WO2013172322A1

WO2013172322A1 - Multicore optical connector, optical connector connection structure

Info

Publication number: WO2013172322A1
Application number: PCT/JP2013/063360
Authority: WO
Inventors: 齋藤　恒聡
Original assignee: 古河電気工業株式会社
Priority date: 2012-05-14
Filing date: 2013-05-14
Publication date: 2013-11-21
Also published as: JP2017187789A; JP6157457B2; JPWO2013172322A1; JP6407360B2

Abstract

A hole (7) is provided in a ferrule (5). The hole (7) is of a substantially regular hexagonal shape, and passes through the ferrule (5) from front to back. A bundle structure (9) is inserted inside the hole (7), and the bundle structure (9) is affixed to an inner surface of the hole (7). The bundle structure (9) is configured from multiple fiber optic core wires (3). In the bundle structure (9), the fiber optic core wires (3) are placed in a substantially hexagonal shape in closest placement. An end surface of the bundle structure (9) is exposed at the leading edge surface of the ferrule (5). On the leading edge surface of the ferrule (5), guide holes (11) that are a guide mechanism are formed at both sides of the hole (7).

Description

Multi-fiber optical connector, optical connector connection structure

The present invention relates to a multi-core optical connector having a plurality of cores, and an optical connector connection structure in which a multi-core fiber and a multi-core optical connector are connected.

Due to the rapid increase in traffic in recent optical communications, the limit of transmission capacity is approaching in the single core optical fiber currently used. Therefore, as a means for further expanding the communication capacity, a multi-core fiber in which a plurality of cores are formed in one fiber has been proposed.

As such a multi-core fiber, for example, there is a fiber in which a plurality of core portions are provided inside a cladding portion, and a flat portion perpendicular to the longitudinal direction is formed on a part of the outer periphery of the cladding portion (Patent Document 1). ).

When multi-core fiber is used as a transmission line, a multi-core fiber connector is required for easy connection. Moreover, each core part of this multi-core fiber needs to be connected to a corresponding core part of another multi-core fiber, another optical fiber, an optical element, or the like to transmit and receive transmission signals. As a method of connecting such a multi-core fiber and a single-core fiber, a multi-core fiber is connected to a bundle fiber in which single-core optical fibers are arranged at positions corresponding to the core portion of the multi-core fiber, and a transmission signal is transmitted. A method of transmitting and receiving has been proposed (Patent Document 2).

Further, as a method for producing such a bundle optical fiber, a method of bundling a plurality of single core fibers by bundling at a predetermined interval has been proposed (Patent Document 3).

JP 2010-152163 A JP 62-47604 A Japanese Patent Laid-Open No. 03-12607

As described above, when each core part of a multi-core fiber is connected to, for example, another optical fiber core wire, the core parts are optically connected to each other between the end face of the multi-core fiber and each optical fiber core wire. Need to be connected precisely. However, since the core interval of the multi-core fiber is usually narrow (for example, 40 to 50 μm), the optical fiber core wire that can be connected thereto is extremely thin. For this reason, such an optical fiber core wire has poor handleability.

In particular, in the case of a single mode fiber, the positional deviation of the connecting portion needs to be 1 to 2 μm or less, so that a very high positional accuracy is required. Therefore, a multi-core fiber connector that can be easily connected and a multi-core optical connector that can be easily connected to a multi-core fiber, such as connection between conventional optical fiber cores, are desired.

The present invention has been made in view of such problems, and a multi-core fiber connector that can be connected to other multi-core fibers, or a multi-core optical connector that can arrange an optical fiber core wire with high accuracy, and the same. An object of the present invention is to provide an optical connector connection structure. In the present invention, the multi-fiber optical connector is an optical connector having a plurality of cores in one connector, and the plurality of cores may be multi-core fibers (in this case, particularly called multi-core fiber connectors). In some cases, each may be a separate optical fiber.

In order to achieve the above-described object, the first invention is a multi-fiber optical connector comprising a first ferrule that holds a multi-core fiber having a plurality of cores or a bundle structure of a plurality of optical fiber core wires, The first ferrule is formed with a hole corresponding to the multi-core fiber or the bundle structure, and guide mechanisms formed on both sides of the hole, and the multi-core fiber or the bundle structure is inside the hole. It is a multi-fiber optical connector characterized by being fixed to.

The hole is a circular hole, and a multi-core fiber may be fixed to the hole. In this case, it is desirable that L ≧ 10d when the core pitch of the multi-core fiber is d μm and the distance between the center of the hole and the guide mechanism is L μm.

The multi-core fiber may be fixed to the first ferrule while being inserted into a capillary. In this case, the end face of the capillary may protrude from the end face of the first ferrule. The end surface of the multi-core fiber may be spherically polished in advance.

The multi-core fiber protrudes from the end face of the capillary, the end of the capillary is located inside the first ferrule, the capillary is not exposed at the end face of the first ferrule, and the multi-core fiber is It may be exposed.

The multi-core fiber protrudes from the end face of the capillary, one end of the capillary is located inside the first ferrule, and the capillary is not exposed on the front end face of the first ferrule, The multi-core fiber is exposed, the other end of the capillary is exposed to the rear end face side of the first ferrule, and a plurality of optical fiber cores are bonded to a fiber bundle fixed to another capillary, The optical fiber cores of the fiber bundles and the cores of the multi-core fibers may be optically connected.

The outer periphery of the multi-core fiber may be covered with a covering portion or a capillary, and the radius of the covering portion or the capillary may be twice or more the core pitch of the multi-core fiber.

