JPH01302205A - Optical fiber filter - Google Patents

Optical fiber filter

Info

Publication number
JPH01302205A
JPH01302205A JP63132487A JP13248788A JPH01302205A JP H01302205 A JPH01302205 A JP H01302205A JP 63132487 A JP63132487 A JP 63132487A JP 13248788 A JP13248788 A JP 13248788A JP H01302205 A JPH01302205 A JP H01302205A
Authority
JP
Japan
Prior art keywords
optical fiber
wavelength
winding
single mode
mode optical
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
JP63132487A
Other languages
Japanese (ja)
Inventor
Osamu Kojima
修 小島
Nobuyuki Misono
御園　信行
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 JP63132487A priority Critical patent/JPH01302205A/en
Publication of JPH01302205A publication Critical patent/JPH01302205A/en
Pending legal-status Critical Current

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
    • G02B6/24—Coupling light guides
    • G02B6/26—Optical coupling means
    • G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
    • G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
    • G02B6/29331—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating by evanescent wave coupling
    • G02B6/29332—Wavelength selective couplers, i.e. based on evanescent coupling between light guides, e.g. fused fibre couplers with transverse coupling between fibres having different propagation constant wavelength dependency

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Optical Filters (AREA)
  • Light Guides In General And Applications Therefor (AREA)

Abstract

PURPOSE:To facilitate connection and to allow wavelength selection at a low insertion loss and low cost by winding a part of a single mode optical fiber to form a winding part and executing demultiplexing in this winding part. CONSTITUTION:The single mode optical fiber 1 is wound on a winding shaft 2 to form the winding part 3. Both ends of the optical fiber 1 are fixed to a fixing base 4 consisting of glass, plastic, etc., and the winding shaft 2 is fixed in the form of sandwiching the same between a disk 6 having the diameter larger than the diameter of said shaft and a fixing plate 5. Since the loss in the bend part of the optical fiber is large on the light wavelength of a long wavelength, the bending curvature and number of turns are changed by utilizing this wavelength characteristic of the bending loss, by which the cut-off wavelength is properly selected. The connection is facilitated and the demultiplexing is executed at the low cost without using a lens, etc., if optical fibers for waveguide are fusion-spliced to both ends of this optical fiber.

Description

【発明の詳細な説明】 ［産業上の利用分野］ 本発明は、長波長の光を遮断する光フアイバフィルタに
関するしのである。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical fiber filter that blocks long wavelength light.

［従来の技術］ 従来より、光フアイバ用の波長選択フィルタとしては、
光ファイバとの整合性の上からプリズムや回折格子より
ら、波長選択素子として誘電体多層膜を用いたものが知
られている。たとえば、第５図に示すように、誘電体多
層膜７を２つの分布屈折率ロッドレンズ８．８で挟んだ
構造のものがあり、小形で安定性に浸れた特長を有する
。このシステムにおいては、波長がそれぞれλ１、λ、
である光を２波多重して入射用光ファイバ９で伝送し、
２つの分布屈折率ロッドレンズ８．８で挾まれた誘電体
多層膜７により波長が選択され、波長がλ２である光の
みが光ファイバｌＯに分波されろように機能するもので
ある。尚、誘電体多層膜は、波長の１／２あるいは１／
４に近い光学的な厚みを有する高屈折率誘電体膜と低屈
折率誘電体膜とを交互に積層したものであり、誘電体多
層膜における高屈折率膜材料としてＴ　ｉ　Ｏ２やＺｎ
Ｓが、また低屈折率膜材料として５ｉｏｔやＡｌｔｏｓ
などが用いられている。誘電体多層膜フィルタにおける
波長選択性特性は、誘電体膜の層数、膜材料などに大き
く依存するものである。[Conventional technology] Traditionally, wavelength selection filters for optical fibers include:
It is known that a dielectric multilayer film is used as a wavelength selection element rather than a prism or a diffraction grating in terms of compatibility with an optical fiber. For example, as shown in FIG. 5, there is a structure in which a dielectric multilayer film 7 is sandwiched between two distributed index rod lenses 8, 8, and has the features of being small and highly stable. In this system, the wavelengths are λ1, λ,
Two waves of light are multiplexed and transmitted through the input optical fiber 9,
The wavelength is selected by the dielectric multilayer film 7 sandwiched between the two distributed index rod lenses 8.8, and functions so that only light having a wavelength of λ2 is branched to the optical fiber IO. Note that the dielectric multilayer film has a wavelength of 1/2 or 1/2.
It is made by alternately laminating high refractive index dielectric films and low refractive index dielectric films having an optical thickness close to 4.5 mm, and uses TiO2 or Zn as the high refractive index film material in the dielectric multilayer film.
S is also used as a low refractive index film material such as 5iot and Altos.
etc. are used. The wavelength selectivity characteristic of a dielectric multilayer filter largely depends on the number of dielectric film layers, the film material, and the like.

