JP2004295157A - Method for manufacturing small-sized composite type optical fiber coupler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small-sized composite type optical fiber coupler in which a plurality of optical fibers formed of fusion-drawn parts are united with a common substrate and stored in one composite package. <P>SOLUTION: Exposed cores of 1st and 2nd, and 3rd and 4th optical fibers are arranged on a substrate in parallel and a 1st alignment part which is formed between the 1st and 2nd exposed cores and a 2nd alignment part which is formed between the 3rd and 4th exposed core are formed adjacently to each other; and the two alignment parts are heated under the same heating conditions and the same tension is applied to the four optical fibers to form 1st and 2nd fusion-drawn parts. Then the four optical fibers including the 1st and 2nd fusion-drawn parts are joined with the substrate and stored in the same package. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small composite optical fiber coupler, and more particularly, to a method of manufacturing a small composite optical fiber coupler in which a plurality of optical fiber couplers each formed of a fusion-spread portion are integrated on a common substrate and housed in the same composite package. About.

A conventional example will be described with reference to FIG.
FIG. 4A shows that the exposed core wire 11 and the exposed core wire 21 of the two optical fibers 1 and 2 are aligned with each other on the surface of the substrate 7 and subjected to a fusion stretching process. 2 shows a 2 × 2 fusion-stretched optical fiber coupler in which a portion 120 is formed and the entire fusion-stretched portion 120 including the substrate 7 is accommodated in a package 8.
A conventional example of a composite optical fiber coupler will be described with reference to FIG. This conventional example is a 2 × 2 optical fiber coupler of a 2in1 package in which two 2 × 2 fusion-stretched optical fiber couplers of FIG. 4A are prepared and housed in a common composite package 80.

Another conventional example of the composite optical fiber coupler will be described with reference to FIG. This conventional example is a 2 × 4 tree optical fiber coupler configured by preparing three 2 × 2 optical fiber couplers shown in FIG. As shown in the figure, the 2 × 4 tree optical fiber coupler includes two 2 × 2 optical fiber couplers shown in FIG. This is a composite optical fiber coupler in which one core wire 21 and one core wire 11 of each of the two optical fiber couplers are connected to the core wires 11 and 12 of a third 2 × 4 tree optical fiber coupler. The composite optical fiber coupler is also housed in a common composite package 80.
JP-A-7-318745 JP-A-2-7007 JP-A-7-92345 JP-A-3-220507 Japanese Utility Model Publication No. 5-25405 JP 2000-9960 A

  In the conventional example of the composite optical fiber coupler shown in FIG. 4B, two 2 × 2 fusion-stretched optical fiber couplers housed in a package 8 are prepared, and these are housed in a single composite package 80. Because of the configuration, the outer dimensions of the composite package 80 are larger than the outer dimensions of the individual packages 8 of the 2 × 2 optical fiber coupler package, and are about twice as large in the radial direction. That is, the diameter φ of the package 8 is about 3 mm, and the total length is about 50 mm. Accordingly, in the conventional example of FIG. 4B, the diameter φ of the package 8 is enlarged to 6 mm and the total length is increased to about 50 mm.

Another conventional example of the composite optical fiber coupler illustrated and described with reference to FIG. 5 is also manufactured by connecting 2 × 2 optical fiber couplers housed in a package 8 similarly to the conventional example of FIG. Therefore, the outer dimensions of the composite package 80 are approximately twice as large in the radial direction as the outer dimensions of the individual packages 8, and the overall length is approximately twice as large as the individual packages 8.
An object of the present invention is to provide a compact composite optical fiber coupler which solves the above-mentioned problem by integrating a plurality of optical fiber couplers formed by fusion-spreading portions on a common substrate and housing them in the same composite package. .

  Claim 1: A plurality of fusion extending portions 120 and 340 having a plurality of optical fibers 1, 2, 3 and 4 to form an optical coupler are formed close to each other on a common substrate 7, A method of manufacturing a small composite type optical fiber coupler in which these fusion-bonded and stretched portions integrated into the same 7 are housed in the same composite package 80 has been proposed.

Claim 2: In the compact composite optical fiber coupler according to claim 1, a further fusion-stretched portion 230 that optically couples to both of the fusion-stretched portions 120 and 340 formed close to each other is formed. A manufacturing method of small composite optical fiber coupler was proposed.
In a third aspect of the present invention, in the method of manufacturing a small-sized composite optical fiber coupler, the adjacent fusion-bonded stretching sections 120 and 340 are simultaneously fused and stretched by the same burner. And create it.

