JP2017167299A - Optical fiber bundle structure and manufacturing method thereof, optical connector, and optical fiber connection structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical fiber bundle structure and the like in which a distance from a center of the bundle structure to cores of the respective optical fibers becomes substantially constant.SOLUTION: An optical fiber bundle structure 1 includes a plurality of coated optical fibers 5 of a same diameter, a capillary 3 for holding the coated optical fibers 5, and the like. The coated optical fiber 5 comprises a core 7, and a clad 9 for enclosing the core 7. The plurality of coated optical fibers 5 are mutually twisted inside the capillary 3, with an axial direction of the capillary 3 used as a central axis. The coated optical fibers 5 are inserted into the capillary 3 and fixed to the capillary 3 with an adhesive 11 in the twisted state. At a tip end (an end face of the capillary 3) of the optical fiber bundle structure 1, the plurality of coated optical fibers 5 (the core 7) are fixed to the capillary 3 so as to be located at respective vertices of a rectangular polygon.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical fiber bundle structure or the like that can be connected to a multi-core fiber or the like in which cores are arranged at predetermined intervals.

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

  When a multi-core fiber is used as a transmission line, each core of this multi-core fiber must be connected to a corresponding core of another multi-core fiber, a separate single-core fiber, a light emitting / receiving element, or the like to send and receive transmission signals. is there. As a method of connecting a multi-core fiber and a single-core fiber, there is a method of transmitting and receiving transmission signals by connecting a multi-core fiber and a bundle fiber in which single-core optical fibers are arranged at positions corresponding to the core of the multi-core fiber. It has been proposed (Patent Document 1).

JP 62-47604 A

  As multi-core fibers, a fiber in which the core pitch is constant and each core is arranged on each vertex of a regular polygon has been studied. For example, a multi-core fiber having a core arrangement (square arrangement) that forms a substantially square shape by connecting the centers of four cores has been studied. Therefore, there is a demand for an optical fiber bundle structure that can be connected to a multi-core fiber in which a core is arranged on each vertex of such a regular polygon.

  However, when trying to obtain an optical fiber bundle structure in which the core is arranged on each vertex of the regular polygon, the arrangement of the optical fiber cores may be shifted. For example, the four optical fiber core wires may not be squarely arranged but may be arranged like a substantially rhombus. That is, it is difficult to arrange the optical fiber core wire so that the core is positioned on each vertex of the regular polygon.

  On the other hand, there is a method in which the inner diameter of the hole of the capillary used in the optical fiber bundle structure is reduced to reduce the clearance with respect to the optical fiber core wire. However, if the inner diameter of the hole is reduced, it becomes difficult to insert the optical fiber core wire into the hole. It is also difficult to achieve the required hole dimensional accuracy.

  The present invention has been made in view of such a problem, and an object thereof is to provide an optical fiber bundle structure or the like in which a core is arranged on each vertex of a regular polygon.

  In order to achieve the above-mentioned object, the first invention comprises a plurality of optical fiber cores of three or more and capillaries holding the plurality of optical fiber cores, and the plurality of optical fiber cores. Are twisted with respect to each other about the axial direction of the capillary inside the capillary, and a plurality of the cores of the optical fiber cores are located on each vertex of a regular polygon. An optical fiber bundle structure characterized in that an optical fiber core wire is fixed to the capillary.

  Adjacent optical fiber core wires may be in contact with each other on the end face of the capillary.

  The respective optical fiber core wires may be separated from each other on the end face of the capillary.

  The number of the optical fiber core wires may be four or five.

  It is desirable that the twisting pitch of the optical fiber core wire in the capillary is 90 ° to 360 ° / 10 mm.

  The inner diameter of the capillary is a circumscribed circle when the adjacent optical fiber cores are placed in contact with each other such that the cores of the plurality of optical fiber cores are positioned on the vertices of the regular polygon. It is desirable that it is larger than the diameter by 0.5 μm or more.

