JPH0356907A - Production of polarization maintaining type optical fiber coupler - Google Patents
Production of polarization maintaining type optical fiber couplerInfo
- Publication number
- JPH0356907A JPH0356907A JP19315689A JP19315689A JPH0356907A JP H0356907 A JPH0356907 A JP H0356907A JP 19315689 A JP19315689 A JP 19315689A JP 19315689 A JP19315689 A JP 19315689A JP H0356907 A JPH0356907 A JP H0356907A
- Authority
- JP
- Japan
- Prior art keywords
- diameter
- fiber
- polarization
- small
- 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
- 230000010287 polarization Effects 0.000 title claims abstract description 15
- 239000013307 optical fiber Substances 0.000 title claims description 42
- 238000004519 manufacturing process Methods 0.000 title claims description 14
- 239000000835 fiber Substances 0.000 claims abstract description 70
- 238000000034 method Methods 0.000 claims description 20
- 238000005498 polishing Methods 0.000 claims description 8
- 238000005530 etching Methods 0.000 abstract description 7
- 230000008878 coupling Effects 0.000 abstract description 5
- 238000010168 coupling process Methods 0.000 abstract description 5
- 238000005859 coupling reaction Methods 0.000 abstract description 5
- 238000010438 heat treatment Methods 0.000 abstract description 3
- 238000003466 welding Methods 0.000 abstract 3
- 230000003247 decreasing effect Effects 0.000 abstract 1
- 239000011162 core material Substances 0.000 description 42
- 238000005253 cladding Methods 0.000 description 15
- 230000003287 optical effect Effects 0.000 description 11
- 238000010586 diagram Methods 0.000 description 7
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 6
- 230000004927 fusion Effects 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 4
- 230000001902 propagating effect Effects 0.000 description 4
- 239000000758 substrate Substances 0.000 description 4
- 230000002427 irreversible effect Effects 0.000 description 3
- 238000005036 potential barrier Methods 0.000 description 3
- 235000011293 Brassica napus Nutrition 0.000 description 2
- 240000008100 Brassica rapa Species 0.000 description 2
- 235000000540 Brassica rapa subsp rapa Nutrition 0.000 description 2
- 238000004891 communication Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000003780 insertion Methods 0.000 description 2
- 230000037431 insertion Effects 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 239000010453 quartz Substances 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 241000270295 Serpentes Species 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000001427 coherent effect Effects 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 239000002019 doping agent Substances 0.000 description 1
- 238000001312 dry etching Methods 0.000 description 1
- 238000007688 edging Methods 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 238000007517 polishing process Methods 0.000 description 1
- 230000000644 propagated effect Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 239000004575 stone Substances 0.000 description 1
- 238000001039 wet etching Methods 0.000 description 1
Landscapes
- Optical Fibers, Optical Fiber Cores, And Optical Fiber Bundles (AREA)
Abstract
Description
【発明の詳細な説明】
「産業上の利用分野」
この発明は、高性能の偏波保持形光ファイノくカプラに
係わり、特に低損失の偏波保持形光ファイバカプラの製
造方法に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a high-performance polarization-maintaining optical fiber coupler, and more particularly to a method for manufacturing a low-loss polarization-maintaining optical fiber coupler.
「従来の技術」
従来、光信号を結合または分岐する際などに使用される
光ファイバカプラの１つとして、融着延仲形光ファイバ
カプラが知られている。この融着通仲形光ファイバカプ
ラは、複数本の光ファイノくを接触状態で並列させ、一
部を加熱融着し、更に延伸を行って融着延伸部を形成し
て作製されろ。"Prior Art" Conventionally, a fused and stretched optical fiber coupler has been known as one type of optical fiber coupler used for coupling or branching optical signals. This fused through-type optical fiber coupler is produced by arranging a plurality of optical fibers in parallel in contact with each other, heating and fusing some of them, and then stretching them to form a fused and drawn portion.
この融着延伸形光ファイバカプラは、使用する光ファイ
バの種類によって、単一モード光ファイバカプラ、偏波
保持形光ファイノくカブラ等を構成することができる。This fusion-stretched optical fiber coupler can be configured as a single-mode optical fiber coupler, a polarization-maintaining optical fiber coupler, or the like, depending on the type of optical fiber used.
第１１図は、従来の偏波保持形光ファイノ゛＜カプラ（
以下、カブラという）の一例を示す図である。Figure 11 shows a conventional polarization-maintaining optical fiber < coupler (
FIG. 2 is a diagram illustrating an example of an example (hereinafter referred to as a "cabra").
このカプラｌは、２本の偏波保持形光ファイノ＜２の一
部に融着延伸部３を形成して構成されている。This coupler 1 is constructed by forming a fused and stretched portion 3 on a part of two polarization-maintaining optical fins <2.
