JPH0695167B2 - Wide wavelength range low dispersion single mode fiber - Google Patents
Wide wavelength range low dispersion single mode fiberInfo
- Publication number
- JPH0695167B2 JPH0695167B2 JP61046599A JP4659986A JPH0695167B2 JP H0695167 B2 JPH0695167 B2 JP H0695167B2 JP 61046599 A JP61046599 A JP 61046599A JP 4659986 A JP4659986 A JP 4659986A JP H0695167 B2 JPH0695167 B2 JP H0695167B2
- Authority
- JP
- Japan
- Prior art keywords
- layer
- refractive index
- radius
- single mode
- mode 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.)
- Expired - Fee Related
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
- G02B6/03605—Highest refractive index not on central axis
- G02B6/03611—Highest index adjacent to central axis region, e.g. annular core, coaxial ring, centreline depression affecting waveguiding
-
- 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
- G02B6/03627—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 - +
-
- 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 - + -
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Optical Fibers, Optical Fiber Cores, And Optical Fiber Bundles (AREA)
Description
【発明の詳細な説明】 〔目 次〕 概 要 産業上の利用分野 従来の技術（第９図〜第12図） 発明が解決しようとする問題点 問題点を解決するための手段（第１図） 作 用（第２図） 実施例 （第１の実施例）（第３図，第４図） （第２の実施例）（第５図，第６図） （第３の実施例）（第７図，第８図） 発明の効果 〔概 要〕 コアを構成する最内層と、第２層と、第３層と、クラツ
ドを構成する最外層とを内側から順次同心円筒状に多重
に構成された多重構造屈折率分布シングルモードフアイ
バをMCVD法によつて形成し、最内層における第２層と接
する部分の屈折率を半径の増加する方向にゆるやかに減
少して第２層に接続するように変化させるとともに、第
２層，第３層，最外層の屈折率をそれぞれ一定とし、最
内層における最大屈折率の部分の屈折率と最外層の屈折
率との差および第３層の屈折率と最外層の屈折率との差
をそれぞれ正の所定値とし、第２層の屈折率と最外層の
屈折率との差を負の所定値とし、最内層の半径を所定値
とし、最内層の半径と第２層の半径との比および最内層
の半径と第３層の半径との比をそれぞれ所定値とするこ
とによつて、低分散となる範囲を広くするとともに、基
本モードにカツトオフとなる領域を生じないようにし
て、曲げに対する損失を小さくする。さらにこの場合、
最内層の第２層と接する部分の屈折率が半径の増加する
方向にゆるやかに減少するので、この部分においてフア
イバ長手方向における屈折率のゆらぎが生じにくく、製
造上の原因に基づく損失増加および波長分散の劣化が防
止される。DETAILED DESCRIPTION OF THE INVENTION [Table of Contents] Outline of Industrial Application Conventional Technology (FIGS. 9 to 12) Problems to be Solved by the Invention Means for Solving Problems (FIG. 1) ) Operation (Fig. 2) Example (First Example) (Figs. 3 and 4) (Second Example) (Figs. 5 and 6) (Third Example) ( (FIGS. 7 and 8) Effect of the invention [Outline] The innermost layer that constitutes the core, the second layer, the third layer, and the outermost layer that constitutes the cladding are sequentially concentrically formed from the inside to form a concentric cylinder. The constructed multi-structured refractive index distribution single mode fiber is formed by the MCVD method, and the refractive index of the portion in contact with the second layer in the innermost layer is gradually decreased in the direction of increasing radius to connect to the second layer. And the refractive index of the second layer, the third layer, and the outermost layer are made constant, and the maximum refractive index of the innermost layer is changed. Between the refractive index of the outermost layer and the refractive index of the outermost layer and the difference between the refractive index of the third layer and the refractive index of the outermost layer are set to positive predetermined values, respectively. The difference is set to a negative predetermined value, the radius of the innermost layer is set to a predetermined value, and the ratio of the radius of the innermost layer to the radius of the second layer and the ratio of the radius of the innermost layer to the radius of the third layer are set to predetermined values, respectively. As a result, the range of low dispersion is widened, and the cutoff region is not generated in the fundamental mode to reduce the bending loss. Further in this case,
Since the refractive index of the portion of the innermost layer that is in contact with the second layer gradually decreases in the direction of increasing radius, fluctuations of the refractive index in the longitudinal direction of the fiber are less likely to occur in this portion, and increase in loss and wavelength Dispersion degradation is prevented.
