Method for connecting multi-core fiber and device for connecting multi-core fiber

Abstract

To provide a method and device for connecting a multi-core fiber, capable of suppressing a variation between cores having connection loss.SOLUTION: A method for connecting a multi-core fiber 2 capable of connecting a pair of multi-core fibers 2a and 2b comprises the fusion step S2 of performing discharge by a pair of high voltage discharge electrodes 61a and 61b to fuse both the multi-core fibers 2a and 2b. The fusion step S2 comprises rotating the pair of multi-core fibers 2a and 2b around the central axis C of a clad 22 until the discharge ends after the discharge starts.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a multi-core fiber splicing method and a multi-core fiber splicing device. [Background technology]

[0002] A multicore fiber splicing device is a device used to splice a pair of multicore fibers, and includes, as its main components, an alignment device for accurately aligning the parts to be spliced, and a heater unit for generating heat to fuse the ends of the multicore fibers together. As the heater unit, for example, a pair of opposing high-voltage discharge electrodes is used.

[0003] When connecting multi-core fibers, rotational alignment is performed to make the cores of the respective multi-core fibers face each other. Patent Document 1 listed below discloses a method for aligning a multi-core fiber when the core positions do not have rotational symmetry.

[0004] Patent Document 2 listed below discloses a technique for fusing rotationally aligned multi-core fibers by discharge between a pair of opposing high-voltage discharge electrodes. In this fusion splicing, the ends of the aligned multi-core fibers are butted together, and a high voltage is applied to the discharge electrodes to cause an arc discharge, which melts the glass portion of the optical fiber with the generated heat, thereby fusing the fibers. Fusion splicing by discharge forms a physically strong joint, and a stable connection is maintained for a long period of time. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2018-4685 A [Patent Document 2] International Publication No. 2019 / 163150 Summary of the Invention [Problem to be solved by the invention]

[0006] In the case of fusion splicing by electric discharge, uneven temperature distribution may occur during arc discharge. In that case, when splicing multi-core fibers, variations in the melting of the glass of each core may occur, which may increase variations in the connection state between cores and increase variations in connection loss between cores.

[0007] Therefore, an object of the present invention is to provide a multi-core fiber splicing method and a multi-core fiber splicing device that can suppress variations in splice loss between cores. [Means for solving the problem]

[0008] A first aspect of the present invention is a method for connecting a pair of multi-core fibers, comprising a fusion step of generating discharge between a pair of high-voltage discharge electrodes to fuse the multi-core fibers together, wherein in the fusion step, the pair of multi-core fibers are rotated around the central axis of the cladding from the start of the discharge to the end of the discharge.

[0009] According to the first aspect, since the multicore fiber rotates between the start and end of discharge, the heating of each core can be averaged and the difference in thermal history of each core can be reduced. Therefore, according to the first aspect, the variation in the connection state of each core can be reduced, and the variation in connection loss between cores can be reduced.

[0010] A second aspect of the present invention is the method for connecting multi-core fibers according to the first aspect, characterized in that in the fusion step, the discharge is composed of a plurality of pulse discharges, and the pair of multi-core fibers is rotated between the pulse discharges.

[0011] According to the second aspect, the period between one pulse discharge and the next successive pulse discharge can be lengthened, so that the rotational position of the multi-core fiber can be controlled accurately, and therefore, fusion can be performed with good reproducibility.

[0012] A third aspect of the present invention is the method for connecting a multi-core fiber according to the second aspect, characterized in that in the multi-core fiber, the central axis of each core is arranged in an N-fold rotational symmetry with the central axis of the cladding as the center of symmetry, the pulse discharge is performed M times, where M is a number that is a multiple or divisor of N, and the pair of multi-core fibers are each rotated 360° / M times between the pulse discharges.

[0013] According to the third aspect, for example, if the central axes of the cores are arranged in an N-rotationally symmetrical manner and the number of discharges is M, which is a divisor of N, the difference in thermal history between the cores can be reduced with a discharge rotational speed smaller than N.

[0014] A fourth aspect of the present invention is the method for connecting multi-core fibers according to the first aspect, wherein the pair of multi-core fibers are rotated around the central axis of the cladding during the discharge.

[0015] According to the fourth aspect, since discharge and rotation are performed within the same period, the difference in thermal history between the cores can be reduced in a short time.

