JPS6238310B2 - - Google Patents
Info
- Publication number
- JPS6238310B2 JPS6238310B2 JP56173370A JP17337081A JPS6238310B2 JP S6238310 B2 JPS6238310 B2 JP S6238310B2 JP 56173370 A JP56173370 A JP 56173370A JP 17337081 A JP17337081 A JP 17337081A JP S6238310 B2 JPS6238310 B2 JP S6238310B2
- Authority
- JP
- Japan
- Prior art keywords
- cladding
- core
- sio
- optical fiber
- glass
- 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
Links
- 238000005253 cladding Methods 0.000 claims description 20
- 239000013307 optical fiber Substances 0.000 claims description 13
- 239000011521 glass Substances 0.000 claims description 10
- 230000010287 polarization Effects 0.000 claims description 10
- 229910004298 SiO 2 Inorganic materials 0.000 claims description 9
- 239000011248 coating agent Substances 0.000 claims description 5
- 238000000576 coating method Methods 0.000 claims description 5
- 238000000034 method Methods 0.000 description 8
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 7
- 230000005540 biological transmission Effects 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 5
- 239000002019 doping agent Substances 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 238000009826 distribution Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000000377 silicon dioxide Substances 0.000 description 3
- 238000000151 deposition Methods 0.000 description 2
- 229910005793 GeO 2 Inorganic materials 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000011534 incubation Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C03C13/00—Fibre or filament compositions
- C03C13/04—Fibre optics, e.g. core and clad fibre compositions
- C03C13/045—Silica-containing oxide glass compositions
Landscapes
- Chemical & Material Sciences (AREA)
- Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Optical Fibers, Optical Fiber Cores, And Optical Fiber Bundles (AREA)
- Glass Compositions (AREA)
Description
【発明の詳細な説明】
本発明はクラツドの断面が楕円形の定偏波型光
フアイバに関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a constant polarization optical fiber whose cladding has an elliptical cross section.
クラツドを楕円にし、コアに異方性歪を起こ
し、光弾性効果によつて長軸、短軸方向の屈折
率、従つて伝搬定数の差を大きくし、長軸、短軸
の偏波を保存するいわゆる定偏波型光フアイバが
知られている。 The cladding is made into an ellipse, causing anisotropic strain in the core, and the photoelastic effect increases the difference in refractive index and propagation constant in the major and minor axis directions, preserving polarization in the major and minor axes. A so-called constant polarization type optical fiber is known.
一般に光フアイバはマルチモード伝送用として
コア径の比較的大きいものが実用されているが、
定偏波型光フアイバ径が比較的小さいものであ
る。 Generally, optical fibers with relatively large core diameters are used for multimode transmission, but
The constant polarization type optical fiber has a relatively small diameter.
また、一般に実用されているようなコアにドー
パントを含有させたものを内寸法によつて製造し
ようとすると、良く知られている中心抜け現象に
より中心部の屈折率分布が大きく乱れ、伝送特性
上好ましくないが、コア径の小さな定偏波型光フ
アイバでは、特にその影響が大きく伝送特性が劣
る。 In addition, if we try to manufacture a core containing a dopant, which is commonly used in practice, by adjusting the inner dimensions, the refractive index distribution in the center will be greatly disturbed due to the well-known center drop phenomenon, which will affect the transmission characteristics. Although undesirable, this effect is particularly large in polarization-constant optical fibers with small core diameters, resulting in poor transmission characteristics.
そこでコアにドーパントを含まない高純度シリ
カを採用することで、この問題を解消することが
考えられるが、高純度シリカは融点が高く、ドー
パントを多く含むガラスとは熱膨張係数も相違し
ている。 Therefore, it is possible to solve this problem by using high-purity silica that does not contain dopants in the core, but high-purity silica has a high melting point and a coefficient of thermal expansion that is different from glass that contains a large amount of dopants. .
異方性歪を起こすクラツド材料としてはB2O3
が有力とされており、GeO2―B2O3―SiO2系ガラ
スをクラツド材料として用いることも提案されて
いる。 B 2 O 3 is a cladding material that causes anisotropic strain.
is considered to be a promising material, and the use of GeO 2 -B 2 O 3 -SiO 2 glass as the cladding material has also been proposed.