本発明は広波長域低分散シングルモードフアイバに関
し、特に使用できる波長領域が十分広いとともに曲げに
よる損失が小さく、かつフアイバの構造不完全に基づく
損失増加を生じない広波長域低分散シングルモードフア
イバに関するものである。The present invention relates to a wide wavelength range low dispersion single mode fiber, and more particularly to a wide wavelength range low dispersion single mode fiber which has a sufficiently wide wavelength range and a small loss due to bending, and which does not cause an increase in loss due to structural incompleteness of the fiber. It is a thing.
光通信においては、使用できる波長領域が広いことが必
要である。広波長域低分散シングルモードフアイバは、
この目的に適合するものとして開発が進められている
が、使用できる波長領域がより広いとともに曲げによる
損失が小さく、かつ製造上の原因による構造不完全に基
づく損失増加を生じないものが要望されている。In optical communication, it is necessary that the usable wavelength range is wide. Wide wavelength range low dispersion single mode fiber
Development is in progress to meet this purpose, but a wavelength range that can be used is wider, there is less loss due to bending, and there is a demand for one that does not cause loss increase due to structural imperfections due to manufacturing reasons. There is.
従来、広波長域低分散シングルモードフアイバとして、
Ｗ型シングルモードフアイバが提案されている。これは
第９図にその断面構造を示すようなものであつて、コア
11の屈折率をn1,クラツド12の屈折率をn2（n1＞n2）と
したとき、コア11とクラツド12の中間に屈折率n3（n3＜
n2）なる中間層13を設けたものである。この場合の遅延
時間τの特性は各部の波長に対する群屈折率の違いに基
づいて、第10図において（ａ）に示すようなものとな
る。すなわちコア11の部分の特性Ａとクラツド12の部分
の特性Ｂと中間層13の部分の特性Ｃとによつて、フアイ
バの特性はＤで示すように３次曲線の形状となる。なお
Ｅは対照のために、通常のシングルモードフアイバの特
性を示したものである。これによつて波長分散ｍは、同
図（ｂ）においてＦで示されるように２つの波長で０と
なる特性を示し、Ｇで示す通常のシングルモードフアイ
バの場合と比較して、広波長域低分散となる。Conventionally, as a wide wavelength range low dispersion single mode fiber,
A W-type single mode fiber has been proposed. This is as shown in the sectional structure of FIG.
When the refractive index of 11 is n 1 and the refractive index of the cladding 12 is n 2 (n 1 > n 2 ), the refractive index n 3 (n 3 <n 3 <n 3 is between the core 11 and the cladding 12.
The intermediate layer 13 of n 2 ) is provided. The characteristic of the delay time τ in this case is as shown in FIG. 10 (a) based on the difference in the group refractive index with respect to the wavelength of each part. That is, due to the characteristic A of the core 11, the characteristic B of the cladding 12 and the characteristic C of the intermediate layer 13, the fiber has a cubic curve shape as indicated by D. For reference, E represents the characteristic of a normal single mode fiber. As a result, the chromatic dispersion m exhibits a characteristic that it becomes 0 at two wavelengths as indicated by F in the same figure (b), and it has a wider wavelength range than in the case of a normal single mode fiber indicated by G. Low dispersion.
しかしながら第９図に示されたようなＷ型シングルモー
ドフアイバは、使用領域が必ずしも十分広くないだけで
なく、フアイバに曲げを生じたときの放射損失が実用上
問題となる程大きいという問題がある。However, the W-type single-mode fiber as shown in FIG. 9 has a problem that the use area is not always sufficiently wide and the radiation loss when the fiber is bent is large enough to be a practical problem. .
