JP2855531B2 - Quartz glass-based high-strength optical fiber and method of manufacturing the same - Google Patents
Quartz glass-based high-strength optical fiber and method of manufacturing the sameInfo
- Publication number
- JP2855531B2 JP2855531B2 JP1277263A JP27726389A JP2855531B2 JP 2855531 B2 JP2855531 B2 JP 2855531B2 JP 1277263 A JP1277263 A JP 1277263A JP 27726389 A JP27726389 A JP 27726389A JP 2855531 B2 JP2855531 B2 JP 2855531B2
- Authority
- JP
- Japan
- Prior art keywords
- cladding
- optical fiber
- refractive index
- layer
- doped
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- 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
- C03B37/025—Manufacture of glass fibres or filaments by drawing or extruding, e.g. direct drawing of molten glass from nozzles; Cooling fins therefor from reheated softened tubes, rods, fibres or filaments, e.g. drawing fibres from preforms
- C03B37/027—Fibres composed of different sorts of glass, e.g. glass optical fibres
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Optical Fibers, Optical Fiber Cores, And Optical Fiber Bundles (AREA)
- Manufacture, Treatment Of Glass Fibers (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 この発明は、最外層に表面強化層が形成された石英ガ
ラス系高強度光ファイバおよびその製造方法に関するも
のである。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-strength silica glass optical fiber having a surface reinforcing layer formed on the outermost layer, and a method for manufacturing the same.
伝送損失特性を低下させることなく高強度を有する石
英ガラス系光ファイバとして第３図に示すものが検討さ
れている。図において、１はGeドープシリカコア、２は
シリカクラッド、３は圧縮応力が残留せしめられたＦド
ープシリカ表面強化層で、その軟化温度がシリカクラッ
ド２よりも低いために線引き中にクラッドよりも後から
固化し、クラッドが線引き時に受けた引張応力の開放に
より収縮するときに圧縮応力が残留される。その結果、
光ファイバがその圧縮応力に見合う以上の引張力を受け
るまで実質的に引張張力を受けることにならないので、
ファイバ表面傷の成長が抑制され高強度化が図られたフ
ァイバとなる。As shown in FIG. 3, a silica glass optical fiber having high strength without deteriorating transmission loss characteristics has been studied. In the figure, 1 is a Ge-doped silica core, 2 is a silica clad, and 3 is an F-doped silica surface reinforcing layer in which a compressive stress is left. When the clad contracts due to release of the tensile stress received during drawing, a compressive stress remains. as a result,
Since the optical fiber is not subjected to a substantial tensile force until the optical fiber receives a tensile force greater than the compressive stress,
The growth of fiber surface flaws is suppressed, and the fiber has high strength.
しかしながら、通常このファイバの元になるプリフォ
ームの製造に当たっては、専ら表面強化層となる部分の
軟化温度がクラッドのそれよりも十分低くなるようにと
いう配慮がなされ、そのため表面強化層となる部分への
ふっ素のドープ量が3mg/g程度のプリフォームが作ら
れ、これを線引張力150g程度で線引してファイバとして
いた。ところが、得られたファイバの屈折率分布は第４
図のように表面強化層の屈折率がクラッドのそれよりも
低くなっており、そのためコア−クラッド部でSMファイ
バを構成しても、クラッドを第２のコアとし表面層を第
２のクラッドとするマルチモードも伝搬し光学的に不都
合が生じるという問題があった。However, in the production of the preform from which this fiber is based, care is usually taken to ensure that the softening temperature of the surface reinforcing layer is sufficiently lower than that of the cladding, so A preform with a fluorine doping amount of about 3 mg / g was produced, and this was drawn into a fiber by a drawing tension of about 150 g. However, the refractive index distribution of the obtained fiber is
As shown in the figure, the refractive index of the surface enhancement layer is lower than that of the clad. Therefore, even if an SM fiber is formed in the core-clad portion, the clad is the second core and the surface layer is the second clad. However, there is a problem in that the multi-mode that propagates also causes optical inconvenience.