  According to the first invention, since the optical fiber cores are twisted with each other, the optical fiber cores are arranged so that the circumscribed circle of the optical fiber core bundles becomes as small as possible in the cross section perpendicular to the longitudinal direction of the optical fiber cores. A line is placed. That is, the arrangement of the optical fiber cores in which the cores of the plurality of optical fiber cores are positioned on the vertices of the regular polygon is a stable arrangement. For this reason, an optical fiber core wire can be easily made into this arrangement.

  Moreover, if the state which twisted the optical fiber core wire mutually is maintained, adjacent optical fiber core wires can be made to contact. For this reason, the optical fiber bundle structure where the adjacent optical fiber core wires contacted can be obtained easily.

  Further, when the twisting force of the tip of the optical fiber core wire is released from the state where the optical fiber core wires are twisted with each other, the optical fiber core wire moves so as to spread outward due to the restoring force against the twist. Since this restoring force is substantially constant with respect to each optical fiber core wire, each optical fiber core wire can be similarly moved outward. For this reason, the optical fiber bundle structure of the state which has located the core of the some optical fiber core wire on each vertex of a regular polygon can be obtained easily. At this time, each optical fiber core wire may be in contact with the capillary.

  In addition, this is particularly effective when the optical fiber cores are not in the close-packed arrangement as in the case of four or five optical fiber cores.

  In addition, if the twisting amount of the optical fiber core wire is 90 ° to 360 ° / 10 mm, the above-described effects can be reliably obtained.

  In addition, by making the inner diameter of the capillary 0.5 μm or more larger than the diameter of the circumscribed circle when adjacent optical fibers are arranged in contact with each other, the operation of inserting the optical fiber core wire into the capillary is easy. .

  A second invention is an optical connector characterized in that the optical fiber bundle structure according to the first invention is accommodated.

  According to the second invention, an optical connector that can be connected to a multi-core fiber or the like can be obtained.

  A third invention is a connection structure between an optical fiber bundle structure and a multi-core fiber according to the first invention, wherein the multi-core fiber includes a plurality of cores and a clad surrounding the core, and the multi-core is provided. The optical fiber connection structure is characterized in that each of the cores of the fiber and the core of each of the optical fiber core wires of the optical fiber bundle structure are optically connected.

  The optical fiber bundle structure according to the first aspect of the present invention is a connection structure between a light emitting / receiving element, wherein the light receiving / emitting element includes a plurality of light receiving / emitting parts, and the light receiving / emitting part of the light receiving / emitting element; It is good also as an optical fiber connection structure characterized by optically connecting with the core of each said optical fiber core wire of the said optical fiber bundle structure.

  According to the third invention, the multi-core fiber or the light emitting / receiving element can be efficiently fanned out.

  According to a fourth aspect of the present invention, there is provided a step of inserting three or more optical fiber core wires into the capillary, and the capillary and the plurality of optical fiber core wires relatively with the axial direction of the capillary as a central axis. In the twisting step and at the tip of the capillary, the adjacent optical fiber core wires are in contact with each other, and the core of the optical fiber core wire is disposed on each vertex of the regular polygon And a step of adhering a plurality of the optical fiber core wires to the capillary in a state.

  A step of inserting three or more optical fiber core wires into the capillary; a step of relatively twisting the capillary and the plurality of optical fiber core wires with the axial direction of the capillary as a central axis; , The step of releasing the collective gripping of the distal end portion of the optical fiber core wire, and the adjacent optical fiber core wires are separated from each other at the distal end portion of the capillary, and the core of the optical fiber core wire is And a step of adhering a plurality of the optical fiber core wires to the capillary in a state of being disposed on each vertex of a regular polygon. It is good.

  According to the fourth invention, it is possible to easily obtain an optical fiber bundle structure in which optical fiber core wires are arranged such that cores of a plurality of optical fiber core wires are positioned on each vertex of a regular polygon.

  ADVANTAGE OF THE INVENTION According to this invention, the optical fiber bundle structure etc. which the core has arrange | positioned on each vertex of a regular polygon can be provided.

