JPS61122612A - Optical fiber - Google Patents

Optical fiber

Info

Publication number
JPS61122612A
JPS61122612A JP59243169A JP24316984A JPS61122612A JP S61122612 A JPS61122612 A JP S61122612A JP 59243169 A JP59243169 A JP 59243169A JP 24316984 A JP24316984 A JP 24316984A JP S61122612 A JPS61122612 A JP S61122612A
Authority
JP
Japan
Prior art keywords
layer
refractive index
optical fiber
multimode
mode
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
Application number
JP59243169A
Other languages
Japanese (ja)
Inventor
Hiroshi Kajioka
博 梶岡
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.)
Hitachi Cable Ltd
Original Assignee
Hitachi Cable 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 Hitachi Cable Ltd filed Critical Hitachi Cable Ltd
Priority to JP59243169A priority Critical patent/JPS61122612A/en
Publication of JPS61122612A publication Critical patent/JPS61122612A/en
Pending legal-status Critical Current

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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
    • G02B6/03638—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
    • G02B6/0365—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 - - +
    • 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
    • G02B6/028—Optical fibres with cladding with or without a coating with core or cladding having graded refractive index
    • G02B6/0281—Graded index region forming part of the central core segment, e.g. alpha profile, triangular, trapezoidal core

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Optical Fibers, Optical Fiber Cores, And Optical Fiber Bundles (AREA)

Abstract

PURPOSE:To increase a transmission band numerical aperture of a multi-mode waveguide by forming the first layer (refractive index n1) of the center through the fourth layer to a concentric circle shape, setting a refractive index of each layer as n1>n2>n4>n3, and using the first layer and the second layer as a single mode waveguide and a multi-mode waveguide, respectively. CONSTITUTION:An optical fiber 5 is constituted of a four layer sectional structure in which the second layer 2, the third layer 3 and the fourth layer 4 (refractive indexes n2, n3 and n4) have been formed in a concentric circle shape toward the outside of the diameter direction from the first layer (refractive index n1) of a circular section of the center. The large and small relation of the refractive index of each layer is as shown by n1>n2>n4>n3, and the first layer 1 and the second layer 2 are used as a single mode waveguide and a multi-mode waveguide, respectively.

Description

【発明の詳細な説明】 ［産業上の利用分野１ 本発明は単一モード導波路と多モード導波路とを右する
複合型の光ファイバに係り、特に多モード導波路の伝送
帯域・同口数を増大し得る光ファイバに関する。[Detailed Description of the Invention] [Industrial Application Field 1] The present invention relates to a composite optical fiber that has a single mode waveguide and a multimode waveguide, and particularly relates to a multimode waveguide transmission band and a multimode waveguide. This invention relates to an optical fiber that can increase

［従来の技術］ 従来の実用化されている通信用光ファイバは、一般にコ
ア／クラッド／サポートの三層構造をなし、伝搬モード
上、単一モードファイバと多モードファイバとに分けら
れる。単一モードファイバと多モードファイバとは異な
る断面構造と屈折率分布を有しており、１本の光フアイ
バ導波路が単一モード機能と多モード櫨能の両機能をあ
わせ持つものではない。[Prior Art] Conventional communication optical fibers that have been put into practical use generally have a three-layer structure of core/cladding/support, and are divided into single mode fibers and multimode fibers based on the propagation mode. A single mode fiber and a multimode fiber have different cross-sectional structures and refractive index distributions, and a single optical fiber waveguide does not have both single mode and multimode functions.

現在、高度情報システムの幹線伝送路としては単一モー
ドファイバが玉流となっているが、加入者系光ファイバ
に単一モードファイバ、多モードファイバのいずれを採
用すべきかその選択が問題となっている。即ち、加入者
系光ファイバに多モードファイバを採用した場合、将来
加入者（家庭など）からの発生情報量が増大するとこれ
に対応できなくなる一方、単一モードファイバを採用し
た場合、現状では、高価なレーザを用いなければならな
いこと、光デバイスが多数必要であること、工事費が高
くつくことなどの短所がある。Currently, single-mode fibers are commonly used as the main transmission line for advanced information systems, but the question is whether to use single-mode fibers or multi-mode fibers for subscriber optical fibers. ing. In other words, if a multimode fiber is used as the subscriber optical fiber, it will not be possible to cope with the increase in the amount of information generated by subscribers (households, etc.), but if a single mode fiber is used, currently, Disadvantages include the need to use expensive lasers, the need for a large number of optical devices, and high construction costs.

