JPS5821210A - Production of optical fiber sheet - Google Patents

Abstract

PURPOSE:To obtain a sheet having good dimensional accuracy of the spaces between respective optical fiber strands by juxtaposing plural pieces of preformed optical fiber base aterials, attaching cladding members on both sides of the juxtaposed base material group with said group in-between and stretching the same into one body under heating. CONSTITUTION:Plural pieces of slender bar-like optical fiber base materials 1 made by stretching base materials beforehand to about 8mm. outside diameter are juxtaposed in parallel that tight contact with each other. Plates 2, 2' of, for example, ''Vycor '' glass having a softening temp. lower than that of the materials 1 and a coefft. of thermal expansion nearly equal to that of said materials are attached on both sides along the juxtaposing direction and both ends of the plates 2, 2' are melt stuck, whereby a base material group 11 is produced. With one end part of the group 11 held supported, the other end part is fed into a heating furnace where said part is stretched and drawn out successively to one body under heating, whereby a long sized optical fiber sheet 4 having prescribed thickness, width and good accuracy in the spaces between the respective core layers 1a-1h is manufactured easily and efficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing an optical fiber sheet for transmitting a plurality of optical signals in parallel in the field of optical communication or optical information processing.

The optical fiber F-) is used for parallel processing of multiple optical signals by connecting a light emitting device with a light receiver configured in an array, or for Fac V mm document reading device, etc. In general, a large number of optical fibers are arranged in parallel and close together or in parallel at a predetermined interval, and the positions of both ends of each optical fiber in the length direction correspond to each other by, for example, an extrusion resin coating method. They are integrated into a sheet by a common covering layer.

However, in the conventional manufacturing method of the dog fiber sheet as described above, a plurality of small diameter optical fibers are arranged in parallel and V
-) shape is not easy to form, and the manufacturing cost is high. Furthermore, there is a problem in that it is difficult to obtain a highly accurate spacing between the fiber strands of each party that are integrated into a sheet.

An object of the present invention is to solve the above-mentioned conventional drawbacks by arranging a plurality of pre-formed Hikari 7 Eyeper preforms in parallel, and sandwiching the parallel preform groups on both sides of the parallel preform group.
By drawing the optical fibers while simultaneously heating and integrating them with a coating member attached that has a softening temperature lower than that of the primary base material, the lines between each optical fiber strand integrated in a V-shaped shape are formed. It is an object of the present invention to provide a manufacturing method that can efficiently form an optical fiber V-) with good interval dimension accuracy.

The KgA2+ manufacturing method of the present invention will be described below using the drawings! l! The examples will be explained in detail.

FIG. 1 is a schematic perspective view showing an embodiment of a method for continuously manufacturing an optical fiber V-) according to the present invention.

First, a plurality of optical fiber preforms each having a core layer and a cuturad layer around it are manufactured by a well-known chemical vapor deposition method (CVD method), and in this example, the preforms are heated and stretched to have an outer diameter of approximately IK mold a thin rod-shaped base material of about 8 cod. A plurality of such thin bar-shaped base materials 1 (eight in this case) are arranged parallel to each other and in close contact with each other, and the parallel base material group 11 is sandwiched on both sides of the parallel base material group jl along the parallel direction. In addition, a covering member having a softening temperature lower than that of the softening skin of the thin rod-shaped base material l, and having a thermal expansion coefficient close to that of the material and having good workability, such as a high silicate gaff, which is generally also called Vycor glass, is used. About g
, 'sw' thick glass plate 2.2' is attached as shown. At this time, at both ends of the parallel base material group 11, the ends of the glass plates 2°, . Next, one end of the parallel base material group 11 to which the glass plates 2.2 described above are clamped is supported by a feeding device (not shown), and the pond end is placed in the heating furnace 8 K11l.
1 Sequential feeding is included using the raising device.

If it is continuously stretched at a predetermined drawing speed while being heated and integrated, the thickness will be about 460 pm, for example, as shown in FIG.
With a width of about 1.6 W and a spacing width of 200 μm between the core layers ta to th, it is possible to easily and inexpensively obtain a long optical fiber sheet 4 with good spacing accuracy.

In addition, in the above-mentioned embodiment, an example was explained in which the covering members 2゜2' made of glass plates were attached to both sides of the parallel base material group 11 along the parallel direction, but the present invention is applicable to the shape of such covering members. For example, without limitation, as shown in FIG. 8, a plurality of thin rod-shaped covering members 22 made of high silicate glass or the like and having an appropriate outer diameter are attached to both sides of the parallel base material group 11 as shown in the figure. In addition, if there is a risk that the thin bar base materials 1 on the most sides of the parallel base material group 11 may be deformed during the sheet forming process, the thin bar base materials 1 on both sides may be
There is also a supplementary thin rod 28 made of the thin rod-shaped covering member on the outside of the
By attaching it as shown in the figure, the deformation of the effective part can be eliminated. Furthermore, when changing the interval width between each core layer in the optical fiber F-), it is necessary to change the ratio of the core diameter to the outer diameter of the optical fiber base material, which is the main component, or to arrange multiple thin rod base materials in parallel. In this process, two spacing adjusting thin plates, etc., made of the same material as the cuturad layer of the base material and having a predetermined thickness or outer diameter are interposed between each thin bar base material. Able to achieve purpose.

As is clear from the above description, according to the manufacturing method of the present invention, a plurality of thin rod-shaped optical fiber preforms are arranged in parallel, and a covering member is attached to both sides of a group of nine parallel preforms. By successively heating and drawing to form an optical fiber V-fold, it is possible to efficiently and easily produce a long optical fiber sheet with excellent spacing accuracy between each core part configured in a common coating layer. It has the advantage of being inexpensive as it reduces manufacturing man-hours and is applicable to the manufacturing of various optical fiber sheets that process multiple optical signals in parallel in optical communication systems, optical information processing systems, etc. This is extremely advantageous.

Note that the optical fiber V formed by the manufacturing method of the present invention
-), it is also possible to easily apply the resin coating following the main manufacturing process.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view illustrating an embodiment of the method for manufacturing an optical fiber sheet according to the present invention, FIG. 2 is a schematic diagram illustrating an optical fiber V-) according to the present invention, and FIG. IIl of the optical fiber V-) according to the invention! FIG. 2 is a schematic perspective view illustrating an example of a pond construction method. In the figure, 1 is a thin rod-shaped optical fiber preform, ta to 1h are core layers in the optical fiber V-), and 2.2'. 22 is a coating member, 8 is a heating furnace, and 4-wire optical fiber V-1.
, 11 indicates a group of parallel base materials, and 2B indicates a complementary thin rod. Figure 1 Figure 2 Figure 3 Figure 1

Claims (1)

[Claims] A plurality of pre-formed optical fiber base materials are arranged in parallel, and on both sides of the parallel base material group! tllli3 A method for manufacturing an optical fiber V-t, which is characterized in that a group of parallel base materials is attached with a covering member sandwiched therebetween and simultaneously heated and stretched to form an optical fiber sheet F.