この発明者等は、この問題点を解決すべく鋭意研究し
た結果、クラッドと表面強化層との屈折率差がＦをドー
プしたことにより本来低下する推定値よりも小さい、す
なわち表面強化層に圧縮応力が付与されて光弾性効果に
より屈折率が高められたということから、もっと表面強
化層に圧縮応力を付与して光弾性効果が高めれば、さら
に屈折率が上昇してクラッドと等しいかもしくはそれ以
上になしうるとの知見を得た。この発明はこの知見に基
づいてなされたもので、第１の請求項に係る発明は、コ
ア−クラッド−表面強化層からなる石英ガラス系高強度
光ファイバであって、前記クラッド層は何もドープされ
ていないか、もしくはふっ素がドープされてあって、前
記表面強化層が前記クラッド層よりも多い量のふっ素が
ドープされて軟化温度がクラッドよりも低くされ、かつ
圧縮応力が残留せしめられて屈折率がクラッドと等しい
か、もしくはそれ以上とされてなることを特徴とする石
英ガラス系高強度光ファイバである。The present inventors have conducted intensive studies to solve this problem, and as a result, the difference in the refractive index between the cladding and the surface enhancement layer is smaller than the estimated value originally reduced due to the doping of F, that is, the compression of the surface enhancement layer is reduced. Since the refractive index was increased by the photoelastic effect by applying stress, if compressive stress is further applied to the surface reinforcing layer to increase the photoelastic effect, the refractive index further increases and is equal to or equal to that of the clad. We have found that we can do this. The present invention has been made based on this finding, and the invention according to the first claim is a quartz glass-based high-strength optical fiber comprising a core-cladding-surface enhancement layer, wherein the cladding layer is entirely doped. The surface enhancement layer is doped with a larger amount of fluorine than the cladding layer, so that the softening temperature is lower than that of the cladding, and the compressive stress remains, and the surface reinforcement layer is refracted. A quartz glass-based high-strength optical fiber characterized by having a ratio equal to or higher than that of the cladding.
また、第２の請求項に係る発明は、コア−クラッド−
表面強化層からなり、前記クラッド層は何もドープされ
ていないか、もしくはふっ素がドープされてあって、表
面強化層に前記クラッド層よりも多い量のふっ素がドー
プされて軟化温度および屈折率がクラッドのそれよりも
低くされた石英ガラス系光ファイバプリフォームを、上
記表面強化層の屈折率がクラッドのそれと等しいか、も
しくはそれ以上となる線引張力で線引きすることを特徴
とする石英ガラス系高強度光ファイバの製造方法であ
る。The invention according to a second aspect is characterized in that the core-clad-
The cladding layer is not doped at all or is doped with fluorine, and the surface enhancement layer is doped with a larger amount of fluorine than the cladding layer, so that the softening temperature and the refractive index are reduced. A silica glass-based optical fiber preform made lower than that of the cladding, wherein the refractive index of the surface reinforcing layer is equal to or higher than that of the cladding, and the silica glass is drawn. This is a method for manufacturing a high-strength optical fiber.
第１図は、クラッドと表面強化層との間の比屈折率
〔△−＝｛（表面強化層の屈折率−クラッドの屈折率）
／クラッドの屈折率｝×100％〕に対する線引張力との
関係を示している。すなわち、表面強化層にＦをドープ
し、クラッドにはＦをドープするかもしくはドープしな
い場合の両者の相対的なＦのドープ量差に基づく比屈折
率差△−を種々変えてプリフォームを作り、そうして得
られたプリフォームを種々の線引張力で線引きして得ら
れるファイバの表面強化層の屈折率を測定し、その屈折
率がクラッドと等しい点を結んでそれを直線Ａで示し、
斜線部分はその屈折率がクラッドよりも大きな部分を示
している。そこで直線Ａから斜線領域内の線引張力で線
引きすればクラッドを第２のコアとするマルチモードの
伝搬を阻止できる。FIG. 1 shows the relative refractive index between the cladding and the surface reinforcing layer [△ − = ｛(refractive index of surface reinforcing layer−refractive index of cladding).
/ Refractive index of clad｝ × 100%] with respect to drawing tension. That is, a preform is prepared by variously changing the relative refractive index difference △ − based on the relative difference in the F doping amount between the case where the surface enhancement layer is doped with F and the case where the cladding is doped or not. The refractive index of the surface reinforcing layer of the fiber obtained by drawing the preform thus obtained with various drawing tensions is measured, and the point where the refractive index is equal to that of the cladding is connected and indicated by a straight line A. ,
The hatched portion indicates a portion whose refractive index is larger than that of the clad. Therefore, if a line is drawn from the straight line A by a drawing tension in a shaded region, multi-mode propagation using the clad as the second core can be prevented.
直径5mmのGeO2（6wt％）−SiO2（94wt％）コア、SiO2
クラッド（外径58mm）、Ｆ−SiO2表面強化層（Ｆ含有量
0.5mm/g、外径60mm）の石英ガラス系光ファイバプリフ
ォーム（クラッドと表面強化層の△−＝0.05％）を線引
張力150gで線引きして外径120μｍのSMファイバとし、
その上に250μｍ厚さにUV樹脂をコーティングした。得
られたファイバの屈折率分布を第２図に示す。図から明
らかなように、表面強化層の屈折率ｎは、1.4591であ
り、クラッドのそれよりも高くなっている。GeO 2 (6 wt%)-SiO 2 (94 wt%) core with a diameter of 5 mm, SiO 2
Cladding (58 mm outer diameter), F-SiO 2 surface strengthening layer (F content
A quartz glass based optical fiber preform (0.5 mm / g, outer diameter 60 mm) (△ − = 0.05% of cladding and surface reinforcing layer) is drawn with a drawing tension of 150 g to form an SM fiber with an outer diameter of 120 μm.