［発明が解決しようとする問題点］ このように、単一モードファイバ、多モードファイバの
いずれにも長短があり、現在は多モードファイバを用い
、将来、情報世が増大したら単一モードファイバに切り
換えるのがよい。[Problems to be solved by the invention] As described above, both single-mode fiber and multi-mode fiber have their advantages and disadvantages.Currently, multi-mode fiber is used, and in the future, when the information world increases, single-mode fiber will be used. It is better to switch.

しかしながら、光ファイバの布設工事は一回でしかも一
本の光ファイバで済ませたい。このような要求に応えら
れるものとして、単一モードコアと多モードコアとを併
有する複合型の光ファイバが知られている（特開昭５６
−１９００８号）。この複合型の光ファイバは、通常の
多モード光ファイバの多モードコアの中心部に単一モー
ドコアを形成したもので、屈折率がクラッド、多モード
コア。However, we would like to install the optical fiber only once and with only one optical fiber. A composite optical fiber that has both a single mode core and a multimode core is known as a fiber that can meet these demands (Japanese Patent Application Laid-Open No. 56-1991).
-19008). This composite optical fiber has a single mode core formed in the center of the multimode core of a normal multimode optical fiber, and has a refractive index of cladding and multimode core.

単一モードコアの順で高くなったピラミッド形の屈折率
分布となっている。It has a pyramid-shaped refractive index distribution that increases in order of single mode core.

ところが、このようなピラミッド形の屈折率分布のもの
では、多モードコアの伝送帯域が狭い。However, with such a pyramid-shaped refractive index distribution, the transmission band of the multimode core is narrow.

また、多モードコアの開口数を増大すべく石英製のクラ
ッドに対し多モードコアの屈折率を大きくすると、多モ
ードコアよりも更に単一モードコアの屈折率を大きくす
る必要があり、屈折率を上げるためのＧｅ等のドーパン
ト濃度が高くなり単−モードコアの伝送損失が増加して
しまう。Additionally, if the refractive index of the multimode core is increased relative to the quartz cladding in order to increase the numerical aperture of the multimode core, it is necessary to increase the refractive index of the single mode core even more than that of the multimode core. As the concentration of dopants such as Ge increases, the transmission loss of the single-mode core increases.

［発明の目的］ 本発明は以上の従来技術の問題点を解消すべく創案され
たものであり、本発明の目的は、多モード導波路の伝送
帯域を広くできると共に、単−モード導波路の伝送損失
を増加させることなく多モード導波路の開口数を大きく
することができる単一モード導波路と多モード導波路と
を有する複合型の光ファイバを提供することにある。′
［発明の概要］ 上記の目的を達成するために、本発明は、中心の円形断
面の第一層（屈折率ｎ＋　）より径方向外方に向って第
二層、第三層、第四層（屈折率ｎ２゜ｎ３　、　ｎａ　
）が同心円状に形成された４層断面構　　　）造を有し
、各層の屈折率の大小関係がｎ＋　＞ｒＮ＞ｎ４＞ｎ３
であると共に、第一層が単一モード導波路として第二層
が多モード導波路として構成されてなるものである。[Object of the Invention] The present invention has been devised to solve the problems of the prior art described above, and an object of the present invention is to widen the transmission band of a multimode waveguide, and to widen the transmission band of a single mode waveguide. An object of the present invention is to provide a composite optical fiber having a single mode waveguide and a multimode waveguide, which can increase the numerical aperture of the multimode waveguide without increasing transmission loss. ′
[Summary of the Invention] In order to achieve the above object, the present invention has a second layer, a third layer, and a fourth layer radially outward from a first layer (refractive index n+) having a circular cross section at the center. (Refractive index n2゜n3, na
) has a 4-layer cross-sectional structure formed concentrically, and the magnitude relationship of the refractive index of each layer is n+ > rN > n4 > n3
In addition, the first layer is configured as a single mode waveguide and the second layer is configured as a multimode waveguide.

