JPH0662313B2 - Method for manufacturing optical fiber made of chalcogenide glass having core / clad structure - Google Patents
Method for manufacturing optical fiber made of chalcogenide glass having core / clad structureInfo
- Publication number
- JPH0662313B2 JPH0662313B2 JP63038474A JP3847488A JPH0662313B2 JP H0662313 B2 JPH0662313 B2 JP H0662313B2 JP 63038474 A JP63038474 A JP 63038474A JP 3847488 A JP3847488 A JP 3847488A JP H0662313 B2 JPH0662313 B2 JP H0662313B2
- Authority
- JP
- Japan
- Prior art keywords
- core
- tube
- clad
- glass
- crucible
- 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 - Lifetime
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
- C03B37/01—Manufacture of glass fibres or filaments
- C03B37/02—Manufacture of glass fibres or filaments by drawing or extruding, e.g. direct drawing of molten glass from nozzles; Cooling fins therefor
- C03B37/022—Manufacture of glass fibres or filaments by drawing or extruding, e.g. direct drawing of molten glass from nozzles; Cooling fins therefor from molten glass in which the resultant product consists of different sorts of glass or is characterised by shape, e.g. hollow fibres, undulated fibres, fibres presenting a rough surface
- C03B37/023—Fibres composed of different sorts of glass, e.g. glass optical fibres, made by the double crucible technique
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B2201/00—Type of glass produced
- C03B2201/80—Non-oxide glasses or glass-type compositions
- C03B2201/86—Chalcogenide glasses, i.e. S, Se or Te glasses
Description
【発明の詳細な説明】 ［産業上の利用分野］ 本発明は光の透過性に優れたコア・クラッド構造を有す
る光ファイバーの製造方法に関する。TECHNICAL FIELD The present invention relates to a method for producing an optical fiber having a core / clad structure having excellent light transmittance.
［従来の技術］ 光ファイバーは情報伝送、エネルギー伝送、計測等の様
々な用途に応用されつつあり、その材質にはシリカをは
じめとした酸化物ガラス、フッ化ジルコニウムを主成分
にしたフッ化物ガラス、銀やタリウムのハロゲン化物で
作られたハライド結晶及びイオウ、セレン、テルルの化
合物で作られたカルコゲナイドガラス等が知られてい
る。[Prior Art] Optical fibers are being applied to various applications such as information transmission, energy transmission, and measurement. The material thereof is oxide glass such as silica, fluoride glass containing zirconium fluoride as a main component, Halide crystals made of halides of silver and thallium and chalcogenide glasses made of compounds of sulfur, selenium and tellurium are known.
一般に光ファイバーは（屈折率の高い）コア材料の外周
をコアよりも屈折率の低いある有限の厚さのクラッド材
料で被った、いわゆるコア・クラッド構造にすることが
好ましい。これはファイバーの伝送損失を向上させるた
めだけでなく、ファイバーの機械的強度や耐候性の向上
のためにも望ましい。Generally, it is preferable that the optical fiber has a so-called core-clad structure in which the outer periphery of a core material (having a high refractive index) is covered with a clad material having a refractive index lower than that of the core and having a finite thickness. This is desirable not only for improving the transmission loss of the fiber, but also for improving the mechanical strength and weather resistance of the fiber.
コア・クラッド構造を有するファイバーの製造方法とし
ては、クラッドとなるチューブ状のガラスの中にコアと
なるロッド状のガラスを挿入し、その先端部を溶融紡糸
するロッドインチューブ法が、石英ガラスファイバーの
製造に従来から利用されている。As a method for producing a fiber having a core / clad structure, a rod-in-tube method in which a rod-shaped glass that serves as a core is inserted into a tube-shaped glass that serves as a clad, and the tip end thereof is melt-spun is a quartz glass fiber. Has been conventionally used for manufacturing
［発明が解決しようとする課題］ しかし、上記のようなロッドインチューブ法により光フ
ァイバーを製造する際には、コア・クラッド界面への泡
や異物の混入を防ぎ、熱的安定性を保って紡糸するため
の高度の技術を必要とする。特にカルコゲナイドガラス
の場合には、僅かな温度変化でも粘度が著しく変動する
うえ、その紡糸は非酸化性雰囲気で行なわなければなら
ないため、ロッドインチューブ法をそのまま適用できな
いという問題点があった。[Problems to be Solved by the Invention] However, when an optical fiber is manufactured by the rod-in-tube method as described above, spinning is performed while preventing bubbles and foreign matter from entering the core-clad interface and maintaining thermal stability. Requires advanced technology to do. Particularly in the case of chalcogenide glass, there is a problem that the rod-in-tube method cannot be applied as it is because the viscosity changes remarkably even with a slight temperature change and the spinning must be performed in a non-oxidizing atmosphere.
