JP2599451B2 - Manufacturing method of optical fiber base material - Google Patents
Manufacturing method of optical fiber base materialInfo
- Publication number
- JP2599451B2 JP2599451B2 JP63307014A JP30701488A JP2599451B2 JP 2599451 B2 JP2599451 B2 JP 2599451B2 JP 63307014 A JP63307014 A JP 63307014A JP 30701488 A JP30701488 A JP 30701488A JP 2599451 B2 JP2599451 B2 JP 2599451B2
- Authority
- JP
- Japan
- Prior art keywords
- deposition layer
- particle deposition
- glass fine
- fine particle
- 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.)
- 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
- C03B37/012—Manufacture of preforms for drawing fibres or filaments
- C03B37/014—Manufacture of preforms for drawing fibres or filaments made entirely or partially by chemical means, e.g. vapour phase deposition of bulk porous glass either by outside vapour deposition [OVD], or by outside vapour phase oxidation [OVPO] or by vapour axial deposition [VAD]
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General 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)
- Manufacture, Treatment Of Glass Fibers (AREA)
Description
【発明の詳細な説明】 ［産業上の利用分野］ 本発明は、光ファイバ母材の製造方法に関するもので
ある。The present invention relates to a method for producing an optical fiber preform.
［従来技術］ 従来の光ファイバ母材の製造は、第５図に示すように
容器１の長手方向の両端寄りの給気口2A,2Bから給気
し、長手方向の中央の排気口３から排気しつつ、該容器
１内でコア又はコアと一部のクラッドからなる脱水，ガ
ラス化された棒状の光ファイバ母材基体４を回転させつ
つその軸心方向に往復移動させ、バーナ５で光ファイバ
母材基体４の外周にガラス微粒子を吹付けてガラス微粒
子堆積層６を形成し、得られた光ファイバ母材中間体７
を取出してガラス微粒子堆積層６の脱水，ガラス化する
ことにより行っていた。[Prior Art] In the conventional production of an optical fiber preform, as shown in FIG. 5, air is supplied from air supply ports 2A and 2B near both ends in the longitudinal direction of a container 1, and from a central exhaust port 3 in the longitudinal direction. While evacuating, the dehydrated and vitrified rod-shaped optical fiber preform base 4 composed of the core or the core and a part of the clad is rotated and reciprocated in the axial direction in the container 1 while rotating. Glass fine particles are sprayed on the outer periphery of the fiber preform base 4 to form a glass fine particle deposition layer 6, and the obtained optical fiber preform intermediate 7
This is performed by removing the glass particles and dehydrating and vitrifying the glass particle deposition layer 6.
この場合、クラッドとなるガラス微粒子堆積層６の厚
さは、コア径とクラッド径の比が所望の値となるように
制御する必要がある。In this case, it is necessary to control the thickness of the glass particle deposition layer 6 serving as the clad so that the ratio of the core diameter to the clad diameter becomes a desired value.
従来は、光ファイバ母材を作る中間段階の製品である
ガラス微粒子堆積層６の厚さを制御して最終的なコア／
クラッド径比を所望の値にすることが困難なため、光フ
ァイバ母材中間体７の形成後に、脱水，ガラス化してコ
ア／クラッド径比を測定し、所望の値が得られていない
場合には、エッチングしてクラッド径を小さくしたり、
或いは逆に再度不足分のガラス微粒子堆積層を形成し、
脱水，ガラス化してクラッド径を大きくしたりして調節
していた。Conventionally, the thickness of the glass fine particle deposition layer 6, which is an intermediate product for producing an optical fiber preform, is controlled to obtain a final core /
Since it is difficult to set the clad diameter ratio to a desired value, the core / clad diameter ratio is measured after dehydration and vitrification after the formation of the optical fiber preform intermediate 7, and if the desired value is not obtained, Can be etched to reduce clad diameter,
Or, conversely, a glass fine particle deposition layer of insufficient amount is formed again,
Dehydration and vitrification were used to increase the cladding diameter.
［発明が解決しようとする課題］ しかしながら、このような光ファイバ母材の製造方法
では、光ファイバ母材の外径の再調節工程の付加によ
り、歩留りが悪く、光ファイバの製造コストが高くなる
と共に通常の倍以上の製造時間を要するという問題点が
あった。[Problems to be Solved by the Invention] However, in such a method of manufacturing an optical fiber preform, the yield is poor and the manufacturing cost of the optical fiber is increased due to the addition of the step of adjusting the outer diameter of the optical fiber preform. In addition, there is a problem that the production time is required to be twice or more than usual.