A UV resin was coated thereon to a thickness of 250 μm. FIG. 2 shows the refractive index distribution of the obtained fiber. As is clear from the figure, the refractive index n of the surface enhancement layer is 1.4491, which is higher than that of the cladding.
また、このファイバの伝送特性を測定したところ、従
来のそれがクラッド部をコアとするマルチモードを伴う
伝搬であるのに対して、この発明のファイバは完全なシ
ングルモードファイバであり、マルチモードの伝搬は認
められなかった。Also, when the transmission characteristics of this fiber were measured, the fiber of the present invention was a completely single mode fiber, whereas the conventional one was propagation with multimode having a cladding core. No transmission was observed.
さらに、その破断強度を測定したところ、従来の高強
度ファイバのそれと比較して遜色ないものであった。Further, when the breaking strength was measured, it was inferior to that of the conventional high-strength fiber.
直径5mmのGeO2（5wt％）−SiO2（95wt％）コア、Ｆ−
SiO2クラッド（Ｆ含有量0.5mg/g、外径58mm）、Ｆ−SiO
2表面強化層（Ｆ含有量1.0mm/g、外径60mm）の石英ガラ
ス系光ファイバプリフォーム（クラッドと表面強化層の
△−＝0.05％）を線引張力150gで線引きして外径125μ
ｍのSMファイバとし、その上に250μｍ厚さにUV樹脂を
コーティングした。このときの表面強化層の屈折率ｎ
は、1.4584であり、クラッドのそれよりも５×10-4だけ
高かった。GeO 2 (5 wt%)-SiO 2 (95 wt%) core with a diameter of 5 mm, F-
SiO 2 clad (F content 0.5mg / g, outer diameter 58mm), F-SiO
( 2 ) A silica glass-based optical fiber preform having a surface reinforcing layer (F content: 1.0 mm / g, outer diameter: 60 mm) (（ − = 0.05% of the cladding and the surface reinforcing layer) is drawn with a drawing tension of 150 g to an outer diameter of 125 μm.
m SM fiber, and UV resin was coated thereon to a thickness of 250 μm. The refractive index n of the surface reinforcing layer at this time
Was 1.4584, 5 × 10 -4 higher than that of the cladding.
かくして得られたファイバの伝送特性を測定したが、
実施例Ｉと同様にマルチモードの伝搬は見られなかっ
た。また、破断強度も実施例Ｉとほとんど差異はなかっ
た。The transmission characteristics of the fiber thus obtained were measured.
As in Example I, no multimode propagation was observed. The breaking strength was almost the same as that of Example I.
この発明は、以上のようにＦドープシリカによる表面
強化層を有するファイバを形成するにあたり、元になる
プリフォームの線引張力を表面強化層の屈折率がクラッ
ドのそれと等しいかもしくはそれ以上になる線引張力で
線引きするので、表面強化層には単に圧縮応力が残留す
るだけでなく、その屈折率がクラッドよりも低くなるこ
とがないのでマルチモードの伝搬のない高強度ファイバ
を得ることができる。According to the present invention, in forming a fiber having a surface reinforcing layer made of F-doped silica as described above, the drawing tension of the original preform is reduced by a wire whose refractive index of the surface reinforcing layer is equal to or higher than that of the cladding. Since the drawing is performed by the tensile force, not only the compressive stress remains in the surface reinforcing layer, but also the refractive index does not become lower than that of the cladding, so that a high-strength fiber without multi-mode propagation can be obtained.