[0016] A fifth aspect of the present invention is a multi-core fiber splicing device that splices a pair of multi-core fibers, comprising: an alignment device that can adjust the rotational position of each of the multi-core fibers; a fusion splicer that can fuse the multi-core fibers by generating an electric discharge between a pair of high-voltage discharge electrodes that face each other across the butt joint position of the multi-core fibers; and a control device, wherein the control device controls the fusion splicer to generate an electric discharge and fuse the multi-core fibers together, and controls the alignment device to rotate the pair of multi-core fibers around the central axis of the cladding from the start of the electric discharge to the end of the electric discharge.

[0017] According to aspect 5, since the multicore fiber rotates between the start and end of the discharge, heating of each core can be averaged, and the difference in thermal history of each core can be reduced. Therefore, according to aspect 5, the variation in the connection state of each core can be reduced. As a result, the variation in connection loss between cores can be reduced. [Effects of the Invention]

[0018] As described above, according to the present invention, a multi-core fiber splicing method and a multi-core fiber splicing device are provided that can suppress variations in splice loss between cores. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a diagram schematically showing a cross section perpendicular to the longitudinal direction of a multi-core fiber. [Figure 2] FIG. 2 is a diagram schematically illustrating a multi-core fiber splicing device according to an embodiment of the present invention. [Figure 3] FIG. 3 is a flowchart showing a method for connecting multi-core fibers using the multi-core fiber connection device according to the embodiment of the present invention. [Figure 4] FIG. 4 is a diagram showing a schematic view of the fusion step. [Figure 5] FIG. 5 is a diagram schematically illustrating the fusion step according to the modified example. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, embodiments for carrying out a method for connecting multicore fibers 2 and a multicore fiber connecting device 1 according to the present invention will be illustrated with reference to the accompanying drawings. The embodiments illustrated below are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention can be modified and improved from the following embodiments within the scope of the claims without departing from the spirit thereof. Furthermore, in this specification, the dimensions of each component may be exaggerated to facilitate understanding.

[0021] First, the multi-core fiber 2 to be connected by the multi-core fiber connection device 1 according to this embodiment will be described.

[0022] FIG. 1 is a diagram schematically showing a cross section perpendicular to the longitudinal direction of a multicore fiber 2. The multicore fibers 2 connected to each other have the same configuration. The multicore fiber 2 includes a plurality of cores 21a to 21c, a cladding 22 surrounding the outer peripheral surface of each core 21, an inner protective layer 23 covering the outer peripheral surface of the cladding 22, and an outer protective layer 24 covering the outer peripheral surface of the inner protective layer 23. In this specification, when the cores 21a, 21b, 21c, etc. are not to be distinguished from each other, they will be referred to as cores 21. Note that in FIG. 1, the central axis CC of the core 21 is shown only for one core 21a, and the central axes CC of the cores 21 are omitted for the other cores 21b and 21c. In this embodiment, the central axes CC of the cores 21a to 21c are arranged on the vertices of an equilateral triangle centered on the central axis C of the cladding 22. Therefore, the cores 21a to 21c are arranged in a three-way rotational symmetry with the central axis C as the center.

[0023] Next, the configuration of the multi-core fiber splicing device 1 according to this embodiment will be described.

[0024] 2 is a diagram schematically illustrating the multicore fiber splicing device 1. The multicore fiber splicing device 1 mainly includes an alignment device 40 that adjusts the positions of the multicore fibers 2a and 2b, a fusion splicer 60 that fuses the multicore fibers 2a and 2b together, and a control device 30.

[0025] The configuration of the multicore fibers 2a and 2b is the same as that of the multicore fiber 2. Therefore, in this specification, when there is no need to distinguish between the multicore fibers 2a and 2b, they may be referred to as the multicore fiber 2. Furthermore, when there is no need to distinguish between the end faces 50a and 50b of the multicore fibers 2a and 2b that are fused to each other, they may be referred to as the end face 50.

[0026] The alignment device 40 includes XYZ position adjustment devices 41a and 41b that adjust the positions of the multicore fibers 2a and 2b in the XYZ directions, and rotary alignment devices 42a and 42b that rotate the multicore fibers 2a and 2b around the central axis C of the cladding 22.

[0027] The alignment device 40 includes an end face measuring device 70. The end face measuring device 70 measures the end faces 50a and 50b of the multi-core fibers 2a and 2b to obtain position information of the central axes CC of the cores 21 and the like.

