JPS6365412A - Connector for optical fiber - Google Patents

Abstract

PURPOSE:To easily and surely branch a multiple-core optical fiber to single core optical fibers different in clad diameter by using an optical fiber connector consisting of optical fibers each having a clad different in shape. CONSTITUTION:In the optical fiber connector 10 on the multiple-core optical fiber 11 side, respective optical fibers are joined so that the long sides of clads 2 of respective optical fibers are brought into contact with each other. In the optical fiber connector 10 on the single core optical fiber 12 side, respective optical fibers are joined so that the short sides of the clads of respective optical fibers are brought into contact with each other. Since the joint sides of respective optical fibers are different on both the end parts of the optical fiber connector 10, one end is aligned and the whole optical fibers are twisted by 90 deg. on the way. Consequently, the optical fiber connector 10 for branching a multiple- core optical fiber 11 to single core optical fibers 12 can be easily produced and both the end parts of the connector 10 may be simply abutted upon the multiple-core optical fiber 11 and the single core optical fibers 12.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an optical fiber connector used for branching a multi-core optical fiber into single-core optical fibers having different cladding diameters.

Conventional technologyFor the purpose of realizing high-density information transmission, a large number of core materials,
Bicore optical fibers have been developed that are housed within an integrated cladding. Figures 4 (a> to (C)) are examples of the structure of such a multi-core optical fiber. Figure 4 (a) shows a structure in which the core 1 is integrated with the clad 2 fused together. An example is shown in FIG. 4(b) where a plurality of cores 1 are included in a common cladding 2 having a circular cross section. The configuration is the same as that of the illustrated multi-core optical fiber, but the difference is that the cross section of the cladding 2 is shaped like a circle partially cut out by a straight line.

Generally, a single-core optical fiber requires a certain degree of rigidity from the viewpoint of strength and workability, so the core diameter is 50.
The standard outer diameter of the cladding is 125 μm, which is relatively large. On the other hand, a multi-core optical fiber has an integrated cladding, and the amount of glass per core can be reduced, so the outer diameter is smaller.

Therefore, it is necessary to connect claddings having different diameters.

Branching into single-core optical fibers is not easy, since all of the multi-core optical fibers with the various shapes exemplified above require the above-mentioned operations.

However, there are naturally ways to solve this problem. For example, Japanese Patent Laid-Open No. 60-230607 discloses a method of branching a multi-core optical fiber into a single-core optical fiber using a tapered glass waveguide. Another example is a method of configuring a branch circuit using a GI rod lens, which was announced in Lecture No. 2113 at the 1985 IEICE General Conference.

Furthermore, a method announced at Lecture No. 2111 of the 1985 IEICE General Conference was to use a small-diameter optical fiber with the same core diameter, cladding diameter, and relative refractive index difference as the bi-core optical fiber at the branch section. be.

Problems to be Solved by the Invention However, the three solutions described above each have the following problems.

In the method using a tapered glass waveguide, it is not easy to manufacture the tapered glass waveguide.

In a branch circuit using a CI type rod lens, fiber positioning is not easy. In particular, if there is a misalignment between the connected fibers, crosstalk will occur.

Furthermore, in the method of using a small-diameter optical fiber at the branch, the small-diameter fiber is used to match the structure of the multi-core optical fiber, so the fiber should be butted so that its core exactly matches the single-core optical fiber. It becomes difficult to

The present invention makes it possible to easily and reliably match optical fibers with different cladding diameters, which is a problem when conventionally branching a multi-core optical fiber and connecting it to a single-core optical fiber. The purpose of the present invention is to provide an optical fiber connector.

Means for Solving the Problems The optical fiber connector of the present invention for solving the above-mentioned problems when branching a multi-core optical fiber into a single-core optical fiber corresponds to the number of cores of the multi-core optical fiber. a number of optical fibers, each of which has a cladding having a width equal to the spacing between adjacent cores of the multi-core optical fiber at the end thereof connected to the multi-core optical fiber; arranged and integrated so that the cross sections are aligned in a straight line, each having a cladding having a width equal to the cladding diameter of the single-core optical fiber at the end connected to the single-core optical fiber, They are arranged and integrated so that the cross sections are aligned in a straight line.

Each of the optical fibers constituting the optical fiber connector has a uniform cross section in the axial direction, from an end connected to the multi-core optical fiber to an end connected to the single-core optical fiber. It has been rotated 90 degrees between the two parts.

The cross section of each optical fiber used in this optical fiber connector can be rectangular or elliptical, for example.

Function As described above, the optical fiber connector of the present invention takes advantage of the fact that the cladding cross section of each optical fiber is irregularly shaped, so that the side connected to a multi-core optical fiber and the side connected to a single-core optical fiber are separated. The optical fibers are connected to each other in different directions according to their respective cladding diameters. Each of the optical fibers that make up the optical fiber connector has a uniform cross section in the length direction, so in order to perform the above joining, first align and join the short diameter parts of the irregular cross sections, then twist the entire body 90 degrees. Align the other ends at the major diameter and join.

In this manner, by integrating each optical fiber having a simple shape using a simple joining method, it is possible to easily produce an optical fiber connector that branches a multi-core optical fiber into a single-core optical fiber.