本発明では、第三層および第四層からなるクラッドのう
ら、その内側のクラッド部分く第三層）の屈折率が小さ
い、いわゆるＷ形となっている。In the present invention, the refractive index of the inner cladding portion (the third layer) behind the cladding consisting of the third layer and the fourth layer is so-called W-shaped.

このため、第二層の多モード導波路の広帯域化を実現で
きる。更にＷ形なので、第二層の屈折率を上げることな
く、即ち第一層（単一モード導波路）の伝送損失の増大
となるその高屈折率化を招くことなく、第二層と第三層
との比屈折率差を増加でき、多モード導波路の開口数を
大きくできる。Therefore, it is possible to realize a broadband multimode waveguide in the second layer. Furthermore, since it is W-shaped, the second layer and the third layer can be connected without increasing the refractive index of the second layer, that is, without increasing the refractive index of the first layer (single mode waveguide), which increases the transmission loss. The relative refractive index difference with the layer can be increased, and the numerical aperture of the multimode waveguide can be increased.

［実施例］ 以下に本発明の実施例を添付図面に従って詳述する。[Example] Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

光ファイバ５は、第１図の横断面および第２図の半径方
向の屈折率分布に示す如く、屈折率ｎ１・半径ａ１の円
形断面の第一層１とその外周部を順次被う屈折率ｎ２　
・半径ａ２の第二層２．屈折率ｎ３　・半径ａ３の第三
層３および屈折率ｎ４　・半径ａ４の第四層４とからな
る。As shown in the cross section in FIG. 1 and the radial refractive index distribution in FIG. n2
- Second layer 2 with radius a2. It consists of a third layer 3 having a refractive index n3 and a radius a3, and a fourth layer 4 having a refractive index n4 and a radius a4.

第一層１の半径ａ１は単一モード条件を満足するように
決定される。単一モード条件は動作波長。The radius a1 of the first layer 1 is determined to satisfy the single mode condition. Single mode condition is the operating wavelength.

比屈折率差などに依存するが、半径ａ１は大体、動作波
長０，８−帯では２．５±０５ＩＩＭ、１．３μｓ帯で
は４±０，５ｕＩｎ１１５１１！ｎ帯では５．５±０．
５虜となる。Although it depends on the relative refractive index difference, the radius a1 is approximately 2.5±05IIM in the 0.8-band operating wavelength and 4±0.5uIn11511 in the 1.3μs band! In the n band, it is 5.5±0.
5 Become a prisoner.

第二層２の半径ａ２は、光源との結合の点からは大きい
程よいが、経済性や耐応力特性の点から６８＋以上で２
５〜４０μｓの範囲が妥当であると考える。また、他の
ファイバとの接続の互換性（多モード光ファイバのコア
直径とファイバ直径との比が５０／１２５　、８０／１
２５に標準化される動向にある）の点からもａ２は２５
〜４０μｓが望ましい。The radius a2 of the second layer 2 is preferably larger than 68+ from the point of view of coupling with the light source, but from the point of view of economy and stress resistance.
We believe that a range of 5 to 40 μs is appropriate. Also, compatibility with other fibers (the ratio of the core diameter of the multimode optical fiber to the fiber diameter is 50/125, 80/1
25), a2 is 25.
~40 μs is desirable.

