JPH08334653A - Multiple optical fiber connector - Google Patents

Abstract

PURPOSE: To provide a multiple optical fiber connector which is simple and is easy to assemble. CONSTITUTION: Short-sized optical fibers 2 are respectively housed in a multi- fiber ferrule 1 having plural small-diameter holes of the inside diameter slightly larger than its outside diameter. The end face sides of these short-sized optical fibers 2 are polished to mirror finished surfaces together with the end face part 4 of the ferrule 3 for multiple fibers. The rear end face of the short-sized optical fibers 2 are fixed by aligning this end face to about the middle of aligning grooves 5 formed at equal intervals and is cut or polished to the mirror finished surface. An optical adhesive is applied on the rear end face of the short-sized optical fibers 2 and the ferrule 3 for multiple fibers is made into the structure opened on the top end side from about the middle to the rear end face. A U-shaped elastic material 7 is mounted at the rear part of the ferrule 3. After the respective optical fibers 12 of a coated fiber ribbon 9 are inserted into the small-diameter holes of the multiple fiber ferrule 1, the fibers are fitted into the elastic material 7 and are fixed. On the other hand, the root parts of the optical fiber parts 12 of the coated fiber ribbon 9 are pressed and fixed to the aligning grooves by a cover 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber connector for connecting optical fibers to each other, and more particularly, to a multi-core collective connection type optical fiber connector using an optical tape core wire.

[0002]

2. Description of the Related Art Along with the increase in transmission capacity, the number of optical fibers is increasing, and a tape core wire for holding a plurality of optical fibers at a time has been developed. As an optical fiber connector for connecting the tape core wires at a time, Japanese Patent Laid-Open No. 63-
A multi-fiber optical fiber connector using a V-groove or molding is known as disclosed in Japanese Patent No. 56619 and Japanese Patent Laid-Open No. 3-179405. FIG. 9 shows a perspective view of an example of a conventional optical fiber connector for a ribbon cable. The ferrule 24 of this multi-fiber optical fiber connector has multi-fiber ferrules 25 formed at equal intervals to fix the strands of the optical fiber ribbon 26. By fitting the guide pin 29 into the alignment hole 28, it is possible to connect the optical fiber strands of the facing multi-core ferrule with high accuracy.

[0003]

In the structure of the conventional multi-fiber optical fiber connector, the multi-fiber ferrule 24 has the multi-fiber ferrule small-diameter hole 25 formed therein, and the optical tape core wire 26 is formed in the inner peripheral portion thereof. The wire portion is fixed by adhesion, and the end face 27 of the ferrule is mirror-polished. Alternatively, as disclosed in the above-mentioned Japanese Laid-Open Patent Publication No. 3-179405, the element wire portion 2 of the optical tape core wire is formed in the V groove formed on the ceramic or the like.
9 has a structure in which it is fixed by adhesion.

In order to assemble such an optical fiber connector, it is necessary to remove excess adhesive on the ferrule end face portion 27 and polish the tip of the optical fiber to a mirror surface after the optical fiber is fixed by adhesion. Therefore, when it is desired to assemble an optical fiber connector at a site where an optical fiber is installed, it is necessary to bring a polishing machine to the site. Therefore, there is a problem that the optical fiber connector cannot be assembled in a place where it is difficult to secure a power source or a space in a building or on the road. Further, there is also a problem that the time required for polishing is great and the assembling time becomes long.

Further, the conventional multi-core optical fiber connector has a structure in which the optical tape core wire is fixed to the ferrule with an adhesive. Usually, the adhesive has a time limit called "pot life" during use, and the assembly time may be limited by the pot life. Also,
Even if a photo-curable adhesive is used, it is usually necessary to block light, which limits the ease of storage and use of the adhesive. Furthermore, in the case of a thermosetting adhesive, a thermosetting device is necessary, and in the case of a photocuring adhesive, a light irradiator is indispensable, which also causes a problem in workability on site construction. .

In view of the above problems of the conventional optical fiber connector, the present invention provides a simple and easy-to-assemble multicore optical fiber connector and an optical fiber connecting method using the same.

