Connection method and connection device

Abstract

This connection method comprises: a step for preparing a first optical fiber member including a target element to be rotationally aligned at a position shifted from a central axis on an end surface, and a plurality of second optical fiber members each including a target element to be rotationally aligned at a position shifted from the central axis on the end surface; a step for rotationally aligning the first optical fiber member by rotating same by a predetermined rotation angle around the central axis of the first optical fiber member so as to reduce the amount by which the target element included in the first optical fiber member is shifted with respect to the target element included in one second optical fiber member among the plurality of second optical fiber members arranged side by side; and a step for connecting the end surface of the first optical fiber member to the end surface of the one second optical fiber member. In the step for rotationally aligning, the one second optical fiber member is not rotated.

Description

Connection method and connection device

[0001] This application claims priority to Japanese Patent Application No. 2024-032323 filed on March 4, 2024, and incorporates by reference all of the contents of said Japanese application.

[0002] Patent Document 1 discloses a multi-core connector including a multi-core optical fiber (hereinafter, multi-core optical fiber will be referred to as "MCF").

[0003] JP 2015-052704 A

[0004] A connection method according to one embodiment of the present disclosure comprises the steps of preparing a first optical fiber member including a target element to be rotationally aligned at a position offset from the central axis on its end face, and a plurality of second optical fiber members, each including a target element to be rotationally aligned at a position offset from the central axis on its end face; performing rotational alignment by rotating the first optical fiber member by a predetermined rotation angle around the central axis of the first optical fiber member so as to reduce the amount of deviation of the target element included in one second optical fiber member among the plurality of second optical fiber members arranged side by side; and connecting the end face of the first optical fiber member to the end face of one second optical fiber member, wherein the one second optical fiber member is not rotated in the rotational alignment step.

[0005] FIG. 1 is a plan view showing a schematic configuration of a measurement system including a splicing device according to one embodiment. FIG. 2A is a cross-sectional view of a measurement target fiber taken along line IIa-IIa in FIG. 1. FIG. 2B is a cross-sectional view of an input fiber taken along line IIb-IIb in FIG. 1. FIG. 3 is a cross-sectional view of a holder taken along line III-III in FIG. 1. FIG. 4 is a diagram showing functional components of the controller shown in FIG. 1. FIG. 5A is a diagram showing an end face of an input fiber. FIG. 5B is a diagram showing an end face of a measurement target fiber. FIG. 5C is a diagram for explaining the rotation angle of the input fiber required for rotational alignment. FIG. 6 is a flowchart showing steps for carrying out a splicing method according to one embodiment. FIG. 7 is a plan view showing a splicing device that carries out one step of FIG. 6. FIG. 8 is a plan view showing a splicing device that carries out another step of FIG. 6. FIG. 9 is a cross-sectional view showing a modified example of a support mechanism that supports a measurement target fiber.

[0006] [Problem to be Solved by the Present Disclosure] Conventionally, when inspecting a multi-core single-core optical fiber (hereinafter, single-core optical fiber will be referred to as "SCF") mounted in a cable, an operation of connecting a multi-core SCF to a single-core SCF connected to a measuring instrument has been performed in order to input measurement light from the measuring instrument into the multi-core SCF. In this operation, before connecting the multi-core SCF to the single-core SCF, the three-dimensional position of the multi-core SCF with respect to the single-core SCF is adjusted so that the positions of the cores of the multi-core SCF coincide with the positions of the cores of the single-core SCF.

[0007] When testing a multi-fiber MCF as described above instead of a multi-fiber SCF, it is expected that the operation of splicing the multi-fiber MCF to a single-fiber MCF connected to a measuring instrument will be performed. This operation requires not only adjusting the three-dimensional position of the multi-fiber MCF relative to the single-fiber MCF to align the positions of the cores of the multi-fiber MCF with those of the cores of the single-fiber MCF, but also adjusting the rotational positions of the single-fiber MCF and the multi-fiber MCF. In this case, it is expected that the operation of dividing the multi-fiber MCF into multiple single-fiber MCFs will be required to adjust the rotational position of the multi-fiber MCF. The occurrence of such an operation may reduce the efficiency of the operation of splicing the single-fiber MCF and the multi-fiber MCF. It is also expected that the operation of rotating each of the multiple divided single-fiber MCFs will be required. This operation may also reduce the efficiency of the operation of splicing the single-fiber MCF and the multi-fiber MCF.

