893A patent/JP3356503B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100368575B1 (en) * | 1999-11-12 | 2003-01-24 | 대한전선 주식회사 | Non-zero dispersion shifted fiber manufacturing method |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3356503B2 (en) | 2002-12-16 |
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