(A) is a side view which shows the optical fiber bundle structure 1, (b) is a front view of the optical fiber bundle structure 1, Comprising: The arrow A figure of (a). (A), (b) is a figure which shows the process of manufacturing the optical fiber bundle structure 1. FIG. (A), (b) is a figure which shows the process of manufacturing the optical fiber bundle structure 1. FIG. (A), (b) is a conceptual diagram which shows the movement state of the optical fiber core wire at the time of manufacturing the optical fiber bundle structure 1. FIG. (A) is a side view which shows the optical fiber bundle structure 1a, (b) is a front view of the optical fiber bundle structure 1a, Comprising: The H arrow directional view of (a). (A), (b) is a figure which shows the process of manufacturing the optical fiber bundle structure 1a. (A), (b) is a conceptual diagram which shows the movement state of the optical fiber core wire at the time of manufacturing the optical fiber bundle structure 1a. FIG. 3 is a cross-sectional view showing the optical connector 10. (A) is a figure which shows the optical fiber connection structure 20, (b) is the KK sectional view taken on the line of (a). (A) is a figure which shows the optical fiber connection structure 20a, (b) is the LL sectional view taken on the line of (a).

(Optical fiber bundle structure 1)
Hereinafter, the optical fiber bundle structure 1 will be described. 1A is a side view of the optical fiber bundle structure 1, and FIG. 1B is a front view of the optical fiber bundle structure 1 as viewed from the direction A in FIG.

The optical fiber bundle structure 1 includes a plurality of optical fiber cores 5 having the same diameter, a capillary 3 that holds the optical fiber core wires 5, and the like. The optical fiber core wire 5 includes a core 7 and a clad 9 surrounding the core 7. In the following description, the case where there are four optical fiber cores 5 is shown, but other optical fiber core wires 5 may be used.
The outer diameter of one optical fiber is, for example, 30 μm to 80 μm, and the core diameter is 6 μm to 12 μm.

  The plurality of optical fiber core wires 5 are twisted in one direction inside the capillary 3 with the axial direction of the capillary 3 as the central axis. The optical fiber core wire 5 is inserted into the capillary 3 and is fixed to the capillary 3 with the adhesive 11 in a twisted state.

  As shown in FIG.1 (b), in the front-end | tip part (end surface of the capillary 3) of the optical fiber bundle structure 1, several optical fiber core wire 5 (core 7) is each regular polygon (a figure is square). It is fixed to the capillary 3 so as to be located on the apex. Moreover, the adjacent optical fiber core wires 5 are in contact with each other on the end face of the capillary 3.

  Although details will be described later, by twisting the optical fiber core wire 5, the optical fiber core wire 5 is arranged so that the cores 7 of the plurality of optical fiber core wires 5 are positioned on each vertex of the regular polygon. be able to. That is, the plurality of optical fiber core wires 5 are arranged in contact with each other so that the distances from the twisting center of the optical fiber core wire 5 are equal. In addition, the twist center of the optical fiber core wire 5 is a center position of a regular polygon having the core positions of the plurality of optical fiber core wires 5 as apexes.

  Here, when the cores 7 of the plurality of optical fiber cores 5 are positioned on the vertices of the regular polygon and arranged in contact with each other, a circumscribed circle including all the optical fiber core wires 5 (FIG. 1). The diameter of the circle D) indicated by the dotted line in (b) is the smallest.

Here, the inner diameter of the capillary 3 (C in FIG. 1B) is desirably 0.5 μm or more larger than the diameter of the circumscribed circle D (B in FIG. 1B). By doing in this way, the operation | work which inserts the some optical fiber core wire 5 in the capillary 3 becomes easy. However, if the difference between the diameter B of the circumscribed circle D and the inner diameter C of the capillary 3 is too large, when forming a connection structure between the optical fiber bundle structure and the multicore fiber shown in FIG. Since there is a problem that the end face displacement with respect to the capillary 3 becomes large, the difference between the diameter B of the circumscribed circle D and the inner diameter C of the capillary 3 is preferably 30 μm or less. When the end face displacement between capillaries increases, the adhesive may not be evenly applied to the end face, and distortion may occur during curing or temperature change.