[0007]

In order to solve the above-mentioned problems, in the multi-fiber optical fiber connector of the present invention, short optical fibers are preliminarily housed in multi-fiber ferrules, and the rear end of the short optical fiber is separated from the ferrule. Jumping out. The protruding portions of the respective short optical fibers are respectively arranged on the array grooves formed at a predetermined interval and fixed in advance. An optical matching agent is applied to the rear end of the short optical fiber. On the other hand, the end face side is mirror-polished and has a sub-assembled structure. The optical fiber of the optical fiber ribbon is arranged in the array groove of the sub-assembled ferrule so that the tip of the optical fiber is abutted against the rear end surface of the short optical fiber. Then, the tape core wire is fixed by a cover that fits into the case in which the array groove is arranged.

Since the ferrule end surface is already mirror-polished as described above, it is only necessary to abut each of the multi-core optical fibers of the tape core wire to the corresponding short optical fiber on the array groove. Then, the optical fiber connector can be assembled by fixing the multi-fiber optical fiber on the line side by using a fastening mechanism for pushing. here,
Since no adhesive is used not only for fixing the optical fibers but also for fixing the multi-core optical fibers, it is possible to easily assemble them.

[0009]

EXAMPLE A multi-fiber optical fiber connector of the present invention,
A detailed description will be given with reference to the drawings.

FIG. 1 is a perspective view of an embodiment of a multi-fiber optical fiber connector of the present invention. 2 is a vertical sectional view of FIG.

The multi-fiber ferrule 3 has a short optical fiber 2
The small diameter holes 1 having an inner diameter slightly larger than the outer diameter are formed at equal intervals. In this embodiment, a commonly used quartz optical fiber is used for the short optical fiber 2, and since the outer diameter thereof is 125 μm, a small diameter hole of 126 μm is formed. Further, in this embodiment, a four-core optical fiber connector will be described.

Four short optical fibers 2 are inserted into the small-diameter holes 1 and fixed by adhesion. The end face side, together with the end face portion 4 of the multi-core ferrule 3, is obliquely mirror-polished to prevent reflection of light after connection. The end face of the short optical fiber 2 has a structure in which it projects from the end face portion 4 of the multi-core ferrule 3 on the same plane or by about a sub-μm. On the other hand, the rear end face of the short optical fiber 2 is fixed to the center of the alignment groove 5 which is continuous with the multi-fiber ferrule 3 and is formed at equal intervals so that the optical axis of the short optical fiber 2 is equal. , Its end face is mirror-cut. The end face of the short optical fiber 2 on the end face 4 side may be mirror-polished into a convex shape. Also, the rear end surface may be mirror-polished instead of being cut.

An optical matching agent (matching agent) having a refractive index substantially equal to the refractive index of 1.42 of the core of the optical fiber is applied to the rear end surface of the short optical fiber 2.

On the other hand, as shown in FIG. 1, the multi-core ferrule 3 has a shape in which the upper surface portion is cut off from the middle to the rear end surface. It has a U-shaped cross-section with an open upper surface so as to cover this rear part. A case 7 formed of an elastic body is fixed here. Further, the hook 10 is provided on the inner peripheral side surface of the upper end of the elastic body case 7.
Are formed.

The cover 8 is structured to be fitted inside the elastic band case 7 so that the tape core wire 9 can be fixed to the inside from the upper portion of the multi-core ferrule 3. Further, the hook 10 of the elastic body case 7 is formed with a recess 11 that can be fitted. In addition, a block-shaped elastic body is arranged on the bottom surface of the cover 8, and the element wire portion 12 of the tape core wire is pressed from the upper surface at the position of the rear end surface of the short optical fiber 2.
As a result, the short optical fiber 2 and the optical axis are aligned and fixed in the alignment groove 6.

A core wire fixing groove A15 and a core wire fixing groove B16 are formed inside the elastic body case 7 and the cover 8 so that the core wire portion 14 of the tape core wire 9 can be included therein. In the middle of each groove, the core portion 1 of the tape core wire 9
4 so that they can be crimped and fixed by fitting,
18 is formed.

Next, a method for connecting multi-core optical fibers to each other using the multi-core optical fiber connector of the present invention will be described. To assemble and connect the multi-fiber optical fiber connector of the present invention at an optical fiber laying construction site or the like,
First, the end portion of the core wire of the tape core wire 9 to be assembled is removed by a predetermined amount, and the end surface A19 is cut into a mirror surface.
After that, the end face B2 of the short optical fiber 2 is slid along the groove 5 of the multi-fiber ferrule 3 toward the end face 4 side of the multi-fiber ferrule 1.
Hit 0. Then, cover 8 with the multi-core ferrule 3
Fit into the elastic body case 7 from above. Due to abnormal work, the multi-fiber optical fiber connector can be assembled.