[0008] The present disclosure provides a connection method and a connection device that can improve work efficiency.

[0009] Effect of the Present Disclosure The connection method and connection device according to the present disclosure can improve work efficiency.

[0010] [Description of Embodiments of the Present Disclosure] First, the contents of the embodiments of the present disclosure will be listed and described.

[0011] (1) A connection method according to one embodiment of the present disclosure includes the steps of: preparing a first optical fiber member including a target element to be rotationally aligned at a position offset from the central axis on its end face; and preparing a plurality of second optical fiber members, each including a target element to be rotationally aligned at a position offset from the central axis on its end face; performing rotational alignment by rotating the first optical fiber member by a predetermined rotation angle around the central axis of the first optical fiber member so as to reduce the amount of deviation of the target element included in one of the plurality of second optical fiber members arranged side by side relative to the target element included in one second optical fiber member; and connecting the end face of the first optical fiber member to the end face of one second optical fiber member, wherein the one second optical fiber member is not rotated in the rotational alignment step.

[0012] For example, when inspecting a plurality of second optical fiber members bundled together, a task of connecting a first optical fiber member connectable to a measuring instrument to a second optical fiber member is required to input measurement light into one of the plurality of second optical fiber members. To connect the first optical fiber member to the second optical fiber member, a rotational alignment task is required to adjust the rotational positions of the first optical fiber member and the second optical fiber member. In the above-described connection method, the rotational position of the first optical fiber member relative to the second optical fiber member is adjusted by rotating only the first optical fiber member by a predetermined rotation angle without rotating the second optical fiber member. When rotational alignment of only the first optical fiber member is performed in this manner, even when a plurality of second optical fiber members are bundled, there is no need to separate the plurality of second optical fiber members one by one. This reduces the effort required for the rotational alignment task compared to when rotational alignment of a plurality of second optical fiber members is performed. Furthermore, when rotational alignment of only the first optical fiber member is performed in this manner, there is no need to rotate each of the plurality of second optical fiber members. This reduces the effort required for the rotational alignment task compared to when rotational alignment of a plurality of second optical fiber members is performed. These features improve the efficiency of the task of connecting a first optical fiber member to a second optical fiber member.

[0013] (2) The splicing method described in (1) above may further include the steps of capturing an image of an end face of one second optical fiber member, detecting a rotational position of a target element included in one second optical fiber member using the image of the end face of the one second optical fiber member, and calculating a deviation of the rotational position of the target element included in the first optical fiber member relative to the rotational position of the target element included in one second optical fiber member as a predetermined rotation angle. In this case, the calculation of the rotation angle of the first optical fiber member can be automated, thereby improving the efficiency of the work of rotationally aligning the first optical fiber member.

[0014] (3) In the step of performing rotational alignment in the connection method described in (1) or (2), the holder that holds the first optical fiber member may be rotated by a predetermined rotation angle by a motor. In this case, the operation of rotating the first optical fiber member by the predetermined rotation angle can be automated, thereby further improving the efficiency of the operation of rotational alignment of the first optical fiber member.

[0015] (4) A splicing device for implementing the splicing method described in any one of (1) to (3) above, comprising: a support mechanism for supporting a plurality of second optical fiber members arranged side by side; and a rotational alignment mechanism for supporting a first optical fiber member arranged facing one second optical fiber member and rotatably holding the first optical fiber member around the central axis of the first optical fiber member, wherein the first optical fiber member is held by the rotational alignment mechanism in a state rotated by a predetermined rotation angle, and an end face of the first optical fiber member is connected to an end face of one second optical fiber member. With this splicing device, rotational alignment of the first optical fiber member relative to the second optical fiber member can be performed by rotating only the first optical fiber member without rotating the second optical fiber member. When rotational alignment of only the first optical fiber member is performed in this manner, even if multiple second optical fiber members are bundled, there is no need to separate the multiple second optical fiber members one by one, thereby reducing the effort required for the rotational alignment compared to when multiple second optical fiber members are rotationally aligned. Furthermore, when rotational alignment of only the first optical fiber member is performed in this manner, there is no need to rotate each of the multiple second optical fiber members, thereby reducing the effort required for the rotational alignment compared to when multiple second optical fiber members are rotationally aligned. These features make it possible to improve the efficiency of the work of connecting the first optical fiber member to the second optical fiber member.