このような定偏波型光フアイバの製造方法とし
ては、内付法、外付法、ロツドインチユーブ法な
ど種々考えられているが、反応温度が高温であれ
ばあるほど外側のガラス被覆からコア方向にOH
基が拡張するため伝送損失が増大する傾向にあ
る。 Various methods have been considered for producing such constant polarization optical fibers, including the internal method, external method, and rod incubation method, but the higher the reaction temperature, the more the outer glass coating OH toward the core
As the base expands, transmission loss tends to increase.
そこでクラツドの材質として反応温度の比較的
低いP2O5―B2O3―SiO2系ガラスを採用すること
が提案され、このようなクラツドであればロツド
インチユーブ法及び外付法とロツドインチユーブ
法の組合せ法により比較的伝送損失の低い光フア
イバが得られたが、低損失化に有効な内付法の採
用が未だ困難であつた。 Therefore, it was proposed to use P 2 O 5 -B 2 O 3 -SiO 2 glass, which has a relatively low reaction temperature, as the material for the cladding. Although an optical fiber with relatively low transmission loss has been obtained by a combination of the rod in-tube method, it has still been difficult to employ the inlay method, which is effective in reducing loss.
即ちクラツドが硬すぎると、内付後クラツドの
みを楕円形に形成することが難しく、また軟かす
ぎると内面に反応温度の高いコアを形成すること
が不可能であつた。 That is, if the cladding is too hard, it is difficult to form only the cladding into an elliptical shape after internalization, and if it is too soft, it is impossible to form a core with a high reaction temperature on the inner surface.
特に、特開昭56―99306号公報に記載されてい
るような定偏波型光フアイバの場合には、高純度
シリカコアを採用すると、B2O3を含む楕円層が
B2O3を20モル％以上も含有していることから、
コアと最外層の両方に比較して熱膨張係数があま
りにも違い過ぎ、製造過程や製造後においてクラ
ツドが入り、現実に実用できるものは極めて少な
い。 In particular, in the case of polarization-controlled optical fibers such as those described in JP-A-56-99306, when a high-purity silica core is used, an elliptical layer containing B 2 O 3 is formed.
Since it contains more than 20 mol% of B 2 O 3 ,
The thermal expansion coefficients are too different compared to both the core and the outermost layer, and cladding occurs during the manufacturing process or after manufacturing, so there are very few products that can be put to practical use.
つまり、コアと最外層が高純度シリカでその間
の楕円形クラツドB2O3を20モル％以上含む構造
は、理論的には存在するものの、工業的には非現
実的なものと言わざるを得ない。 In other words, although a structure in which the core and outermost layer are made of high-purity silica and the elliptical cladding between them contains 20 mol% or more of B 2 O 3 exists theoretically, it is unrealistic from an industrial perspective. I don't get it.
本発明は斯かる状況に鑑み、比較的ポピユラー
でかつ低損失化に有効な内付法で容易に製造で
き、一層の低損失化が達成できた定偏波型光フア
イバを提供することを目的とする。 In view of this situation, the present invention aims to provide a constant polarization optical fiber that is relatively popular and can be easily manufactured using an internal attachment method that is effective in reducing loss, and can achieve even lower loss. shall be.
本発明の構成を、一実施例を示す図面を参照し
て具体的に説明する。 The configuration of the present invention will be specifically explained with reference to the drawings showing one embodiment.
第１図において、１はコアであり高純度SiO2
で形成され、２は断面楕円形のクラツドであり、
３は実質SiO2で形成されたガラス被覆である。 In Figure 1, 1 is the core, which is made of high purity SiO 2
2 is a clad with an oval cross section,
3 is a glass coating made essentially of SiO 2 .
ここで、クラツドにB2O3が添加されているの
は定偏波型光フアイバに必須の異方性歪を付与す
るためであり、その点では公知の特開昭56―
99306号に記載されている発明の趣旨と一致して
いる。 Here, the reason why B 2 O 3 is added to the cladding is to impart anisotropic strain that is essential to a constant polarization type optical fiber.
This is consistent with the gist of the invention described in No. 99306.
また、P2O5はこれを添加すると粘度、反応温
度が下がることが良く知られているので、必要に
応じてクラツドにP2O5を含有させてもよいので
ある。 Furthermore, since it is well known that the addition of P 2 O 5 lowers the viscosity and reaction temperature, P 2 O 5 may be included in the cladding if necessary.