  In addition, as shown in FIG. 8 described later, when the end face of the optical fiber bundle is used as a connector end face, the difference between the diameter B of the circumscribed circle D and the inner diameter C of the capillary 3 depends on the allowable amount of optical axis deviation. It is necessary to determine appropriately. For example, when a general single mode fiber is used as the plurality of optical fibers 5, the difference between the diameter B of the circumscribed circle D and the inner diameter C of the capillary 3 is preferably 2 μm or less, and 1 μm or less. As a result, the optical axis deviation can be further reduced.

  In addition, the twist pitch of the optical fiber core wire 5 inside the capillary 3 is 90 ° to 360 ° / 10 mm (the optical fiber core wire 5 is twisted 90 ° to 360 ° per 10 mm length of the capillary 3. Is desirable). By setting the angle to 90 ° / 10 mm or more, the optical fiber core wire 5 can be surely arranged squarely. In addition, if it exceeds 360 ° / 10 mm, distortion to the optical fiber core wire 5 becomes large and manufacturability deteriorates, which is not desirable.

(Manufacturing method of optical fiber bundle structure 1)
Next, a method for manufacturing the optical fiber bundle structure 1 will be described. First, as shown in FIG. 2A, three or more optical fiber core wires 5 are bundled and inserted into the capillary 3 (arrow E in the figure). The inside of the capillary 3 is filled with an adhesive 11 (not shown) in advance. Instead of filling the capillary 3 with the adhesive 11, the adhesive 11 may be applied in the vicinity of the tip of the optical fiber core wire 5.

  FIG. 2B is a diagram illustrating a state where the optical fiber core wire 5 is inserted into the capillary 3. As shown in FIG. 2 (b), the tip of the optical fiber core wire 5 is projected from the tip of the capillary 3. The adhesive 11 is not applied in advance inside the capillary 3 or in the vicinity of the tip of the optical fiber core 5, but after the optical fiber core 5 is inserted, the adhesive 11 is filled into the capillary 3. May be.

Next, as shown in FIG. 3A, the tips of the plurality of optical fiber core wires 5 are collectively held by the grip portion 12, and the capillary 3 and the plurality of optical fiber core wires 5 are connected to the capillary 3. Twist relatively with the axial direction as the central axis (arrow F in the figure). Thereby, the optical fiber core wire 5 is maintained in a twisted state. In this state, the adhesive 11 inside the capillary 3 is cured.
As described above, the twisting amount of the optical fiber core wire 5 is desirably 90 ° to 360 ° per 10 mm length of the capillary 3.

  Note that only the tip portion of the optical fiber core wire 5 may be bonded or fused in advance to be integrated. By doing in this way, the optical fiber core wire 5 can be easily twisted. The tip of the optical fiber core 5 is grasped or integrated in a state where the optical fiber core wire 5 is arranged so that the core 7 of the optical fiber core wire 5 is positioned on each vertex of the regular polygon. It is preferable. By doing in this way, the twisted optical fiber core wire is also easily arranged so that the core 7 of the optical fiber core wire 5 is positioned on each vertex of the regular polygon.

  FIG. 4A and FIG. 4B are conceptual cross-sectional views showing movement of the optical fiber core wire 5 when the optical fiber core wire 5 is twisted. As shown in FIG. 4A, the optical fiber core wire 5 is arranged with a certain degree of freedom inside the capillary 3 before the optical fiber core wire 5 is twisted. That is, the optical fiber core wires 5 are not arranged at a predetermined interval.

  From this state, when the optical fiber core wires 5 are twisted to each other, a force (arrow G in the drawing) toward the center direction is applied to each of the optical fiber core wires 5. Since the force applied to each optical fiber core wire 5 is substantially equal, each optical fiber core wire 5 is stabilized at a position closest to the twisting center.

That is, as shown in FIG. 4B, each optical fiber core wire 5 is at a position where the distance from the twisting center of the optical fiber core wire 5 is substantially the same, and adjacent optical fiber core wires 5 are adjacent to each other. The state of being arranged so as to be in contact with each other is a stable arrangement. That is, the plurality of optical fiber cores 5 are arranged so that the core 7 of the optical fiber core wire 5 is positioned on each vertex of the regular polygon. Thus, the optical fiber core wire 5 can be easily arranged in a square.
At this time, the distance between the cores in the cross section perpendicular to the longitudinal direction (the distance between the core centers of the optical fiber core wire 5) is made equal to the core pitch (the distance between the core centers) of the multicore fiber or the light emitting / receiving element to be connected. The outer diameter of the optical fiber core wire 5 is set.