これはＷ型シングルモードフアイバの場合、第10図
（ａ）の遅延特性において破線で示すように短波長域に
基本モードにカツトオフがあり、ある波長以上は伝送で
きなくなる性質があるが、曲げによつてこの傾向が助長
されるためであると考えられる。In the case of the W-type single mode fiber, the fundamental mode has cutoff in the short wavelength region as shown by the broken line in the delay characteristic of FIG. This is probably because this tendency is promoted.
これに対して、第11図に示すような４重構造を具えるこ
とによつて、これらの問題点を解決した広波長域低分散
シングルモードフアイバがある。On the other hand, there is a wide wavelength range low dispersion single mode fiber which solves these problems by having a quadruple structure as shown in FIG.
すなわちコアを構成する最内層21と、第２層22と、第３
層23と、クラツドを構成する最外層24とを内側から順次
同心円筒状に多重に構成された多重構造屈折率分布シン
グルモードフアイバを構成し、最内層21の屈折率と最外
層24の屈折率との差および第３層23の屈折率と最外層24
の屈折率との差を正の所定値とし、第２層22の屈折率と
最外層24の屈折率との差を負の所定値とし、最内層21の
径を所定値とし、最内層21の径と第２層22の径との比お
よび最内層21の径と第３層23の径との比をそれぞれ所定
値として、これら各部の屈折率と径に適当な値を与える
ことによつて、広い波長領域において使用可能にすると
ともに曲げによる損失を小さくすることができる。That is, the innermost layer 21 that constitutes the core, the second layer 22, and the third layer
The layer 23 and the outermost layer 24 constituting the cladding are sequentially arranged from the inside in a concentric cylindrical multi-layered structure to form a multi-mode refractive index distribution single mode fiber, and the refractive index of the innermost layer 21 and the refractive index of the outermost layer 24. And the refractive index of the third layer 23 and the outermost layer 24
Is set to a positive predetermined value, the difference between the refractive index of the second layer 22 and the outermost layer 24 is set to a negative predetermined value, and the diameter of the innermost layer 21 is set to a predetermined value. By setting the ratio of the diameter of the second layer 22 to the diameter of the second layer 22 and the ratio of the diameter of the innermost layer 21 to the diameter of the third layer 23 to predetermined values, appropriate values can be given to the refractive index and the diameter of each of these portions. Therefore, it can be used in a wide wavelength range and the loss due to bending can be reduced.
第12図はこの場合の特性例を示し、最内層21の特性ａ
と、第２層22の特性ｂと、第３層23の特性ｃと、クラツ
ドを構成する最外層14の特性ｄとによつて、フアイバの
遅延時間τの特性はｅで示すように４次曲線の形状とな
る。これによつて波長分散ｍは（ｂ）に示すように右上
がりの特性となる。これを第９図に示されたＷ型シング
ルモードフアイバの場合と比較すると、低分散となる範
囲が広いとともに、カツトオフとなる領域を生じないた
め、曲げによる損失も小さくなる。FIG. 12 shows a characteristic example in this case, and the characteristic a of the innermost layer 21
According to the characteristic b of the second layer 22, the characteristic c of the third layer 23, and the characteristic d of the outermost layer 14 constituting the cladding, the characteristic of the delay time τ of the fiber is quaternary as shown by e. It has a curved shape. As a result, the chromatic dispersion m has an upward-sloping characteristic as shown in (b). Comparing this with the case of the W-type single-mode fiber shown in FIG. 9, the range of low dispersion is wide, and since there is no cut-off region, the loss due to bending is also small.