[0016] (5) In the connection device described in (4) above, each of the plurality of second optical fiber members may include a front portion including an end face and a rear portion excluding the front portion, the front portion of each of the plurality of second optical fiber members may be supported by a support mechanism, and the front portions of each of the plurality of second optical fiber members may be bundled with a resin material. With this configuration, when rotationally aligning the second optical fiber member, the plurality of second optical fiber members may be separated one by one, which eliminates the need for labor, and the above-mentioned effects may be fully exerted.

[0017] (6) In the connection device described in (4) above, each of the plurality of second optical fiber members may include a front portion including an end face and a rear portion excluding the front portion, the front portion of each of the plurality of second optical fiber members may be supported by a support mechanism, and the rear portions of each of the plurality of second optical fiber members may be bundled with a resin material. With this configuration, when rotationally aligning the second optical fiber member, the plurality of second optical fiber members may be separated one by one, which eliminates the need for labor, and the above-mentioned effects may be fully exerted.

[0018] (7) In the connection device described in (4) above, each of the plurality of second optical fiber members may include a front portion including an end face and a rear portion excluding the front portion, the front portion of each of the plurality of second optical fiber members may be supported by a support mechanism, and the front portion and the rear portion of each of the plurality of second optical fiber members may be bundled with a resin material. With this configuration, when rotationally aligning the second optical fiber member, the plurality of second optical fiber members may be separated one by one, which is time-consuming, and therefore the above-mentioned effect can be fully exhibited.

[0019] (8) In the connection device described in any one of (4) to (7) above, the rotational alignment mechanism may include a holder that holds the first optical fiber member, a motor coupled to the holder, and a controller that is communicatively connected to the motor and controls the rotation angle of the motor so that the holder rotates by a predetermined rotation angle. In this case, the operation of rotating the first optical fiber member by the predetermined rotation angle can be automated, thereby improving the efficiency of the operation of rotational alignment of the first optical fiber member.

[0020] (9) In the connection device described in (8) above, the rotational alignment mechanism may further include an imaging unit that images an end face of one of the second optical fiber members, and the controller may include a detection unit that detects the rotational position of the target element of the second optical fiber member using the image of the end face of one of the second optical fiber members, a calculation unit that calculates, as a predetermined rotation angle, a deviation of the rotational position of the target element included in the first optical fiber member relative to the rotational position of the target element included in one of the second optical fiber members, and an output unit that outputs a control signal to the motor to rotate the holder by the predetermined rotation angle. In this case, the operation of calculating the rotation angle of the first optical fiber member can be automated, thereby further improving the efficiency of the operation of rotational aligning the first optical fiber member.

[0021] (10) In the connection device described in (8) or (9), the holder may include a holder portion that holds the first optical fiber member, a rotating portion that is connected to the holder portion and is rotatable around the central axis of the first optical fiber member in response to rotation of the motor, a driving force transmitting portion that transmits the rotational driving force of the motor to the rotating portion, and a rotation support portion that rotatably supports the rotating portion. In this case, it is easy to implement a configuration that automatically rotates the first optical fiber member by a predetermined rotation angle around the central axis.

[0022] (11) In the connection device described in (10), the holder may include a support base having a V-groove for supporting the first optical fiber member, and a lid placed on the support base to cover the first optical fiber member. In this case, the first optical fiber member can be easily set in the holder.