また、第二層２．第三層３．第四層４からなるＷ形屈折
率分布の屈折率差パラメータｐ、Ｑは次のような値とす
るのがよい（ｐ＝　（ｎ２−ｎａ　）／ｎ２、Ｑ−（ｒ
ｚ　−ｒ１３　）／ｎ２）。まず、耐応力特性の点から
ｆ）＋Ｑ≧０．００７が望ましく、それ以下の場合には
光ファイバ５にナイロンジャケットを施した後に低温で
光損失が増加したり、高密度にケーブル実装した時に光
損失が増加したりする。Also, the second layer 2. Third layer 3. The refractive index difference parameters p and Q of the W-shaped refractive index distribution consisting of the fourth layer 4 are preferably set to the following values (p = (n2-na)/n2, Q-(r
z −r13 )/n2). First, from the point of view of stress resistance characteristics, f)+Q≧0.007 is desirable; if it is less than that, optical loss may increase at low temperatures after applying a nylon jacket to the optical fiber 5, or when the cable is mounted in high density. Light loss may increase.

ｐは伝送帯域から決定されるが、第二層２を多モードフ
ァイバとしての帯域をとるためにｐ≦０、００５とする
。またｑは大きい程望ましいが、実際には製造法によっ
て定まり、ｑ≦　０．００４が安定している。Although p is determined from the transmission band, p≦0, 005 is set to ensure that the second layer 2 has a band as a multimode fiber. Although it is desirable that q be larger, it actually depends on the manufacturing method, and is stable when q≦0.004.

このように、本発明の光ファイバ５は、従来のＷ正屈折
率分布の多モード光ファイバの多モードコア（第二層２
）の中心部に単一モード導波路（第一層１）を形成した
ことに特徴があり、Ｗ形となっているため、第二層２の
多モード導波路の広帯域化を推進できる。また、第二層
２を高開口数にしたいが、そのためには第二層２の多モ
ードコア部の屈折率とその外周のクラッド部の屈折率と
の差を大きくする必要があるが、第三層３の屈折率ｎ３
が低いので第二層２の屈折率ｎ２を上げることなく高開
口数にできる。更に第二層２の屈１　　　折＄ｎ２を上
げずに済むので、第一層１の屈折率ｎ１を増大さける必
要がなく、第一層１のドーパント濃度増加による伝送損
失を防止できる。なお、第四層４は５ｉ０２製であり、
第三層３は５ｉ０２にフッ素をドープさせて屈折率を下
げ、第一層１゜第二層２には５ｉ０２にＧｅＯ２をドー
プさせて屈折率を上げる。As described above, the optical fiber 5 of the present invention has a multimode core (second layer 2
) is characterized in that a single mode waveguide (first layer 1) is formed in the center, and is W-shaped, making it possible to increase the band width of the multimode waveguide in the second layer 2. In addition, we would like to make the second layer 2 have a high numerical aperture, but in order to do so, it is necessary to increase the difference between the refractive index of the multimode core part of the second layer 2 and the refractive index of the cladding part on its outer periphery. Refractive index n3 of three layers 3
Since n is low, a high numerical aperture can be achieved without increasing the refractive index n2 of the second layer 2. Furthermore, since it is not necessary to increase the refraction $n2 of the second layer 2, there is no need to increase the refractive index n1 of the first layer 1, and transmission loss due to an increase in the dopant concentration of the first layer 1 can be prevented. Note that the fourth layer 4 is made of 5i02,
In the third layer 3, 5i02 is doped with fluorine to lower the refractive index, and in the first layer 1° and second layer 2, 5i02 is doped with GeO2 to increase the refractive index.

なお、上記実施例では、第二層２はステップインデック
ス形の屈折率分布であったが、第二層２をステップイン
デックス形の両肩部がやや落ちた第３図に示す如き擬似
ステップインデックス形としてもよい。In the above embodiment, the second layer 2 had a step index type refractive index distribution, but the second layer 2 had a step index type with a pseudo step index type shown in FIG. You can also use it as

本発明の光ファイバ５の製造方法としては、第一層１と
第二層２をＶＡＤ法で製造し、一方、第三層３と第四層
４を石英パイプの内壁にフッ素をドープしたＳｉＯ＋層
を堆積するＭＣＶＤ法で製造し、これらをロッドインチ
ューブ法で一体化させて製造する方法がある。As for the manufacturing method of the optical fiber 5 of the present invention, the first layer 1 and the second layer 2 are manufactured by the VAD method, while the third layer 3 and the fourth layer 4 are made of SiO+ doped with fluorine on the inner wall of a quartz pipe. There is a method of manufacturing by depositing layers using an MCVD method and integrating these layers by a rod-in-tube method.