第11図に示された従来の広波長域低分散シングルモード
フアイバは、第３層23の部分の屈折率を高くすることが
その性能向上のために望ましい。しかしながら最内層21
における第２層22と接する部分において、製造上の原因
に基づく構造不完全を生じ、この部分の屈折率にフアイ
バの長手方向においてゆらぎを生じやすい。そのため第
３層23の存在による低分散化の効果が減殺されるととも
に、光損失が増加するという問題があつた。In order to improve the performance of the conventional wide wavelength low dispersion single mode fiber shown in FIG. 11, it is desirable to increase the refractive index of the third layer 23. However, the innermost layer 21
In the portion contacting with the second layer 22 in, structural imperfections due to manufacturing reasons occur, and fluctuations in the refractive index of this portion tend to occur in the longitudinal direction of the fiber. Therefore, there is a problem that the effect of lowering the dispersion due to the presence of the third layer 23 is diminished and the optical loss increases.
本発明の目的は、使用できる波長領域が十分広いととも
に曲げによる損失が小さく、かつフアイバの構造不完全
に基づく損失増加を生じない広波長域低分散シングルモ
ードフアイバを提供することにある。An object of the present invention is to provide a wide wavelength range low dispersion single mode fiber in which the usable wavelength range is sufficiently wide, the loss due to bending is small, and the loss increase due to the imperfect structure of the fiber does not occur.
第１図は本発明の原理的構成を示している。 FIG. 1 shows the basic configuration of the present invention.
最大屈折率の部分の屈折率n1を有する半径r1の最内層
（１）と、屈折率n2を有する半径r2の第２層（２）と、
屈折率n3を有する半径r3の第３層（３）と、屈折率n4を
有する半径r4の最外層（４）とを順次同心円筒状に多重
に構成した多重構造屈折率分布シングルモードフアイバ
をMCVD法によつて形成し、 最内層（１）における第２層（２）と接する部分の屈折
率が半径の増加する方向にゆるやかに減少して第２層
（２）に接続するように変化するとともに、 第２層（２），第３層（３），最外層（４）の屈折率
n2,n3,n4をそれぞれ半径方向に一定とし、 最内層（１）における最大屈折率の部分の屈折率n1と最
外層（４）の屈折率n4との差Δ１を1.0％〜1.1％とし、 第２層（２）の屈折率n2と最外層（４）の屈折率n4との
差Δ２を−0.3％〜−0.2％とし、 第３層（３）の屈折率n3と最外層（４）の屈折率n4との
差Δ３を0.2±0.02％とし、 最内層（１）の半径r1を３±0.3μｍとし、 最内層（１）の半径r1と第２層（２）の半径r2との比を
2.3とし、 最内層（１）の半径r1と第３層（３）の半径r3との比を
３とする。An innermost layer (1) with a radius r 1 having a refractive index n 1 in the maximum refractive index portion, and a second layer (2) having a radius r 2 having a refractive index n 2 .
A multi-layered refractive index distribution single in which a third layer (3) having a refractive index n 3 and a radius r 3 and an outermost layer (4) having a refractive index n 4 and a radius r 4 are sequentially and multiply formed in a concentric cylindrical shape. A mode fiber is formed by the MCVD method, and the refractive index of the portion of the innermost layer (1) which is in contact with the second layer (2) gradually decreases in the direction of increasing radius and is connected to the second layer (2). And the refractive index of the second layer (2), the third layer (3), and the outermost layer (4)
With n 2 , n 3 and n 4 being constant in the radial direction, the difference Δ 1 between the refractive index n 1 of the maximum refractive index portion of the innermost layer (1) and the refractive index n 4 of the outermost layer (4) is 1.0. % and to 1.1%, the difference delta 2 between the refractive index n 4 of the refractive index n 2 and the outermost layer of the second layer (2) (4) -0.3% -0.2%, the third layer (3) The difference Δ 3 between the refractive index n 3 and the refractive index n 4 of the outermost layer (4) is 0.2 ± 0.02%, the radius r 1 of the innermost layer (1) is 3 ± 0.3 μm, and the radius of the innermost layer (1) is The ratio of r 1 to the radius r 2 of the second layer (2) is
2.3 and, and 3 the ratio between the radius r 3 of radius r 1 and the third layer of the innermost layer (1) (3).
