JP3871737B2 - Manufacturing method of tape-shaped multi-core fiber - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a tape-shaped multi-core fiber used for a line sensor, a light guide, and the like, and provides a method with little disturbance in the core arrangement regardless of a small-diameter core.
[0002]
[Prior art]
As a method for manufacturing a tape-shaped multi-core fiber, the present inventors have previously proposed Japanese Patent Application No. 6-90743 and Japanese Patent Application No. 6-106248.
The former is a method in which a quartz plate having slit-like through holes is prepared, optical fibers are arranged in a row in the slit-like through holes and used as a base material, and melt drawing is performed from one end to form a tape-like multi-core fiber. is there. The latter is a method in which a quartz plate having a wide groove is prepared, optical fibers are arranged in a row in the groove, a quartz plate is placed on the quartz plate, and a base material is formed. is there.
[0003]
[Problems to be solved by the invention]
However, in these methods, in order to obtain a tape-shaped multi-core fiber having a thin core, if the diameter of the optical fiber aligned with the slit-like through hole or wide groove is set to 100 μm or less, it becomes too thin and difficult to align. In some cases, the tape-shaped multi-core fiber obtained sometimes has pixel misalignment, vacancy, etc., and the yield does not increase.
[0004]
[Means for Solving the Problems]
The present invention has been made to solve the above-described problems. The invention according to claim 1 is characterized in that a plurality of optical fibers of a predetermined length of silica glass system are arranged in parallel and fixed to each other to form a primary mother. A step of melting the primary base material from one end thereof, cutting it into a predetermined length and making it a secondary base material, and moistening the secondary base material in pure water, A step of placing the individual pieces in a groove in a grooved quartz glass plate and covering them with a quartz glass plate to fix them together to form a tertiary base material; A tape-shaped multi-core fiber manufacturing method characterized by comprising a step of melting and drawing a material from one end to form a tape-shaped multi-core fiber.
[0005]
The invention according to claim 2 is characterized in that a plurality of silica glass optical fibers having a predetermined length are arranged in parallel and fixed to each other to form a primary base material, and the primary base material is one end thereof. And then drawing the molten metal into a secondary base material by cutting it into a predetermined length , and superimposing a plurality of secondary base materials in pure water in the slits of a quartz glass plate with a slit. process and method for producing a tape-shaped multicore fiber characterized by comprising the tertiary base material and a step of a tape-like multi-core fiber to melt drawn from one end thereof which is inserted while applying ultrasonic vibration to the tertiary base material It is in.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
1 to 4 are explanatory views showing an embodiment of the method of the present invention. In FIG. 1, reference numeral 1 denotes a primary base material, which is a quartz optical fiber having an outer diameter of about 0.5 to 3 mm and a length of about 100 to 1000 mm (for example, GeO ₂ —SiO ₂ core, SiO ₂ cladding, core and cladding) The relative refractive index difference Δ = 1.0%) is arranged in a line of about 5 to 20 and welded with an oxyhydrogen flame burner or the like to form an interdigital shape. It is not always necessary to perform the welding process between the fibers at this time, and in the case of a base material having a length of about 500 mm, it may be at three locations, both ends and an intermediate portion.
[0007]
This interdigital primary base material is melt-drawn from one end and cut to an appropriate length to obtain a desired size (length 100 to 500 mm, width 0.5 to 5 mm, height 0.1 to 0.25 mm). The next base material. By adjusting the furnace temperature to 2000 to 2200 ° C. at the time of this drawing, one in which the cross-sectional shape of a desired diameter is preserved by fusing the side surfaces of each fiber is obtained.
Note that a quartz plate having a substantially equal cross-sectional size may be welded to the tip of the primary base material as a weight at the start of drawing.
[0008]
On the other hand, a quartz plate 2 having a wide groove 22 as shown in FIG. 2 is prepared. The dimensions of the quartz plate are typically about 100 mm wide, 5 mm thick, and 500 mm long. The width of the groove 22 is 2 to 4 mm narrower than the width of the quartz plate, and 20 to 200 two. The width is set such that the next base material is arranged in a line, and the depth of the groove is preferably 50 to 2000 μm, particularly 100 to 200 μm.
[0009]
Then, a plurality of secondary base materials are arranged in a line in the groove 22 of the quartz plate 2 as shown in FIG. For this alignment work, a dried secondary base material may be used, but the alignment can be performed more smoothly by being wetted with pure water or the like.
As shown in FIG. 4, the quartz plate 3 is covered on the quartz plate in which the secondary base material is accommodated, and the outer surfaces on which the upper and lower quartz plates are overlapped are welded with an oxyhydrogen burner or the like to form the tertiary base material 4. And This tertiary preform 4 is heated to 1700-2000 ° C. using a heating furnace, melt drawn from one end thereof, and a desired tape-shaped multicore fiber having a width of 0.5-10 mm (500-10000 μm) and a thickness of 25-500 μm. And
[0010]
The tape-like multi-core fiber is coated with a thermosetting resin or an ultraviolet curable resin immediately after the drawing.
Prior to drawing, a quartz tube 5 is attached to one end of the tertiary base material 4 and a dummy quartz plate 6 having the same cross-sectional size is welded to the other end as shown in FIG. However, if melt drawing is performed from the side of the dummy quartz plate 6, it is efficient because bubbles or the like do not enter into the obtained tape-shaped multi-core fiber and most of the tertiary base material can be made into a product. .