  The tip of the optical fiber core wire 5 is collectively grasped, and the adhesive 11 is cured in a state where the optical fiber core wires 5 are twisted with each other, so that the optical fiber core wire 5 is twisted and adhered to the capillary 3 To be fixed. That is, in a state where the adjacent optical fiber cores 5 are in contact with each other at the tip of the capillary 3 and the core 7 of the optical fiber core 5 is positioned on each vertex of the regular polygon. A plurality of optical fiber core wires 5 are bonded to the capillary 3. Thereafter, as shown in FIG. 3B, the optical fiber core wire 5 protruding from the capillary 3 is removed, and the optical fiber core wire 5 and a part of the end face of the capillary 3 are polished, so that an optical fiber bundle structure is obtained. 1 can be obtained.

  As described above, according to the present embodiment, the plurality of optical fiber cores 5 can be easily arranged so that the core 7 of the optical fiber core wire 5 is positioned on each vertex of the regular polygon. Can do. For this reason, the optical fiber bundle structure arrange | positioned so that the core 7 may be located on each vertex of a regular polygon can be obtained easily.

  Further, since the inner diameter of the capillary 3 can be provided with respect to the circumscribed circle of the plurality of optical fiber cores 5, the optical fiber core wire 5 can be easily inserted into the capillary 3.

In addition, although the case where the number of the optical fiber cores 5 is four has been described, as described above, the present invention can be applied to other numbers as long as it is a bundle structure of three or more optical fiber cores 5. Is possible. For example, in the case of five, it can arrange | position so that the core position of the optical fiber core wire 5 may become a vertex position of a regular pentagon.
In the present invention, the optical fiber cores 5 can be easily disposed even with respect to, for example, four or five optical fiber cores 5 that do not have a hexagonal close-packed arrangement. At this time, for example, it is not necessary to arrange a dummy fiber or the like at the center so that the arrangement does not collapse, so the structure is simple and the productivity is excellent.

When there are six or more optical fiber cores, the optical fiber cores 5 may be arranged at the center of the regular polygon. In this case, a bundle structure can be similarly easily obtained by twisting only the optical fiber core wire 5 arranged in the periphery without twisting the optical fiber core wire arranged in the center.
Further, when the number of the optical fiber cores arranged in the center is a plurality of three or more, the core 7 of the optical fiber core wires arranged in the center is formed by twisting the optical fiber core wires arranged in the center. The optical fiber bundle structure arranged so as to be positioned on each vertex of the regular polygon can be easily obtained.

(Optical fiber bundle structure 1a)
Next, a second embodiment will be described. FIG. 5A is a side view of the optical fiber bundle structure 1a, and FIG. 5B is a front view of the optical fiber bundle structure 1a, as viewed from the direction H in FIG. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals as those in FIG.

  The optical fiber bundle structure 1a has substantially the same configuration as the optical fiber bundle structure 1, but the arrangement of the optical fiber core wire 5 in the capillary 3 is different.

  In the optical fiber bundle structure 1 a, the optical fiber core wires 5 are separated from each other on the end face of the capillary 3. In the present embodiment, the optical fiber core wire 5 contacts the inner surface of the capillary 3.

  The plurality of optical fiber core wires 5 are twisted together inside the capillary 3 with the axial direction of the capillary 3 as the central axis. Moreover, the some optical fiber core wire 5 is arrange | positioned so that the core 7 of the optical fiber core wire 5 may be located on each vertex of a regular polygon.

  When the optical fiber core wire 5 is in contact with the inner surface of the capillary 3 as in this embodiment, the inter-core distance (distance between the core centers of the optical fiber core wire 5) in the cross section perpendicular to the longitudinal direction is the multi-core to be connected. The inner diameter of the capillary 3 is set so as to be equal to the core pitch (distance between core centers) of a fiber, a light emitting / receiving element or the like.