ところで、上記カプラｌを作製する場合に使用される偏
波保持形光ファイバ２は、一種の単一モード光ファイバ
であるが、厳密には伝搬する二つのモードの縮退が解け
ているので、伝搬定数の異なる二つの直交モードが存在
する。第１２図は、偏波保持形光ファイバの一例を示す
図であって、この偏波保持形光ファイバ２は、中心部の
コア３と、コア両側部に配された応力付与部５と、それ
らを囲むクラッド６とから構成されている。この応力付
与部５はファイバ内に不均一の応力を発生させるための
ものであり、コア４およびその周辺領域には、いわゆる
異方性の応力がかかり、主としてコア４を伝搬する光は
、直交する２つのモード（ｘ，ｙ）に分かれて伝搬する
ようになっている。このような偏波保持形光ファイバ２
は、偏波面を一定に保持したままで光を伝送することか
できるため、コヒーレント光通信や、ファイバ型の光干
渉計を原理とするファイバセンサ、光ファイバジャイロ
スコープなどに応用されている。By the way, the polarization-maintaining optical fiber 2 used in manufacturing the above-mentioned coupler l is a kind of single-mode optical fiber, but strictly speaking, the two propagating modes are degenerated, so the propagation There are two orthogonal modes with different constants. FIG. 12 is a diagram showing an example of a polarization-maintaining optical fiber, and this polarization-maintaining optical fiber 2 includes a core 3 at the center, stress applying portions 5 arranged on both sides of the core, It is composed of a cladding 6 surrounding them. This stress applying section 5 is for generating non-uniform stress within the fiber, so-called anisotropic stress is applied to the core 4 and its surrounding area, and the light propagating mainly through the core 4 is orthogonal to each other. The signal is split into two modes (x, y) and propagated. Such a polarization maintaining optical fiber 2
Since it is possible to transmit light while keeping the plane of polarization constant, it is applied to coherent optical communications, fiber sensors based on fiber-type optical interferometers, and optical fiber gyroscopes.
上記偏波保持形光ファイバ２の材料としては、通常はコ
ア材料としてＧ ｅ Ｏ ２添加石英ガラス、クラソド
材料として石英ガラスが使用され、また応力付与部の材
料としては石英にＢ，０３のような石英の熱膨張係数を
高めるような材料を添加した材料が使用される。モして
Ｂ ！ ０ ３を添加した石英ガラスからなる応力付与
部５の屈折率は、第１３図に示すように、クラッド部６
の屈折率よりも低くなる。また応力付与部のドーバント
としてＧｅＯｔ、Ａ ＬＯ ３を使用した場合には、第
１４図に示すように応力付与部の屈折率がコアよりも高
くなる場合もある。As for the material of the polarization maintaining optical fiber 2, silica glass doped with G e O 2 is usually used as the core material, quartz glass is used as the cladding material, and quartz with B,03 or the like is used as the material for the stress applying part. A material with added material that increases the coefficient of thermal expansion of quartz is used. Mote B! As shown in FIG. 13, the refractive index of the stress applying portion 5 made of quartz glass doped with
is lower than the refractive index of Furthermore, when GeOt or A LO 3 is used as a dopant in the stress-applying portion, the refractive index of the stress-applying portion may be higher than that of the core, as shown in FIG. 14.
「発明が解決しようとする課題」
しかしながら、応力付与部５の屈折率がクラッド６の屈
折率と異なる偏波保持形光ファイバ２を用いてカプラｌ
を構成する場合、次の問題があった。``Problems to be Solved by the Invention'' However, it is difficult to connect a coupler using a polarization-maintaining optical fiber 2 in which the refractive index of the stress applying portion 5 is different from that of the cladding 6.
When configuring , I had the following problem.