本発明の目的は、外径の再調節工程を省略して能率よ
く低コストで製造ができる光ファイバ母材の製造方法を
提供することにある。An object of the present invention is to provide a method of manufacturing an optical fiber preform that can be manufactured efficiently and at low cost by omitting a step of adjusting the outer diameter.
［課題を解決するための手段］ 上記の目的を達成するための本発明の手段を説明する
と、本発明はコア又はコアと一部のクラッドからなる脱
水，ガラス化された棒状の光ファイバ母材基体の外周に
ガラス微粒子を吹付けてガラス微粒子堆積層を設けるこ
とにより光ファイバ母材中間体を形成し、該光ファイバ
母材中間体の前記ガラス微粒子堆積層の脱水，ガラス化
を行って光ファイバ母材を得る光ファイバ母材の製造方
法において、前記ガラス微粒子堆積層に放射線を照射
し、前記放射線の透過側で前記ガラス微粒子堆積層の径
方向の複数箇所の透過放射線強度を、前記ガラス微粒子
堆積層の径方向に並んだ複数のシンチレーション検出器
で測定して前記ガラス微粒子堆積層の各位置の密度を求
め、且つ前記ガラス微粒子堆積層の径方向寸法を求め、
これらの値から前記ガラス微粒子堆積層の全体積量を求
め、この値が所望の値となるまで前記ガラス微粒子の堆
積を行うことを特徴とする。Means for Solving the Problems The means of the present invention for achieving the above object will be described. The present invention provides a dehydrated and vitrified rod-shaped optical fiber preform comprising a core or a core and a part of a clad. An optical fiber preform intermediate is formed by spraying glass fine particles on the outer periphery of the substrate to form a glass fine particle deposition layer, and dehydrating and vitrifying the glass fine particle deposition layer of the optical fiber preform intermediate to form a light beam. In the method for producing an optical fiber preform for obtaining a fiber preform, the glass fine particle deposition layer is irradiated with radiation, and the transmitted radiation intensity at a plurality of radial positions of the glass fine particle deposition layer on the transmission side of the radiation, the glass A plurality of scintillation detectors arranged in the radial direction of the fine particle deposition layer measure the density at each position of the fine glass particle deposition layer, and the radial size of the fine glass particle deposition layer ,
From these values, the total volume of the glass fine particle deposition layer is obtained, and the glass fine particles are deposited until this value reaches a desired value.
［作用］ このようにガラス微粒子堆積層の径方向の複数点の密
度を、このガラス微粒子堆積層を透過した放射線の透過
強度をこのガラス微粒子堆積層の径方向に並んだ複数の
シンチレーション検出器で測定することにより求め、こ
れら密度と径方向の寸法とから、ガラス微粒子堆積層の
全体積量を求め、この値が所望の値になるまでガラス微
粒子の堆積を行うと、光ファイバ母材を作る最終工程で
その外径の再調整を行う必要がなくなる。特に、ガラス
微粒子堆積層の径方向に並んだ複数のシンチレーション
検出器によれば、ガラス微粒子堆積層の堆積密度を径方
向に高精度で測定することができるので、ガラス微粒子
堆積層の径方向の堆積終了時点の判定を容易に行うこと
ができる。[Function] As described above, the density at a plurality of points in the radial direction of the glass fine particle deposition layer is determined, and the transmission intensity of the radiation transmitted through the glass fine particle deposition layer is determined by a plurality of scintillation detectors arranged in the radial direction of the glass fine particle deposition layer. From the density and the radial dimension, the total volume of the glass fine particle deposition layer is determined by measuring, and when the glass fine particles are deposited until this value becomes a desired value, an optical fiber preform is produced. There is no need to readjust the outer diameter in the final step. In particular, according to a plurality of scintillation detectors arranged in the radial direction of the glass fine particle deposition layer, the deposition density of the glass fine particle deposition layer can be measured with high accuracy in the radial direction. It is possible to easily determine the end time of the deposition.
［実施例］ 以下、本発明の実施例を図面を参照して詳細に説明す
る。なお、図において、前述した第５図と対応する部分
には、同一符号を付けて示している。Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the figure, parts corresponding to those in FIG. 5 described above are denoted by the same reference numerals.