［発明が解決しようとする課題］ しかしながら、上記、誘電体多層膜フィルタを波長選択
性素子としてもちいた場合には、ロッドレンズ等の光学
素子を使用するため、光学素子相互の接続にあたり微細
な光軸調整を必要とするばかりでなく、光ファイバとの
接続部にも種々の部品が必要となり、これらのことがコ
ストアップの要因にもつながるという欠へかあった。ま
た、多重数の増大に伴い、中心波長の異なる誘電体多層
膜を用意する必要があり、波長多重数の増大とともに挿
入損失が増加するという欠点があった。[Problems to be Solved by the Invention] However, when the above dielectric multilayer filter is used as a wavelength-selective element, optical elements such as rod lenses are used, so when connecting the optical elements to each other, fine light is generated. Not only does it require axis adjustment, but also various parts are required for the connection to the optical fiber, which is disadvantageous in that it also leads to an increase in cost. Furthermore, as the number of multiplexed wavelengths increases, it is necessary to prepare dielectric multilayer films with different center wavelengths, and there is a drawback that insertion loss increases as the number of multiplexed wavelengths increases.

よって、本発明では、微細な光軸調整をすることなく、
発光素子および受光素子との結合が容易で、しかも低コ
ストで波長を選択することができる光ファイバ形フィル
タを、シングルモード光ファイバを用いることにより堤
供することを目的とする。Therefore, in the present invention, without making fine optical axis adjustments,
It is an object of the present invention to provide an optical fiber type filter that can be easily coupled with a light emitting element and a light receiving element and can select a wavelength at low cost by using a single mode optical fiber.

［課題を解決するための手段］ シングルモード光ファイバの一部を巻き回して巻回部を
形成し、この巻回部において分波することをその解決手
段とした。[Means for Solving the Problem] The solution was to wind a part of a single mode optical fiber to form a wound portion, and to perform demultiplexing in this wound portion.

［作用　］ シングルモード光ファイバの曲げ損失は、光の波長に対
して長波長側で大きい。この曲げ損失の波長特性を利用
して、ンングルモ゛−ド光ファイバの一部を巻き回して
巻回部を設け、この巻回部で波長分離を行うことにより
長波長を遮断する。[Function] The bending loss of a single mode optical fiber is large on the long wavelength side with respect to the wavelength of light. Utilizing the wavelength characteristics of this bending loss, a part of the bundle mode optical fiber is wound to provide a winding section, and the winding section performs wavelength separation to cut off long wavelengths.

［実施例コ 第１図ないし第３図は本発明の光フアイバフィルタの実
施例を示すものであり、図中符号ｌはシングルモード光
ファイバである。このシングルモード光ファイバｌは円
筒状の光ファイバ巻き付は軸２に巻き付けられ、巻回部
３が形成されるとともに、ノングルモード光ファイバｌ
の両端は、ガラス、プラスチックなどからなる固定台４
、・１にそれぞれ固定されている。光ファイバ巻き付は
輔２および固定台４．４は、矩形の固定数５にそれぞれ
取り付けられ、光ファイバ巻き付は軸２はその直径より
大きい直径を持っ円板６と固定数５とにはさまれている
。[Example 1] Figures 1 to 3 show examples of the optical fiber filter of the present invention, and the reference numeral l in the figures represents a single mode optical fiber. This single mode optical fiber l is a cylindrical optical fiber wound around a shaft 2 to form a winding part 3, and a non-gle mode optical fiber l.
Both ends are fixed bases 4 made of glass, plastic, etc.
, and are fixed at 1, respectively. The optical fiber winding shaft 2 and the fixed base 4.4 are respectively attached to the rectangular fixed number 5, and the optical fiber winding shaft 2 has a diameter larger than that of the disk 6 and the fixed number 5. I'm trapped.