次に上記製造方法により製造した光ファイバの具体例に
ついて述べる。この光ファイバの屈折率。Next, a specific example of an optical fiber manufactured by the above manufacturing method will be described. The refractive index of this optical fiber.

寸法は次の通りである。即ち、Ｊｓ　　（＝　（ｎ＋　
−ｎ４）　／　ｎ４）　＝　０．００３、ｐ＝　０．０
０２、ｑ＝０、００６、ａ＋＝５１Ｉ１１、ａ２＝３０
４、δ（＝８３−ａ２）＝６−１２ａａ＝１２５虜であ
る。The dimensions are as follows. That is, Js (= (n+
-n4) / n4) = 0.003, p = 0.0
02, q=0, 006, a+=51I11, a2=30
4, δ(=83-a2)=6-12aa=125 prisoners.

この光ファイバの第一層１を励振したとき波長λ＝１３
−で伝送損失０．８ｄＢ／　ＫＩｎ、第二層２を励振し
たとぎ損失１ｄＢ／／ｈ、伝送帯域１２０ＭＨｚ−鳩が
得られた。従って１．Ｒｂ伝送後には１２０／ｆｆＨＨ
７となる。現行の３２Ｈｂ／ｓ　、　　６．３Ｈｂ／ｓ
のディジタル信号を１０触程度伝送するためには、それ
ぞれ１２０ＭＨｚ−級、５０ＨｔｌＺ−７にあれば十分
であり、これらはｐ＝　０．００２、ｐ＝　０．００５
とすることにより達成できる。When the first layer 1 of this optical fiber is excited, the wavelength λ=13
A transmission loss of 0.8 dB/KIn, a 1 dB loss when exciting the second layer 2, and a transmission band of 120 MHz were obtained. Therefore 1. 120/ffHH after Rb transmission
It becomes 7. Current 32Hb/s, 6.3Hb/s
In order to transmit about 10 digital signals, it is sufficient to use 120 MHz-class and 50 HtlZ-7, respectively, and these are p = 0.002 and p = 0.005.
This can be achieved by

第４図、第５図には、本発明の複合型の光ファイバ５に
使用する光源６と受光器７の一例を示す。4 and 5 show an example of a light source 6 and a light receiver 7 used in the composite optical fiber 5 of the present invention.

光源６は第一層１．第二層２に対応した同心配置のレー
ザダイオード８と発光ダイオード９とを有する。また、
受光器７も第一層１．第二層２に対応した同心配置のア
バランシュフォトダイオード１０とフォトダイオード１
１とを有する。The light source 6 is connected to the first layer 1. It has a laser diode 8 and a light emitting diode 9 arranged concentrically corresponding to the second layer 2. Also,
The light receiver 7 also has the first layer 1. Avalanche photodiode 10 and photodiode 1 arranged concentrically corresponding to the second layer 2
1.

［発明の効果］ 以上の説明により明らかなように本発明によれば次のよ
うな優れた効果を発揮する。[Effects of the Invention] As is clear from the above description, the present invention exhibits the following excellent effects.

（１）Ｗ形の多モード光ファイバの多モードコア（第二
層）の中心部に単一モード尊波用コア（第−Ｂ）を形成
したため、第二層の多モード導波路の広帯域化が図れる
。(1) A single-mode frequency core (No.-B) is formed in the center of the multi-mode core (second layer) of the W-shaped multi-mode optical fiber, resulting in a broadband multi-mode waveguide in the second layer. can be achieved.

（２）　　第一層の伝送損失の増加となるその屈折率の
増加を招くことなく、第二層の開口数を大きくできる。(2) The numerical aperture of the second layer can be increased without increasing the refractive index of the first layer, which would increase transmission loss.