本実施例では、第１図及び第２図に示すように、容器
１内でコア4Aとクラッド4Bとからなる脱水，ガラス化さ
れた棒状の光ファイバ母材基体４を回転させつつその軸
心方向に往復移動させ、バーナ５で光ファイバ母材基体
４の外周にガラス微粒子（SiO2）を吹付けてガラス微粒
子堆積層６を徐々に形成する。この場合、光ファイバ母
材基体４の両端はチャック８で支持され、図示しない駆
動手段で軸心のまわりに回転されつつ軸心方向に往復移
動される。ガラス微粒子堆積層６は、バーナ５により加
熱されつつ繰り返し堆積が行われるので、内側の層ほど
密度が次第に大きくなる。In this embodiment, as shown in FIGS. 1 and 2, a dehydrated and vitrified rod-shaped optical fiber preform base 4 composed of a core 4A and a clad 4B is rotated in a container 1 while its axis is rotated. The glass fine particles (SiO 2 ) are sprayed on the outer periphery of the optical fiber preform base 4 by the burner 5 to gradually form the glass fine particle deposition layer 6. In this case, both ends of the optical fiber preform base 4 are supported by the chuck 8 and reciprocated in the axial direction while being rotated about the axis by driving means (not shown). The glass fine particle deposition layer 6 is repeatedly deposited while being heated by the burner 5, so that the inner layer has a gradually increased density.
一方、容器１には、ガラス微粒子堆積層６を径方向に
横切る一方の側にＸ線発生源の如き放射線発生源９を設
け、その反対側には放射線検出器10を設け、ガラス微粒
子堆積層６を透過にしてきた放射線を検出する。なお、
放射線発生源９と放射線検出器10の保護のために、容器
１との間にはそれぞれ窓11,12が設けられている。放射
線検出器10としてマルチ検出器を用いると、ガラス微粒
子堆積層６の径方向の各位置の密度を測定することがで
きる。マルチ検出器は、ガラス微粒子堆積層６の半径方
向に並んだ多数のシンチレーション検出器S1〜Snで構成
されている。これらシンチレーション検出器S1〜Snは、
相対応するガラス微粒子堆積層６の各部の密度を、その
各部を透過した放射線の透過放射線強度を測定すること
により知ることができる。なお、ガラス化されたクラッ
ド4bは密度が高いので、放射線検出器10によって該クラ
ッド4bとガラス微粒子堆積層６との境界を知ることがで
きる。また、空気層とガラス微粒子堆積層６との境界層
も放射線検出器10によって知ることができる。更に、ガ
ラス微粒子堆積層６の径方向の各位置の寸法は、各シン
チレーション検出器S1〜Snから知ることができる。これ
らの値からガラス微粒子堆積層６の全体積量を求め、こ
の値が所望の値となる迄、ガラス微粒子の堆積を行う。
特に、ガラス微粒子堆積層の径方向に並んだ複数のシン
チレーション検出器によれば、ガラス微粒子堆積層の堆
積密度を径方向に高精度で測定することができるので、
ガラス微粒子堆積層の径方向の堆積終了時点の判定を容
易に行うことができる。On the other hand, the container 1 is provided with a radiation source 9 such as an X-ray source on one side crossing the glass particle deposition layer 6 in the radial direction, and a radiation detector 10 on the other side. The radiation transmitted through 6 is detected. In addition,
Windows 11 and 12 are provided between the container 1 and the radiation source 9 to protect the radiation source 9 and the radiation detector 10, respectively. If a multi-detector is used as the radiation detector 10, the density of each position in the radial direction of the glass particle deposition layer 6 can be measured. The multi-detector is composed of a large number of scintillation detectors S1 to Sn arranged in the radial direction of the glass particle deposition layer 6. These scintillation detectors S1 to Sn
The corresponding density of each part of the glass fine particle deposition layer 6 can be known by measuring the transmitted radiation intensity of the radiation transmitted through each part. Since the vitrified clad 4b has a high density, the boundary between the clad 4b and the glass particle deposition layer 6 can be known by the radiation detector 10. Further, the boundary layer between the air layer and the glass particle deposition layer 6 can be known by the radiation detector 10. Further, the size of each position in the radial direction of the glass particle deposition layer 6 can be known from each of the scintillation detectors S1 to Sn. From these values, the total volume of the glass fine particle deposition layer 6 is obtained, and the deposition of the glass fine particles is performed until this value reaches a desired value.