第２図は第１図に原理的構成を示す広波長域低分散シン
グルモードフアイバにおける遅延特性（ａ）と波長分散
（ｂ）とを示したものである。すなわち（ａ）に示すよ
うに、コアを構成する最内層１の特性ａと、第２層の特
性ｂと、第３層の特性ｃと、クラツドを構成する最外層
４の特性ｄとによつて、フアイバの遅延時間τの特性は
ｅで示すように４次曲線の形状となり、波長分散ｍは
（ｂ）に示すように右上がりの特性となる。これによつ
て低分散となる範囲が広いとともに、短波長域において
基本モードにカツトオフとなる領域を生じないため、曲
げに対する損失も小さくなる。かつこの場合、最内層１
の第２層２と接する部分の屈折率が半径の増加する方向
にゆるやかに減少するので、この部分においてフアイバ
長手方向における屈折率のゆらぎが生じにくく、製造上
の原因に基づく構造不完全が防止される。FIG. 2 shows the delay characteristic (a) and the chromatic dispersion (b) in the wide wavelength region low dispersion single mode fiber whose principle configuration is shown in FIG. That is, as shown in (a), the characteristics a of the innermost layer 1 constituting the core, the characteristics b of the second layer, the characteristics c of the third layer, and the characteristics d of the outermost layer 4 constituting the cladding are determined. On the other hand, the characteristic of the delay time τ of the fiber has the shape of a quartic curve as shown by e, and the chromatic dispersion m has the characteristic of rising to the right as shown in (b). As a result, the range of low dispersion is wide, and the cut-off region does not occur in the fundamental mode in the short wavelength region, so the bending loss is small. And in this case, the innermost layer 1
Since the refractive index of the portion in contact with the second layer 2 gradually decreases in the direction in which the radius increases, fluctuations in the refractive index in the longitudinal direction of the fiber hardly occur in this portion, and structural imperfections due to manufacturing reasons are prevented. To be done.
（第１の実施例） 第３図は本発明の一実施例を示したものであつて、第１
図におけると同一部分を同じ番号で示している。(First Embodiment) FIG. 3 shows an embodiment of the present invention.
The same parts as in the figure are indicated by the same numbers.
本実施例における各部の半径は第３図に示されるよう
に、 r1＝３μｍ r2＝6.9μｍ r3＝9.1μｍ r4＝クラツド半径 である。また各部の屈折率差は、第４層の屈折率n4（石
英）を基準として、 Δ１＝1.05％ Δ２＝−0.3％ Δ３＝0.19％ である。この場合の主要諸元は第１表に示すごとくであ
つた。The radius of each part in this embodiment is r 1 = 3 μm r 2 = 6.9 μm r 3 = 9.1 μm r 4 = clad radius, as shown in FIG. The refractive index difference between the respective parts is Δ 1 = 1.05% Δ 2 = −0.3% Δ 3 = 0.19% based on the refractive index n 4 (quartz) of the fourth layer. The main specifications in this case are as shown in Table 1.
本実施例による広波長域低分散シングルモードフアイバ
の波長分散の一例は、第４図に示されるようなものであ
つて、従来のシングルモードフアイバの場合およびＷ型
シングルモードフアイバの場合と比べて、十分良好であ
ることがわかる。 An example of chromatic dispersion of the wide wavelength region low dispersion single mode fiber according to the present embodiment is as shown in FIG. 4, which is compared with the conventional single mode fiber and the W type single mode fiber. It turns out that it is good enough.
（第２の実施例） 第５図は本発明の他の実施例を示したものであつて、1.
55μｍ帯を対象とするものであり、第１図におけると同
一部分を同じ番号で示している。(Second Embodiment) FIG. 5 shows another embodiment of the present invention.
It is intended for the 55 μm band, and the same parts as in FIG. 1 are indicated by the same numbers.
本実施例においては、各部の寸法および屈折率を第５図
に示すように３種類に変化させた場合を例示しており、
それぞれを（太実線），（破線），（細実線）で
区別して示すと、 r1＝3.1μｍ ＝3.5μｍ ＝3.4μｍ r2＝6.8μｍ ＝7.0μｍ ＝7.6μｍ r3＝9.2μｍ ＝11.2μｍ ＝13.64μｍ r4＝クラツド半径 である。In this embodiment, the size and the refractive index of each part are changed to three types as shown in FIG.