The hole may have a substantially regular hexagonal shape, and a bundle structure in which a plurality of optical fiber core wires corresponding to the shape of the hole are bundled into a substantially regular hexagonal shape in a close-packed arrangement may be fixed to the hole.

At the end face of the first ferrule, the hexagonal size of the hole is larger than the size of the circumscribed hexagon of the bundle structure, and a gap is formed between the inner surface of the hole and the circumscribed hexagon, The bundle structure is preferably fixed inside the hole while being pressed in the direction of an arbitrary corner of the hexagon of the hole.

The hole is formed such that a corner portion is in a vertical direction of the first ferrule and is perpendicular to the direction in which the guide mechanism is provided, and the bundle structure is either up or down with respect to the hole. You may fix to the said hole in the state pressed on the direction.

The hole has a tapered portion in which the size of the hole is changed inside the first ferrule, from the insertion side of the bundle structure of the hole toward the exposed side of the end surface of the bundle structure of the hole. It is desirable that the hole has a reduced diameter.

It is desirable that the diameter of the hole is reduced from the insertion side of the bundle structure of the hole toward the exposed side of the end surface of the bundle structure of the hole.

A plurality of the holes may be formed in the first ferrule, and a plurality of the bundle structures may be disposed in the respective holes.

According to the first invention, it can be used as a so-called MT connector (Mechanically Transferable Connector) having a guide mechanism, and can be handled in the same manner as a conventional connector. Therefore, it is excellent in handleability. In particular, the structure similar to the MT connector is formed by a shift in the rotation direction of the guide mechanism because a pair of guide mechanisms are formed at positions apart from both sides with respect to, for example, a multi-core fiber or bundle structure disposed in the center. The effect is reduced at the center. Therefore, such a structure is particularly advantageous for multi-core fibers that require precise placement.

Further, when the core pitch of the multi-core fiber is d μm and the distance between the center of the hole and the guide mechanism is L μm, if the dimensional accuracy with the connection target of the guide mechanism is 1 μm or less, L ≧ 10 d is obtained. Even when the maximum core pitch of the fiber is 60 μm and the rotational deviation in the guide mechanism is 1 μm, the core positional deviation of the multi-core fiber can be 0.1 μm or less.

Here, if the core misalignment is 0.1 μm or less, the transmission loss can be suppressed to 0.002 dB or less. Although there is a possibility of deviation not only in the rotation direction but also in the X axis direction and the Y axis direction, even in this case, if the deviation is about 0.1 μm, the transmission loss is about 0.04 dB, which is large. There is no effect.

In addition, when a multi-core fiber is inserted into a capillary, the outer diameter becomes large and the handling is excellent. In addition, since the outer diameter of the capillary is large when rotational alignment is performed, the rotational movement distance of the core of the multi-core fiber can be made smaller than the rotational movement distance of the outer peripheral surface of the capillary. Therefore, fine adjustment of the rotation of the multi-core fiber is easy. Therefore, highly accurate alignment work is possible.

In addition, by performing end surface spherical polishing in a state where the multi-core fiber is fixed to the capillary, for example, it is possible to connect another multi-core fiber to be connected to a PC (Physical Contact).

Also, the capillary can be rotated in the vicinity of the end face by protruding the tip of the capillary from the first ferrule. Therefore, the length of the ferrule can be shortened.

In addition, if the ferrule is formed with a substantially hexagonal hole, which is a close-packed arrangement of optical fiber core wires, a multi-fiber connector having a bundle structure that can be connected to a multi-core fiber can be obtained. At this time, the bundle structure in which the optical fiber core wires are bundled in the closest arrangement is inserted into the hole and fixed. Therefore, the positional accuracy of the optical fiber core wire is high.

Also, a gap is formed between the circumscribed regular hexagon of the bundle structure and the inner surface of the hole of the ferrule, so that the bundle structure (optical fiber core wire) can be easily inserted into the hole. Further, by pressing the bundle structure against the corner of the hole, the bundle structure can be arranged at an accurate position with respect to the ferrule while maintaining the close-packed arrangement of the bundle structure.

Moreover, by forming the hexagonal direction of the holes so that the corners come in the vertical direction of the ferrule, the bundle structure can be easily pressed against the corners.

In addition, by forming a tapered part that changes the size of the hole inside the ferrule and increasing the size of the hole on the insertion side of the bundle structure, insertion into the hole of the bundle structure (optical fiber core wire) is improved. To do. Further, the bundle structure is guided to a normal position on the exposed surface side by the internal tapered shape, and the bundle structure can be arranged on the ferrule with high positional accuracy.

Also, by forming a plurality of holes in one ferrule and arranging a bundle structure in each hole, it is possible to arrange the optical fiber core wires with high density and connect to other multi-core fibers or the like.

2nd invention is the joining structure of the multi-core optical connector concerning 1st invention, and a multi-core fiber connector, Comprising: The said multi-core fiber connector is the 2nd which hold | maintains another multi-core fiber and another multi-core fiber. And the second ferrule has the other multi-core fiber fixed thereto, a guide mechanism formed on both sides of the other multi-core fiber, and a guide mechanism of the multi-fiber optical connector; Are connected to each other, and each core of the other multi-core fiber is optically connected to each core of the multi-core fiber or each core of the optical fiber core wire constituting the bundle structure. It is a connector connection structure.

According to the second invention, it is possible to easily connect multi-core fibers and multi-core fibers or a bundle structure in which multi-core fibers and a plurality of optical fiber cores are bundled.