In particular, according to a plurality of scintillation detectors arranged in the radial direction of the glass fine particle deposition layer, the deposition density of the glass fine particle deposition layer can be measured with high accuracy in the radial direction.
It is possible to easily determine the end point of the deposition of the glass fine particle deposition layer in the radial direction.
ガラス微粒子堆積層６の全体積量の目標値は、予め実
験で求め、図示しない制御装置内に入力しておく。The target value of the total volume of the glass particle deposition layer 6 is obtained in advance by an experiment and is input into a control device (not shown).
このようにして光ファイバ母材中間体７を得ると、ガ
ラス化後に外径の再調整を行う必要がなくなる。When the optical fiber preform intermediate 7 is thus obtained, it is not necessary to readjust the outer diameter after vitrification.
実験例 コア4aをSiO2とGeO2の２成分で作り、その外周にクラ
ッド4bをVAD法で付けてガラス化した光ファイバ母材基
体４を装置にセットする。この光ファイバ母材基体４の
外周にガラス微粒子SiO2を付けてガラス微粒子堆積層６
を形成し、ガラス化後のコアとクラッドの比が10:125と
なるようにガラス微粒子の堆積を行った。ガラス微粒子
堆積層６の密度は、0.2〜0.7であるが、放射線によって
各部の密度を計測して行うと、過不足なく、ガラス微粒
子堆積層６の堆積を行うことができる。放射線発生源９
は200kVの白色Ｘ線発生源とし、窓11,12の枠には重金属
を用いてＸ線の散乱を防ぎ、また塩素によって侵食され
ないようにしている。また、窓11,12の放射線通過孔に
は、テトラフロロエチレンを詰めて、容器１の内外を気
密に区画した。Experimental Example A core 4a is made of two components of SiO 2 and GeO 2 , and a cladding 4b is attached to the outer periphery of the core 4a by a VAD method, and a vitrified optical fiber preform base 4 is set in the apparatus. A glass fine particle deposition layer 6 is formed by attaching glass fine particles SiO 2 to the outer periphery of the optical fiber preform base 4.
Was formed, and glass particles were deposited so that the ratio of the core to the clad after vitrification was 10: 125. Although the density of the glass particle deposition layer 6 is 0.2 to 0.7, if the density of each part is measured by radiation, the deposition of the glass particle deposition layer 6 can be performed without excess or deficiency. Radiation source 9
Is a 200kV white X-ray source, and heavy metal is used for the windows 11 and 12 to prevent X-ray scattering and to prevent erosion by chlorine. The radiation passage holes of the windows 11 and 12 were filled with tetrafluoroethylene, and the inside and outside of the container 1 were airtightly partitioned.
なお、ガラス微粒子堆積層６の付け始めには、その密
度の測定をしなくともよい。ガラス微粒子堆積層６の付
け終わる頃に、比重の計測を径方向の複数点で行い、最
終層の付け終り時期を決めればよい。ガラス微粒子堆積
層６は往復移動されるので、第４図に示すように全体の
半分以上の密度を測定できる。It is not necessary to measure the density of the glass particle deposition layer 6 at the beginning. Around the time when the deposition of the glass fine particle deposition layer 6 is completed, the measurement of the specific gravity is performed at a plurality of points in the radial direction, and the timing at which the final layer is completed may be determined. Since the glass particle deposition layer 6 is reciprocated, the density of more than half of the whole can be measured as shown in FIG.
この場合、バーナ５からの火炎の熱影響を避けるた
め、放射線発生源９と放射線検出器10とは、バーナ５か
ら少し離して設定している。In this case, the radiation source 9 and the radiation detector 10 are set slightly apart from the burner 5 in order to avoid the thermal influence of the flame from the burner 5.