(Manufacturing method of optical fiber bundle structure 1a)
Next, a manufacturing method of the optical fiber bundle structure 1a will be described. First, as shown in FIG. 6A, three or more optical fiber cores 5 are bundled and inserted into the capillary 3 by the same procedure as in the first embodiment, and the capillary 3 and the optical fibers are inserted. The core 5 is twisted relatively with the axial direction of the capillary 3 as the central axis (arrow I in the figure).

  In the present embodiment, in a state where the optical fiber core wires 5 are twisted with each other, the tip portions of the optical fiber core wires 5 are separated from each other on the tip end portion side of the capillary, and the optical fiber core wires contact the inner surface of the capillary. The plurality of optical fiber core wires 5 are collectively grasped in a state in which the optical fiber is in the state of being in operation.

  Alternatively, as in the first embodiment, first, the plurality of optical fiber cores 5 are relatively twisted with the axial direction of the capillary 3 as the central axis in a state where the tips of the plurality of optical fiber cores 5 are collectively grasped. . Next, before the adhesive in the capillary is completely cured, the gripping of the distal end portion of the optical fiber core wire is released, and the distal end portions of the optical fiber core wires 5 are separated from each other on the distal end side of the capillary, The adhesive in the capillary is cured while the optical fiber core wire is in contact with the inner surface of the capillary.

  FIG. 7A and FIG. 7B are conceptual cross-sectional views showing movement of the optical fiber core wire 5 when the gripping of the optical fiber core wire 5 is released. As shown in FIG. 7A, when the optical fiber core wires 5 are twisted to each other, a force toward the center direction is applied to each optical fiber core wire 5. Since the force applied to each optical fiber core wire 5 is substantially equal, each optical fiber core wire 5 is stabilized at a position closest to the twisting center.

  From this state, when the tip of the optical fiber core wire 5 is not gripped and the twist is naturally released, each optical fiber core wire 5 tries to recover from the twist (arrow J in the figure). At this time, since the adhesive 11 is filled around the optical fiber core 5, the optical fiber core 5 moves so as to spread outward slowly due to the viscosity of the adhesive 11. Further, the optical fiber core wires 5 come into contact with the inner surface of the capillary 3 and stop moving.

  At this time, since the force applied to each optical fiber core 5 (force to spread outward) is substantially the same, the core 7 of each optical fiber core 5 is placed on each vertex of the regular polygon. A plurality of optical fiber core wires 5 are arranged so as to be positioned at the positions. At this time, the adjacent optical fiber core wires 5 are separated from each other and do not contact each other (see FIG. 7B).

  As described above, the adhesive 11 is cured with the ends of the plurality of optical fiber cores 5 opened, so that the optical fiber core wires 5 are slightly restored from the twisted state. Is bonded and fixed to the capillary 3. That is, the adjacent optical fiber core wires 5 are separated from each other at the tip of the capillary 3 and the cores 7 of the optical fiber core wires 5 are positioned on the vertices of the regular polygon. In this state, the plurality of optical fiber core wires 5 are bonded to the capillary 3. Thereafter, as shown in FIG. 6 (b), the optical fiber core wire 5 protruding from the capillary 3 is removed, and the optical fiber core wire 5 and a part of the end face of the capillary 3 are polished, so that an optical fiber bundle structure is obtained. 1a can be obtained.

  As described above, according to the second embodiment, the same effects as those of the first embodiment can be obtained. That is, for example, a square-arranged optical fiber bundle structure can be easily obtained.

  In the present embodiment, the optical fiber cores 5 are not brought into contact with each other, and the cores 7 of the optical fiber core wires 5 are positioned on the vertices of the regular polygon. Can be arranged.

  In the illustrated example, the optical fiber core wire 5 is in contact with the inner surface of the capillary 3 when the optical fiber core wire 5 is slightly restored from the twisted state. However, this embodiment is not limited thereto. Absent. For example, even if the optical fiber core wire 5 is not in contact with the inner surface of the capillary 3, each core 7 is positioned on each vertex of the regular polygon with the optical fiber core wires 5 being separated from each other. Should just be arranged.