When each is distinguished by (thick solid line), (dashed line), and (thin solid line), r 1 = 3.1 μm = 3.5 μm = 3.4 μm r 2 = 6.8 μm = 7.0 μm = 7.6 μm r 3 = 9.2 μm = 11.2 μm = 13.64 μm r 4 = cladding radius.
また各部の屈折率差は最外層の屈折率n4（石英）を基準
として、 Δ１＝1.1％ ＝1.0％ ＝1.02％ Δ２＝−0.3％ ＝−0.2％ ＝−0.1％ Δ３＝0.2％ ＝0.21％ ＝0.22％ である。この場合の主要諸元は第１表に示すごとくであ
つた。The refractive index difference between the respective parts is Δ 1 = 1.1% = 1.0% = 1.02% Δ 2 = -0.3% = -0.2% = -0.1% Δ 3 = 0.2 based on the refractive index n 4 (quartz) of the outermost layer. % = 0.21% = 0.22%. The main specifications in this case are as shown in Table 1.
本実施例による広波長域低分散シングルモードフアイバ
の波長分散の一例は、第６図に示されるようなものであ
つて、従来のシングルモードフアイバの場合およびＷ型
シングルモードフアイバの場合と比べて、十分良好であ
ることがわかる。 An example of the wavelength dispersion of the wide wavelength range low dispersion single mode fiber according to the present embodiment is as shown in FIG. 6, and is compared with the conventional single mode fiber and the W type single mode fiber. It turns out that it is good enough.
（第３の実施例） 第７図は本発明のさらに他の実施例を示したものであつ
て、1.3μｍ〜1.55μｍ帯を対象とし、第１図における
と同一部分を同じ番号で示している。(Third Embodiment) FIG. 7 shows still another embodiment of the present invention, which is intended for the 1.3 μm to 1.55 μm band, and the same parts as those in FIG. 1 are indicated by the same numbers. There is.
本実施例においては、各部の半径および屈折率を第７図
に示されるように、６種類に変化させた場合を例示して
おり、それぞれを（３点鎖線），（２点鎖線），
（破線），（実線），（点線），（長破線）で区
別して示すと、 r1＝5.2μｍ ＝4.7μｍ ＝4.3μｍ ＝4.0μｍ ＝3.7μｍ ＝3.5μｍ r2＝7.2μｍ 〜 r3＝12.0μｍ 〜 r4＝クラツド半径 である。また各部の屈折率差は、クラツドの屈折率n
4（石英）を基準として、 Δ１＝0.624％ ＝0.677％ ＝0.730％ ＝0.783％ ＝0.836％ ＝0.890％ Δ２＝−0.25％ 〜 Δ３＝0.2％ 〜 である。この場合の主要諸元は第３表に示すごとくであ
つた。In this embodiment, as shown in FIG. 7, the radius and the refractive index of each part are changed to six types, respectively (three-dot chain line), (two-dot chain line),
By distinguishing between (dashed line), (solid line), (dotted line), and (long broken line), r 1 = 5.2 μm = 4.7 μm = 4.3 μm = 4.0 μm = 3.7 μm = 3.5 μm r 2 = 7.2 μm ~ r 3 = 12.0 μm to r 4 = cladding radius. Also, the difference in the refractive index of each part is
Based on 4 (quartz), Δ 1 = 0.624% = 0.677% = 0.730% = 0.783% = 0.836% = 0.890% Δ 2 = -0.25% ~ Δ 3 = 0.2% ~. The main specifications in this case are as shown in Table 3.
本実施例による広波長域低分散シングルモードフアイバ
の波長分散の一例は、第８図に示されるようなものであ
つて、従来のシングルモードフアイバの場合およびＷ型
シングルモードフアイバの場合と比べて、十分良好であ
ることがわかる。 An example of the wavelength dispersion of the wide wavelength range low dispersion single mode fiber according to the present embodiment is as shown in FIG. 8, which is compared with the conventional single mode fiber and the W type single mode fiber. It turns out that it is good enough.