According to the present invention, it is possible to provide a multi-core optical connector that can be connected to a multi-core fiber and can arrange optical fiber core wires with high accuracy, and an optical connector connection structure using the same.

The figure which shows the multi-core optical connector 20. FIG. The front view of the multi-fiber optical connector 20. FIG. 3A and 3B are views showing the state of the tip of the capillary 33 in the multi-fiber optical connector 20, respectively. 4A is a diagram showing a method for aligning the multi-fiber optical connector 20, and FIG. 4B is a diagram showing a method for aligning the multi-fiber optical connector 20a. 5A and 5B are diagrams showing the multi-fiber optical connector 1, in which FIG. 5A is a perspective view and FIG. 5B is a cross-sectional view taken along line AA in FIG. 6A is a front view of the multi-fiber optical connector 1, and FIG. 6B is an enlarged view of a portion B in FIG. 6A. It is a figure which shows the construction method of the bundle structure 9, Comprising: Fig.7 (a) is a front view, FIG.7 (b) is sectional drawing. 8A is a front view of the multi-fiber optical connector 1a, and FIG. 8B is an enlarged view of a portion E in FIG. 8A. The front view of the multi-fiber optical connector 1b. FIG. 10A is a front view of the multi-fiber optical connector 1c, and FIG. 10B is a front view of the multi-fiber optical connector 1d. FIG. 11A is a front view of the multi-fiber optical connector 1e, and FIG. 11B is a front view of the multi-fiber optical connector 1f. FIG. 12A shows a multi-fiber optical connector 20b, and FIG. 12B shows a multi-fiber optical connector 20c.

Hereinafter, the multi-fiber optical connector 20 according to the embodiment of the present invention will be described. FIG. 1 is a perspective view showing a multi-fiber optical connector 20, and FIG. 2 is a front view. The multi-fiber optical connector 20 includes a ferrule 23, a multi-core fiber 25, a capillary 29, and the like.

A hole 21 is formed in the ferrule 23 which is the first ferrule. The multi-core fiber 25 is fixed to the capillary 29. The shape of the hole 21 corresponds to the outer shape of the capillary 29, and the multi-core fiber 25 fixed to the capillary 29 is fixed to the hole 21. In addition, on the end face of the ferrule 23, guide holes 27 that are guide mechanisms are formed on both sides of the multi-core fiber 25. Therefore, positioning can be performed at the time of connection with the guide pin formed on the connector to be connected. A guide pin (not shown) can be inserted into the guide hole 27. In addition, a hole 24 communicating with the hole 21 is formed on the upper surface (side surface) of the ferrule 23.

In addition, what is necessary is just to adhere | attach the capillary 29 and the hole 21 with an adhesive agent, for example. In this case, an adhesive may be applied to the inner surface of the hole 21 in advance, and the capillary 29 may be inserted into the hole 21. However, after the capillary 29 is inserted into the hole 21, The hole 21 may be filled with an adhesive from the gap between the capillary 29 and the hole 21.

The multi-core fiber 25 is a fiber in which a plurality of cores are arranged at predetermined intervals and the periphery is covered with a clad. Note that the multi-core fiber 25 has, for example, a total of seven cores as shown in the figure, and is arranged at the center of the multi-core fiber 25 and at each vertex position of a regular hexagon around the center. That is, the central core and the surrounding six cores are all at a constant interval. Further, in the six surrounding cores, the intervals between adjacent cores are also the same.

The end surface of the multi-core fiber 25 (and the capillary 29 holding the same) is exposed at the tip surface of the ferrule 23. Note that the end face of the multi-core fiber 25 (capillary 29) may be polished flat so as to coincide with the end face of the ferrule 23, or may be polished spherically. For example, as shown in FIG. 3A, a spherically polished multi-core fiber 25 (capillary 29) may be exposed on the end face of the ferrule 23. In this case, the end face of the multi-core fiber 25 (capillary 29) and the end face position of the ferrule 23 substantially coincide.

Further, as shown in FIG. 3B, the tip of the multi-core fiber 25 (capillary 29) may be protruded from the tip of the ferrule 23. In this case, the capillary 29 can function as a ferrule and the ferrule 23 can function as a flange portion. However, in the present invention, description will be made assuming that the capillary 29 protrudes from the end face of the ferrule 23.

Each core of the multi-core fiber 25 is arranged at a predetermined position with respect to the ferrule 23. That is, the position of the multi-core fiber 25 in the rotational direction is determined with reference to the guide hole 27 of the ferrule 23.

In the multi-core optical connector 20, in order to position the multi-core fiber 25 in the rotational direction, the arrangement of the core is confirmed with a magnifying camera from the front of the multi-core optical connector 20, or other multi-core fibers and the like are used. Alignment may be performed so that the detection light becomes maximum in the connected state. Specifically, as shown in FIG. 4A, the multi-core fiber 25 is rotationally aligned by rotating the capillary 29 with the capillary 29 inserted through the hole 21 (direction F in the figure). Can do.

Further, a groove 31 may be provided in a part of the ferrule 23 as in the multi-fiber optical connector 20a shown in FIG. The groove 31 is formed on the upper surface of the ferrule 23 in the width direction of the ferrule 23. The depth of the groove 31 from the upper surface of the ferrule 23 is deeper than the distance from the upper surface of the ferrule 23 to the hole 21. Therefore, a part of the capillary 29 is exposed so as to cross the groove 31.

In the multi-fiber optical connector 20a, the rotation alignment of the multi-core fiber 25 can be performed with the capillary 29 exposed in the groove 31. That is, the rotation alignment of the multi-core fiber 25 can be performed by rotating a part of the capillary 29 exposed in the groove 31 (direction F in the figure).