（３）１本の光ファイバで単一モード機能と多モード機
能とを有するので、用途に応じ、あるいは通信需要の状
況に応じて光ファイバの布設をやり直すことなく多モー
ド機能と単一モード機能との間の切換ができ経済性が高
い。(3) Since a single optical fiber has single-mode and multi-mode functions, it is possible to perform multi-mode and single-mode functions without having to reinstall the optical fiber depending on the application or communication demand situation. It is highly economical to be able to switch between

（４）　　容易に製造でき実用性に富む。(4) Easy to manufacture and highly practical.

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

第１図は本発明に係る光ファイバの一実施例を示す横断
面図、第２図は同光ファイバの半径方向の屈折率分布を
示すグラフ、第３図は本発明の光ファイバの他の実施例
における半径方向の屈折率分布を示すグラフ、第４図は
本発明の光ファイバに使用する光源の一例を示す端面図
、第５図は本発明の光ファイバに使用する受光器の一例
を示す端面図である。 図中、１は第一層、２は第二層、３は第三層、４は第四
層、５は光ファイバ、６は光源、７は受光器、８はレー
ザダイオード、９は発光ダイオード、１０はアバランシ
ュフォトダイオード、１１はフォトダイオードである。FIG. 1 is a cross-sectional view showing one embodiment of the optical fiber according to the present invention, FIG. 2 is a graph showing the refractive index distribution in the radial direction of the same optical fiber, and FIG. 3 is a graph showing another example of the optical fiber of the present invention. A graph showing the refractive index distribution in the radial direction in Examples, FIG. 4 is an end view showing an example of the light source used in the optical fiber of the present invention, and FIG. 5 is an example of the light receiver used in the optical fiber of the present invention. FIG. In the figure, 1 is the first layer, 2 is the second layer, 3 is the third layer, 4 is the fourth layer, 5 is the optical fiber, 6 is the light source, 7 is the light receiver, 8 is the laser diode, and 9 is the light emitting diode. , 10 is an avalanche photodiode, and 11 is a photodiode.

Claims (2)

【特許請求の範囲】[Claims] （１）屈折率ｎ＿１の最内層の円形断面の第一層と屈折
率ｎ＿２の第二層と屈折率ｎ＿３の第三層と屈折率ｎ＿
４の第四層との４層同心円状の断面構造を有する光ファ
イバにおいて、上記各層の屈折率の大小関係がｎ＿１＞
ｎ＿２＞ｎ＿４＞ｎ＿３であると共に、第一層が単一モ
ード導波路として第二層が多モード導波路として構成さ
れていることを特徴とする光ファイバ。(1) A first layer with a circular cross section of the innermost layer with a refractive index n_1, a second layer with a refractive index n_2, a third layer with a refractive index n_3, and a refractive index n_
In an optical fiber having a four-layer concentric cross-sectional structure with the fourth layer of No. 4, the magnitude relationship of the refractive index of each layer is n_1>
An optical fiber characterized in that n_2>n_4>n_3, the first layer is configured as a single mode waveguide, and the second layer is configured as a multimode waveguide. （２）上記第一層の半径ａ＿１と上記第二層の半径ａ＿
２との大小関係がａ＿２≧６ａ＿１であることを特徴と
する特許請求の範囲第１項記載の光ファイバ。(2) Radius a_1 of the first layer and radius a_ of the second layer
2. The optical fiber according to claim 1, wherein a_2≧6a_1.
JP59243169A 1984-11-20 1984-11-20 Optical fiber Pending JPS61122612A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP59243169A JPS61122612A (en) 1984-11-20 1984-11-20 Optical fiber

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP59243169A JPS61122612A (en) 1984-11-20 1984-11-20 Optical fiber

Publications (1)

Publication Number Publication Date
JPS61122612A true JPS61122612A (en) 1986-06-10

Family

ID=17099836

Family Applications (1)