応力付与部５の屈折率がクラッド６の屈折率よりも低い
場合には、２本の偏波保持形光ファイバ２を融着延伸す
る際、融着が進むにつれてコア４径が細くなり、モード
のパワーはコア４から太きくはみ出して隣接するファイ
バのモードと結合するようになるが、この時、応カ付与
部５の屈折率がクラッド６よりも低いとすると、コア４
の光パワーは、この応力付与郎５が一種のポテンシャル
障壁となってその外側には余り広がらない。しかし、カ
ブラｌのモードのパワーの広がりはかなり大きいので、
いくらかの光はポテンシャル障壁を乗り越えてその外側
に到達する。またカブラｌでは、ファイバが太い状態か
ら一旦細められ２本のファイバ間で結合した後、再び元
の太さに戻ってゆくが、この「一旦細められた」状態で
応力付与部を越えてその外則に結合した光パワーは、「
再び太くなる」ときに必ずしもすべて元のファイバのコ
アに戻ってこない。すなわち応力付与部５かこの場合に
もポテンシャル障壁として働き、ファイバ径が再び太く
なったときにクラッド６外周部にまで達した光パワーが
コアに再び戻ってくるのを妨げるしのと考えられる。If the refractive index of the stress applying part 5 is lower than the refractive index of the cladding 6, when the two polarization-maintaining optical fibers 2 are fused and drawn, the diameter of the core 4 becomes thinner as the fusion progresses, and the mode The power of the core 4 thickly protrudes from the core 4 and becomes coupled with the mode of the adjacent fiber, but at this time, if the refractive index of the stress imparting part 5 is lower than that of the cladding 6, the power of the core 4
The optical power does not spread much outside the stress applying layer 5, which acts as a kind of potential barrier. However, the power spread of Kabra l's mode is quite large, so
Some light crosses the potential barrier and reaches the outside. In addition, in Cobra l, the fiber is thinned from a thick state, and after being coupled between two fibers, it returns to its original thickness again, but in this "once thinned" state, it crosses the stress applying part and The optical power combined externally is ``
When it becomes thick again, it doesn't necessarily all come back to the original fiber core. In other words, it is considered that the stress applying portion 5 acts as a potential barrier in this case as well, and prevents the optical power that has reached the outer peripheral portion of the cladding 6 from returning to the core when the fiber diameter increases again.
また応力付与部５の屈折率をコア４よりも高くした場合
にも、それと同様の現象が起こる。すなわち延伸前の光
パワーは、コア４に十分に閉じ込められているが、延伸
されるとコア４から外に大きくはみ出すようになる。コ
ア４からはみ出した光は、今度はこの屈折率の高い応力
付与部５に結合して応力付与部５中を伝搬するようにな
る。しかし、融着延伸部３から離れて再び元のファイバ
径に戻ったとき、応力付与部５に結合した光パワーが再
びコア４に再結合しないことか普通である。A similar phenomenon also occurs when the refractive index of the stress applying portion 5 is made higher than that of the core 4. In other words, the optical power is sufficiently confined in the core 4 before stretching, but after stretching, the optical power protrudes outward from the core 4 to a large extent. The light that has protruded from the core 4 is now coupled to the stress applying section 5 having a high refractive index and propagates through the stress applying section 5. However, when the fiber is separated from the fusion-stretching section 3 and returns to its original diameter, it is normal that the optical power coupled to the stress-applying section 5 is not re-coupled to the core 4.
なぜなら、屈折率の高い応力付与部５をｔつのコアとみ
なすと、このコアを伝搬する光の伝搬定算は、ファイバ
中心部の真のコアを伝搬する光の伝搬モードの伝搬定数
とは一般に等しくなく、一旦応力付与部のモードに結合
すると１００％元のコアに戻ってくることがないからで
ある。This is because, if the stress applying section 5 with a high refractive index is regarded as t cores, the propagation calculation of light propagating through these cores is generally different from the propagation constant of the propagation mode of light propagating through the true core at the center of the fiber. This is because they are not equal, and once coupled to the mode of the stress-applying part, it does not return 100% to the original core.
本発明は、上記事情に鑑みてなされたもので、融着延伸
量を少なくし不必要にコアからの光の漏出を防止して、
カブラの低損失化を図ることのできる製造方法の提供を
目的としている。The present invention has been made in view of the above circumstances, and reduces the amount of fusion stretching to prevent unnecessary leakage of light from the core.
The purpose of this invention is to provide a manufacturing method that can reduce the loss of Kabra.
「課題を解決するための手段」
上記課題を解決するための手段として、本発明は、｛夏
数の偏波保持形光ファイバを各々接触状態で並列し、次
いてその一部を加熱融着し、更に延伸を行って融着延伸
部を形成する扁波保持形光ファイバカプラの製造方法に
おいて、上記扁波保持形光ファイバの一部をエソチング
処理し、細径化して細径ファイバを作製し、次いでこの
細径ファイバどうしあるいは細径ファイバと細径化しな
い扁波保持形光ファイバとを並列させ、次いで該細径部
分を融着延伸することを特徴とする偏波保持形先ファイ
バカプラの製造方法である。"Means for Solving the Problems" As a means for solving the above problems, the present invention provides a method for arranging a number of polarization-maintaining optical fibers in parallel in contact with each other, and then heating and fusing some of them. In the manufacturing method of a flattened wave-retaining optical fiber coupler in which a fused and stretched portion is formed by further drawing, a part of the flattened wave-retaining optical fiber is subjected to etoching treatment to reduce its diameter to produce a small-diameter fiber. A polarization-maintaining tip fiber coupler characterized in that the small-diameter fibers or the small-diameter fiber and a flattened wave-maintaining optical fiber whose diameter is not reduced are arranged in parallel, and then the small-diameter portions are fused and drawn. This is a manufacturing method.