[0023] (12) In the connection device described in (10) or (11) above, the driving force transmission unit may be a plurality of gear grooves formed on the outer peripheral surface of the rotating unit, which makes it possible to more reliably rotate the first optical fiber member by a predetermined rotation angle around the central axis using a motor.

[0024] (13) In the connection device described in (12) above, the rotation support unit may include a cylindrical first rotation guide unit coupled to the rotating unit and rotatable around the central axis together with the rotating unit, and a second rotation guide unit including a guide hole into which the first rotation guide unit is inserted, and a gap may be provided between the inner circumferential surface of the guide hole and the outer circumferential surface of the first rotation guide unit. In this case, rotation of the first rotation guide unit relative to the second rotation guide unit is permitted while reducing the risk that the rotation center of the first rotation guide unit will be significantly misaligned with the central axis of the first optical fiber member. As a result, a configuration in which the first optical fiber member is rotated around the central axis by a predetermined rotation angle using a motor can be more reliably implemented.

[0025] (14) In the connection device described in (13), the holder may include a slit formed across the rotating part and the rotation support part and extending in a direction intersecting the direction in which the first optical fiber member extends, and a portion of the first optical fiber member extending from the holder part to the rotation support part may be disposed in the slit. In this case, the first optical fiber member can be easily set in the holder by moving the first optical fiber member along the slit.

[0026] (15) In the splicing device described in any one of (4) to (14) above, the support mechanism may include a support base portion having a plurality of V-grooves formed therein that support the plurality of second optical fiber members, and a support base accommodating portion having an accommodating recess for accommodating the support base portion. In this case, by removing the support base portion from the support base accommodating portion, it can be replaced with another support base portion having a plurality of V-grooves formed therein that have a different arrangement pitch and size from the plurality of V-grooves. In this way, by replacing the support base portion with another support base portion, the arrangement pitch and size of the plurality of V-grooves can be freely adjusted. Therefore, by preparing multiple types of support base portions having V-grooves formed therein that match the arrangement pitch and outer diameter of multiple types of second optical fiber members, it is possible to accommodate multiple types of second optical fiber members simply by changing the support base portion.

[0027] (16) In the splicing device according to any one of (4) to (15), each of the first optical fiber member and the plurality of second optical fiber members may be any one of a multi-core optical fiber, a polarization-maintaining fiber, and a bundle fiber. In this case, when splicing the end face of the first optical fiber member to the end face of the second optical fiber member, rotational alignment of the first optical fiber member with respect to the second optical fiber member is required, so that the above-mentioned effects can be fully exhibited.

[0028] [Details of the Embodiments of the Present Disclosure] Specific examples of connection methods and connection devices according to embodiments of the present disclosure will be described below with reference to the drawings. The present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims. In the following description, the same elements in the drawings will be given the same reference numerals, and duplicate descriptions will be omitted as appropriate.

[0029] 1 is a plan view showing a schematic configuration of a measurement system 1 including a connection device according to this embodiment. As shown in FIG. 1, the measurement system 1 includes a measurement device 3 and a connection device 5.

[0030] The measurement device 3 is a device that measures the optical characteristics of the multi-core optical fiber 12 to be measured. The measurement device 3 measures the optical characteristics of the multi-core optical fiber 12 using, for example, an optical time domain reflectometer (OTDR). In this case, the measurement device 3 incidents measurement light Lm onto an end face 2a of one single-core optical fiber F2 among the plurality of single-core optical fibers F2 included in the multi-core optical fiber 12 and receives the light returning from the end face 2a. The measurement device 3 then measures optical characteristics such as light loss or crosstalk occurring in the single-core optical fiber F2 based on the intensity of the received light. The measurement device 3 may incident measurement light Lm onto the single-core optical fiber F2 from the end face 2a and measure the optical characteristics of the single-core optical fiber F2 based on the intensity of light emitted from another end face (not shown) of the single-core optical fiber F2 located opposite the end face 2a. The end face 2a is an end face of the single-core optical fiber F2 along the X direction, which is the longitudinal direction of the single-core optical fiber F2. Hereinafter, one single-core optical fiber F2 to be measured will be referred to as the "measurement target fiber F2" (second optical fiber member).