Application Number Title Priority Date Filing Date
JP59243169A Pending JPS61122612A (en) 1984-11-20 1984-11-20 Optical fiber

Country Status (1)

Country Link
JP (1) JPS61122612A (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6343107A (en) * 1986-08-08 1988-02-24 エィ・テイ・アンド・ティ・コーポレーション Optical fiber
JPS63208004A (en) * 1987-02-25 1988-08-29 Sumitomo Electric Ind Ltd Optical fiber
WO2007119509A1 (en) * 2006-04-05 2007-10-25 Nippon Telegraph And Telephone Corporation Double-core optical fiber
WO2008105173A1 (en) * 2007-02-26 2008-09-04 Mitsubishi Cable Industries, Ltd. Optical fiber
WO2009066429A1 (en) * 2007-11-19 2009-05-28 Mitsubishi Cable Industries, Ltd. Optical fiber and method for producing the same
JP2010049064A (en) * 2008-08-22 2010-03-04 Nippon Telegr & Teleph Corp <Ntt> Dual mode optical fiber
JP2016075792A (en) * 2014-10-07 2016-05-12 矢崎総業株式会社 Multimode optical fiber
WO2019243777A1 (en) * 2018-06-22 2019-12-26 Fibercore Limited Composite single-mode/multimode optical fiber

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5619008A (en) * 1979-07-25 1981-02-23 Nippon Telegr & Teleph Corp <Ntt> Optical fiber and its manufacture
JPS5647531A (en) * 1979-09-27 1981-04-30 Hitachi Metals Ltd Low melting magnetic alloy

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5619008A (en) * 1979-07-25 1981-02-23 Nippon Telegr & Teleph Corp <Ntt> Optical fiber and its manufacture
JPS5647531A (en) * 1979-09-27 1981-04-30 Hitachi Metals Ltd Low melting magnetic alloy

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6343107A (en) * 1986-08-08 1988-02-24 エィ・テイ・アンド・ティ・コーポレーション Optical fiber
JPS63208004A (en) * 1987-02-25 1988-08-29 Sumitomo Electric Ind Ltd Optical fiber
WO2007119509A1 (en) * 2006-04-05 2007-10-25 Nippon Telegraph And Telephone Corporation Double-core optical fiber
JP2012048248A (en) * 2006-04-05 2012-03-08 Nippon Telegr & Teleph Corp <Ntt> Double-core optical fiber
JPWO2007119509A1 (en) * 2006-04-05 2009-08-27 日本電信電話株式会社 Double core optical fiber
JP2011191782A (en) * 2006-04-05 2011-09-29 Nippon Telegr & Teleph Corp <Ntt> Double core optical fiber
WO2008105173A1 (en) * 2007-02-26 2008-09-04 Mitsubishi Cable Industries, Ltd. Optical fiber
JP2008209603A (en) * 2007-02-26 2008-09-11 Mitsubishi Cable Ind Ltd Optical fiber
JPWO2009066429A1 (en) * 2007-11-19 2011-03-31 三菱電線工業株式会社 Optical fiber and manufacturing method thereof
WO2009066429A1 (en) * 2007-11-19 2009-05-28 Mitsubishi Cable Industries, Ltd. Optical fiber and method for producing the same
US8396340B2 (en) 2007-11-19 2013-03-12 Mitsubishi Cable Industries, Ltd. Optical fiber and method for fabricating the same
JP5476125B2 (en) * 2007-11-19 2014-04-23 三菱電線工業株式会社 Optical fiber and manufacturing method thereof
JP2010049064A (en) * 2008-08-22 2010-03-04 Nippon Telegr & Teleph Corp <Ntt> Dual mode optical fiber
JP2016075792A (en) * 2014-10-07 2016-05-12 矢崎総業株式会社 Multimode optical fiber
WO2019243777A1 (en) * 2018-06-22 2019-12-26 Fibercore Limited Composite single-mode/multimode optical fiber
US11808613B2 (en) 2018-06-22 2023-11-07 Fibercore Limited Composite single-mode/multimode optical fiber

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