本発明の目的は、コア・クラッド界面への泡や異物の混
入を防いで紡糸することのできるカルコゲナイドガラス
製光ファイバーの製造法を提供するにある。また本発明
の別の目的は、紡糸の際の材料の蒸発、凝集が起こりに
くく、かつ材料がガラス材料で熱的安定性に劣る場合に
も材料の失透が起こりくにい低い温度で紡糸することが
できるコア・クラッド構造を有するカルコゲナイドガラ
ス製光ファイバーの製造方法を提供するにある。It is an object of the present invention to provide a method for producing an optical fiber made of chalcogenide glass which can prevent bubbles and foreign substances from entering the core / clad interface and can be spun. Another object of the present invention is to spin at a low temperature at which evaporation and aggregation of the material during spinning hardly occur, and devitrification of the material hardly occurs even when the material is a glass material and poor in thermal stability. Another object of the present invention is to provide a method for producing an optical fiber made of chalcogenide glass having a core / clad structure capable of achieving the above.
［課題を解決するための手段］ 本発明に係る光ファイバーの製造方法は、クラッド用チ
ューブの中に該クラッドチューブよりも屈折率の高いコ
ア用ロッドを挿入してルツボ中に密封し、チューブとロ
ッドの間隙の気体の圧力よりもチューブ外周の気体圧力
の方が高くなるように圧力を調整しながら、該チューブ
と該ロッドとを同時に線引きすることによってコア・ク
ラッド構造を有するカルコゲナイドガラス製光ファイバ
ーを得ることを特徴とするものである。[Means for Solving the Problems] In the method of manufacturing an optical fiber according to the present invention, a core rod having a refractive index higher than that of the clad tube is inserted into the clad tube, and the core tube is hermetically sealed in the crucible. A chalcogenide glass optical fiber having a core / clad structure is obtained by simultaneously drawing the tube and the rod while adjusting the pressure so that the gas pressure around the tube is higher than the gas pressure in the gap. It is characterized by that.
本発明の方法において、クラッド用チューブとコア用ロ
ッドとの間隙の気体の圧力は大気圧以下、好ましくは10
-2torr以下であり、かつ該チューブ外周とルツボとの間
隙の気体圧力を大気圧を超えた圧力に保持する。チュー
ブとロッドの間隙の圧力が大気圧よりも高くなると、ま
たチューブ外周の圧力が大気圧よりも低くなると得られ
るファイバーのコア・クラッド界面に気泡を生じやす
い。In the method of the present invention, the pressure of the gas in the gap between the cladding tube and the core rod is atmospheric pressure or less, preferably 10
The pressure is −2 torr or less, and the gas pressure in the gap between the outer circumference of the tube and the crucible is maintained at a pressure exceeding atmospheric pressure. When the pressure in the gap between the tube and the rod is higher than the atmospheric pressure, and when the pressure on the outer circumference of the tube is lower than the atmospheric pressure, bubbles are easily generated at the core-clad interface of the obtained fiber.
本発明では、クラッドチューブとコアロッドを下部にノ
ズルを備えたルツボ内に収容して密封し、該ルツボのノ
ズル近傍のチューブ及びロッドを両者のガラス転移温度
よりも高い温度に加熱して線引きすることによってコア
・クラッド界面のなめらかな光ファイバーを製造するこ
とができる。In the present invention, the clad tube and the core rod are housed and sealed in a crucible having a nozzle at the bottom, and the tube and the rod in the vicinity of the nozzle of the crucible are heated to a temperature higher than the glass transition temperature of both and drawn. Thus, an optical fiber with a smooth core / clad interface can be manufactured.
また、本発明では、ノズル付ルツボ内部を窒素、アルゴ
ン等の不活性ガスで充分に置換した後に加熱、紡糸する
ことが好ましい。また結晶化しやすいガラス材料の場合
には紡糸中のルツボとクラッドチューブとの間隙の気体
の圧力を大気圧を超えた圧力、約１kg／cm2から２kg／c
m2程上げることによって紡糸温度を下げることができ、
その結果、ガラスの失透が抑制される。Further, in the present invention, it is preferable that the inside of the crucible with a nozzle is sufficiently replaced with an inert gas such as nitrogen or argon and then heated and spun. In the case of a glass material that is easily crystallized, the pressure of the gas in the gap between the crucible and the clad tube during spinning exceeds the atmospheric pressure, approximately 1 kg / cm 2 to 2 kg / c.
