JP3306160B2 - Manufacturing method of tape-shaped multi-core fiber preform - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a tape-shaped multi-core fiber preform, which is suitable for use in image transmission of a simulator, and has a small-diameter, multi-core, long and small-fiber spacing. A method for easily obtaining a fiber is provided.

[0002]

2. Description of the Related Art In general, the following are examples of an array-like transmission line in which a number of optical fibers are coherently arranged. Fibers are arranged one by one, fixed at both ends with an adhesive and polished, and are usually called bundle type, and the middle is independent and rich in flexibility. FIG. 4 is an enlarged perspective view of the mold array, in which 1 is a plurality of optical fiber ends arranged side by side and adjacent sides are fixed to each other with an adhesive.
2 is a holding member for supporting the ends of the optical fibers, 3
Is the center of a multiplicity of optical fibers that are simply bundled without each gluing together. The starting member to be a fiber should be of an appropriate thickness (3 to 20 m
m), cut to a certain length (about 10 to 50 cm), arrange them in a required number, and sequentially heat and weld between the fibers with an oxyhydrogen flame or the like. This is further referred to as a tape-shaped bunch fiber by performing a melt drawing.

[0003]

However, in the case of the bundle type array shown in the following, it is difficult to align thin (about 10 .mu.m) fibers, the number of fibers is limited to several hundred at most, and the fiber has extremely low durability. The problem of breakage can be significant. In addition, in the case of the bunch fiber, if the fiber of the primary drawing does not have a diameter of 3 mm or more, deformation occurs at the time of heat welding and the alignment is broken. If the fiber is made thicker, the fiber preform for secondary drawing becomes too thick and drawing is not easy. Therefore, the obtained tape-shaped fiber cannot be used for transmitting a simulator image which requires a small diameter, a multi-core, a long length, and a small fiber interval.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and the invention according to claim 1 is characterized in that a comb having a large number of grooves extending in a longitudinal direction at predetermined intervals. There is provided a method of manufacturing a tape-shaped multi-core fiber preform in which a mold-shaped glass substrate for cladding is prepared, a groove of the substrate is filled with a core glass, and a glass layer serving as a cladding is formed on the entire surface. Also, the present invention is characterized in that
The described invention provides a comb-shaped clad glass substrate having a number of grooves extending in the length direction at predetermined intervals,
A core glass is provided so as to fill the groove of the base and extend over the entire surface thereof, and is removed except for a part which becomes a core formed in the groove of the core glass, and then a glass layer serving as a clad is formed over the entire surface. And a method for manufacturing a tape-shaped multi-core fiber preform. The number of grooves formed on the substrate is about 500 to 3000, the width between grooves, that is, the width of the comb is about 10 to 50, and the formation of the grooves is performed by grinding or using photolithography and etching together. by. The glass serving as the core and the clad may be directly vitrified, may be transparent vitrified through glass fine particles, or may be a sol-gel method.

[0005]

A simple process of appropriately selecting the intervals between the combs and the intervals and the number of grooves formed by the combs of the comb-shaped substrate serving as the cladding, filling the interior of the grooves with a core material, and covering the entire surface with the cladding material. The desired tape-shaped multi-core fiber preform can be easily obtained by simply drawing the tape-shaped multi-core fiber preform.

[0006]

[Embodiment 1] FIG. 1 is a process drawing showing an embodiment of the manufacturing method of the present invention, wherein a indicates a base 10 prepared in advance. The base 10 is made of a comb-shaped quartz glass having a comb shape as a whole, and has a large number of comb-shaped portions 12 formed at predetermined intervals and a large number of grooves 14 formed between the comb-shaped portions 12.
It consists of The size of the base is, for example, 5
0-300 mm, width 30-200 mm, width of comb part 2
5-180mm, 500-3000 grooves, 1 width
0 to 50 mm. b is a deposition step in which GeO ₂ —SiO ₂ glass microparticles serving as a core are formed on the entire surface of the substrate 10 by a flame hydrolysis method using an oxyhydrogen burner. The relative refractive index difference Δ of the obtained GeO ₂ —SiO ₂ core glass with respect to SiO ₂ is set to 0.5 to 3.0%. c is a state diagram after this deposition step, in which many grooves are filled with GeO ₂ —SiO ₂ glass fine particles,
In addition, GeO ₂ —SiO ₂ glass fine particles are also formed on the surface of many comb-like portions 12. Ge formed on this base
The O ₂ —SiO ₂ glass particles are heated to 1000 to 1800 ° C. to be vitrified transparently. d is a surface grinding step for removing the GeO ₂ —SiO ₂ glass layer at portions other than the grooves.
e is a cladding formation step, to form a SiO ₂ glass fine particle layer to be the cladding over the entire surface, transparent vitrification the SiO ₂ glass fine particle layer. After that, if necessary, the surface of the clad layer, which has been made vitrified, is smoothed by flame or grinding and polishing. Through the above steps, a tape-shaped multi-core fiber preform having a GeO ₂ —SiO ₂ glass portion serving as a core at predetermined intervals is obtained. This base material was drawn to form a tape-shaped multi-core fiber having a width of 25 mm, a height of 0.6 mm, and a core diameter of 8 μm, and a coating of UV resin or the like was applied thereon to a thickness of 30 μm to obtain a desired tape-shaped multi-core fiber. When a simulator image transmission bundle was created using this tape-shaped multi-core fiber, the pixel array was uniform and had a characteristic of a bending radius of 100 mm or less.
The flexibility was outstanding.