［発明の効果］ 以上説明したように本発明では、ガラス微粒子堆積層
の径方向の複数点の密度を、このガラス微粒子堆積層を
透過した放射線の透過強度をこのガラス微粒子堆積層の
径方向に並んだ複数のシンチレーション検出器で測定す
ることにより求め、これらの密度と径方向の寸法とか
ら、ガラス微粒子堆積層の全体積量を求め、この値が所
望値になるまでガラス微粒子の堆積を行うので、クラッ
ドを過不足なく堆積できる利点がある。また本発明によ
れば、径方向の複数箇所の密度の測定を行うので、ガラ
ス微粒子堆積層の密度の測定精度が上り、ガラス微粒子
堆積の終了時期の判定精度が上り、コアとクラッドとの
径比の精度が向上できる。特に、ガラス微粒子堆積層の
径方向に並んだ複数のシンチレーション検出器によれ
ば、ガラス微粒子堆積層の堆積密度を径方向に高精度で
測定することができるので、ガラス微粒子堆積層の径方
向の堆積終了時点の判定を容易に行うことができる。従
って、この工程の歩留が飛躍的に上昇すると共に、従来
何度も計測と堆積，ガラス化を繰り返していた多くの工
程が一挙に短縮されるので、換言すれば外径の再調節工
程を省略できるので、人工，光熱費，材料収率で大幅な
コストダウンが可能である。[Effects of the Invention] As described above, in the present invention, the density at a plurality of points in the radial direction of the glass fine particle deposition layer is determined by changing the transmission intensity of radiation transmitted through the glass fine particle deposition layer in the radial direction of the glass fine particle deposition layer. Determined by measuring with a plurality of aligned scintillation detectors, from these densities and radial dimensions, determine the total volume of the glass fine particle deposition layer, and deposit glass fine particles until this value reaches a desired value. Therefore, there is an advantage that the clad can be deposited without excess or shortage. Further, according to the present invention, since the measurement of the density at a plurality of locations in the radial direction is performed, the measurement accuracy of the density of the glass fine particle deposition layer increases, the determination accuracy of the end time of the glass fine particle deposition increases, and the diameter of the core and the clad increases. The accuracy of the ratio can be improved. In particular, according to a plurality of scintillation detectors arranged in the radial direction of the glass fine particle deposition layer, the deposition density of the glass fine particle deposition layer can be measured with high accuracy in the radial direction. It is possible to easily determine the end time of the deposition. Therefore, the yield of this process is dramatically increased, and many processes that have been repeatedly repeated for measurement, deposition, and vitrification are shortened at once. In other words, the outer diameter readjustment process is required. Since it can be omitted, it is possible to significantly reduce costs in terms of artificial, utility costs and material yield.
第１図及び第２図は本発明の方法を実施する装置の一実
施例の横断面図及び容器の一部を破断して内部を開示し
た斜視図、第３図は本実施例における放射線発生源，光
ファイバ母材中間体，放射線検出器等の関係を示した斜
視図、第４図は光ファイバ母材中間体の上半部縦断側面
図、第５図は従来の装置の横断面図である。 １……容器、３……排気口、４……光ファイバ母材基
体、５……バーナー、６……ガラス微粒子堆積層、７…
…光ファイバ母材中間体、８……チャック、９……放射
線発生源、10……放射線検出器、11,12……窓、S1〜Sn
……シンチレーション検出器。1 and 2 are cross-sectional views of one embodiment of an apparatus for carrying out the method of the present invention and perspective views showing the inside of a container with a part cut away, and FIG. 3 shows radiation generation in the present embodiment. Perspective view showing the relationship between the source, the optical fiber preform intermediate, the radiation detector, etc., FIG. 4 is a vertical sectional side view of the upper half of the optical fiber preform intermediate, and FIG. 5 is a cross-sectional view of a conventional apparatus. It is. DESCRIPTION OF SYMBOLS 1 ... Container, 3 ... Exhaust port, 4 ... Optical fiber preform base material, 5 ... Burner, 6 ... Glass particle deposition layer, 7 ...
... intermediate optical fiber preform, 8 ... chuck, 9 ... radiation source, 10 ... radiation detector, 11,12 ... window, S1-Sn
...... Scintillation detector.