The spinning temperature can be lowered by raising it by about m 2 .
As a result, devitrification of the glass is suppressed.
［実施例］ 次に本発明の方法を実施例に基づいてさらに詳細に説明
する。[Examples] Next, the method of the present invention will be described in more detail with reference to Examples.
実施例１ 第１図に示した構成の装置を使用して、本発明の方法に
従い、コア・クラッド構造を有するカルコゲナイドガラ
スファイバーを製造した。Example 1 A chalcogenide glass fiber having a core-clad structure was manufactured according to the method of the present invention using the apparatus having the configuration shown in FIG.
Ｇｅ：25モル％、Ａｓ：20モル％、Ｓｅ：25モル％、Ｔ
ｅ：30モル％の組成を有し、直径 8.5mm、長さ 150mmの
コアロッドガラス１を、Ｇｅ：20モル％、Ａｓ：30モル
％、Ｓｅ：30モル％、Ｔｅ：20モル％の組成を有し、内
径 9.0mm、外径12.5mm、長さ 150mmのクラッド用ガラス
チューブ２の中に入れ、これを底部に紡糸ノズル８を備
えたルツボ３の中に垂直に収容した。そして、加圧用不
活性ガス入口９及び減圧用吸引口10、雰囲気調整箱12の
不活性ガス入口11よりアルゴンガスを300cc／分の流量
で流し込み、ルツボ３内及び雰囲気調整箱12内を充分に
アルゴンガスで置換した。Ge: 25 mol%, As: 20 mol%, Se: 25 mol%, T
The core rod glass 1 having a composition of e: 30 mol% and a diameter of 8.5 mm and a length of 150 mm was prepared with a composition of Ge: 20 mol%, As: 30 mol%, Se: 30 mol%, Te: 20 mol%. It was placed in a glass tube 2 for cladding having an inner diameter of 9.0 mm, an outer diameter of 12.5 mm and a length of 150 mm, which was vertically housed in a crucible 3 having a spinning nozzle 8 at the bottom. Then, argon gas is introduced at a flow rate of 300 cc / min from the pressurizing inert gas inlet 9 and the depressurizing suction port 10 and the inert gas inlet 11 of the atmosphere adjusting box 12 to sufficiently fill the crucible 3 and the atmosphere adjusting box 12. It was replaced with argon gas.
次いで加圧用不活性ガス入口９、減圧用吸引口10からの
アルゴンガスの供給を止め、ルツボ３の紡糸ノズル近傍
のみを局部的に加熱できるヒーター17を 380℃まで昇温
し、ルツボ３内のガラスチューブ２及びガラスロッド１
を、ガラス転移温度よりも高い温度に加熱して両者を融
着させた後、再び加圧用不活性ガス入口９からアルゴン
ガスを供給してルツボ３内を 1.5kg／cm2に加圧すると
同時に、コア用ガラスロッド１とクラッド用ガラスチュ
ーブ２の間隙を吸引チューブ７を通して吸引口10より10
-2torrにまで減圧した。融着して流動状態にあるガラス
ロッド１とガラスチューブ２はコア・クラッド構造を保
持したまま紡糸ノズル８から押し出された。Then, the supply of argon gas from the pressurizing inert gas inlet 9 and the depressurizing suction port 10 is stopped, the heater 17 capable of locally heating only the vicinity of the spinning nozzle of the crucible 3 is heated to 380 ° C., and the inside of the crucible 3 is heated. Glass tube 2 and glass rod 1
Is heated to a temperature higher than the glass transition temperature to fuse the two, and then argon gas is supplied again from the inert gas inlet 9 for pressurization to pressurize the crucible 3 to 1.5 kg / cm 2 at the same time. , Through the suction tube 7 through the gap between the core glass rod 1 and the clad glass tube 2 through the suction port 10
The pressure was reduced to -2 torr. The glass rod 1 and the glass tube 2 which were fused and in a fluidized state were extruded from the spinning nozzle 8 while maintaining the core-clad structure.