[0028] Regarding the end face measuring device 70, when the distance between the end faces 50a, 50b is short and it is difficult to install an image acquiring device such as a camera, a reflecting mirror may be inserted between the end faces 50a, 50b, and a reflected image of the end faces 50a, 50b reflected in the reflecting mirror may be acquired by the image acquiring device, and position information and the like of each core 21 may be acquired from the acquired image. Also, images of the side faces of the multicore fibers 2a, 2b may be directly acquired by the image acquiring device, and position information and the like of each core 21 may be acquired from the acquired image.

[0029] The fusion splicer 60 has a pair of high-voltage discharge electrodes 61a, 61b, and generates an arc discharge by applying a high voltage between the pair of high-voltage discharge electrodes 61a, 61b to fuse the end faces 50a, 50b of the butted multi-core fibers 2a, 2b. In this embodiment, the fusion splicer 60 is configured so that the multi-core fibers 2a, 2b to be spliced ​​are respectively arranged horizontally. The high-voltage discharge electrodes 61a, 61b may be movable.

[0030] The control device 30 is composed of, for example, an integrated circuit such as a microcontroller, an IC (Integrated Circuit), an LSI (Large-scale Integrated Circuit), or an ASIC (Application Specific Integrated Circuit), or an NC (Numerical Control) device. Furthermore, when an NC device is used, the control device 30 may or may not use a machine learning device.

[0031] The control device 30 executes a program to control the alignment device 40, the fusion splicer 60, and the end face measuring device 70 as follows. The program and the like are stored in a memory (not shown) provided in the control device 30.

[0032] The control device 30 calculates control information for controlling the alignment device 40 and the fusion splicer 60 based on position information such as the central axis C of each core 21 and cladding 22 of the end face 50 measured by the end face measuring device 70. The control information may be stored in advance in a memory (not shown).

[0033] Furthermore, the control device 30 controls the XYZ position adjusting device 41 of the alignment device 40 based on the above control information etc., to adjust the position in the XYZ axis directions for each of the pair of multi-core fibers 2 a, 2 b. Furthermore, the control device 30 controls the rotary aligners 42 a, 42 b based on the above control information etc., to rotate each of the pair of multi-core fibers 2 a, 2 b around the central axis C of the cladding 22.

[0034] The control device 30 controls the fusion splicer 60 based on the above control information, etc., to generate a discharge between a pair of high-voltage discharge electrodes 61a, 61b possessed by the fusion splicer 60, thereby fusing the butted and rotationally aligned multi-core fibers 2a, 2b together.

[0035] Next, a method for connecting a pair of multi-core fibers 2a and 2b using the multi-core fiber connecting device 1 will be described.

[0036] 3 is a flowchart showing a method for connecting a pair of multi-core fibers 2a and 2b. The method for connecting a pair of multi-core fibers 2a and 2b mainly comprises an aligning step S1 and a fusion splicing step S2.

[0037] <Alignment step S1> This step is a step of rotating and aligning the multicore fibers 2a and 2b so that the end faces 50a and 50b of the multicore fibers 2a and 2b, which are to be connected to each other, face each other and the cores 21 face each other.

[0038] First, a pair of multi-core fibers 2 a, 2 b are prepared. Before each of the multi-core fibers 2 a, 2 b is set in the fusion splicer 60, the inner protective layer 23 and the outer protective layer 24 are stripped off near the end faces 50 of each of the multi-core fibers 2 a, 2 b to be spliced.

[0039] 2, the multicore fibers 2a, 2b are set in the fusion splicer 60 with the end faces 50 to be spliced ​​of the multicore fibers 2a, 2b facing each other. Then, the control device 30 aligns the central axes C of the claddings 22 of the multicore fibers 2a, 2b. That is, the control device 30 controls the XYZ position adjustment device 41 to position the multicore fibers 2a, 2b such that the central axes C of the claddings 22 of the multicore fibers 2a, 2b are positioned on the same straight line.

[0040] Next, the control device 30 controls the rotation aligners 42a, 42b of the alignment device 40 based on the image of the end face 50 measured by the end face measuring device 70, and rotationally aligns the multicore fibers 2a, 2b so that the cores 21a to 21c of the multicore fibers 2a, 2b face each other. It is preferable that the angle formed between the end face 50a of one multicore fiber 2a and the end face 50b of the other multicore fiber 2b is 0.5° or less. Note that when aligning the central axes C of the claddings 22 of the pair of multicore fibers 2a, 2b or when performing rotational alignment, for example, the side faces of the multicore fibers 2a, 2b may be observed with an image acquiring device (not shown) and the alignment may be performed based on the acquired images of the side faces of the multicore fibers 2a, 2b.