また請求項ｌ記・戟の偏波保持形光ファイバカプラの製
造方法において、上記細径ファイバの代わりに、偏波保
持形光ファイバの一部を、そのコア近傍まで研摩した研
摩ファイバを用いてら良い。Further, in the method for manufacturing a polarization-maintaining optical fiber coupler according to claim 1, a polished fiber obtained by polishing a part of the polarization-maintaining optical fiber to the vicinity of its core is used instead of the above-mentioned small diameter fiber. good.
以下、図面を参照して本発明方法を詳細に説明する。Hereinafter, the method of the present invention will be explained in detail with reference to the drawings.
第１図ないし第７図は、本発明によるカブラの製造方法
の一例を示す図である。なおこの例では、第２図に示す
ようにコア４と、その両叫に配された応力付与部５と、
それらを囲んだクラッド６とからムる偏波保持形光ファ
イバ２（以下、ファイバという）を用いてカプラを作製
する例を示すものてある。FIGS. 1 to 7 are diagrams showing an example of a method for manufacturing a turnip according to the present invention. In this example, as shown in FIG. 2, the core 4 and the stress applying parts 5 arranged on both sides thereof,
An example is shown in which a coupler is manufactured using a polarization-maintaining optical fiber 2 (hereinafter referred to as fiber) which is comprised of a cladding 6 surrounding them.
この例では、まずファイバ２の一部をエッチング処理し
て細径化し、第１図に示すように一部に細径部分７が形
成された細径ファイバ８を作製する。この細径部分７は
、第２図に示すように２つの応力付与部５の近傍までク
ラッド６を除去して形岐されろ。なお、このエソチング
処理に使用されるエッチング剤としては、クラッド６を
構戊する石英ガラスを腐食させろフノ酸などのエッチン
グ液が好適に使用される。また細径部分７の長さ｛よ特
に限定されないが、通常ｌＯ〜５０ｍｍ程度とするのが
望ましい。In this example, first, a part of the fiber 2 is etched to reduce its diameter, thereby producing a small-diameter fiber 8 in which a part of the fiber 2 has a small-diameter portion 7, as shown in FIG. This narrow diameter portion 7 is shaped by removing the cladding 6 up to the vicinity of the two stress applying portions 5, as shown in FIG. As the etching agent used in this etching process, an etching solution such as a hydrofluoric acid which corrodes the quartz glass constituting the cladding 6 is preferably used. Further, the length of the narrow diameter portion 7 is not particularly limited, but it is usually desirable to set it to about 10 to 50 mm.
次に、第３図に示すように、２本の細径ファイバ８を並
列させ、各々の細径部分７を接触状態とし、好ましくは
接触状態とした細径部分７の両側を固定治具で固定する
。またこのときの各ファイバの偏波方向は、第４図に示
すように各々のＸ偏波軸が平行に、ｙ偏波軸が同一直線
上に並ぶように各々のファイバの位置微調整を行う。次
に、第５図に示すように、接触状態とした細径郎分７を
酸水素バーナ９で加熱融着させ、更に融着部分１０を廷
伸して融着延伸部１ｌを形成する。以上の各操作によっ
て第６図に示すカブラｌ２が作製される。Next, as shown in FIG. 3, two small-diameter fibers 8 are arranged in parallel, and the small-diameter portions 7 of each fiber are brought into contact with each other. Fix it. At this time, the polarization direction of each fiber is adjusted by finely adjusting the position of each fiber so that the X polarization axes are parallel and the Y polarization axes are aligned on the same straight line, as shown in Figure 4. . Next, as shown in FIG. 5, the thin diameter sections 7 brought into contact are heated and fused using an oxyhydrogen burner 9, and the fused portion 10 is further stretched to form a fused and stretched portion 1l. Through each of the above operations, the cover l2 shown in FIG. 6 is manufactured.
この融着延伸部１ｌでは、第７図に示すように各々のフ
ァイバ２のコア４が接近して光パワーの結合がなされる
ようになっている。例えばこのカブラｌ２の４つのボー
トＡ．Ｂ Ｃ．Ｄのうち、ボートＡにＸ偏波或いはｙ
偏波の光を入射させると、ボートＣとボートＤか与所定
の分岐比で分岐された偏波光が出射されるようになって
いる。In this fusion-stretching section 1l, as shown in FIG. 7, the cores 4 of the respective fibers 2 are brought close to each other so that optical power is coupled. For example, this Cabra l2's four boats A. B C. Of D, boat A has X polarization or y polarization.
When polarized light is input, polarized light is split from boat C and boat D at a predetermined splitting ratio and output.