これら各実施例においては、最内層１の第２層と接続す
る部分において、製造上の原因に基づく構造不完全を生
じ、この部分の屈折率にフアイバの長手方向においてゆ
らぎを生じることがなく、従つて光損失が増加すること
はなく、また第３層の部分の屈折率を高くしても波長分
散が劣化することはなかつた。In each of these examples, in the portion of the innermost layer 1 connected to the second layer, structural imperfections due to manufacturing causes occur, and the refractive index of this portion does not fluctuate in the longitudinal direction of the fiber. Therefore, the optical loss did not increase, and the wavelength dispersion did not deteriorate even if the refractive index of the third layer portion was increased.
またこれら各実施例において、最内層１の中心部分にお
いて屈折率の低下を生じている。これはMCVD法によつて
製作されたプリフオームのコラプス工程時、加熱によつ
て中心部の不純物が逸失するためであるが、これによつ
て本発明の効果に影響を受けることはない。Further, in each of these examples, the refractive index is lowered in the central portion of the innermost layer 1. This is because during the collapse process of the preform manufactured by the MCVD method, the impurities in the central portion are lost due to heating, but this does not affect the effect of the present invention.
以上説明したように本発明の広波長域低分散シングルモ
ードフアイバは、 曲げ損失が小さい。As described above, the wide wavelength low dispersion single mode fiber of the present invention has a small bending loss.
広い波長領域（1.2μｍ〜1.7μｍ）で使用可能であ
る。It can be used in a wide wavelength range (1.2 μm to 1.7 μm).
製造上の原因に基づく損失増加および波長分散の劣化
が防止される。Increased loss and chromatic dispersion degradation due to manufacturing causes are prevented.
ものであつて、従来技術によるものと比べて格段に優れ
ている。However, it is significantly superior to the conventional ones.
第１図は本発明の原理的構成を示す図、 第２図は本発明の広波長域低分散シングルモードフアイ
バの特性を示す図、 第３図は本発明の一実施例を示す図、 第４図は第３図の実施例におけ波長分散を示す図、 第５図は本発明の他の実施例を示す図、 第６図は第５図の実施例における波長分散を示す図、 第７図は本発明のさらに他の実施例を示す図、 第８図は第７図の実施例における波長分散を示す図、 第９図はＷ型シングルモードフアイバの構成を示す図、 第10図はＷ型シングルモードフアイバの特性の例を示す
図、 第11図は従来の広波長域低分散シングルモードフアイバ
の構成を示す図、 第12図は第11図の広波長域低分散シングルモードフアイ
バの特性の例を示す図である。 １……最内層 ２……第２層 ３……第３層 ４……最外層FIG. 1 is a diagram showing a principle configuration of the present invention, FIG. 2 is a diagram showing characteristics of a wide wavelength region low dispersion single mode fiber of the present invention, FIG. 3 is a diagram showing one embodiment of the present invention, 4 is a diagram showing chromatic dispersion in the embodiment of FIG. 3, FIG. 5 is a diagram showing another embodiment of the present invention, FIG. 6 is a diagram showing chromatic dispersion in the embodiment of FIG. FIG. 7 is a diagram showing still another embodiment of the present invention, FIG. 8 is a diagram showing chromatic dispersion in the embodiment of FIG. 7, FIG. 9 is a diagram showing the configuration of a W-type single mode fiber, and FIG. Shows a characteristic example of a W-type single mode fiber, FIG. 11 shows a configuration of a conventional wide wavelength range low dispersion single mode fiber, and FIG. 12 shows a wide wavelength range low dispersion single mode fiber of FIG. It is a figure which shows the example of the characteristic of. 1 ... innermost layer 2 ... second layer 3 ... third layer 4 ... outermost layer
Claims (1)
が内側から順次同心円筒状に多重に構成された多重構造
屈折率分布シングルモードフアイバにおいて、 最内層における第２層と接する部分の屈折率が半径の増
加する方向にゆるやかに減少して第２層に接続するよう
に変化するとともに、 第２層と第３層と最外層の屈折率をそれぞれ半径方向に
一定とし、 最内層における最大屈折率の部分の屈折率と最外層の屈
折率との差が1.0％〜1.1％であり、 第２層の屈折率が半径方向に一定で最外層の屈折率との
差が−0.3％〜−0.2％であり、 第３層の屈折率が半径方向に一定で最外層の屈折率との
差が0.2％±0.02％であり、 最外層の屈折率が半径方向に一定であつて、 最内層の半径が３±0.3μｍであり、 最内層の半径と第２層の半径との比が2.3であり、 最内層の半径と第３層の半径との比が３であることを特
徴とするMCVD法によつて作られた広波長域低分散シング