[0031] 2A is a cross-sectional view of multiple measurement target fibers F2 taken along line IIa-IIa in FIG. 1. As shown in FIG. 2A, each of the multiple measurement target fibers F2 extends along the X direction and is arranged along the Y direction, which is perpendicular to the X direction. Each measurement target fiber F2 is an optical fiber component that requires rotational alignment. In this embodiment, a case where the measurement target fiber F2 is an MCF is exemplified as an optical fiber component that requires rotational alignment. The measurement target fiber F2 includes a glass fiber 21 and a coating resin 22 that coats the outer peripheral surface of the glass fiber 21. The glass fiber 21 includes multiple cores 21a and a cladding 21b. The cladding 21b is a common cladding that surrounds the multiple cores 21a.

[0032] The multiple cores 21a are arranged at positions offset from the central axis C2 in a cross section perpendicular to the central axis C2 of the measurement target fiber F2. Fig. 2A illustrates four cores 21a, with all of the cores 21a arranged at positions offset from the central axis C2. The number and arrangement of cores included in the measurement target fiber F2 are not limited to the example shown in Fig. 2A and can be changed as appropriate. For example, the measurement target fiber F2 may include a central core arranged on the central axis C2 in addition to peripheral cores arranged around the central axis C2. The number of cores included in the measurement target fiber F2 may be two, or may be five or more.

[0033] The multiple cores 21a are refractive index change portions having a different refractive index from the cladding 21b. When the measurement target fiber F2 has a refractive index change portion located at a position offset from the central axis C2, the measurement target fiber F2 needs to be rotationally aligned around the central axis C2. In addition to MCF, examples of optical fiber components that require rotational alignment include bundle fibers and polarization-maintaining fibers. Polarization-maintaining fibers include a core located at the central axis of the polarization-maintaining fiber and a stress-applying portion located at a position offset from the central axis. In a bundle fiber, multiple SMFs are bundled, and the core of at least one SMF is located at a position offset from the central axis of the bundle fiber. The cores of the bundle fiber and the stress-applying portion of the polarization-maintaining fiber are each refractive index change portions having a different refractive index from the cladding. Therefore, if the cores and stress-applying portions are considered refractive index change portions, an optical fiber component that requires rotational alignment includes a refractive index change portion located at a position offset from the central axis.

[0034] As shown in FIG. 1 , the measurement apparatus 3 includes a measuring instrument 33 and a fan-in / fan-out (FIFO) device 35. The measuring instrument 33 uses the FIFO device 35 to input measurement light Lm to the end face 2a of the measurement target fiber F2 and measure the light returning to the end face 2a. A single-core optical fiber F1 connected to the measurement target fiber F2 and a single-core optical fiber F3 connected to the measuring instrument 33 are connected to the FIFO device 35. The single-core optical fiber F1 is, for example, an input MCF for inputting the measurement light Lm into the measurement target fiber F2. Hereinafter, the single-core optical fiber F1 will be referred to as the "input fiber F1" (first optical fiber member) in the following description.

[0035] The end face 1a of the incident fiber F1 faces the end face 2a of the measurement target fiber F2 along the X direction. The incident fiber F1 has the same outer diameter as the measurement target fiber F2. The end face 1a of the incident fiber F1 faces and is connected to the end face 2a of the measurement target fiber F2. "The end face 1a is connected to the end face 2a" includes both a case where the end face 1a is directly connected to the end face 2a and a case where the end face 1a is indirectly connected to the end face 2a via another member.

[0036] 2B is a cross-sectional view of the input fiber F1 taken along line IIb-IIb in FIG. 1. As shown in FIG. 2B, the input fiber F1, like the measurement target fiber F2, is an MCF that requires rotational alignment. The input fiber F1 includes a glass fiber 31 and a coating resin 32 that coats the outer surface of the glass fiber 31. The glass fiber 31 includes multiple cores 31a and a clad 31b. The clad 31b is a common clad that surrounds the multiple cores 31a. The multiple cores 31a are arranged at positions offset from the central axis C1 of the input fiber F1 in a cross section perpendicular to the central axis C1. Each core 31a is arranged at a position corresponding to each core 21a (see FIG. 2A) of the measurement target fiber F2 and is optically connected to each core 21a.

