JPH08166521A - Coated fiber ribbon type optical fiber coupler and its production - Google Patents

Abstract

PURPOSE: To obtain a coated fiber ribbon type optical fiber coupler formed with a fusion stretching type optical fiber coupler in the intermediate part of coated optical fiber ribbons and a process for producing such coupler easily at a good yield. CONSTITUTION: The coatings of terminal parts 16a, 16b at respectively one-side ends of two sheets of the optical fiber optical fiber ribbons 10a, 10b are removed to expose bare optical fibers 3a, 3b,... and the end faces 9a of the respective corresponding bare optical fibers 3a, 3b are fusion spliced to each other to form one sheet of the coated optical fiber ribbon 19 having the intermediate bare fiber parts 18. The adjacent >=2 fibers of the bare optical fibers 3a-3b,... of the intermediate bare fiber parts 18 are brought into contact with each other and the bare optical fibers in contact with each other are fused to each other and are stretched to form the fusion stretched parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber ribbon type optical fiber coupler (hereinafter referred to as "tape type coupler") and a manufacturing method thereof, and particularly to an optical fiber optical fiber ribbon (hereinafter referred to as "tape optical fiber"). The present invention relates to a tape-type coupler in which a fusion splicing type optical fiber coupler is formed in the middle part of the above and a simple and high-yield manufacturing method thereof.

[0002]

2. Description of the Related Art In the fields of optical communication and optical measurement, fusion-stretching type optical fiber couplers (hereinafter referred to as "optical fiber couplers") are widely used for the purpose of branching and combining lights.
This optical fiber coupler generally has a structure in which an input port composed of M optical fibers and an output port composed of N optical fibers are optically coupled at a fusion splicing portion, and is an M × N type. It is called an optical fiber coupler.

This optical fiber coupler is conventionally shown in FIG.
It is manufactured by the method shown in FIGS.
That is, first, in FIG. 7A, the coating of the intermediate portion of the two optical fibers 1a and 1b having the coating 2 is stripped off to expose the bare optical fibers 3a and 3b, respectively, and the bare optical fibers 3a and 3b are exposed. Parallel. Next, as shown in FIG. 7B, at least a part of the bare optical fibers 3a and 3b arranged in parallel are brought into contact with each other, and the contact portions 5 thereof are fused to each other by using an oxyhydrogen flame 6 (or a discharge arc or the like). Then, it is stretched and stretched to form a fusion stretched portion 7 optically coupled between the optical fibers 1a and 1b as shown in FIG. 7 (c). Next, as shown in FIG. 7D, the entire exposed optical fiber bare wires 3a and 3b including the fusion extending portion 7 are housed in a protective case 8, and the covering portions and protective cases on both sides of the bare wire portion are protected. Both ends of 8 are bonded and sealed with a sealing resin 8p. As a result, the coating portion of the optical fiber 1a becomes the ports 9a and 9b,
2x with ports 9c and 9d covering the optical fiber 1b
A type 2 optical fiber coupler is obtained.

On the other hand, conventionally, in order to increase the transmission density in an optical fiber cable, a tape core wire formed by arranging a plurality of optical fiber element wires in parallel and fixing them with a collective coating has been widely used. An example of this tape core wire is shown in FIG. In FIG. 8, a tape core wire 10 comprises a plurality of optical fiber bare wires 13 _a , 13 _b formed by applying a primary coating coating 12 a and a secondary coating 12 b to a bare optical fiber 3.
... 13 _n-1 and 13 _n are arranged in parallel, and in this state, collective coating 14
It is covered and fixed with and is formed into a flat tape shape. The collective coating 14 may be a tape-bonding type in which resin tapes are sandwiched from above and below to be bonded.

Since the tape core wire 10 is formed in the shape of a flat tape, it is easy to handle individual optical fiber strands, and the integration density of optical fibers is high, so that a large number of optical paths can be handled collectively. it can. Therefore, there is a strong demand for applying the tape core wire to other optical circuits in addition to simple optical transmission. Therefore, it was considered to incorporate the above optical fiber coupler into the tape core wire 10. In order to meet this demand, for example, as shown in FIG. 9, mechanically removing the coating of the intermediate portion of the two tape core wires 10c and 10d,
A plurality of intermediate bare wire portions are overlapped with each other to overlap each other, the bare wire portions 3-3 that have been overlapped with each other are brought into contact with each other, and the bare wire portions that have come into contact with each other are fused and stretched to form a fused stretched portion 7. A tape type coupler having a 2 × 2 type optical fiber coupler has been proposed (see Japanese Patent Laid-Open No. 63-205615).