ところで、上記カプラｌ２は、２本の細径ファイバ８の
各々の細径部分７を融着延仲して融着延伸部ｌ１を形成
するので、融着廷伸前の２つのコア４間の距離が小さい
ために、所定の分岐比を得るために必要な延伸量を少な
くすることができる。By the way, since the above-mentioned coupler l2 fuses and stretches the narrow diameter portions 7 of each of the two small diameter fibers 8 to form the fused and stretched portion l1, the distance between the two cores 4 before the fusion and stretching is Because of the small distance, the amount of stretching required to obtain a given branching ratio can be reduced.
その結果、融着延伸部１ｌにおいてコア４から漏出した
光が応力付与部５に乗り移ったり、応力付与部５を乗り
越えてその外側のクラッド６に結合して非可逆的な結合
を生じる不具合を防止することができ、カブラの挿入損
失の低下を抑制して低損失のカブラを作製することがて
きる。As a result, light leaking from the core 4 in the fused and stretched portion 1l is prevented from transferring to the stress applying portion 5, or from overcoming the stress applying portion 5 and bonding to the cladding 6 on the outside, resulting in irreversible bonding. This makes it possible to suppress the reduction in the insertion loss of the coupler and produce a coupler with low loss.
なお、先の例ではファイバ２外周を湿式エッチング法に
より細径化したが、エソチング法はこれに限定されるこ
となく、例えばフッ素ガスなどの石英ガラス腐食性ガス
を含むバーナ炎でエッチングすべき部分を乾式エッチン
グする方法なども好適に使用される。In the previous example, the outer periphery of the fiber 2 was reduced in diameter by a wet etching method, but the etching method is not limited to this. A method of dry etching is also suitably used.
第８図および第１０図は本発明方法の他の例を説明する
ための図である。FIG. 8 and FIG. 10 are diagrams for explaining other examples of the method of the present invention.
この例では、まず、第８図に示すように、ファイバ２の
一部のクラッド６部分を、そのＸ偏波軸と平行に、コア
４近傍部まで研摩して研摩而ｌ３を形成する。この研摩
面ｌ３の形或長さは特に限定されないが、通常ｌＯ〜５
０ｍｍ程度が望ましい。In this example, first, as shown in FIG. 8, a portion of the cladding 6 of the fiber 2 is polished parallel to its X polarization axis to a portion near the core 4 to form a polished portion 13. The shape or length of this polishing surface l3 is not particularly limited, but is usually lO~5.
Approximately 0 mm is desirable.
またファイバ２の軸方向を一定方向に揃えた状態て、コ
ア４近傍まで研摩する方法としては、ファイバ２埋設用
の溝が形収された基板の溝内にファイバ２を挿入し、袖
方向を揃え、冫：’Ｖ内に接若剤を注入して固化させて
、この基板にファイハ金塊設固定し、次に、この基板の
溝側の而を研摩して、ファイバ２のコア・１近傍まで研
摩が進行した段１１粁で研摩を中止し、基仮からファイ
バを取り外すことによって容易に行うことができる。In addition, as a method of polishing the fiber 2 to the vicinity of the core 4 while aligning the axial direction of the fiber 2 in a certain direction, insert the fiber 2 into a groove of a substrate in which a groove for embedding the fiber 2 is formed, and then align the fiber 2 in the sleeve direction. Alignment: Inject the adhesive into the V and let it solidify, fix the fifer gold ingot to this substrate, and then polish the groove side of this substrate to align the area near the core 1 of fiber 2. This can be easily done by stopping the polishing at step 11, when the polishing has progressed up to the point 11, and removing the fiber from the base.
次に、第９図に示すように、研摩面ｌ３を形成した２本
の研摩ファイバｌ４を並列させ、各々の研摩面１３を第
１０図に示すような状態で接触させる。このとき、接触
させた研摩面１３の両側のファイバを固定治具で固定し
ておくのが望ましい。Next, as shown in FIG. 9, two polished fibers 14 having polished surfaces 13 formed thereon are arranged in parallel, and their respective polished surfaces 13 are brought into contact as shown in FIG. 10. At this time, it is desirable to fix the fibers on both sides of the polished surface 13 that are in contact with each other using a fixing jig.
次に、各ファイバの研摩而１３か接触した部分を醗水素
バーナで加熱融着させ、更に融着部分を延伸して融着延
伸部を形成する。これらの各操作によってカブラが作製
される。Next, the portion of each fiber in contact with the polishing member 13 is heated and fused using a hydrogen burner, and the fused portion is further stretched to form a fused and stretched portion. Each of these operations produces a turnip.