[0011]
FIG. 6 shows a quartz plate 10 having a slit-like through hole 100 used in another example of the method of the present invention. The width, thickness and length of the quartz plate 10 are the same as that of the quartz plate, and the slit width is parallel. Depending on the number of secondary base materials to be made, it is slightly larger than the width. Then, a predetermined number of secondary base materials are inserted into this slit in a row to form a tertiary base material.
The insertion of the secondary base material into the slit can be facilitated by performing ultrasonic vibration in pure water. Subsequent handling can be performed in exactly the same manner as in the above example.
[0012]
【Example】
Example 1
Fifteen silica fibers having a diameter of 2 mmφ and a length of 500 mm (for example, GeO ₂ —SiO ₂ core, SiO ₂ clad, relative refractive index difference between core and clad Δ = 1%) were prepared. These fibers are arranged in a row, and both ends and the center are welded to each other with an oxyhydrogen burner to form a primary base material. The primary base material is heated to 2000 ° C. and melt drawn from one end to obtain a width of 3 mm and a thickness. Fifteen pieces of tape-like fibers having a thickness of 0.2 mm were prepared and cut into a length of 450 mm to form secondary base materials.
On the other hand, a quartz glass plate having a width of 48 mm, a thickness of 2.5 mm, a length of 500 mm, a groove width of 45 mm, and a depth of 0.21 mm is prepared, and 15 secondary mothers moistened with pure water in the groove. The materials are arranged in a row, dried and covered with a quartz glass plate having a width of 48 mm, a thickness of 2.5 mm, and a length of 500 mm, and the overlapped portion of both quartz glass plates is welded with an oxyhydrogen burner to form a tertiary base material. did. A dummy quartz glass plate is welded to one end of the tertiary base material and a quartz tube is welded to the other end, and the dummy quartz glass plate side is heated to 2170 ° C. while evacuating from the quartz tube side, and melt drawing is performed. A tape-shaped multi-core fiber having a length of 160 m, a width of 2.4 mm, a thickness of 0.25 mm, and a core number of 225 was coated with an ultraviolet curable resin to a thickness of 100 μm.
The obtained tape-shaped multi-core fiber had no pixel deviation and no pixel vacancy despite the thin pixel diameter of 7.5 μm.
[0013]
Example 2
The same secondary base material as in Example 1 was used. On the other hand, a quartz glass plate having a width of 48 mm, a thickness of 5 mm, a length of 500 mm, a slit width of 45 mm, and a height of 0.21 mm is prepared, and ultrasonic vibration is applied to 15 secondary base materials in the slit in pure water. They were arranged in a row while being applied, and dried to obtain a tertiary base material.
Thereafter, in the same manner as in Example 1, a tape-shaped multi-core fiber having a length of 160 m, a width of 2.4 mm, a thickness of 0.25 mm, and a core number of 225 was formed, and an ultraviolet curable resin was coated thereon to a thickness of 100 μm.
The obtained tape-shaped multi-core fiber had no pixel deviation and no pixel vacancy despite the thin pixel diameter of 7.5 μm.
[0014]
【The invention's effect】
In the method of the present invention, a plurality of fibers are prepared in advance, arranged in a row and fixed to each other to form an interdigital shape, and melted and drawn into a plurality of grooves or slits formed in a plate-like body. Therefore, it is easy to align the fibers, and a tape-shaped multi-core fiber that does not disturb the pixel arrangement even when a thin fiber is used can be obtained.
[Brief description of the drawings]
FIG. 1 is a perspective view of multi-core fibers arranged in a tape shape.
FIG. 2 is a perspective view of a quartz plate that accommodates multi-core fibers arranged in a tape shape.
FIG. 3 is a perspective view showing a state in which a secondary base material is accommodated in a quartz plate.
FIG. 4 is a perspective view of a state in which a secondary base material is accommodated in a quartz plate and covered.
FIG. 5 is a side view of a state in which a quartz tube is attached to one end of a tertiary base material and a dummy quartz tube is attached to the other end.
FIG. 6 is a perspective view of a quartz plate 10 having slit-like through holes.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Primary base material 2 Quartz plate 22 Groove 3 Quartz plate cover 4 Tertiary base material 5 Quartz tube 6 Dummy quartz plate 10 Quartz plate 100 Slit strip through-hole

Claims (2)

A process in which a plurality of silica glass optical fibers having a predetermined length are arranged in parallel and fixed to each other to form a primary base material, and the primary base material is melt-drawn from one end thereof, and then cut into a predetermined length. a step of the next preform, the secondary preform moistened in pure water, the plurality houses are aligned in the groove of the plate-like body of silica glass-based grooved quartz glass thereon A tape-shaped multi-core comprising a step of covering a system plate-like body and fixing them together to form a tertiary base material, and a step of melting and drawing the tertiary base material from one end thereof to form a tape-shaped multi-core fiber Fiber manufacturing method. A process in which a plurality of silica glass optical fibers having a predetermined length are arranged in parallel and fixed to each other to form a primary base material, and the primary base material is melt-drawn from one end thereof, and then cut into a predetermined length. A step of forming a secondary base material, and a step of inserting a plurality of secondary base materials into a slit of a quartz glass plate with a slit while applying ultrasonic vibration in pure water to form a tertiary base material And a step of melting and drawing the tertiary base material from one end thereof to form a tape-shaped multicore fiber.

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