[0006]

When an optical fiber coupler is to be incorporated in the middle of a tape core wire by the conventional technique, as described above, first, the coating of the middle portion of the tape core wire is removed to remove the bare wire. Need to be exposed. However, in the tape core wire 10, the individual bare wires 3 are arranged very close to each other, and each bare wire 3 has a double coating 11, 12.
It is extremely difficult to remove all of these intermediate coatings without damaging any bare wire in the middle portion of the tape core wire since all of them are covered with the collective coating 14 in addition to the above. is there. There is a good possibility that a part of the bare wire will be damaged in the process of removing the coating. Now, for example, if a tape core of 16 cores is used and the probability of successful sheath removal per core is 95%, the probability of stripping all 16 cores without damage is (0.95) ¹⁶ , that is, Only about 40%. Therefore, the production yield is low, and if the yield is to be improved, meticulous attention is required and work efficiency is significantly reduced. The present invention has been made to solve the above problems, and an object thereof is to provide a manufacturing method for manufacturing a tape-type coupler by a simple method with a good yield, and a tape-type coupler manufactured by this manufacturing method. It is in.

[0007]

The above object is to remove the coating on one end of each of the two tape cores including at least two bare wires to expose the bare wires, and to remove the respective tape cores. The end faces of the corresponding bare wires of the wire are fusion-bonded to each other to form one tape core wire having an intermediate bare wire portion, and two or more bare wires adjacent to the intermediate bare wire portion are contacted with each other, The problem can be solved by providing a method of manufacturing a tape-type coupler in which the bare wires in contact with each other are fused and stretched to form a fused stretched portion. The present invention also provides a tape type coupler manufactured by the above manufacturing method. This tape-type coupler is preferably provided with a means for protecting the intermediate bare wire portion including the fusion-bonded stretched portion.

[0008]

When the end bare wire portions formed at the end portions of the two tape core wires are fused and connected to each other, one tape core wire having the intermediate bare wire portion is formed. When adjacent bare wires are brought into contact with each other in the intermediate bare wire portion and fused and stretched, the fused and stretched bare wire forms one unit of an optical fiber coupler.

[0009]

EXAMPLES The present invention will be described in more detail by way of examples. (Embodiment 1) FIGS. 1 to 6 show a method of manufacturing the tape-type coupler of Embodiment 1 in the order of steps. In FIG. 1, first, two tape core wires 10a, 1 including eight bare wires 3a, 3b, ...
0b is prepared, and one of these ends 16a,
Remove the coating on 16b. This removal of the end coating is a technique that has already been matured and can be performed safely and quickly. Next, as shown in FIG.
a, 10b corresponding exposed bare wire 3a-3a, 3b-
The end faces 11 of 3b, ... Are fusion-spliced to each other. This connection means a physical / optical connection. For fusion bonding of the end face 11, for example, a technique of arc discharge 17 can be used. As a result, the two tape cores 10a and 10b are optically connected to each other, and the one tape core 1 having the intermediate bare wire portion 18 is provided.
9 is formed.

Next, as shown in FIG. 3, the exposed bare wires 3a, 3b, 3c, 3d, ... Of the intermediate bare wire portion 18 are brought into contact with adjacent two cores 3a-3b, 3c-3d ,. , And contact portions 20a, 20b, ... This contact part 20
To form a, 20b, ..., For example, as shown in FIG.
A comb-tooth-shaped width-shifting jig 21 having a narrower interval toward the base is provided at each of both ends of the contact portions 20a, 20b, ... It is possible to use a method of inserting so as to include 3b, 3c-3d, .... In addition, the set of contacted bare wires should be kept in contact with each other even if the width-shifting jig 21 is removed so that both ends of the contact portions 20a, 20b, ... You may fix it.

Then, as shown in FIG.
are heated and melted by using, for example, an oxyhydrogen flame or an arc discharge (not shown), and are fused and stretched to form respective fused stretched portions 22a, 22b ,. At this time, since the bare wires 3a, 3b, ... Are arranged on one plane, the fusion-stretching is uniformly performed. Here, four sets of 2 × 2 type optical fiber coupler units (hereinafter referred to as “coupler units”) 25a, 25b, 25
A tape-type coupler incorporating c and 25d is obtained.

Since the intermediate bare wire portion 18 formed with the coupler units 25a, ... Is easily damaged by an external force, as shown in FIG. 6, in order to prevent this, the covering portions 23a on both sides of the intermediate bare wire portion 18, The tape type coupler of the first embodiment is completed by attaching the case 24 that houses the intermediate bare wire portion 18 with the intermediate wire 23b interposed therebetween. The case 24 can be formed of a quartz plate or a synthetic resin.