この例による製造方法では、ファイバ２の一部のクラッ
ド６部分をコア４近傍部まで研摩して研摩面ｌ３を形成
して研摩ファイバｌ４とし、２本の研摩ファイバ１４を
並列させて各々の研摩面１３を接触させ、この研摩部分
を融着延伸して融着廷仲部を形成ずるので、融看延仲１
１７１の２つのコア間の距離が小さく、所定の分岐比を
得ろために必要な通仲量を少なくすることかてきる。そ
の結果、１七石延伸部においてコア・１から漏出した光
が応力付与部５に乗り移ったり、応力付与部５を乗り越
えてその外側のクラノト６に結合して非可逆的な結合を
生じる不具合を防止することができ、カブラの仲人損失
の低下を抑制して低損失のカブラを作製することができ
ろ。In the manufacturing method according to this example, a part of the cladding 6 of the fiber 2 is polished to the vicinity of the core 4 to form a polished surface l3 to form a polished fiber l4, and two polished fibers 14 are arranged in parallel and each polished Since the surfaces 13 are brought into contact and this polished part is fused and stretched to form the fused middle part, the fused middle part 1
Since the distance between the two cores of 171 is small, the amount of communication necessary to obtain a predetermined branching ratio can be reduced. As a result, light leaking from the core 1 in the 17-stone extension part transfers to the stress-applying part 5, or crosses over the stress-applying part 5 and combines with the outer part of the core 1, causing an irreversible bond. It would be possible to prevent this, suppress the decline in Kabra matchmaker losses, and create a Kabra with low losses.
まｆ二研摩法によって融着延伸すへき部分のコア間の距
離を少なくするので、コア間の距離を極めて正確に制御
することができる。Since the distance between the cores in the fusion-stretched part is reduced by the second polishing method, the distance between the cores can be controlled extremely accurately.
「実施例 １」
第２図に示すものと同じ断而構逍を有し、コア径ＩＯμ
ｍ、応力付与部径３３μｍ、クラソド外径１２５μｍの
偏波保持形光ファイバを用い、このファイバの一部をフ
ッ酸エソチング液中に浸漬してエゾチング処理を行った
。このエッチング処理によって上記ファイバの一部に長
さ３０ｍｍの細径部分を形成した。この細径部分の外径
（第２図の図中符号Ｉ７の長さ）は９０μｍであった。"Example 1" It has the same cutting structure as shown in Fig. 2, and has a core diameter of IOμ.
Using a polarization-maintaining optical fiber with a stress applying part diameter of 33 μm and a Clathod outer diameter of 125 μm, a part of this fiber was immersed in a hydrofluoric acid ethosing solution to perform an etching treatment. Through this etching process, a narrow diameter portion with a length of 30 mm was formed in a part of the fiber. The outer diameter of this narrow diameter portion (length of reference numeral I7 in FIG. 2) was 90 μm.
次に、２本の細径ファイバを並列させ、各々の細径部分
を接触させ、酸水素バーナで細径部分を融着し、更に延
伸して融着延伸部を形成してカブラを作製した。この実
際の延伸部の長さは約１５ｍｍであった。Next, two small-diameter fibers were arranged in parallel, their small-diameter parts were brought into contact, and the small-diameter parts were fused using an oxyhydrogen burner, and further stretched to form a fused and stretched part to produce a turncoat. . The actual length of this stretch was approximately 15 mm.
得られたカプラの挿入損失を測定した結果、損失は０．
０５ｄＢと非常に低く、また偏波モード間の′ノ口スト
ークは−３０ｄＢ以上と良好であった。As a result of measuring the insertion loss of the obtained coupler, the loss was 0.
It was very low at 0.05 dB, and the 'noguchi stalk between polarization modes was good at -30 dB or more.
「実施例２ 」
先の実施例ｌで使用したものと同じファイバを用い、こ
のファイバを溝付き基板の溝内に埋設固后′シ、次にこ
の基阪の溝側の面を研摩して、ファイバのクラッド部分
をコア近傍まで研摩して研摩ｉｉｉｊを形威した。なお
、研摩面からコアまでの距離は５μｍとした。次に、研
摩面を形成した２木の研摩ファイバを並列させ、各々の
研摩面を接触させ、その両側を固定治具で固定した。次
に、研摩面部分を酸水素バーナで加熱融着し、更にその
一部を延伸した。このときの延伸量は、研摩を施さない
ファイバを用いて融着延伸する場合の約１／３の８ｍｍ
で済んだ。"Example 2" Using the same fiber as that used in the previous Example 1, this fiber was embedded in the groove of a grooved substrate, and then the groove side surface of this base plate was polished. , the cladding portion of the fiber was polished to the vicinity of the core to perform polishing III. Note that the distance from the polished surface to the core was 5 μm. Next, the two abrasive fibers with abrasive surfaces formed thereon were arranged in parallel, their respective abrasive surfaces were brought into contact, and both sides of the abrasive fibers were fixed using a fixing jig. Next, the polished surface portion was heated and fused using an oxyhydrogen burner, and a portion thereof was further stretched. The amount of stretching at this time is 8 mm, which is about 1/3 of that in the case of fusion stretching using unpolished fibers.