ここで、光ファイバ巻き付は軸２の直径、ずなイっちシ
ングルモード光ファイバｌの巻回直径（曲率）は、通常
、２０ｍｌ１１から８０ｍｍ程度とされ、また、シング
ルモード光ファイバｌの巻回数は、１回から２０回程度
とされる。通常、シングルモード光ファイｌの曲げ曲率
を変化させることによって分波波長（カットオフ波長）
が変化し、また巻回数を変化させれば、曲げ損失を変化
させることができるので、シングルモード光ファイバｌ
の曲げ曲率およびその巻回数を変化させれば、カットオ
フ波長および減衰量を、適宜選択することができる。Here, the diameter of the optical fiber winding is the diameter of the shaft 2, and the winding diameter (curvature) of the Zunaichi single mode optical fiber l is usually about 20 ml11 to 80 mm, and the winding of the single mode optical fiber l is The number of times is approximately 1 to 20 times. Usually, the demultiplexing wavelength (cutoff wavelength) is determined by changing the bending curvature of a single mode optical file.
By changing the number of turns and changing the number of turns, the bending loss can be changed.
By changing the bending curvature and the number of turns, the cutoff wavelength and attenuation amount can be appropriately selected.

このような光フアイバフィルタは、シングルモード光フ
ァイバｌの両端に、導波用光ファイバを融着接続法など
によって接続して、使用に供される。Such an optical fiber filter is used by connecting waveguide optical fibers to both ends of a single mode optical fiber l by fusion splicing or the like.

また、シングルモード光ファイバｌを光ファイバ巻き付
は軸２に巻き回したのち、接着剤なとによって固定し、
巻き付は軸２を抜き取って、空芯コイル型の光フアイバ
フィルタとすることも可能である。In addition, after winding the single mode optical fiber l around the shaft 2, it is fixed with an adhesive or the like.
It is also possible to wind the filter by removing the shaft 2 to form an air-core coil type optical fiber filter.

［実験例］ 第１図ないし第３図に示した光フアイバフィルタを作成
した。シングルモード光ファイバ１には、光フアイバ外
径が２５０μｍであるＵＶ被覆シングルモード光ファイ
バを用いた。そのコア直径、クラッド直径はそれぞれ９
μｍ、１２５μｍであり、比屈折率差は０２％である。[Experimental Example] Optical fiber filters shown in FIGS. 1 to 3 were created. As the single mode optical fiber 1, a UV coated single mode optical fiber having an outer diameter of 250 μm was used. Its core diameter and cladding diameter are each 9
μm, 125 μm, and the relative refractive index difference is 02%.

このシングルモード光ファイバｌの一部に一定の曲率を
与えるため、直径７０ｍｍの巻き付は軸２に９回、シン
グルモード光ファイバｌを巻き付けて、本発明の光フア
イバフィルタを完成させた。In order to give a certain curvature to a part of the single mode optical fiber 1, the single mode optical fiber 1 having a diameter of 70 mm was wound around the shaft 2 nine times to complete the optical fiber filter of the present invention.

第４図は、このシングルモード光ファイバフィルタの波
長−損失特性を示すグラフである。第４図から明らかな
ように、このシングルモード光ファイバフィルタは、１
．５５μｍ波長を遮断しく損失＝１０ｄＢ以上）、１．
３μｍ波長を通過する（挿入損失０．５ｄＢ以下）特性
を有していることが判明した。即ち、上記シングルモー
ド光ファイバフィルタを用いれば、１．３／１．５μｍ
波長多重ンステムにおいて、そのアイソレーションを上
げることが可能となる。FIG. 4 is a graph showing the wavelength-loss characteristics of this single mode optical fiber filter. As is clear from FIG. 4, this single mode optical fiber filter has 1
．． 55 μm wavelength is blocked (loss = 10 dB or more), 1.
It was found that it has a characteristic of passing a wavelength of 3 μm (insertion loss of 0.5 dB or less). That is, if the above single mode optical fiber filter is used, the diameter of 1.3/1.5 μm
In wavelength multiplexing systems, it becomes possible to increase the isolation.