Test Example The optical characteristics of the tape-type coupler of Example 1 were tested. The optical fiber used for this tape type coupler is a single mode optical fiber. Table 1 shows other specifications of the tape type coupler.

[0014]

[Table 1]

The tape-type coupler has a coupling degree of 50% at each 1.3 μm wavelength of the formed coupler units 25a, ..., And corresponds to a so-called 3 dB optical fiber coupler. 4 sets of coupler units 25
The binding degree and excess loss were measured for a, 25b, 25c, and 25d. Table 2 shows the results.

[0016]

[Table 2]

From the results shown in Table 2, it can be seen that the target coupling degree was obtained and the excess loss was maintained at an extremely low level in all the coupler units in the tape type coupler of Example 1.

In the above embodiment, four sets of coupler units are formed by using eight ribbons, but it goes without saying that the number of ribbons is not limited to this.
For example, it is possible to use a tape core of 9 cores and form 8 sets of 4 cores to form 4 sets of 2 × 2 type coupler units, and use the remaining 1 core for transmission line monitoring. Also, for example, by using a 9-core tape core, a 3 × 3 type coupler unit is
It is also possible to form a set.

Further, the tape type coupler of the present invention can be applied to any conventionally known optical fiber coupler. For example, a so-called WDM (wavelength multiplex type optical fiber coupler) in which the coupling degrees between the different wavelengths are approximately 0% and 100%, or a so-called WIC (wavelength dependence reduced optical fiber) having a constant coupling characteristic in a wide wavelength band. It is also applicable to couplers, etc.

[0020]

The tape-type coupler of the present invention removes the coating on the end portions of two tape cores by using the already mature coating stripping technique, and connects both exposed bare wires to each other to form an intermediate layer. Since it is obtained by the manufacturing method for forming the bare wire portion, damage that occurs with a high probability in the conventional method of directly peeling off the coating of the intermediate portion of the tape core wire can be avoided. Also, since two or more adjacent cores of the parallel bare wires are brought into contact with each other and fused and stretched,
The heating of fusion drawing is performed uniformly, and the overall effect of these is that a tape-type coupler can be manufactured at a high yield in a continuous process at high speed.

[Brief description of drawings]

FIG. 1 is a plan view showing a first manufacturing process in an embodiment of the present invention.

FIG. 2 is a plan view showing a next manufacturing process in the embodiment of FIG.

FIG. 3 is a plan view showing a further manufacturing process in the embodiment of FIG.

FIG. 4 is a cross-sectional view showing an aspect of using one jig for carrying out the process of FIG. 3, as seen from the axial center direction of the intermediate bare wire portion.

FIG. 5 is a plan view showing the next manufacturing step in the embodiment of FIG.

FIG. 6 is a plan view showing the tape-type coupler of the first embodiment.

FIG. 7 is a plan view showing a manufacturing process of an example of a conventional optical fiber coupler in the order of (a) to (d).

FIG. 8 is a cross-sectional view showing an example of a tape core wire as viewed in the axial direction.

FIG. 9 is a perspective view showing an example of a tape-type coupler according to a conventional technique.

[Explanation of symbols]

3a, 3b, 3c, 3d ... Optical fiber bare wire, 10a, 1
0b, 19 ... Tape core wire, 11 ... End surface, 16a, 16b
... Terminal part, 18 ... Intermediate bare wire part, 20a, 20b ... Contact part, 22a, 22b ... Fusion extension part, 23a, 23b ... Both side coating part, 24 ... Case, 25a, 25b, 25c, 2
5d ... Coupler unit.

Claims (3)

[Claims] 1. A bare optical fiber is exposed by removing a coating on one end of each of the two bare optical fibers including bare optical fibers. The corresponding end faces of the bare optical fibers are fusion-spliced to each other to form a single optical fiber tape core wire having an intermediate bare wire portion, and two or more bare optical fibers adjacent to the intermediate bare wire portion are bare. A method for producing a tape-fiber optical fiber coupler in which wires are brought into contact with each other, and the bare bare optical fibers are fused and stretched to form a fused stretched portion. 2. A tape optical fiber type optical fiber coupler manufactured by the manufacturing method according to claim 1. 3. A tape optical fiber type optical fiber coupler according to claim 2, further comprising means for protecting the intermediate bare wire portion including the fusion spliced portion.