It should be noted that the radius of the capillary 29 is preferably at least twice the core pitch of the multi-core fiber 25. For example, if the outer diameter of the capillary 29 is 200 μm (radius 100 μm) with respect to the multi-core fiber 25 having a core pitch of 50 μm, the moving distance of the core is 0.5 μm with respect to the moving distance 1 μm of the outer peripheral surface of the capillary 29. Accordingly, the rotational position can be adjusted with double accuracy.

In the above example, the multi-core fiber 25 is inserted into the capillary 29 and fixed, but the capillary 29 is not necessarily required. For example, if a coating portion is formed on the outer periphery of the multicore fiber 25, the coating portion may be fixed to the ferrule 23. Even in this case, it is desirable that the radius of the covering portion is twice or more the core pitch. It is also possible to fix the multi-core fiber 25 from which the coating has been removed at the end face of the ferrule 23, and in this case, more precise positioning is possible.

As described above, according to the present embodiment, since the guide hole 27 is formed in the ferrule 23, the MT connector type multi-fiber optical connector 20 can be obtained. Therefore, if it has a structure that can be connected to the connector, it can be easily connected to a multi-core connector such as a multi-core fiber.

Next, the multi-fiber optical connector 1 that can be connected to the multi-fiber optical connector 20 will be described. FIG. 5 is a view showing the multi-fiber optical connector 1, FIG. 5 (a) is a perspective view of the multi-fiber optical connector 1, and FIG. 5 (b) is a cross-sectional view taken along line AA of FIG.

The ferrule 5 is provided with a hole 7. The hole 7 has a substantially regular hexagonal shape and penetrates the ferrule 5 in the front-rear direction. A bundle structure 9 is inserted into the hole 7, and the bundle structure 9 is fixed to the inner surface of the hole 7. That is, the bundle structure 9 is fixed to the ferrule 5. A hole 6 communicating with the hole 7 is formed on the upper surface (side surface) of the ferrule 5.

In addition, what is necessary is just to adhere | attach the bundle structure 9 and the hole 7 with an adhesive agent, for example. In this case, an adhesive may be applied to the inner surface of the hole 7 in advance, and the bundle structure 9 may be inserted into the hole 7. However, after the bundle structure 9 is inserted into the hole 7, the hole that is a filling hole for the adhesive The hole 7 may be filled with an adhesive.

The bundle structure 9 is composed of a plurality of optical fiber cores 3. As shown in FIG. 5B, the optical fiber core wire 3 is inserted into the hole 7 of the ferrule 5 from the rear. In addition, although the optical fiber core wire 3 has a coating | coated part, the said coating | coated part is removed in the edge part of the optical fiber core wire 3. FIG. Therefore, the bundle structure 9 is formed in a region where the covering portion is removed.

Inside the hole 7, a tapered portion that gradually decreases in diameter from the rear to the front of the ferrule 5 is formed. That is, on the insertion side of the optical fiber core wire 3, the diameter of the hole 7 is large, and the diameter of the hole 7 becomes smaller toward the distal end side. The inner diameter at the rear end of the hole 7 is sufficiently larger than the bundle structure 9. Accordingly, the insertability of the bundle structure 9 (or the optical fiber core wire 3) is excellent. In addition, the inner diameter of the hole 7 on the side where the bundle structure 9 is inserted can insert all the number of optical fiber core wires 3 (including the covering portion) constituting the bundle structure 9. Therefore, the end portion of the covering portion (boundary with the covering removing portion) can be disposed inside the ferrule 5.

In the illustrated example, the bundle structure 9 including seven optical fiber cores 3 is shown, but the present invention is not limited to this. As long as the optical fiber cores 3 can be arranged close-packed in a substantially hexagonal shape, the number of the optical fiber cores 3 such as all 19 is not limited. Further, by appropriately adjusting the diameter of the optical fiber disposed at the center and the diameter of the optical fiber disposed at the outer periphery, for example, ten optical fibers arranged in close contact with one optical fiber are arranged. It is also possible to obtain a bundle structure.

At the front end surface of the ferrule 5, the end surface of the bundle structure 9 (that is, all the optical fiber core wires 3 constituting this) is exposed. At this time, the end surface of the bundle structure 9 is formed on the same plane as the front end surface of the ferrule 5.

Guide holes 11 that are guide mechanisms are formed on both sides of the hole 7 on the tip surface of the ferrule 5. Therefore, positioning can be performed at the time of connection with the guide pin formed on the connector to be connected. A guide pin (not shown) can be inserted into the guide hole 11.

FIG. 6A is a front view of the multi-fiber optical connector 1. As shown to Fig.6 (a), in this embodiment, the hole 7 is formed so that a pair of opposing corner | angular part of hexagon shape may face the left-right direction (coexisting direction of the guide hole 11).

FIG. 6B is an enlarged view of a portion B in FIG. As shown in FIG. 6B, the bundle structure 9 is fixed to the hole 7 with an adhesive 13. Here, as described above, the optical fiber core wires 3 are arranged in a hexagonal shape in a close-packed arrangement. That is, the bundle structure 9 is assumed to be a circumscribed regular hexagon 15 that is in contact with the outer surfaces of all the optical fiber cores 3 arranged on the outer periphery of the bundle structure 9.