  In the above-described embodiment, even when the tip of the optical fiber core 5 is twisted without being gripped, the twisted state of the optical fiber core 5 is realized by the viscosity of the adhesive. It is possible to obtain a desired twisted state by curing the adhesive before the twisted state returns to the untwisted state.

  Further, instead of maintaining the state where the optical fiber core wire 5 is twisted, the optical fiber core wire 5 may be continuously twisted for a predetermined time. For example, the capillary 3 may be continuously rotated for a predetermined period before the adhesive is cured and the optical fiber core wire 5 is completely bonded. By doing in this way, it can suppress that the twist of the optical fiber core wire 5 returns too much.

(Optical connector 10)
Next, the optical connector 10 using the optical fiber bundle structure 1 (1a) will be described. FIG. 8 is a cross-sectional view of the optical connector 10. The optical connector 10 accommodates the optical fiber bundle structure 1 or the optical fiber bundle structure 1a therein.

  The capillary 3 in the optical fiber bundle structure 1 (1a) functions as a ferrule 13. That is, a plurality of optical fiber core wires 5 are inserted into the ferrule 13 in a twisted state. Moreover, the optical fiber core wire 5 is arrange | positioned so that the core 7 of each optical fiber core wire 5 may be located on each vertex of a regular polygon in the end surface of the ferrule 13. FIG.

  By using such an optical connector 10, it is possible to connect to a multi-core fiber or the like built in another connector.

(Optical fiber connection structure 20)
Next, an optical fiber connection structure will be described. Fig.9 (a) is a figure which shows the optical fiber connection structure 20, FIG.9 (b) is KK sectional view taken on the line of Fig.9 (a). The optical fiber connection structure 20 is a connection structure between the optical fiber bundle structure 1 or the optical fiber bundle structure 1 a and the multicore fiber 15.

  The multi-core fiber 15 is inserted into the capillary 17 and fixed with resin or the like. In the multi-core fiber 15, a plurality of cores 19 are arranged at a predetermined interval, and a clad 21 is provided so as to surround the core 19. In the example shown in the figure, the four cores 19 are arranged in a square arrangement.

  The number of optical fiber cores 5 is the same as the number of cores 19 of the multi-core fiber 15. Further, the pitch of the cores 7 of the optical fiber cores 5 (the core pitch between the adjacent optical fiber cores 5) substantially matches the pitch of the cores 19 of the multicore fiber 15.

  The optical fiber bundle structure 1 (1a) and the multi-core fiber 15 are connected by adhesion or fusion. Further, the core 7 of the optical fiber core 5 and the core 19 of the multi-core fiber 15 are optically connected.

  According to the optical fiber connection structure 20, each core 19 of the multicore fiber 15 and each core 7 of the optical fiber core wire 5 can be optically connected. At this time, in the optical fiber bundle structure 1 (1a), since the optical fiber core wires 5 are arranged at a predetermined interval, the interval between the cores 7 can be kept constant with high accuracy.

(Optical fiber connection structure 20a)
Next, another optical fiber connection structure will be described. Fig.10 (a) is a figure which shows the optical fiber connection structure 20a, FIG.10 (b) is LL sectional drawing (front view of the light emitting / receiving element 23) of Fig.10 (a). The optical fiber connection structure 20 a is a connection structure between the optical fiber bundle structure 1 or the optical fiber bundle structure 1 a and the light receiving and emitting element 23.

  In the light emitting / receiving element 23, the light emitting / receiving sections 25 are arranged at a predetermined interval. In the example shown in the figure, the light emitting / receiving unit 25 is arranged in a square arrangement. The number of optical fiber cores 5 is the same as the number of light emitting / receiving units 25. Further, the pitch of the cores 7 of the optical fiber core wire 5 (the core pitch between the adjacent optical fiber core wires 5) is substantially the same as the pitch of the light emitting / receiving unit 25.

  By joining the optical fiber bundle structure 1 (1a) and the light receiving / emitting element 23, the core 7 of the optical fiber core wire 5 and the light receiving / emitting part 25 of the light receiving / emitting element 23 are optically connected.