[0041] In this way, the multi-core fibers 2a and 2b are aligned.

[0042] <Fusing step S2> This step is a step in which discharge is generated by the pair of high-voltage discharge electrodes 61a, 61b, and the pair of multi-core fibers 2a, 2b are fused together. In this step, the control device 30 controls the fusion splicer 60 to generate discharge by the pair of high-voltage discharge electrodes 61a, 61b, and fusion splice the respective multi-core fibers 2a, 2b. Also, in this step, the control device 30 controls the rotary alignment machines 42a, 42b to rotate the pair of multi-core fibers 2a, 2b around the central axis C of the cladding 22 from the start of discharge until the end of discharge. Note that the pair of multi-core fibers 2a, 2b are rotated while the rotational alignment is maintained. Therefore, the pair of multi-core fibers 2a, 2b are rotated in the same direction by the same rotation angle.

[0043] Here, an example of the relationship between discharge and rotation in the fusion step S2 will be shown.

[0044] FIG. 4 is a timing chart of the fusion step S2. In FIG. 4, the vertical axis represents the discharge intensity, and the horizontal axis represents time. As described above, the multicore fiber 2 has three cores 21a, 21b, and 21c. The central axes CC of the cores 21 are arranged with the central axis CC of the cladding 22 as the center of symmetry, thus having three-fold rotational symmetry. That is, if the number of cores 21 in the multicore fiber 2 is N, then N=3. In this embodiment, discharge is performed by a plurality of pulse discharges. As shown in FIG. 4, three periods, namely, pulse discharge periods P1, P2, and P3, are provided as periods during which discharge is performed. That is, if the number of discharges is M, then M=3. In addition, a non-discharge period Q1 is provided as a period during which discharge is not performed between the pulse discharge period P1 and the pulse discharge period P2, and a non-discharge period Q2 is provided as a period during which discharge is not performed between the pulse discharge period P2 and the pulse discharge period P3. In this embodiment, the pulse discharge periods P1, P2, P3, and P4 are equal to one another, and the powers of the respective pulse discharges are equal to one another.

[0045] The control device 30 controls the rotary aligners 42a and 42b to rotate the pair of multi-core fibers 2a and 2b, so that at the start of the pulse discharge period P1, the core 21a is at the top and the cores 21b and 21c are at the same height, as shown in the leftmost schematic diagram at the bottom of Fig. 4. Then, the control device 30 controls the fusion splicer 60 to cause discharge during the pulse discharge period P1. Next, during the non-discharge period Q1, the control device 30 controls the rotary aligners 42a and 42b to rotate the multi-core fibers 2a and 2b, so that the core 21c is at the top and the cores 21a and 21b are at the same height, as shown in the central schematic diagram at the bottom of Fig. 4. That is, in the non-discharge period Q1, the control device 30 controls the rotary aligners 42a and 42b to rotate the multi-core fibers 2a and 2b by 120° around the central axis C of the cladding 22 as the rotation axis, and at the start of the pulse discharge period P2, the control device 30 brings the multi-core fibers 2a and 2b into the state shown in the central schematic diagram at the bottom of FIG. 4. Subsequently, the control device 30 controls the fusion splicer 60 to cause discharge during the pulse discharge period P2. Next, in the non-discharge period Q2, the control device 30 controls the rotary aligners 42a and 42b to rotate the multi-core fibers 2a and 2b, and brings the multi-core fibers 2a and 2b into a state where the core 21b is at the top and the cores 21a and 21c are at the same height, as shown in the schematic diagram shown at the rightmost part of the bottom of FIG. That is, in the non-discharge period Q2, the control device 30 controls the rotary aligners 42a and 42b to rotate the multi-core fibers 2a and 2b by another 120°, and at the start of the pulse discharge period P3, the control device 30 brings the multi-core fibers 2a and 2b into the state shown in the schematic diagram shown at the rightmost part of the bottom of FIG. Finally, the control device 30 controls the fusion splicer 60 to perform discharge during the pulse discharge period P3. As can be understood from the above description, in this embodiment, M is 3, and the multi-core fibers 2a, 2b are rotated 360° / M per rotation. Therefore, in the non-discharge periods Q1, Q2, the multi-core fibers 2a, 2b are rotated around the central axis C of the cladding 22, and the direction from the central axis C of the cladding 22 toward the specific core 21 changes before and after the rotation. The specific core 21 is, for example, the core 21a.

[0046] In this way, the multi-core fibers 2a and 2b are connected to each other.