[0037] The incident fiber F1 includes, for example, four cores 31a corresponding to the four cores 21a of the measurement target fiber F2. All of the cores 31a are arranged at positions offset from the central axis C1. The number and arrangement of cores included in the incident fiber F1 are not limited to the example shown in FIG. 2B and can be changed as appropriate. For example, the incident fiber F1 may include a central core arranged at the central axis C1 in addition to peripheral cores arranged around the central axis C1. The number of cores included in the incident fiber F1 may be two, five or more. Like the measurement target fiber F2, the incident fiber F1 may be any optical fiber member that includes a refractive index change portion at a position offset from the central axis, and may be, for example, a bundle fiber or a polarization-maintaining fiber.

[0038] As shown in FIG. 1 , the single-core optical fiber F3 connected to the measuring instrument 33 is, for example, an SCF. The single-core optical fiber F3 is optically connected to one of the multiple cores 31 a of the input fiber F1, namely, a core 31 a (see FIG. 2B ) that corresponds to the core 21 a (see FIG. 2A ) to be measured of the measurement target fiber F2. The measurement light Lm emitted from the measuring instrument 33 and received by the single-core optical fiber F3 passes through the input fiber F1 and is incident on the end face 2 a of the measurement target fiber F2. The light that passes through the measurement target fiber F2 and returns to the end face 2 a from the measurement target fiber F2 passes through the input fiber F1 and the single-core optical fiber F3 and is received by the measuring instrument 33. The measuring instrument 33 measures the optical characteristics of the measurement target fiber F2 based on the received light.

[0039] The splicing device 5 splices the incident fiber F1 to the measurement target fiber F2. The splicing device 5 splices the end face 1a of the incident fiber F1 to the end face 2a of the measurement target fiber F2 with the end face 1a of the incident fiber F1 facing the end face 2a of the measurement target fiber F2. With the end face 1a connected to the end face 2a, the central axis C1 of the incident fiber F1 coincides with the central axis C2 of the measurement target fiber F2, and each core 21a of the incident fiber F1 is optically connected to each core 31a of the measurement target fiber F2 (see FIGS. 2A and 2B ). The splicing device 5 may splice the end face 1a of the incident fiber F1 to the end face 2a of the measurement target fiber F2 simply by butting the end face 1a of the incident fiber F1 against the end face 2a of the measurement target fiber F2.

[0040] The splicing device 5 includes a rotary alignment mechanism 51 that supports the incident fiber F1 and a support mechanism 52 that supports the multiple measurement target fibers F2. The rotary alignment mechanism 51 holds the incident fiber F1 so that it can be rotated and aligned. That is, the rotary alignment mechanism 51 holds the incident fiber F1 rotatably around the central axis C1. The support mechanism 52 is, for example, a resin support base on which the multiple measurement target fibers F2 are placed. The support mechanism 52 only needs to have the function of supporting the multiple measurement target fibers F2, and does not need to hold each measurement target fiber F2 rotatably around the central axis C2. For example, each measurement target fiber F2 may be arranged on the support mechanism 52 so that it does not rotate around the central axis C2. For example, each measurement target fiber F2 may be fixed to the support mechanism 52 with an adhesive, or each measurement target fiber F2 may be fixed to the support mechanism 52 by using a top cover to press each measurement target fiber F2 against the support mechanism 52. In this way, the connection device 5 may be configured to rotate and align only the incident fiber F1 of the incident fiber F1 and the measurement target fiber F2.