  According to the optical fiber connection structure 20a, the core 7 of the optical fiber core wire 5 and the light receiving / emitting part 25 of the light receiving / emitting element 23 can be optically connected. At this time, in the optical fiber bundle structure 1 (1a), since the optical fiber core wires 5 are arranged at a predetermined interval, the interval between the cores 7 can be kept constant with high accuracy.

  As mentioned above, although embodiment of this invention was described referring an accompanying drawing, the technical scope of this invention is not influenced by embodiment mentioned above. 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.

DESCRIPTION OF SYMBOLS 1, 1a ... Optical fiber bundle structure 3 ... Capillary 5 ... Optical fiber core wire 7 ... Core 9 ... Cladding 11 ... Adhesive 12 ... Fixing part 13 ... Ferrule 15 ......... Multi-core fiber 17 ......... Capillary 19 ......... Core 20, 20a ......... Optical fiber connection structure 21 ...... Clad 23 ......... Light emitting / receiving element 25 ......... Light receiving / emitting section

Claims (11)

3 or more optical fiber core wires,
A capillary for holding a plurality of the optical fiber cores;
Comprising
The plurality of optical fiber cores are twisted together with the axial direction of the capillary as a central axis inside the capillary,
An optical fiber bundle structure, wherein the plurality of optical fiber cores are fixed to the capillary so that the cores of the plurality of optical fiber cores are positioned on each vertex of a regular polygon.   The optical fiber bundle structure according to claim 1, wherein the adjacent optical fiber core wires are in contact with each other on an end face of the capillary.   2. The optical fiber bundle structure according to claim 1, wherein the optical fiber core wires are spaced apart from each other at an end face of the capillary.   The optical fiber bundle structure according to any one of claims 1 to 3, wherein the number of the optical fiber core wires is four or five.   The optical fiber bundle structure according to any one of claims 1 to 4, wherein a twist pitch of the optical fiber core wire in the capillary is 90 ° to 360 ° / 10mm. The inner diameter of the capillary is
0.5 μm larger than the diameter of the circumscribed circle when the adjacent optical fiber cores are arranged in contact with each other such that the cores of the plurality of optical fiber cores are positioned on each vertex of the regular polygon The optical fiber bundle structure according to any one of claims 1 to 5, wherein the optical fiber bundle structure is larger than the above.   An optical connector comprising the optical fiber bundle structure according to any one of claims 1 to 6. A connection structure between the optical fiber bundle structure according to any one of claims 1 to 6 and a multi-core fiber,
The multi-core fiber is
A plurality of cores, and a clad surrounding the cores,
Each of the cores of the multi-core fiber is optically connected to each of the cores of the optical fiber cores of the optical fiber bundle structure. A connection structure between the optical fiber bundle structure according to any one of claims 1 to 6 and the light emitting / receiving element,
The light emitting and receiving element is
Having a plurality of light emitting and receiving parts,
An optical fiber connection structure, wherein the light receiving and emitting part of the light emitting and receiving element and the core of each optical fiber core wire of the optical fiber bundle structure are optically connected. Inserting three or more optical fiber core wires into the capillary;
A step of relatively twisting the capillary and the plurality of optical fiber core wires with the axial direction of the capillary as a central axis;
In the state where the adjacent optical fiber cores are in contact with each other at the tip of the capillary, and the core of the optical fiber core is disposed on each vertex of the regular polygon, Bonding the optical fiber core wire to the capillary;
The manufacturing method of the optical fiber bundle structure characterized by comprising. Inserting three or more optical fiber core wires into the capillary;
A step of relatively twisting the capillary and the plurality of optical fiber core wires with the axial direction of the capillary as a central axis;
Opening the collective gripping of the tip of the optical fiber core; and
At the tip of the capillary, the adjacent optical fiber cores are separated from each other, and the core of the optical fiber core wire is disposed on each vertex of a regular polygon. Bonding a plurality of the optical fiber core wires to the capillary;
The manufacturing method of the optical fiber bundle structure characterized by comprising.

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