[0047] As described above, the method for connecting the multi-core fibers 2 of this embodiment includes the fusion step S2 in which discharge is generated by the pair of high-voltage discharge electrodes 61a, 61b to fuse the respective multi-core fibers 2 together, and in the fusion step S2, the pair of multi-core fibers 2a, 2b are rotated around the central axis C of the cladding 22 from the start of discharge to the end of discharge.

[0048] Moreover, the multicore fiber connection device 1 of this embodiment includes an alignment device 40 that can adjust the rotational positions of the multicore fibers 2 a, 2 b, a fusion splicer 60 that generates an electric discharge between a pair of high-voltage discharge electrodes 61 a, 61 b ​​that face each other across the butt joint position of the multicore fibers 2 a, 2 b, and can fuse the multicore fibers 2 a, 2 b together, and a control device 30. The control device 30 controls the fusion splicer 60 to generate an electric discharge between the pair of high-voltage discharge electrodes 61 a, 61 b ​​that face each other across the butt joint position of the multicore fibers 2 a, 2 b, and fuses the multicore fibers 2 a, 2 b together, and controls the alignment device 40 to rotate the pair of multicore fibers 2 a, 2 b around the central axis C of the cladding 22 from the start of the electric discharge to the end of the electric discharge.

[0049] According to such a method for connecting the multi-core fibers 2 and the multi-core fiber connecting device 1, the multi-core fibers 2a, 2b are rotated from the start of discharge to the end of discharge, so that heating of each core 21 can be averaged and differences in thermal history of each core 21 can be reduced. Therefore, variations in the connection state of each core 21 can be reduced. As a result, variations in connection loss between the cores 21 can be reduced.

[0050] In the present embodiment, an example has been shown in which the control device 30 controls the rotary aligners 42a and 42b to rotate the multi-core fibers 2a and 2b in the non-discharge periods Q1 and Q2, that is, an example in which the pair of multi-core fibers 2a and 2b are rotated between successive pulse discharges. However, the multi-core fibers 2a and 2b may be rotated in each of the pulse discharge periods P1, P2, and P3, or the multi-core fibers 2a and 2b may be rotated from the start of discharge to the end of discharge.

[0051] In the above embodiment, the central axis CC of each core 21 is arranged with the central axis C of the cladding 22 as the center of symmetry, and the arrangement of the cores 21 has three-fold rotational symmetry. However, the present invention is not limited to this. That is, in the above embodiment, N=3 and M=3, and the cores 21 were rotated by 360° / M, i.e., 120°, for each pulse discharge. However, M may be a multiple of N. For example, when M is twice N, the cores 21 may be rotated by 360° / 6, i.e., 60° for each pulse discharge. When the arrangement of the cores 21 has four-fold rotational symmetry, N=4, and M may be 4, e.g., 8. When the arrangement of the cores 21 has six-fold rotational symmetry, N=6, and M may be 6, e.g., 12. Note that, from the viewpoint of facilitating control of the rotation of the multi-core fibers 2 a, 2 b, M is preferably within five times N. Furthermore, M is preferably three times N. Furthermore, M is preferably twice N. Furthermore, it is preferable that M is equal to N. However, M does not have to be equal to N, and does not have to be a multiple of N. Furthermore, the number of cores 21, N, and M may be unrelated.

[0052] Furthermore, for example, when the arrangement of the cores 21 in the multicore fiber 2 has six-fold rotational symmetry, N=6. In this case, although the rotation may be 360° / 6=60° per rotation, since one of the divisors of 6 is 2, the control device 30 may control the fusion splicer 60 to perform discharge twice, and the control device 30 may control the rotary aligners 42a and 42b to rotate the multicore fibers 2a and 2b by 360° / 2, i.e., 180°, between each discharge. Furthermore, since the other divisor of 6 is 3, the control device 30 may control the fusion splicer 60 to perform discharge three times, and the control device 30 may control the rotary aligners 42a and 42b to rotate the multicore fibers 2a and 2b by 360° / 3, i.e., 120°, between each discharge.

[0053] That is, in the multi-core fibers 2a and 2b, when the central axis CC of each core 21 is arranged on the vertex of a figure having N-fold rotational symmetry with the central axis C of the cladding 22 as the center of symmetry, discharge may be performed M times, where M is a multiple or sub-multiple of N. In this case, between successive discharges, the pair of multi-core fibers 2a and 2b may each be rotated 360° / M times.