本発明の特徴となるポイントは、このクラツド
２のドープ量をB2O3とP2O5と合計して８〜15モ
ル％としたことである。 The feature of the present invention is that the doping amount of the cladding 2 is 8 to 15 mol % in total with B 2 O 3 and P 2 O 5 .
ドープ量が８モル％未満であると、クラツド２
が硬くなり、内付法で製造した場合に、コア１と
ガラス被覆３を円形に保持しながら、クラツド２
のみを楕円形に形成することが著しく難しく、再
現性が悪い。 When the doping amount is less than 8 mol%, the cladding 2
becomes hard and when manufactured by the internal attachment method, the cladding 2 is held while holding the core 1 and the glass coating 3 in a circular shape
It is extremely difficult to form the chisel into an oval shape, and the reproducibility is poor.
ドープ量が15モル％を越えると、逆にクラツド
２が軟くなり、内付法で製造しようとした場合
に、加熱バーナーの動きに追従して内付けしたク
ラツド２の層が流動してしまい、その内側にコア
を形成することが不可能となる。 If the doping amount exceeds 15 mol%, Clad 2 will become soft, and if you try to manufacture it using the internal deposition method, the layer of Clad 2 attached internally will follow the movement of the heating burner and flow. , it becomes impossible to form a core inside it.
以上説明したような本発明の定偏波型光フアイ
バであれば次のような顕著な効果を奏する。 The polarization constant optical fiber of the present invention as described above provides the following remarkable effects.
(1) コアを高純度SiO2とし、格別のドーパント
を含まないので、低損失であり、内付法により
製造した場合にも中心抜けが発生せず屈折率分
布が乱れないため伝送特性が良好である。(1) The core is made of high-purity SiO 2 and does not contain any special dopants, so it has low loss, and even when manufactured using the internal attachment method, there is no center dropout and the refractive index distribution is not disturbed, so the transmission characteristics are good. It is.
(2) クラツドのドープ量が８〜15モル％であるの
で、内付法が製造することが可能であり、工業
的再現性が高く、しかも一層低損失化が達成で
き信頼性も高い。(2) Since the doping amount of the cladding is 8 to 15 mol %, it is possible to manufacture by the internal deposition method, which has high industrial reproducibility, further reduces loss, and has high reliability.
第１図は本発明の一実施例を示す断面図であ
り、第２図はその屈折率分布を示す線図である。
１：コア、２：クラツド、３：ガラス被覆。
FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG. 2 is a diagram showing its refractive index distribution. 1: core, 2: cladding, 3: glass coating.
Claims (1)
し、該コア１の外側にコア１より屈折率が低く断
面が楕円形のクラツド２を有し、該クラツド２の
外側にガラス被覆３を有するものにおいて、前記
コア１が高純度SiO2からなり、前記クラツド２
がB2O3―SiO2系ガラスもしくはP2O5―B2O3―
SiO2系ガラスからなり、かつ該クラツド２にお
けるP2O5とB2O3の合計ドープ量が８〜15モル％
であることを特徴とする定偏波型光フアイバ。1 The optical fiber has a core 1 with a circular cross section at the center, a cladding 2 with an elliptical cross section and a lower refractive index than the core 1 on the outside of the core 1, and a glass coating 3 on the outside of the cladding 2. The core 1 is made of high-purity SiO 2 and the cladding 2 is made of high purity SiO 2 .
is B 2 O 3 ―SiO 2 glass or P 2 O 5 ―B 2 O 3 ―
Made of SiO 2 glass, and the total doping amount of P 2 O 5 and B 2 O 3 in the cladding 2 is 8 to 15 mol%
A constant polarization optical fiber characterized by:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56173370A JPS5874535A (en) | 1981-10-29 | 1981-10-29 | Constant polarization type optical fiber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56173370A JPS5874535A (en) | 1981-10-29 | 1981-10-29 | Constant polarization type optical fiber |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5874535A JPS5874535A (en) | 1983-05-06 |
| JPS6238310B2 true JPS6238310B2 (en) | 1987-08-17 |
Family
ID=15959131
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56173370A Granted JPS5874535A (en) | 1981-10-29 | 1981-10-29 | Constant polarization type optical fiber |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5874535A (en) |
-
1981
- 1981-10-29 JP JP56173370A patent/JPS5874535A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5874535A (en) | 1983-05-06 |
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