I got away with it.
得られたカプラの特性は次の通りであった。The characteristics of the obtained coupler were as follows.
結合比・・・・・ｌ，１
使用波長・・・・ｉ３μｍ
仲人損失・・・・Ｏ ． ｌ ｄＢ
クロストーク・・・・３２（ＩＢ
温度安定性・・・・結合比変化０ １％以下（−２０〜
＋７０°Ｃ）
「発明の効果」
以上説明したように、本発明方法では次のような効果を
奏する。Coupling ratio...l,1 Wavelength used...i3μm Matchmaker loss...O. l dB Crosstalk...32 (IB Temperature stability... Coupling ratio change 0 1% or less (-20~
+70°C) "Effects of the Invention" As explained above, the method of the present invention has the following effects.
クラゾドをエッヂングして創径化しＩこ細径ファイバあ
るいはクラッドを研摩した研摩ファイバを用い、２本の
ファイバを・止列させて、それらの細径郎分あるいは研
摩部分を融４延仲して融着延伸部を形成するのて、融着
延伸前の２つのコア間の距離が小さく、所定の分岐比を
得ろために必要な廷伸量を少なくすることができる。そ
の結果、融着埋（ｌｌＩ部においてコアから漏出しｆこ
光が応カ付与部に乗り移ったり、応力付与部を乗り越え
てその外側のタラットに結合して非可逆的な結合を生じ
ろ不具合を防止することがてき、カプラの柿入１員失の
低丁を抑制して低損失のカプラを作製ずることがてきる
。Using a fine-diameter fiber whose diameter has been created by edging cladding or a polished fiber whose cladding has been polished, two fibers are lined up and the fine-diameter portion or polished portion is fused and stretched. By forming the fusion-stretched portion, the distance between the two cores before fusion-stretching is small, and the amount of stretching necessary to obtain a predetermined branching ratio can be reduced. As a result, light leaking from the core at the IlI portion may transfer to the stress-applying portion, or may cross over the stress-applying portion and bond to the outer turrets, resulting in irreversible bonding. It is possible to prevent the loss of one member of the coupler, and to manufacture a coupler with low loss.
第１図ないし第７図は本発明方法の一例を示す図であっ
て、第ｌ図は細径ファイバの斜視図、第２図は細径ファ
イバの正面図、第３図は２本の細径ファイバを並列させ
“た状態を示す叫面図、第４図は並列させｆコ２本のフ
ァイバの配置状態を示す正面図、第５図は融？’Ｆ延伸
の状態を示す側面図、第６図はカブラの斜視図、第７図
はカプラの融着延伸部の正面断面図、第８図ないし第１
０図は本発明方法の池の例を説明するための図であって
、第８図は研摩ファイバの正面断面図、第９図は２本の
研摩ファイバを並列させた状態を示す側面図、第１０図
は第９図のＸ−Ｘ線断面図、第１１図は従来の融着延仲
形光ファイバカプラの一例を示す側面図、第１２図は偏
波保持形光ファイバの一例を示す正面図、第１３図およ
び第１４図は偏波保持形光ファイバの脇折率分布の同を
示す図である。
１
Ｉ
・・・ファイバ（偏波保持形光ファイバ）・・・コア
・・・１κ力付与部
・・・クラソト
・・・細径部分、
・・・細径ファイバ
ｌ・・・融着延伸部
２・・・カブラ（偏波保持形光ファイバカプラ）３・・
・研摩而
，１・・・研；ｑフｆイバ。1 to 7 are diagrams showing an example of the method of the present invention, in which FIG. 1 is a perspective view of a small diameter fiber, FIG. 2 is a front view of a small diameter fiber, and FIG. FIG. 4 is a front view showing the arrangement of two fibers in parallel, FIG. 5 is a side view showing the state of fusion-stretching, FIG. 6 is a perspective view of the coupler, FIG. 7 is a front sectional view of the fused and stretched portion of the coupler, and FIGS.
Fig. 0 is a diagram for explaining an example of the pond of the method of the present invention, Fig. 8 is a front sectional view of the abrasive fiber, Fig. 9 is a side view showing a state in which two abrasive fibers are arranged in parallel, Fig. 10 is a cross-sectional view taken along the line X-X of Fig. 9, Fig. 11 is a side view showing an example of a conventional fused and rolled optical fiber coupler, and Fig. 12 is an example of a polarization-maintaining optical fiber. The front view, FIG. 13, and FIG. 14 are diagrams showing the side refractive index distribution of the polarization-maintaining optical fiber. 1 I...Fiber (polarization-maintaining optical fiber)...Core...1κ force applying part...Kurasoto...Small diameter part...Small diameter fiber l...Fusion and stretching part 2...Coupler (polarization maintaining optical fiber coupler) 3...