The size of the substantially regular hexagonal shape of the hole 7 on the tip surface of the ferrule 5 is slightly larger than the circumscribed regular hexagon 15. Therefore, a gap is formed between the inner surface of the hole 7 and the circumscribed regular hexagon 15. The bundle structure 9 is fixed to the hole 7 in a state in which the bundle structure 9 is pressed in the direction of a predetermined corner of the hexagon forming the hole 7 in a front view. For example, in the example shown in FIG. 6B, the bundle structure 9 is fixed to the hole 7 in a state where the bundle structure 9 is pressed to the corner portion in the lower right direction (the direction of arrow C in the figure). Therefore, the gap between the inner surface of the hole 7 and the circumscribed regular hexagon 15 is the largest at the corner opposite to the direction in which the hole 7 is pressed.

Here, if the pressing direction of the bundle structure 9 against the hole 7 is determined to be a fixed direction, and the arrangement of the hole 7 in the ferrule 5 is set in advance accordingly, the arrangement of the end face of the bundle structure 9 with respect to the ferrule 5 Can be made constant. That is, the hole 7 is arranged at a position slightly shifted from the center of the ferrule 5 in the direction opposite to the pressing direction of the bundle structure 9. Therefore, the bundle structure 9 can be arranged at the center of the ferrule 5 by fixing the bundle structure 9 in the hole 7 while being pressed in a predetermined direction. Therefore, the position of the core of each optical fiber core wire 3 constituting the bundle structure 9 can be accurately arranged with respect to the ferrule 5.

In addition, in order to press the bundle structure 9 to the corner | angular part of a predetermined direction, it can carry out as follows, for example. First, in the state where the bundle structure 9 protrudes from the front end surface of the ferrule 5, the bundle structure 9 exposed from the front end surface of the ferrule 5 and the optical fiber core wire 3 exposed from the rear end of the ferrule 5 are formed in the direction in which the holes 7 are formed. Keep parallel to. In this state, the entire bundle structure 9 and the optical fiber core wire 3 may be moved in the direction of the corner to be pressed.

Further, by bending the optical fiber core wire 3 exposed from the rear end of the ferrule 5 in the direction of the corner opposite to the corner to be pressed, the corner portion to press the bundle structure 9 exposed from the front end surface of the ferrule 5. Can be pressed against. In any case, the bundle structure 9 may be fixed to the hole 7 with the bundle structure 9 pressed against a predetermined corner.

Next, an example of a method for constructing the bundle structure 9 is shown. Note that the bundle structure 9 may be formed by any method as long as it can ensure a state where the end portions of the optical fiber core wires 3 are arranged so as to be in close contact with each other.

First, the coating of a predetermined number of optical fiber cores 3 is removed and inserted into a ferrule 5 (or other capillary or the like). At this time, the optical fiber core wire 3 is inserted into the ferrule 5 so that the end of the optical fiber core wire 3 protrudes from the end of the ferrule 5 by the same length (for example, about 10 mm). The optical fiber core wire 3 is temporarily fixed to the ferrule 5.

The tip of the optical fiber core 3 that protrudes from the end of the ferrule 5 is immersed in an adhesive 17 that is stored in advance in a container. In addition, although the adhesive force of the adhesive agent 17 may be weak, the thing of the very low viscosity of 100 cps or less is desirable, for example. As the adhesive, water glass (sol-gel glass) or the like can be used.

FIG. 7 is a conceptual diagram showing the bonding state of the optical fiber cores 3 due to the surface tension of the adhesive 17, FIG. 7 (a) is a front view (for simplicity, only two optical fiber cores 3 are shown), FIG. 7 (b) is a cross-sectional view.

When the plurality of optical fiber cores 3 are simply bundled, a gap may be formed between the optical fiber cores 3. However, by bringing the end of the optical fiber core 3 into contact with the adhesive 17, the adhesive 17 is sucked into the gap between the optical fibers 3 by surface tension (capillary phenomenon). At this time, the optical fiber core wires 3 are brought into close contact with each other by the surface tension (in the direction of arrow D in the figure).

That is, as shown in FIG. 7B, even if a slightly non-uniform gap is formed between the optical fiber cores 3, the adhesive 17 is sucked into the gap, and the optical fiber core 3 Adhere to each other. At this time, the optical fiber cores 3 are surely arranged in a close-packed manner. Such an effect is particularly effective for an extremely fine optical fiber core wire 3 (for example, Φ50 μm or less) as in the present invention.

Next, the bundled optical fiber core wire 3 is bonded to the hole 7 with an adhesive 13 (FIG. 6B). The gap between the hole 7 and the bundle structure 9 and the gap between the fiber core wires are filled with the adhesive 13, and the bundle structure 9 and the hole 7 are bonded. Next, the optical fiber core wire 3 protruding from the ferrule 5 and a part of the ferrule 5 tip surface are polished. Thus, the multi-fiber optical connector 1 is formed.

In this embodiment, the procedure for inserting the plurality of optical fiber core wires 3 through the ferrule 5 is described above, but the present invention is not limited to this. For example, a plurality of optical fiber cores 3 may be closely attached and fixed by the same method as in this embodiment, and then inserted into the ferrule 5 and fixed with an adhesive. In this case, by immersing the optical fiber core wires 3 in the adhesive 17 in a state where the optical fiber core wires 3 are inserted into the cylindrical temporary array member, it is possible to securely fix the optical fiber core wires 3 to the fine structure.

As described above, according to the present embodiment, since the guide hole 11 is formed in the ferrule 5, the MT connector type multi-fiber optical connector 1 can be obtained. Therefore, if it has a structure that can be connected to the connector, it can be easily connected to the multi-core fiber.