[0054] In this embodiment, the control device 30 has been described with an example in which the pulse discharge periods P1, P2, P3, and P4 are equal to one another and the power of each pulse discharge is constant, but the pulse discharge periods P1, P2, P3, and P4 may be different from one another and the power of each pulse discharge may not be constant.

[0055] In this way, when the arrangement of the cores 21 in the multicore fibers 2a and 2b has rotational symmetry, heating according to the rotational symmetry becomes possible, so that heating of the cores 21 can be averaged and differences in thermal history of the cores 21 can be reduced. Therefore, variations in the connection state of the cores 21 can be reduced. As a result, variations in connection loss between the cores 21 can be reduced.

[0056] Next, a modified example will be described. Fig. 5 shows a timing chart of the fusion step S2 according to the modified example. In this modified example, discharge is performed once.

[0057] The control device 30 controls the rotary aligners 42a and 42b to rotate the multicore fibers 2a and 2b so that, by the start of the discharge period R, the core 21a is at the top and the cores 21b and 21c are at the same height as shown in the leftmost schematic diagram at the bottom of Fig. 5 . Then, the control device 30 controls the fusion splicer 60 to perform continuous discharge during the discharge period R. The control device 30 controls the rotary aligners 42a and 42b to rotate the multicore fibers 2a and 2b by 360° at a uniform rotational speed from the start to the end of the discharge period R. In other words, the control device 30 rotates the multicore fibers 2a and 2b until they return to a state in which the core 21a is at the top and the cores 21b and 21c are at the same height as shown in the rightmost schematic diagram of Fig. 5 . For example, the multicore fibers 2a and 2b are rotated so that when one-third of the discharge period R has elapsed, the arrangement of the cores 21 of the multicore fibers 2a and 2b becomes the state of the schematic diagram shown in the second from the left at the bottom of Fig. 5, as indicated by the dashed line in Fig. 5. Furthermore, when two-thirds of the discharge period R has elapsed, the multicore fibers 2a and 2b are rotated so that the arrangement of the cores 21 of the multicore fibers 2a and 2b becomes the state of the schematic diagram shown in the third from the left at the bottom of Fig. 5, as indicated by the dotted line in Fig. 5.

[0058] In this modification, an example has been shown in which, in the fusion step S2, the control device 30 controls the rotary aligners 42a, 42b to continuously rotate the multi-core fibers 2a, 2b during the discharge period R, but the present invention is not limited to this. That is, the multi-core fibers 2a, 2b may be rotated discretely during the discharge period R.

[0059] Although the present invention has been described above using the embodiments as examples, the present invention is not limited to these. [Explanation of symbols]

[0060] 1. Multicore fiber splicing device 2. Multicore fiber 21 Cores 22 Clad 30. Control device 40 Alignment device 60···Fusion splicer C: Central axis of cladding CC: Central axis of the core S2: Fusion step

Claims

1. A method for connecting a pair of multi-core fibers, comprising: a fusion step of generating discharge between a pair of high-voltage discharge electrodes and fusing the multi-core fibers together; Equipped with In the fusion step, the pair of multi-core fibers are rotated around the central axis of the cladding from the start of the discharge to the end of the discharge. A method for connecting multi-core fibers.

2. In the fusion step, the discharge is formed by a plurality of pulse discharges, and the pair of multi-core fibers are rotated around the central axis of the cladding between the pulse discharges. The multi-core fiber splicing method according to claim 1 .

3. In the multicore fiber, the central axes of the cores are arranged in N-fold rotational symmetry with the central axis of the cladding as the center of symmetry, The pulse discharge is performed M times, where M is a number that is a multiple or sub-number of N, Between the pulse discharges, the pair of multi-core fibers are rotated 360° / M around the central axis of the cladding. The multi-core fiber splicing method according to claim 2 .

4. During the discharge, the pair of multi-core fibers are rotated around the central axis of the cladding. The multi-core fiber splicing method according to claim 1 .

5. A multi-core fiber splicing device for splicing a pair of multi-core fibers, an alignment device capable of adjusting the rotational position of each of the multi-core fibers; a fusion splicer capable of fusing the multi-core fibers together by generating discharge between a pair of high-voltage discharge electrodes facing each other across a butted position of the multi-core fibers; a control device; Equipped with The control device controls the fusion splicer to cause discharge and fuse the multi-core fibers together, and controls the alignment device to rotate the pair of multi-core fibers around the central axis of the cladding from the start of the discharge to the end of the discharge. A multi-core fiber splicing device.

Images