  As described above, according to the present invention, as shown in FIG. 3D, the fused and stretched portions 120 and 340 having the same performance are juxtaposed, and the optical fibers 1 to 4 Since the diameter is 0.25 mm, the distance between the fusion extending portion 120 and the fusion extending portion 340 that are close to each other in the radial direction of the composite package 80 is 0.5 mm. The distance between the fusion extending portion 120 or the fusion extending portion 340 and the fusion extending portion 230 separated in the length direction of the composite package 80 is 20 mm. Accordingly, the overall dimensions of the fusion-bonded extension portion and the substrate 7 to be accommodated in the composite package 80 are about 0.25 mm × 4 = 1 mm in the radial direction and about 50 mm in the length direction. As described above, the diameter φ of the conventional package 8 accommodating one fusion-spreading section 120 and the entire substrate 7 on which the fusion-extending section 120 is integrated is about 3 mm and the total length is about 50 mm. In the coupler, the composite package 80 can be designed and manufactured to have almost the same shape and dimensions as the conventional package 8, and can be accommodated therein.

An embodiment of the present invention will be described with reference to the embodiment of FIG. FIG. 1 is a diagram illustrating an embodiment of a 2 × 4 composite optical fiber coupler.
First, four optical fibers 1, 2, 3, 4 are arranged on the surface of the substrate 7 with their exposed core wires 11, 21, 31, 41 arranged side by side. In general, a glass substrate is used as the substrate 7. Here, an alignment portion is formed between the exposed core wire 11 and the exposed core wire 21, and a fusion-stretching process is performed on the alignment portion to form one fusion-stretched portion 120. Then, an alignment portion is formed between the exposed core wire 31 and the exposed core wire 41 adjacent to the alignment portion formed between the exposed core wire 11 and the exposed core wire 21, and a fusion stretching process is performed thereon to perform the fusion stretching portion 340. Is formed at one place.

  These two fusion-stretching processes are performed at the same time because the optical characteristics of the completed fusion-stretching section 120 and the fusion-stretching section 340 need to be equal. In order to realize this, two gas burners are used to heat the alignment part between the exposed core 11 and the exposed core 21 and the alignment part between the exposed core 31 and the exposed core 41 adjacent thereto. At the same time, fusion stretching is performed under the same conditions. Alternatively, the alignment portion between the exposed core wire 11 and the exposed core wire 21 and the alignment portion between the exposed core wire 31 and the exposed core wire 41 adjacent thereto are formed in a symmetrical positional relationship, and one gas burner is used. The two alignment portions are symmetrically heated under the same thermal conditions and subjected to a fusion stretching process to form a fusion stretching portion 120 and a fusion stretching portion 340. These fusion-stretching processes are performed while light is incident from one of the incident sides of the optical fiber to be fusion-stretched, and the light branching ratio in each of the fusion-stretching unit 120 and the fusion-stretching unit 340 is reduced. Stop at 50:50. The branching ratio in the fusion-stretched portion 340 can be set to another necessary branching ratio of 50:50.

  When the fusion-spread portion 120 and the fusion-stretch portion 340 are formed, the optical fibers 1 to 4 including these fusion-stretch portions are bonded and fixed to the substrate 7 as they are. Bonding and fixing of the optical fibers 1 to 4 to the substrate 7 is performed by heating and melting a part of the substrate 7 or using an adhesive. The entirety of the integrated fused extension and the substrate 7 is housed in the same composite package 80, and the production of the composite optical fiber coupler is completed. Prior to the package by the composite package 80, unnecessary incident side optical fibers indicated by chain lines are cut and removed.

  In order to equalize the optical characteristics of the fusion-stretched portion 120 and the fusion-stretched portion 340, it is necessary to adjust and set the heat applied to both alignment portions equally as described above. In order to equalize the heat applied to both alignment portions by using one burner, a burner larger than that used in a general fusion stretching process is used. However, if this large burner is simply a large one, the extension length of the exposed core wire will be long, so the length of the alignment core in the length direction of the exposed core wire will be reduced in accordance with the extension length of the exposed core wire, and Design, manufacture and use a large burner with a larger dimension in the direction perpendicular to the core wire. That is, the distribution of the fusing temperature by heating is short in the direction of extension of the exposed core wire and lengthened in the direction orthogonal to the extension direction of the exposed core wire. Two regions to be subjected to the fusion and stretching process are heated to the same temperature. Design and manufacture a large burner with a shape that suits you. In order to equalize the optical characteristics of the fusion-spreading section 120 and the fusion-stretching section 340, the tension applied to the four optical fibers is further adjusted to be the same so that the tension applied to both alignment sections of the optical fibers is made the same. There is a need to.