Moreover, since the size of the hole 7 is larger than that of the bundle structure 9, the insertion property of the optical fiber core wire is excellent. In particular, since the hole 7 has a tapered portion so that the diameter thereof decreases from the insertion side toward the end face side, the insertion workability of the optical fiber core wire and the like is excellent, and the bundle structure 9 on the end face after the insertion is provided. Position accuracy is also high. Further, since the bundle structure 9 is pressed against a predetermined corner portion of the hole 7 in a close-packed state, the bundle structure 9 can be placed with high accuracy with respect to the ferrule 5.

Next, another embodiment using a bundle structure will be described. 8A and 8B are diagrams showing the multi-fiber optical connector 1a, in which FIG. 8A is a front view, and FIG. 8B is an enlarged view of a portion E in FIG. 8A. In the following description, components having the same functions as those of the multi-fiber optical connector 1 are denoted by the same reference numerals as those in FIGS. 5 to 6, and redundant descriptions are omitted.

The multi-fiber optical connector 1a has substantially the same configuration as the multi-fiber optical connector 1, but the direction of the hole 7 with respect to the ferrule 5a is different. In the multi-fiber optical connector 1a, the holes 7 are arranged so that the corners facing the vertical direction of the ferrule 5a (the direction perpendicular to the direction in which the guide holes 11 are provided) face each other. That is, the direction of the hole 7 in the multi-fiber optical connector 1a is rotated by 30 ° with respect to the direction of the hole 7 in the multi-fiber optical connector 1.

As described above, the substantially regular hexagon of the hole 7 is slightly larger than the circumscribed regular hexagon of the bundle structure 9. Therefore, a gap is formed between the circumscribed regular hexagon of the bundle structure 9 and the inner surface of the hole 7.

In the present embodiment, the bundle structure 9 is pressed in the vertical direction of the hole 7 (downward in the figure and in the direction of arrow E). That is, the bundle structure 9 is pressed against the corners in the vertical direction. In this state, the bundle structure 9 may be fixed to the hole 7.

According to the multi-fiber optical connector 1a, the same effect as the multi-fiber optical connector 1 can be obtained. Further, by pressing the bundle structure 9 in the vertical direction of the ferrule 5a in a predetermined direction, the bundle structure 9 can be accurately arranged with respect to the ferrule 5a. Further, since the bundle structure 9 is pressed in the vertical direction of the ferrule 5a, the direction is easily understood and the workability is excellent.

In the multi-fiber optical connectors 1 and 1a, a bundle structure 9 corresponding to the multi-core fiber 25 to be connected is formed. That is, the bundle structure 9 is composed of the optical fiber cores 3 having the number of cores of the multi-core fiber 25 to be connected. In the bundle structure 9, the optical fiber core wires 3 are arranged corresponding to the core pitch of the multi-core fiber 25 to be connected.

The multi-fiber optical connector 20 and the multi-fiber optical connectors 1 and 1a have forms corresponding to each other. That is, the ferrule 23 corresponds to the ferrule 5, and the pair of guide holes 27 corresponds to the guide hole 11 in the ferrule 5. Accordingly, the guide hole 11 and the guide hole 27 can accurately align the positions of the

ferrules

5 and 23 when connected by a guide mechanism such as a guide pin.

Also, the arrangement of the multi-core fiber 25 with respect to the ferrule 23 and the bundle structure 9 are aligned in advance. For example, the position of the central core is aligned, and the two surrounding cores are arranged in the vertical direction (direction perpendicular to the direction in which the guide hole 27 is provided) as the arrangement of the surrounding cores (six in the figure) relative to the central core It is arranged to face.

As described above, by connecting the multi-core optical connector 1, 1 a having the bundle structure 9 and the multi-core optical connector 20 having the multi-core fiber 25, the multi-core fiber 25 and the optical fiber core wire 3 can be easily connected. be able to. At this time, the multi-fiber optical connectors 1 and 1a and the multi-fiber optical connector 20 can be used in the same manner as conventionally used MT connectors. Therefore, it is excellent in handleability.

Further, since the bundle structure 9 can be accurately arranged with respect to the ferrule 5, if the multi-core fiber 25 is aligned with the ferrule 23, the multi-core fiber 25 and the bundle structure 9 can be accurately connected. it can. That is, an optical connector connection structure that is excellent in connection workability and can be connected with high accuracy can be obtained.

In addition, it cannot be overemphasized that the multi-fiber optical connectors 1 which have the bundle structure 9, and the multi-fiber optical connectors 20 which have the multi-core fiber 25 can be connected.

The embodiment of the present invention has been described above with reference to the accompanying drawings, but the technical scope of the present invention is not affected by the above-described embodiment. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

For example, in the multi-fiber optical connector 1, 1a, one hole 7 is formed in the ferrule 5, but the present invention is not limited to this. FIG. 9 is a diagram showing the multi-fiber optical connector 1b.

In the multi-fiber optical connector 1b shown in FIG. 9, a plurality of holes 7 are arranged with respect to the ferrule 5b. A bundle structure 9 is fixed to each of the holes 7. The number of holes 7 is not limited to the illustrated example. The holes 7 may be arranged in a line in the direction in which the guide holes 11 are provided, or may be arranged in a plurality of lines.

According to the multi-fiber optical connector 1b, more optical fiber core wires 3 can be fixed. For this reason, the optical fiber core wire 3 can be held with high density. In this case, a plurality of multi-core fibers may be similarly arranged in a multi-core optical connector having multi-core fibers to be connected.