FIG. 3 is a vertical sectional view when the tape core wire is assembled, and FIG. 4 is a lateral sectional view of the portion A in FIG. 3 and 4
As shown in FIG. 5, the convex portions A17 and B18 are formed in a wedge shape with the front end side formed vertically and the front end portion inclined so that the tape core wire 9 is not easily pulled out by pulling. . Further, the cover 8 is, as shown in FIG.
Stoppers 21 are formed on the left and right of the block-shaped elastic body 13, and serve as stoppers so as not to crush the strand 12 and the core 14 of the tape core 9 more than necessary. The tape core wire 9 and the short optical fiber 2 are connected by a structure in which an optical matching agent (matching agent) 6 is retained on the end surface of the short optical fiber 2. The optical matching agent can prevent reflection at the connection point between the multi-core optical fiber and the short optical fiber.

The multi-fiber ferrule 3 is molded by plastic, and the multi-fiber ferrule 1 is integrally molded in a cylindrical shape. As shown in FIG. 5, the alignment groove 5 has a structure having a semicircular groove 5a of the same diameter continuous with the multi-core ferrule 1 by integrally molding the same mold. As shown in FIG. 6, this alignment groove is a V groove formed so as to align the optical axis with the fiber of the multi-fiber optical fiber when the short optical fiber 2 fixed to the multi-fiber ferrule 1 is arranged. May be

In the multi-fiber optical fiber connector of the present invention, the ferrule 3 for multi-fiber can be made of silicon or ceramics in addition to the embodiment described above. In this case, the multi-core ferrule 3 also has a shape in which the ferrule end surface side 4 is divided into upper and lower parts in a plane horizontal to the axis of the optical fiber, and the short optical fiber is formed in the alignment groove 5 having the V groove 5a. 2 is fixed. The V groove 5a can be formed by precision machining, but it can also be formed by anisotropic etching using a silicon substrate.

The elastic body case 7 can be formed using elastic metal or plastic. In addition, the block-shaped elastic body 13 is made of rubber such as silicone rubber or the like.
It is made of an alloy 13a such as an aluminum alloy having a shape shown in FIG.

FIG. 8 is a transverse sectional view showing a second embodiment of the multi-fiber optical fiber connector of the present invention. In this embodiment,
The cover and case fit upside down. The cover 22 is formed in the shape of a U with an open bottom surface and is made of an elastic body. Assembling is performed by covering the multi-core ferrule 23 with the cover 22. The hook 10b formed on the lower end of the cover 22 has a multi-core ferrule 2
It is fixed by being fitted in the concave portion 11b of No. 3. In the above-mentioned embodiment of the present invention, needless to say, an adhesive may be used together to strengthen the fixing of the tape core wire.

[0023]

As described above, in the multi-fiber optical fiber connector of the present invention, the ferrule has a structure in which the short optical fiber is built in the multi-fiber ferrule in advance, and the ferrule end surface is mirror-polished. Since no polishing process is required at the time of on-site assembly such as a construction site, it is possible to easily connect the multi-core optical fibers.
For this reason, not only the working time can be saved significantly, but also in a place where it is difficult to bring in the polishing machine, the multi-core optical fiber can be assembled to the tape core wire.

Further, since the optical fiber element wire and the core wire can be fixed by fitting the elastic case and the cover, an adhesive agent is not required for fixing the optical fiber, and more easily in a shorter time. The optical fiber connector can be assembled.

Since the optical matching agent for preventing reflection at the connection point is inside the ferrule, it is less susceptible to external influences. Further, it is not necessary to re-apply the optical matching agent when attaching or detaching the optical fiber connector. Further, the ferrule end surface is mirror-polished in a slanted or convex shape together with the short optical fiber, and the optical fiber end surfaces are directly abutted against each other, so that a connection with low loss and low reflection can be realized.

Further, even if the cover is pressed against the optical fiber element wire, since a stopper is provided, no extra force is applied and stable assembly is possible.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a multi-fiber optical fiber connector of the present invention.

FIG. 2 is a longitudinal sectional view of FIG.