[0007]

[Embodiment 2] FIG. 2 is a process drawing according to another embodiment of the manufacturing method of the present invention, and the same reference numerals denote the same parts as in FIG. A is the same base as a in the first embodiment. B is sol-
This is a step of forming a GeO ₂ —SiO ₂ glass serving as a core by a gel method. Specifically, alkoxides of Ge and Si,
For example, Si (OCH ₃ ) ₄ or Si (OC ₂ H ₅ ) ₄
And Ge (OCH ₃ ) ₄ or Ge (OC ₂ H ₅ ) ₄
Is dissolved in water to prepare a sol solution, and a substrate is dipped in the sol solution or a liquid is sprayed on the surface of the substrate to form a thin film. The thin film is dried and gelled, and further heated to vitrify. 3C is a state diagram in which the entire process is repeated until the thickness of the thin film is increased and the groove is filled. (D) removes a glass portion formed other than the groove in the grinding step. E is a step of forming a SiO ₂ glass to be a clad by the sol-gel method. Specifically, for example, Si (OC
H _{3) 4} or Si (OC ₂ H _{5) 4} to form the or dipping in what was dissolved in water sol solution, or by spraying a liquid to the base plate surface film. This thin film is dried and gelled, and further heated to vitrify, and this is repeated to obtain a predetermined film thickness. The tape-like multi-core fiber preform thus obtained was drawn to obtain a desired tape-like multi-core fiber.

[0008]

According to the method of manufacturing an optical fiber according to the present invention, a substrate serving as a comb-shaped clad having a number of grooves in the longitudinal direction is prepared as described above, and the grooves of the substrate are filled with a core glass. Then, the entire surface of the substrate is covered with clad glass to form a tape-shaped multi-core fiber preform, so if the substrate as a starting member is precisely manufactured, the formation of the subsequent core and clad portions will be formed. Is very simple, so that the tape-shaped multi-core fiber obtained from this base material has a small diameter, multiple cores, a long length, and a small fiber interval.

[Brief description of the drawings]

FIG. 1 is a process chart of the method of the present invention.

FIG. 2 is a process chart of another example of the method of the present invention.

FIG. 3 is an explanatory view of a conventional bundle type array.

FIG. 4 is a partially enlarged perspective view of 1 in FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Comb outer clad base 12 Comb part 14 Groove

Continuation of the front page (72) Inventor Kazuo Sanada 1440 Mutsuzaki, Sakura City, Chiba Prefecture Inside Fujikura Sakura Factory (56) References JP-A-60-225104 (JP, A) JP-A-56-135808 (JP, A) JP-A-57-604 (JP, A) JP-A-61-273505 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02B 6/00 G02B 6/04-6 / 08 G02B 6/12-6/14 C03B 20/00

Claims (4)

(57) [Claims] 1. A comb-shaped glass substrate for cladding having a large number of grooves extending in a longitudinal direction at a predetermined interval is prepared.
A method for producing a tape-shaped multi-core fiber preform, wherein a groove of the substrate is filled with a core glass, and a glass layer serving as a clad is formed on the entire surface. 2. A comb-shaped glass substrate for cladding having a number of grooves extending in a longitudinal direction at a predetermined interval is prepared.
A core glass is provided so as to fill the groove of the base and extend over the entire surface of the base, and is removed except for a part serving as a core formed in the groove of the core glass. A method for producing a tape-shaped multi-core fiber preform, comprising forming a layer. 3. The method for producing a tape-shaped multi-core fiber preform according to claim 1, wherein the core and the clad glass are made vitreous through glass fine particles. 4. The method for producing a tape-shaped multi-core fiber preform according to claim 1, wherein the core and the clad glass are formed by a sol-gel method.