Claims (1)
水，ガラス化された棒状の光ファイバ母材基体の外周に
ガラス微粒子を吹付けてガラス微粒子堆積層を設けるこ
とにより光ファイバ母材中間体を形成し、該光ファイバ
母材中間体の前記ガラス微粒子堆積層の脱水，ガラス化
を行って光ファイバ母材を得る光ファイバ母材の製造方
法において、 前記ガラス微粒子堆積層に放射線を照射し、前記放射線
の透過側で前記ガラス微粒子堆積層の径方向の複数箇所
の透過放射線強度を、前記ガラス微粒子堆積層の径方向
に並んだ複数のシンチレーション検出器で測定して前記
ガラス微粒子堆積層の各位置の密度を求め、且つ前記ガ
ラス微粒子堆積層の径方向寸法を求め、これらの値から
前記ガラス微粒子堆積層の全体積量を求め、この値が所
望の値となるまで前記ガラス微粒子の堆積を行うことを
特徴とする光ファイバ母材の製造方法。An intermediate layer of an optical fiber preform is provided by spraying glass microparticles on an outer periphery of a dehydrated and vitrified rod-shaped optical fiber preform base comprising a core or a core and a part of a clad to provide a glass particle deposition layer. A method for producing an optical fiber preform by forming a body and dehydrating and vitrifying the glass fine particle deposition layer of the optical fiber preform intermediate, wherein the glass fine particle deposition layer is irradiated with radiation. Then, on the transmission side of the radiation, the transmitted radiation intensity at a plurality of radial positions of the glass fine particle deposition layer is measured by a plurality of scintillation detectors arranged in the radial direction of the glass fine particle deposition layer, and the glass fine particle deposition layer is measured. And the radial dimension of the glass fine particle deposition layer is determined, and the total volume of the glass fine particle deposition layer is determined from these values. A method for producing an optical fiber preform, wherein the glass fine particles are deposited until the value reaches a value.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63307014A JP2599451B2 (en) | 1988-12-06 | 1988-12-06 | Manufacturing method of optical fiber base material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63307014A JP2599451B2 (en) | 1988-12-06 | 1988-12-06 | Manufacturing method of optical fiber base material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02153836A JPH02153836A (en) | 1990-06-13 |
| JP2599451B2 true JP2599451B2 (en) | 1997-04-09 |
Family
ID=17963983
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63307014A Expired - Lifetime JP2599451B2 (en) | 1988-12-06 | 1988-12-06 | Manufacturing method of optical fiber base material |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2599451B2 (en) |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6325243A (en) * | 1986-07-18 | 1988-02-02 | Furukawa Electric Co Ltd:The | Production of parent material for optical fiber |
-
1988
- 1988-12-06 JP JP63307014A patent/JP2599451B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02153836A (en) | 1990-06-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4941905A (en) | Methods of soot overcladding an optical preform | |
| JPH10158025A (en) | Production of optical fiber preform | |
| KR840000429B1 (en) | Method of controlling the index profile of optical fiber preforms | |
| US11237322B2 (en) | Optical fiber manufacturing method using relative bulk densities | |
| JPS62123035A (en) | Production of parent material for optical fiber | |
| JPS6356179B2 (en) | ||
| NO158573C (en) | PROCEDURE FOR MANUFACTURING OPTICAL FIBERS. | |
| US4087266A (en) | Optical fibre manufacture | |
| JP2599451B2 (en) | Manufacturing method of optical fiber base material | |
| US4494969A (en) | Method of forming laminated single polarization fiber | |
| JP6875227B2 (en) | Manufacturing method of multi-core optical fiber base material and manufacturing method of multi-core optical fiber | |
| CA1128756A (en) | Method of fabricating optical fibers | |
| JP2610040B2 (en) | Manufacturing method of optical fiber preform | |
| JPS5738329A (en) | Controlling method for deposition of oxide powder in axial vapor deposition method | |
| JPS6296336A (en) | Production of optical fiber preform and apparatus therefor | |
| JP4056778B2 (en) | Manufacturing method of optical fiber preform | |
| JPS6136134A (en) | Method and apparatus for producing preform for stress-imparted polarization-keeping optical fiber | |
| JPH09278453A (en) | Production of blank for rod lens | |
| JP2610040C (en) | ||
| GB2180232A (en) | Optical fibre | |
| CA2340002A1 (en) | Method making a fiber preform using cooled spindle | |
| FI68606C (en) | TILLVERKNINGSMETOD FOER EN ICKE-CYLINDERSYMMETRISK OCH POLARISATIONSBEVARANDE OPTISK FIBER | |
| JPS6096537A (en) | Production of optical fiber preform | |
| JPS60251143A (en) | Treatment of base material for optical glass | |
| JPS6167005A (en) | Manufacture of base material for singly polarizing optical fiber |