Another embodiment of the present invention will be described with reference to FIGS.
In particular, referring to FIG. 3A, four optical fibers 1, 2, 3, and 4 are arranged on the surface of the substrate 7 with their exposed cores 11, 21, 31, and 41 arranged in parallel with each other. Here, a force is applied to both the exposed core wire 21 and the exposed core wire 31 sideways using a tool, and the two are brought closer to each other to form an alignment portion 230 '. Next, referring to FIG. 3B, a force is applied to both the exposed core wire 11 and the exposed core wire 21 to the sides by using a tool, and the exposed core wire 11 and the exposed core wire 21 are brought closer to each other to form an alignment portion 120 '. Further, an alignment part 340 'between the exposed core 31 and the exposed core 41 is formed in parallel with the alignment part 120' between the exposed core 11 and the exposed core 21.

  Referring to FIG. 3 (c), a fusion-stretching process is performed on the alignment unit 230 'while fixing the incident side and applying tension in the direction of the arrow on the emission side to form the fusion-stretching unit 230. . Here, the fusion stretching process is performed while applying tension only to the optical fiber 2 and the optical fiber 3. Alternatively, the operation is performed while applying tension to all of the four optical fibers 1, 2, 3, and 4. The dashed ellipse indicates the area heated by the burner. The fusion-stretching process is performed while light is incident from the incident side of the optical fiber 2, and light is also emitted from the optical fiber 3, and stops when the branching ratio in the fusion-stretching section 230 becomes 50:50. Note that the branching ratio in the fusion-bonded stretching section 230 can be set to another necessary branching ratio other than 50:50.

  Next, referring to FIG. 3 (d), the alignment section 120 'and the alignment section 340' are subjected to fusion stretching while applying tension to the emission side in the direction of the arrow, and the fusion stretching section 120 and the fusion stretching section are applied. 340 is formed. The dashed ellipse indicates a region heated by the burner, and symmetrically heats the alignment unit 120 'and the alignment unit 340'. This fusion-stretching process is performed while light is incident from the incident side of the optical fiber 1 and the optical fiber 4, light is also emitted from the optical fiber 2, and the branching ratio becomes 50:50 in the fusion-stretched portion 120. At the same time, light is also emitted from the optical fiber 3 and stops when the branching ratio becomes 50:50 in the fusion drawing section 340. In addition, the branching ratio in the fusion-stretched portion 120 and the fusion-stretched portion 340 may be set to another necessary branching ratio of 50:50.

  When the fusion-bonded extension 230, the fusion-bonded extension 120, and the fusion-bonded extension 340 are formed, the optical fibers 1 to 4 including these fusion-bonded stretches are directly bonded to the substrate 7 as in the previous embodiment. The whole of the fixed and integrated fusing and extending portion and the substrate 7 are housed in the same composite package 80, and the production of the composite optical fiber coupler is completed. Prior to the package by the composite package 80, unnecessary incident side optical fibers indicated by chain lines are cut and removed.

The figure explaining an Example. The figure explaining another Example. The figure explaining a manufacturing order. The figure explaining a conventional example. The figure explaining other conventional examples.

Explanation of reference numerals

1,2,3,4 Optical fiber 11,21,31,41 Exposed core wire
7 Substrate
120 fusing and stretching part
340 fusing and stretching part
80 Composite Package

Claims (3)

The exposed cores of the first, second, third and fourth optical fibers are arranged in parallel on a substrate,
A first alignment portion formed between adjacent first and second exposed core wires and a second alignment portion formed between adjacent third and fourth exposed core wires are formed to be close to each other. ,
Heating the two alignment sections under the same heat conditions, applying the same tension to the four optical fibers to form first and second fusion-bonded stretch sections,
A method for manufacturing a small-sized composite optical fiber coupler, comprising joining the four optical fibers including the first and second fusion-spread portions to the substrate and housing them in the same package. The exposed cores of the first, second, third and fourth optical fibers are arranged in parallel on a substrate,
A first alignment portion formed between adjacent first and second exposed core wires and a second alignment portion formed between adjacent third and fourth exposed core wires are formed to be close to each other. ,
Forming a third alignment portion between the second and third exposed cores,
Performing a fusion-stretching process on the third alignment portion to form a third fusion-stretch portion;
Heating the first and second alignment sections under the same thermal conditions, applying the same tension to the four optical fibers to form first and second fusion-spread sections,
A method for manufacturing a small-sized composite optical fiber coupler, comprising joining the four optical fibers including the first, second, and third fused extension portions to the substrate and housing the same in the same package. The first and second alignment units are simultaneously heated using a large burner having a small dimension in the length direction of the exposed core wire and a large dimension in the orthogonal direction of the exposed core wire. 2. The method for manufacturing a small composite optical fiber coupler according to item 2.

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