Further, the guide mechanism in the multi-fiber optical connector of the present invention is not limited to the one using a guide hole or the like. For example, when a substantially rectangular ferrule 5c is used as in the multi-fiber optical connector 1c shown in FIG. 10A, the side surface (or the upper and lower surfaces) functions as the guide mechanism 19a. That is, when connecting with another connector or the like, the position of the inner bundle structure 9 in the rotational direction can be determined by matching the directions of the side surfaces or the upper and lower surfaces of the ferrules 5c.

Similarly, as in the multi-fiber optical connector 1d shown in FIG. 10B, a part of the substantially circular ferrule 5d may be cut off to form a flat portion. In this case, this notch becomes the guide mechanism 19b. The position of the multi-fiber optical connector 1d in the rotational direction can also be determined by the guide mechanism 19b.

Further, like the multi-fiber optical connector 1e shown in FIG. 11A, a part of the substantially circular ferrule 5e may be cut out to form a keyway. In this case, this keyway becomes the guide mechanism 19c. The position of the multi-fiber optical connector 1e in the rotational direction can also be determined by the guide mechanism 19c.

Further, as in the multi-fiber optical connector 1f shown in FIG. 11B, a protrusion may be formed on a part of the substantially circular ferrule 5f. In this case, this protrusion becomes the guide mechanism 19d. The position of the multi-fiber optical connector 1f in the rotational direction can also be determined by the guide mechanism 19d.

Note that a multi-core fiber 25 (capillary 29) may be arranged in place of the bundle structure 9 for each multi-fiber optical connector using the bundle structure 9 shown in the above example.

Further, in the multi-fiber optical connector 20 or the like, the capillary 29 may not be provided up to the tip of the ferrule 23. For example, as shown in FIG. 12A, the covering portion at the tip of the multi-core fiber 25 (with a covering portion) is removed, and the exposed multi-core fiber 25 is inserted into a capillary 29 and fixed. At this time, the multi-core fiber 25 protrudes from the tip of the capillary 29.

That is, the removal length of the covering portion of the multi-core fiber 25 is made longer than the length of the capillary 29. Therefore, the end of the capillary 29 is located inside the ferrule 23, and the end of the capillary 29 is not exposed on the end face of the ferrule 23. Note that the end face of the multi-core fiber 25 is cut into a flat surface by a cleaver.

In the ferrule 23, a stepped hole corresponding to the outer diameter of the capillary 29 and the outer diameter of the multi-core fiber 25 is provided. That is, the hole is formed on the front end face side of the ferrule 23 on the optical connection side (left side in the figure) with the first portion corresponding to the outer diameter of the multi-core fiber 25 and on the rear end face side of the ferrule 23 (right side in the figure) with the capillary 29. And a second portion corresponding to the outer diameter. In addition, it may replace with the capillary 29 and may be the coating | coated part of the multi-core fiber 25, It is good also as a bundle structure instead of the multi-core fiber 25.

In the example shown in FIG. 12A, the capillary 29 protrudes from the rear end side of the ferrule 23. However, a part of the capillary 29 is exposed from the upper and lower surfaces or side surfaces of the ferrule 23 and can be rotated. For example, the capillary 29 does not necessarily have to protrude to the rear end side of the ferrule 23. For example, a groove may be formed on the outer peripheral surface of the ferrule 23 so as to reach the hole (second portion), and the internal capillary 29 and the like may be exposed from the groove. After the multi-core fiber 25 is rotationally aligned, the multi-core fiber 25 may be fixed to the ferrule 23 with an ultraviolet curable resin or the like.

By adopting such a configuration, the position of the multi-core fiber 25 can be more precisely positioned with respect to the guide mechanism.

Further, the end face of the multi-core fiber 25 may coincide with the end face of the ferrule 23, and the capillary 29 may be rotationally aligned. Alternatively, the end face of the multi-core fiber 25 may protrude from the end face of the ferrule 23. Rotational alignment may be performed. When the end face of the multicore fiber 25 is protruded, the end of the protruded multicore fiber 25 may be cut or polished after the multicore fiber 25 is fixed.

In addition, by making the end face of the multi-core fiber 25 slightly protrude (2 μm to 10 μm) from the end face of the ferrule 23, the multi-core fibers can be connected to each other by PC.

In this embodiment, the coated multi-core fiber may be exposed at the rear end of the ferrule without using the capillary 29, and the coated portion may be used in the same role as the capillary. In this case, the coated multi-core fiber is disposed on the end face of the ferrule, the coated multi-core fiber is exposed at the rear end of the ferrule, and the coated section is rotated to perform rotational alignment. At this time, if the coating radius is at least twice the core pitch of the multi-core fiber, it is possible to obtain the same effect as when a capillary is used.

Further, similarly to the one illustrated in FIG. 4B, a groove (not shown) may be provided in the ferrule 23 to rotate the capillary or the covering portion exposed from the groove portion. In this case, it goes without saying that the groove provided in the ferrule 23 is provided on the rear end side of the stepped hole.

Also, as shown in FIG. 12B, a bundle structure 9 may be used. For example, the multi-core fiber 25 is inserted into the capillary 29 and fixed, and the capillary 29 is fixed to the ferrule 23 after rotational alignment. Further, the plurality of optical fiber core wires 3 are inserted into the capillary 33 and fixed, for example, in a close-packed state to form a fiber bundle 35. Then, the capillary 33 and the capillary 29 whose end surfaces are polished are made to face each other, and the fiber bundle 35 and the multi-core fiber 25 are rotationally aligned. At this time, it is easy to monitor the optical power at the time of rotational alignment by joining the other MT type connector and the ferrule 23.