In order to connect a multi-core optical fiber and a single-core optical fiber using the above-mentioned optical fiber connector, it is sufficient to simply adjust their core positions in the vertical direction and match them together.

Example The present invention will be explained below with reference to the drawings.

FIGS. 3(a) and 3(b) are examples of cross-sections of each optical fiber used in the optical fiber connecting member of the present invention.

In FIG. 3(a), the core 1 is provided at the center of the cladding 2, which has a rectangular cross section. On the other hand, FIG. 3(b) is an example of the cladding 2 having an elliptical cross section. This also has a core 1 in the center. In both figures, the length of the major diameter portion is equal to the diameter of the cladding of each single-core optical fiber, and the length of the minor diameter portion is equal to the distance between adjacent cores in the multi-core optical fiber.

FIG. 1 is a diagram showing the arrangement when connecting a multi-core optical fiber 11 and a single-core optical fiber 12 using an optical fiber connector 10 according to the present invention. A sectional view of the optical fiber connector 10 shown in FIG. 1 on the side connected to the multi-core optical fiber 11 is shown in FIG. 2(a), and a sectional view of the side connected to the single-core optical fiber 12 is shown in FIG. This is shown in FIG. 2(b). In this embodiment, a branching optical fiber connector 10
The cross section of each optical fiber is rectangular as shown in FIG. 3(a).

The optical fiber connector 10 on the multi-core optical fiber 11 side shown in FIG. 2(a) is joined so that the long sides of the claddings 2 of each optical fiber are in contact with each other.

In contrast, the single-core optical fiber 12 shown in FIG. 2(b)
The side optical fiber connector 10 is joined so that the short sides of the claddings 2 of each optical fiber are in contact with each other.

In this way, since the optical fiber connector 10 has different joining sides for each optical fiber at both ends, it is necessary to align one end and twist the entire connector 90 degrees in the middle.

However, it is not difficult to create this twist when joining each optical fiber.

To connect both ends of the optical fiber connector 100 to the multi-core optical fiber 11 and the single-core optical fiber 12, it is sufficient to simply butt them together. In this case, it is necessary to adjust the mutual core positions in the vertical direction, but this operation is easy.

It is desirable that the core diameters of the multi-core optical fiber 11, the optical fibers constituting the optical fiber connector 10, and the single-core optical fiber 12 are all the same, but connection is possible even if they are different. However, in the latter case, the loss will be large.

Although the embodiment has been explained with reference to the multi-core optical fiber shown in FIG. 4(a), the multi-core optical fibers shown in FIG. 4(b) and FIG. 4(C) can also be modified appropriately. By applying this, it is possible to configure an optical fiber connector.

Note that the present invention can also be used simply to connect optical fibers with different cladding diameters.

As described in detail of the invention, by using an optical fiber connector made of an optical fiber having a irregularly shaped cladding, a multi-core optical fiber can be easily and reliably branched into single-core optical fibers having different cladding diameters. be able to.

Furthermore, the production of optical fiber connectors is
This can be achieved by a simple operation of aligning the short diameter portions of the irregular cross-sections and joining them together, rotating the entire body by 90 degrees, and aligning the other ends with the long diameter portions.

[Brief explanation of drawings]

Figure 1 is a diagram showing the arrangement when connecting a multi-core optical fiber and a single-core optical fiber using the optical fiber connector of the present invention, and Figure 2 (a) is a diagram showing the arrangement when connecting a multi-core optical fiber and a single-core optical fiber. FIG. 2(b) is a cross-sectional view of the side of the optical fiber connector connected to the multi-core optical fiber, and FIG. 2(b) is a cross-sectional view of the side of the optical fiber connector shown in FIG. 1 connected to the single-core optical fiber. FIGS. 3(a) and 3(b) are examples of cross-sectional views of optical fibers used in the optical fiber connector of the present invention; FIGS. 4(a), (b), and (c). is an example of a cross-sectional view of a multi-core optical fiber. (Main reference numbers) 1. Core, 2. Clad, 10. Optical fiber connector, 11. Multi-core optical fiber, 12. Single-core optical fiber.

Claims (4)

[Claims] (1) An optical fiber connector for branching a multi-core optical fiber in which a plurality of cores are arranged in a straight line in cross section into single-core optical fibers having different cladding diameters, The number of optical fibers corresponds to the number of cores of the multi-core optical fiber, and each of these optical fibers is connected to the adjacent core of the multi-core optical fiber at the end on the side connected to the multi-core optical fiber. each having a cladding with a width equal to the spacing, arranged and integrated so that the cross sections are aligned in a straight line, and at the end of the side connected to the single-core optical fiber;
An optical fiber connector characterized in that the connector has a cladding having a width equal to the cladding diameter of the single-core optical fiber, and is arranged and integrated so that the cross sections are aligned in a straight line. (2) Each of the optical fibers constituting the optical fiber connector has a uniform cross section in the axial direction, and is connected to the single-core optical fiber from the end connected to the multi-core optical fiber. The optical fiber connector according to claim 1, wherein the optical fiber connector is turned 90 degrees between the side ends. (3) The optical fiber connector according to claim 2, wherein each of the optical fibers constituting the optical fiber connector has a rectangular cross section. (4) The optical fiber connector according to claim 2, wherein each of the optical fibers constituting the optical fiber connector has an elliptical cross section.