FIG. 3 is a vertical cross-sectional view showing a structure after assembly of an embodiment of a multi-fiber optical fiber connector of the present invention.

FIG. 4 is a cross-sectional view of a portion A of FIGS. 3 and 4.

FIG. 5 is a cross-sectional view of an alignment groove having a semicircular shape used in the multi-fiber optical fiber connector of the present invention.

FIG. 6 is a cross-sectional view of an alignment groove having a V-groove shape used in the multi-fiber optical fiber connector of the present invention.

FIG. 7 is a cross-sectional view of a block-shaped elastic body made of an aluminum alloy used for the alignment groove of the multi-fiber optical fiber connector of the present invention.

FIG. 8 is a cross-sectional view of a second embodiment of the multi-fiber optical fiber connector of the present invention.

FIG. 9 is a perspective view of a conventional multi-fiber optical fiber connector.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Small-diameter hole 2 Short-length optical fiber 3 Ferrule for multi-core 4 Ferrule end face 5 Alignment groove 5a Semicircular groove 5b V groove 6 Optical matching agent 7 Elastic case 8 Cover 9 Tape core wire 10 Hook 10b Hook 11 Recess 11b Recess 12 Element wire portion 13 Block-shaped elastic body 13a Aluminum alloy 14 Core wire portion 15 Core wire fixing groove A 16 Core wire fixing groove B 17 Convex portion A 18 Convex portion B 19 End surface A 20 End surface B 21 Stopper 22 Elastic body cover 23 Multi Ferrule for core 24 Ferrule for multi-core 25 Multi-core ferrule 26 Tape core wire 27 Ferrule end face 28 Alignment hole 29 Guide pin

Claims (12)

[Claims] 1. A plurality of short optical fibers and a hole having an inner diameter slightly larger than the outer diameter of the short optical fibers are formed in parallel, and the plurality of short optical fibers are respectively inserted and fixed, and a front end face is formed. A multi-fiber ferrule processed to match the end face of the short optical fiber, and a plurality of array grooves, and a portion of the short optical fiber protruding from the rear end face of the multi-fiber ferrule is aligned in each of the arrangements. An optical fiber arranging means, and a plurality of optical fiber strands, and a tape core optical fiber in which the end faces of the optical fiber strands are butted to the rear end faces of the short optical fibers arranged in the arranging groove, A multi-fiber optical fiber connector, comprising: the short optical fiber; and a fixing means for pressing the optical fiber strand from above the optical fiber arranging means. 2. The multi-core optical fiber connector according to claim 1, wherein the outer diameter of the short optical fiber is substantially equal to the outer diameter of the optical fiber strand. 3. The multi-fiber optical fiber connector according to claim 2, wherein the fixing means includes a fastening means for fastening the ferrule. 4. The multi-fiber optical fiber connector according to claim 2, wherein an optical matching agent is arranged between the rear end face of the short optical fiber and the optical fiber strand. 5. The multi-fiber optical fiber connector according to claim 2, wherein the array groove has a semicircular shape substantially equal to the outer diameter of the short optical fiber. 6. The multi-fiber optical fiber connector according to claim 2, wherein the array groove is a V groove. 7. The multi-fiber optical fiber connector according to claim 6, wherein the optical fiber arranging means is made of a silicon substrate. 8. The multi-fiber optical system according to claim 2, wherein the rear end face of the short optical fiber and the front end face of the optical fiber element wire are inclined with respect to the center line of the optical fiber. Fiber connector. 9. The multi-fiber optical fiber connector according to claim 2, wherein the rear end surface of the short optical fiber and the front end surface of the optical fiber element wire have a convex shape. 10. The multi-fiber optical fiber connector according to claim 3, wherein the fixing means includes a rear end portion of the multi-fiber ferrule and has a U-shaped cross section which is opened upward. . 11. The fastening means has an elastic body case in which a hook is arranged on an inner peripheral side surface of an upper end portion of the fixing means, and a concave portion which is fitted with the hook on a side surface, and which is used for cutting the multi-core ferrule. The multi-fiber optical fiber connector according to claim 10, further comprising: a cover which is fitted to the taken part from above and fixed to the elastic body case. 12. The multi-fiber optical fiber connector according to claim 3, wherein the fastening means includes a cover having a hook for holding a bottom surface portion of the optical fiber arranging means.