［発明の効果］ 本発明は、シングルモード光ファイバの一部巻き回して
巻回部を形成し、この巻回部において分波することを特
徴とする光ファイバ形フィルタであるので、導波用の光
ファイバとの接続が容易てあり、しから接続による挿入
損失も小さくすることができ、低コストであるという特
徴を有しており、波長多重ノステムにおいて、波長分離
後に挿入してアイソレーションを上げろ目的で使用する
ことにより、その効果を発揮する。[Effects of the Invention] The present invention is an optical fiber filter characterized in that a part of a single mode optical fiber is wound to form a wound portion, and the waves are separated in this wound portion. It is easy to connect to other optical fibers, can reduce insertion loss due to straight connections, and is low cost.In wavelength multiplexing systems, it can be inserted after wavelength separation for isolation. By using it for the purpose of raising it, its effect will be demonstrated.

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

第１図ないし第３図は、本発明の光フアイバフィルタの
実施例を示すものであり、第１図は正面図、第２図は平
面図、第３図は側面図、第４図は光フアイバフィルタの
波長−損失特性を示すグラフ、第５図は、従来例の誘電
体多層膜フィルタを用いた波長選択システムの一例を示
すものである。1 to 3 show an embodiment of the optical fiber filter of the present invention, in which FIG. 1 is a front view, FIG. 2 is a plan view, FIG. 3 is a side view, and FIG. 4 is an optical fiber filter. FIG. 5, a graph showing wavelength-loss characteristics of a fiber filter, shows an example of a wavelength selection system using a conventional dielectric multilayer filter.

Claims (1)

【特許請求の範囲】[Claims] シングルモード光ファイバの一部を巻き回して巻回部を
形成し、この巻回部において分波することを特徴とする
光ファイバフィルタ。An optical fiber filter characterized in that a part of a single mode optical fiber is wound to form a wound portion, and the waves are separated in this wound portion.
JP63132487A 1988-05-30 1988-05-30 Optical fiber filter Pending JPH01302205A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP63132487A JPH01302205A (en) 1988-05-30 1988-05-30 Optical fiber filter

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP63132487A JPH01302205A (en) 1988-05-30 1988-05-30 Optical fiber filter

Publications (1)

Publication Number Publication Date
JPH01302205A true JPH01302205A (en) 1989-12-06

Family

ID=15082523

Family Applications (1)

Application Number Title Priority Date Filing Date
JP63132487A Pending JPH01302205A (en) 1988-05-30 1988-05-30 Optical fiber filter

Country Status (1)

Country Link
JP (1) JPH01302205A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0470497A2 (en) * 1990-07-31 1992-02-12 Fujitsu Limited Optical fiber amplifier
EP0538879A1 (en) * 1991-10-23 1993-04-28 ELECTRONIC PRODUCTION PARTNERS GmbH Wavelength filter for optical waveguides
WO2016002947A1 (en) * 2014-07-04 2016-01-07 古河電気工業株式会社 Optical fiber laser device

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0470497A2 (en) * 1990-07-31 1992-02-12 Fujitsu Limited Optical fiber amplifier
US5155621A (en) * 1990-07-31 1992-10-13 Fujitsu Limited Optical fiber amplifier
EP0538879A1 (en) * 1991-10-23 1993-04-28 ELECTRONIC PRODUCTION PARTNERS GmbH Wavelength filter for optical waveguides
WO2016002947A1 (en) * 2014-07-04 2016-01-07 古河電気工業株式会社 Optical fiber laser device
JPWO2016002947A1 (en) * 2014-07-04 2017-04-27 古河電気工業株式会社 Optical fiber laser equipment
US10530117B2 (en) 2014-07-04 2020-01-07 Furukawa Electric Co., Ltd. Optical fiber laser device
US10862262B2 (en) 2014-07-04 2020-12-08 Furukawa Electric Co., Ltd. Optical fiber laser device

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