こうして得られたファイバーを直ちに樹脂コーター14に
導いて紫外線硬化型樹脂をファイバーにコーティングし
た後、紫外線照射箱15内を通過させ、樹脂を硬化させる
ことによって、コア径 300μｍ、クラッド径 420μｍ、
樹脂コーティング厚30μｍのファイバーを得た。このフ
ァイバーの透過損失曲線を第２図に示す。波長７μｍ付
近において、 0.6dB／ｍであり、コーティングされた樹
脂による吸水は全く見られなかった。なお、第１図中、
５はルツボ３とルツボ用蓋４との接続用樹脂チューブ、
６はクラッド用ガラスチューブ２と吸引用チューブ７と
の接続用樹脂チューブ、13はファイバー線径測定器、16
はプリントローラーである。The fiber thus obtained is immediately guided to the resin coater 14 to coat the fiber with the ultraviolet curable resin, and then the resin is passed through the ultraviolet irradiation box 15 to cure the resin, whereby the core diameter is 300 μm, the clad diameter is 420 μm,
A fiber having a resin coating thickness of 30 μm was obtained. The transmission loss curve of this fiber is shown in FIG. It was 0.6 dB / m in the vicinity of the wavelength of 7 μm, and no water absorption by the coated resin was observed. In addition, in FIG.
5 is a resin tube for connecting the crucible 3 and the crucible lid 4,
6 is a resin tube for connecting the glass tube 2 for cladding and the suction tube 7, 13 is a fiber diameter measuring instrument, 16
Is a print roller.
比較例 実施例でコアに用いたガラスロッドのみを第１図に示す
装置のルツボ３に入れ、ガラスチューブの代りに樹脂被
覆した以外は、実施例１と同様な方法で樹脂クラッドフ
ァイバーを製造した。得られた樹脂クラッドファイバー
の透過損失曲線を第３図に示す。第２図及び第３図を対
比すると、比較例のファイバーには樹脂による吸引が生
じていることが認められた。Comparative Example A resin clad fiber was produced in the same manner as in Example 1 except that only the glass rod used as the core in the example was put in the crucible 3 of the apparatus shown in FIG. 1 and resin coating was performed instead of the glass tube. . The transmission loss curve of the obtained resin clad fiber is shown in FIG. Comparing FIG. 2 and FIG. 3, it was confirmed that the fiber of the comparative example was sucked by the resin.
［発明の効果］ 本発明の方法によれば、従来のロッドインチューブ法で
起こりがちなコア・クラッド界面の泡や異物等の不整が
生じることのない光ファイバーを製造することができ
る。また、カルコゲナイドガラスが失透しやすい場合で
も失透の起こらない低い温度域でコア・クラッド界面の
なめらかな低損失なファイバーを製造することができ
る。[Effect of the Invention] According to the method of the present invention, it is possible to manufacture an optical fiber that is free from irregularities such as bubbles and foreign substances at the core-clad interface, which tend to occur in the conventional rod-in-tube method. Further, even if the chalcogenide glass is easily devitrified, it is possible to manufacture a fiber with a smooth low loss at the core-clad interface in a low temperature range where devitrification does not occur.
第１図は本発明の実施例で使用したファイバー製造装置
の概略断面図、第２図は実施例で得たコア・クラッド型
ガラスファイバーの透過損失曲線を示すグラフ、第３図
は比較例で得た樹脂クラッドガラスファイバーの透過損
失曲線を示すグラフである。 １……コア用ガラスロッド、２……クラッド用ガラスチ
ューブ、３……ノズル付ルツボ、４……ノズル付ルツボ
用蓋、５、６……接続用樹脂チューブ、７……吸引用樹
脂チューブ、８……紡糸用ノズル、９……加圧用不活性
ガス入口、10……減圧用吸引口、11……雰囲気調整箱用
不活性ガス入口、12……雰囲気調整箱、13……ファイバ
ー線径測定器、14……樹脂コーター、15……紫外線照射
箱、16……プリントローラー、17……局部加熱用ヒータ
ー。FIG. 1 is a schematic sectional view of a fiber manufacturing apparatus used in an example of the present invention, FIG. 2 is a graph showing a transmission loss curve of the core-clad type glass fiber obtained in the example, and FIG. 3 is a comparative example. It is a graph which shows the transmission loss curve of the obtained resin clad glass fiber. 1 ... Core glass rod, 2 ... Clad glass tube, 3 ... Nozzle crucible, 4 ... Nozzle crucible lid, 5, 6 ... Connection resin tube, 7 ... Suction resin tube, 8 ... Spinning nozzle, 9 ... Pressurizing inert gas inlet, 10 ... Depressurizing suction port, 11 ... Inert gas inlet for atmosphere adjusting box, 12 ... Atmosphere adjusting box, 13 ... Fiber wire diameter Measuring device, 14 ... Resin coater, 15 ... UV irradiation box, 16 ... Print roller, 17 ... Local heating heater.