第１図は、表面強化層とクラッドとの相対Ｆドープ量と
線引張力との関係を示すグラフ、第２図は、この発明に
よる高強度ファイバの屈折率分布図、第３図は、従来の
高強度ファイバの断面図、第４図は、従来の高強度ファ
イバの屈折率分布図である。 図において、3:表面強化層。FIG. 1 is a graph showing the relationship between the relative F doping amount of the surface reinforcing layer and the cladding and the drawing tension, FIG. 2 is a refractive index distribution diagram of the high-strength fiber according to the present invention, and FIG. FIG. 4 is a refractive index distribution diagram of a conventional high-strength fiber. In the figure, 3: a surface reinforcing layer.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 和田 朗 千葉県佐倉市六崎1440番地 藤倉電線株 式会社佐倉工場内 (72)発明者 山内 良三 千葉県佐倉市六崎1440番地 藤倉電線株 式会社佐倉工場内 (56)参考文献 特開 昭56−62204（ＪＰ，Ａ) 特公 昭64−1415（ＪＰ，Ｂ２) (58)調査した分野(Int.Cl.6，ＤＢ名) G02B 6/00,6/44──────────────────────────────────────────────────続 き Continuing on the front page (72) Akira Wada, Inventor 1440, Mukurosaki, Sakura-shi, Chiba Prefecture Fujikura Electric Wire Co., Ltd.Sakura Plant (56) References JP-A-56-62204 (JP, A) JP-B 64-1415 (JP, B2) (58) Fields investigated (Int. Cl. 6 , DB name) G02B 6 / 00,6 / 44
Claims (2)
ガラス系高強度光ファイバであって、前記クラッド層は
何もドープされていないか、もしくはふっ素がドープさ
れてあって、前記表面強化層が前記クラッド層よりも多
い量のふっ素がドープされて軟化温度がクラッドよりも
低くされ、かつ圧縮応力が残留せしめられて屈折率がク
ラッドと等しいか、もしくはそれ以上とされてなること
を特徴とする石英ガラス系高強度光ファイバ。1. A quartz glass high-strength optical fiber comprising a core-cladding-surface-enhancing layer, wherein the cladding layer is not doped at all or is doped with fluorine. Is characterized by being doped with a larger amount of fluorine than the cladding layer to have a softening temperature lower than that of the cladding, and having a compressive stress remaining and a refractive index equal to or higher than that of the cladding. High-strength silica glass optical fiber.
記クラッド層は何もドープされていないか、もしくはふ
っ素がドープされてあって、表面強化層に前記クラッド
層よりも多い量のふっ素がドープされて軟化温度および
屈折率がクラッドのそれよりも低くされた石英ガラス系
光ファイバプリフォームを、上記表面強化層の屈折率が
クラッドのそれと等しいか、もしくはそれ以上となる線
引張力で線引きすることを特徴とする石英ガラス系高強
度光ファイバの製造方法。2. A cladding layer comprising a core, a cladding and a surface reinforcing layer, wherein the cladding layer is undoped or doped with fluorine, and the surface reinforcing layer has a larger amount of fluorine than the cladding layer. A silica glass-based optical fiber preform doped with a softening temperature and a refractive index lower than that of the clad is drawn with a drawing tension such that the refractive index of the surface reinforcing layer is equal to or higher than that of the clad. A method for manufacturing a high-strength silica glass-based optical fiber.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1277263A JP2855531B2 (en) | 1989-10-26 | 1989-10-26 | Quartz glass-based high-strength optical fiber and method of manufacturing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1277263A JP2855531B2 (en) | 1989-10-26 | 1989-10-26 | Quartz glass-based high-strength optical fiber and method of manufacturing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03139605A JPH03139605A (en) | 1991-06-13 |
| JP2855531B2 true JP2855531B2 (en) | 1999-02-10 |
Family
ID=17581085
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1277263A Expired - Fee Related JP2855531B2 (en) | 1989-10-26 | 1989-10-26 | Quartz glass-based high-strength optical fiber and method of manufacturing the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2855531B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2017015933A (en) * | 2015-07-01 | 2017-01-19 | 株式会社フジクラ | Optical fiber grating, sensor, optical filter, and method for manufacturing optical fiber grating |
| KR20190064120A (en) * | 2017-11-30 | 2019-06-10 | 주식회사 에이엠제이 | Preparing method of strengthened glass fiber and strengthened glass fiber thereof and electronic fiber including the same |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5662204A (en) * | 1979-10-25 | 1981-05-28 | Nippon Telegr & Teleph Corp <Ntt> | Optical transmission fiber and its manufacture |
| JPS641415A (en) * | 1987-06-23 | 1989-01-05 | Mitsui Toatsu Chem Inc | Resin sheet for embedded pipe |
-
1989
- 1989-10-26 JP JP1277263A patent/JP2855531B2/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2017015933A (en) * | 2015-07-01 | 2017-01-19 | 株式会社フジクラ | Optical fiber grating, sensor, optical filter, and method for manufacturing optical fiber grating |
| KR20190064120A (en) * | 2017-11-30 | 2019-06-10 | 주식회사 에이엠제이 | Preparing method of strengthened glass fiber and strengthened glass fiber thereof and electronic fiber including the same |
| KR102007442B1 (en) * | 2017-11-30 | 2019-08-05 | 주식회사 에이엠제이 | Preparing method of strengthened glass fiber and strengthened glass fiber thereof and electronic fiber including the same |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH03139605A (en) | 1991-06-13 |
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