・Kenmaji, 1...Ken; qfu f iba.
Claims (2)
列し、次いでその一部を加熱融着し、更に延伸を行って
融着延伸部を形成する偏波保持形光ファイバカプラの製
造方法において、 上記偏波保持形光ファイバの一部をエッチング処理し、
細径化して細径ファイバを作製し、次いでこの細径ファ
イバどうしあるいは細径ファイバと細径化しない偏波保
持形光ファイバとを並列させ、次いで該細径部分を融着
延伸することを特徴とする偏波保持形光ファイバカプラ
の製造方法。(1) Manufacture of a polarization-maintaining optical fiber coupler in which a plurality of polarization-maintaining optical fibers are arranged in parallel in contact with each other, then a part of the fibers is heated and fused, and further stretched to form a fused and stretched portion. In the method, a part of the polarization maintaining optical fiber is etched,
The method is characterized in that the diameter is reduced to produce a small diameter fiber, then the small diameter fibers or the small diameter fiber and a polarization maintaining optical fiber that is not reduced in diameter are arranged in parallel, and then the small diameter portion is fused and drawn. A method for manufacturing a polarization-maintaining optical fiber coupler.
造方法において、上記細径ファイバの代わりに、偏波保
持形光ファイバの一部を、そのコア近傍まで研摩した研
摩ファイバを用いたことを特徴とする偏波保持形光ファ
イバカプラの製造方法。(2) In the method for manufacturing a polarization-maintaining optical fiber coupler according to claim 1, a polished fiber obtained by polishing a part of the polarization-maintaining optical fiber to the vicinity of its core is used instead of the small diameter fiber. A method for manufacturing a polarization-maintaining optical fiber coupler, characterized in that:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1193156A JP2828276B2 (en) | 1989-07-26 | 1989-07-26 | Manufacturing method of polarization maintaining optical fiber coupler |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1193156A JP2828276B2 (en) | 1989-07-26 | 1989-07-26 | Manufacturing method of polarization maintaining optical fiber coupler |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0356907A true JPH0356907A (en) | 1991-03-12 |
| JP2828276B2 JP2828276B2 (en) | 1998-11-25 |
Family
ID=16303215
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1193156A Expired - Lifetime JP2828276B2 (en) | 1989-07-26 | 1989-07-26 | Manufacturing method of polarization maintaining optical fiber coupler |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2828276B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04315108A (en) * | 1991-04-12 | 1992-11-06 | Nikko Kyodo Co Ltd | Production of polarization maintaining optical fiber coupler |
| US7203397B2 (en) | 2002-08-12 | 2007-04-10 | Fujikura Ltd. | Polarization maintaining optical fiber coupler and method of manufacturing same |
| WO2009035104A1 (en) * | 2007-09-14 | 2009-03-19 | Tatsuta Electric Wire & Cable Co., Ltd. | Optical fiber for optical fiber coupler and optical fiber coupler |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60203904A (en) * | 1984-03-28 | 1985-10-15 | Hitachi Cable Ltd | Manufacture of directional coupler for polarization plane maintaining optical fiber |
| JPS6165205A (en) * | 1984-09-06 | 1986-04-03 | Furukawa Electric Co Ltd:The | Manufacture of optical branching device |
| JPS62116903A (en) * | 1985-11-16 | 1987-05-28 | Sumitomo Electric Ind Ltd | Polarized wave separation type single mode optical fiber coupler |
-
1989
- 1989-07-26 JP JP1193156A patent/JP2828276B2/en not_active Expired - Lifetime
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60203904A (en) * | 1984-03-28 | 1985-10-15 | Hitachi Cable Ltd | Manufacture of directional coupler for polarization plane maintaining optical fiber |
| JPS6165205A (en) * | 1984-09-06 | 1986-04-03 | Furukawa Electric Co Ltd:The | Manufacture of optical branching device |
| JPS62116903A (en) * | 1985-11-16 | 1987-05-28 | Sumitomo Electric Ind Ltd | Polarized wave separation type single mode optical fiber coupler |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04315108A (en) * | 1991-04-12 | 1992-11-06 | Nikko Kyodo Co Ltd | Production of polarization maintaining optical fiber coupler |
| US7203397B2 (en) | 2002-08-12 | 2007-04-10 | Fujikura Ltd. | Polarization maintaining optical fiber coupler and method of manufacturing same |
| WO2009035104A1 (en) * | 2007-09-14 | 2009-03-19 | Tatsuta Electric Wire & Cable Co., Ltd. | Optical fiber for optical fiber coupler and optical fiber coupler |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2828276B2 (en) | 1998-11-25 |
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