Claims (2)
ューブより屈折率の高いコア用ロッドを挿入し、加熱溶
融して紡糸する方法において、前記チューブの中にコア
用ロッドを挿入したものを底部にノズルを備えたルツボ
内に収容して密封し、クラッド用チューブとコア用ロッ
ドとの間隙の気体圧力を大気圧以下とし、かつクラッド
用チューブ外周とルツボとの間隙の気体圧力を大気圧を
超えた圧力として紡糸することを特徴とするコア・クラ
ッド構造を有するカルコゲナイドガラス製光ファイバー
の製造方法。1. A method of inserting a core rod having a refractive index higher than that of the clad tube into the clad tube, heating and melting the fiber, and spinning the clad tube, wherein the core rod is inserted into the tube. It is housed and sealed in a crucible equipped with a nozzle, the gas pressure in the gap between the clad tube and the core rod is below atmospheric pressure, and the gas pressure in the gap between the clad tube outer circumference and the crucible is kept at atmospheric pressure. A method for producing an optical fiber made of chalcogenide glass having a core-clad structure, which comprises spinning at an excessive pressure.
したものを、底部にノズルを備えたルツボ内に収容して
密封し、ルツボ下部のノズル近傍のみを前記チューブお
よびロッドのガラス転移温度よりも高い温度に加熱して
紡糸することを特徴とする請求項１記載のコア・クラッ
ド構造を有するカルコゲナイドガラス製光ファイバーの
製造方法。2. A clad tube having a core rod inserted therein is housed and sealed in a crucible having a nozzle at the bottom, and only the vicinity of the nozzle below the crucible is higher than the glass transition temperature of the tube and rod. The method for producing an optical fiber made of chalcogenide glass having a core-clad structure according to claim 1, characterized in that the fiber is heated to a high temperature for spinning.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63038474A JPH0662313B2 (en) | 1988-02-23 | 1988-02-23 | Method for manufacturing optical fiber made of chalcogenide glass having core / clad structure |
| US07/232,998 US4908053A (en) | 1987-08-19 | 1988-08-17 | Process for producing chalcogenide glass fiber |
| FR888811067A FR2619561B1 (en) | 1987-08-19 | 1988-08-19 | PROCESS FOR PREPARING FIBERS IN CHALCOGENIDE GLASSES |
| GB8819757A GB2208859B (en) | 1987-08-19 | 1988-08-19 | Process for producing chalcogenide glass fibers |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63038474A JPH0662313B2 (en) | 1988-02-23 | 1988-02-23 | Method for manufacturing optical fiber made of chalcogenide glass having core / clad structure |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01215738A JPH01215738A (en) | 1989-08-29 |
| JPH0662313B2 true JPH0662313B2 (en) | 1994-08-17 |
Family
ID=12526249
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63038474A Expired - Lifetime JPH0662313B2 (en) | 1987-08-19 | 1988-02-23 | Method for manufacturing optical fiber made of chalcogenide glass having core / clad structure |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0662313B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20060014523A (en) * | 2004-08-11 | 2006-02-16 | 삼성에스디아이 주식회사 | Method of fabricating spacer and installing spacer on flat panel device |
| JP5362140B1 (en) | 2011-12-19 | 2013-12-11 | オリンパス株式会社 | Optical fiber manufacturing method, optical fiber, and endoscope |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS573608A (en) * | 1980-06-06 | 1982-01-09 | Matsushita Electric Ind Co Ltd | Mixer |
| JPS6124340A (en) * | 1984-07-12 | 1986-02-03 | Fujikura Ltd | Switching method of cable core |
-
1988
- 1988-02-23 JP JP63038474A patent/JPH0662313B2/en not_active Expired - Lifetime
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS573608A (en) * | 1980-06-06 | 1982-01-09 | Matsushita Electric Ind Co Ltd | Mixer |
| JPS6124340A (en) * | 1984-07-12 | 1986-02-03 | Fujikura Ltd | Switching method of cable core |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01215738A (en) | 1989-08-29 |
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