ルモードフアイバ。1. A multi-structured refractive index profile single mode fiber in which an innermost layer, a second layer, a third layer, and an outermost layer are sequentially formed from an inner side in a concentric cylindrical multiple manner. The refractive index of the portion in contact with the layer gradually decreases in the direction of increasing radius and changes to connect to the second layer, and the refractive indices of the second layer, the third layer, and the outermost layer are constant in the radial direction. The difference between the refractive index of the maximum refractive index portion of the innermost layer and the refractive index of the outermost layer is 1.0% to 1.1%, and the refractive index of the second layer is constant in the radial direction and the refractive index of the outermost layer. The difference is −0.3% to −0.2%, the refractive index of the third layer is constant in the radial direction, the difference from the refractive index of the outermost layer is 0.2% ± 0.02%, and the refractive index of the outermost layer is radial. The radius of the innermost layer is 3 ± 0.3 μm, and the ratio of the radius of the innermost layer to the radius of the second layer is 2.3. , The innermost layer of the radius and the third layer of the broad wavelength band low dispersion single mode off multiplexed made Te cowpea the MCVD process, wherein the ratio of the radius of 3.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61046599A JPH0695167B2 (en) | 1986-03-04 | 1986-03-04 | Wide wavelength range low dispersion single mode fiber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61046599A JPH0695167B2 (en) | 1986-03-04 | 1986-03-04 | Wide wavelength range low dispersion single mode fiber |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62215207A JPS62215207A (en) | 1987-09-21 |
| JPH0695167B2 true JPH0695167B2 (en) | 1994-11-24 |
Family
ID=12751762
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61046599A Expired - Fee Related JPH0695167B2 (en) | 1986-03-04 | 1986-03-04 | Wide wavelength range low dispersion single mode fiber |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0695167B2 (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2708754B1 (en) * | 1993-08-04 | 1995-09-08 | Alcatel Cable | Fiber optic cable and associated production method. |
| US5835655A (en) | 1995-01-26 | 1998-11-10 | Corning Incorporated | Large effective area waveguide fiber |
| US5715346A (en) * | 1995-12-15 | 1998-02-03 | Corning Incorporated | Large effective area single mode optical waveguide |
| AU740523B2 (en) * | 1995-12-15 | 2001-11-08 | Corninig Incorporated | Large effective area single mode optical waveguide |
| DE69837506T2 (en) * | 1997-02-26 | 2007-12-27 | Nippon Telegraph And Telephone Corp. | Optical fiber |
| JPH10253847A (en) * | 1997-03-11 | 1998-09-25 | Furukawa Electric Co Ltd:The | Dispersion compensating optical fiber |
| CA2232101A1 (en) | 1997-03-25 | 1998-09-25 | Kazunori Mukasa | Dispersion compensating optical fiber, and wavelength division multiplex light transmission line using the same |
| US6031956A (en) | 1997-11-17 | 2000-02-29 | Corning Incorporated | High performance single mode waveguide |
-
1986
- 1986-03-04 JP JP61046599A patent/JPH0695167B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62215207A (en) | 1987-09-21 |
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