1, 1 a, 1 b, 1 c, 1 d, 1 e, 1 f... Multi-fiber optical connector 3... Optical

fiber core wires

5, 5 a, 5 b, 5 c, 5 d, 5 f,. 9 ......... Bundled structure 11 ......... Guide hole 13 ......... Adhesive 15 ......... Surrounding regular hexagon 17 ......

Adhesives

19a, 19b, 19c, 19d ......... Guide mechanisms 20, 20a ......... Many Optical fiber connector 21 ......... hole 23 ......... ferrule 25 ......... multi-core fiber 27 ......... guide hole 29 ......... capillary 31 ......... groove 33 ......... capillary 35 ......... fiber bundle

Claims

A multi-fiber optical connector,
A first ferrule holding a multi-core fiber having a plurality of cores or a bundle structure of a plurality of optical fiber cores;
In the first ferrule, a hole corresponding to the multi-core fiber or the bundle structure, and guide mechanisms formed on both sides of the hole are formed,
The multi-core optical connector, wherein the multi-core fiber or the bundle structure is fixed inside the hole.
The hole is a circular hole;
The multi-fiber optical connector according to claim 1, wherein the multi-core fiber is fixed in the hole.
3. The multi-fiber optical connector according to claim 2, wherein L ≧ 10d when the core pitch of the multi-core fiber is d μm and the distance between the center of the hole and the guide mechanism is L μm.
The multi-core optical connector according to claim 2, wherein the multi-core fiber is fixed to the first ferrule while being inserted into a capillary.
The multi-fiber optical connector according to claim 4, wherein an end face of the capillary protrudes from an end face of the first ferrule.
The multi-fiber optical connector according to claim 4, wherein the end face of the capillary is polished in advance to a spherical surface.
The multi-core fiber protrudes from the end face of the capillary, the end of the capillary is located inside the first ferrule, the capillary is not exposed at the end face of the first ferrule, and the multi-core fiber is The multi-fiber optical connector according to claim 4, wherein the multi-fiber optical connector is exposed.
The multi-core fiber protrudes from the end face of the capillary, the one end of the capillary is located inside the first ferrule, and the capillary is not exposed on the front end face of the first ferrule, The multi-core fiber is exposed,
The other end of the capillary is exposed to the rear end face side of the first ferrule, and a plurality of optical fiber core wires are bonded to a fiber bundle fixed to another capillary,
5. The multi-fiber optical connector according to claim 4, wherein the optical fiber core wire of each of the fiber bundles and each core of the multi-core fiber are optically connected.
3. The multi-core according to claim 2, wherein an outer periphery of the multi-core fiber is covered with a covering portion or a capillary, and a radius of the covering portion or the capillary is at least twice a core pitch of the multi-core fiber. Optical connector.
The multi-core fiber or the bundle structure is covered with a covering portion or a capillary so that the tip thereof is partially exposed,
The hole corresponds to a first portion corresponding to the outer diameter of the multi-core fiber or the bundle structure on the front end surface side of the optical connection side of the ferrule, and corresponds to an outer diameter of the covering portion or the capillary on the rear end surface side of the ferrule. The second part,
The front end face on the connection side of the ferrule does not expose the covering portion or capillary, and the multi-core fiber or the bundle structure is exposed,
On the rear end face of the ferrule, the multi-core fiber or the bundle structure covered with the covering portion or the capillary is exposed, or a groove reaching the second portion of the hole is provided, and the covering portion extends from the groove. Or the capillary is exposed,
The multi-fiber optical connector according to claim 2, wherein a radius of the covering portion or the capillary is at least twice a core pitch of the multi-core fiber.
The hole is substantially a regular hexagon;
2. The multi-core according to claim 1, wherein the bundle structure in which a plurality of optical fiber core wires corresponding to the shape of the hole are bundled into a substantially regular hexagon in a close-packed manner is fixed to the hole. Optical connector.
In the end face of the first ferrule, the hexagonal size of the hole is larger than the size of the circumscribed hexagon of the bundle structure, and a gap is formed between the inner surface of the hole and the circumscribed hexagon,
12. The multi-fiber optical connector according to claim 11, wherein the bundle structure is fixed in the hole while being pressed in the direction of an arbitrary corner of the hexagon of the hole.
The hole is formed such that a corner portion is in a vertical direction of the first ferrule and is perpendicular to the direction in which the guide mechanism is provided, and the bundle structure is either up or down with respect to the hole. The multi-fiber optical connector according to claim 12, wherein the multi-fiber optical connector is fixed to the hole while being pressed in a direction.
The hole has a tapered portion in which the size of the hole changes inside the first ferrule,
The multi-fiber optical connector according to claim 11, wherein the diameter of the hole is reduced from an insertion side of the bundle structure of the hole toward an exposed side of an end surface of the bundle structure of the hole.
12. The multi-fiber optical connector according to claim 11, wherein a plurality of the holes are formed in the first ferrule, and a plurality of the bundle structures are respectively disposed in the holes.
A multi-core optical connector according to claim 1 and a multi-core fiber connector.
The multi-core fiber connector is
With other multi-core fibers,
A second ferrule holding another multi-core fiber;
Comprising
The other multi-core fiber is fixed to the second ferrule, and a guide mechanism formed on both sides of the other multi-core fiber and a guide mechanism of the multi-fiber optical connector are fitted and connected,
Each core of the other multi-core fiber is optically connected to each core of the multi-core fiber or each core of the optical fiber core wire constituting the bundle structure.