[0041] The support mechanism 52 is fixed so as not to move in, for example, the X, Y, and Z directions. The support mechanism 52 may be mounted on a stage that is movable along the X, Y, and Z directions, in which case the three-dimensional position of the measurement target fiber F2 can be adjusted. The support mechanism 52 supports the front portion P21 of each measurement target fiber F2 arranged along the Y direction. The rear portion P22 of each measurement target fiber F2 that is not supported by the support mechanism 52 is bundled with the rear portions of the other measurement target fibers F2 by a tape-shaped resin material 13. The front portion P21 is a portion of the measurement target fiber F2 that includes the end face 2a. The rear portion P22 is a portion of the measurement target fiber F2 excluding the front portion P21. Instead of the rear portion P22 of each measurement target fiber F2, the front portion P21 may be bundled with the front portion of another measurement target fiber F2 by the resin material 13, or both the front portion P21 and the rear portion P22 may be bundled with another measurement target fiber F2 by the resin material 13.

[0042] 2A , the support mechanism 52 includes, for example, a support surface 522 on which a plurality of V-shaped grooves 521 are formed. The support surface 522 is, for example, a plane extending along the X and Y directions. The plurality of V-shaped grooves 521 extend in the X direction and are aligned along the Y direction in correspondence with the plurality of measurement target fibers F2. The plurality of measurement target fibers F2 are placed in the plurality of V-shaped grooves 521, respectively.

[0043] As shown in FIG. 1 , the rotational alignment mechanism 51 includes a holder 53, a motor 55, a controller 57, and an imaging unit 59. The holder 53 holds the incident fiber F1. The holder 53 is mounted on a stage that is movable along the X, Y, and Z directions. Therefore, the three-dimensional position of the incident fiber F1 is adjustable. The holder 53 is connected to the motor 55 and rotates around the central axis C1 by receiving the rotational driving force of the motor 55. The holder 53 rotates around the central axis C1 while holding the incident fiber F1. This adjusts the rotation angle of the incident fiber F1 around the central axis C1. In other words, rotational alignment of the incident fiber F1 is performed.

[0044] The holder 53 includes a holder portion 531, a rotating portion 532, and a rotation support portion 533. The holder portion 531 holds the input fiber F1. The rotating portion 532 is connected to the holder portion 531 in the X direction. The rotating portion 532 is formed, for example, as one piece with the holder portion 531. The rotating portion 532 rotates around the central axis C1 together with the holder portion 531 in response to rotation of the motor 55. The rotating portion 532 may be formed separately from the holder portion 531. The rotation support portion 533 is formed separately from the rotating portion 532 and the holder portion 531. The rotation support portion 533 supports the rotating portion 532 so that it can rotate around the central axis C1.

[0045] 2B , the holder unit 531 includes a support base 534 that supports the incident fiber F1 and a lid 535 that is placed on the support base 534 so as to cover the incident fiber F1. The support base 534 includes a support surface 534a in which a V-shaped groove 536 is formed. The support surface 534a is, for example, a plane extending along the X and Y directions. The V-shaped groove 536 extends along the X direction on the support surface 534a. The incident fiber F1 is placed in the V-shaped groove 536. With the incident fiber F1 placed in the V-shaped groove 536, the three-dimensional position of the holder 53 relative to the support mechanism 52 is adjusted so that the central axis C1 of the incident fiber F1 coincides with the central axis C2 of the measurement target fiber F2.

[0046] The lid 535 includes a lid inner surface 535a facing the support surface 534a. When the incident fiber F1 is placed in the V-groove 536, the incident fiber F1 contacts the lid inner surface 535a and the inner surface 536a of the V-groove 536. The incident fiber F1 is sandwiched between the lid 535 and the support base 534, and is thereby held in the holder portion 531 so as not to shift position relative to the holder portion 531. As shown in FIG. 1 , when the incident fiber F1 is held in the holder portion 531, an end face 1a of the incident fiber F1 protrudes from the holder 53 in the X direction. The end face 1a of the incident fiber F1 protruding from the holder 53 faces an end face 2a of the measurement target fiber F2 along the X direction.

[0047] FIG. 3 is a cross-sectional view of the holder 53 taken along line III-III in FIG. 1. FIG. 3 shows the rotating portion 532 of the holder 53 in cross section. As shown in FIG. 3, the rotating portion 532 is, for example, disk-shaped and centered on the central axis C1. A plurality of gear grooves 532b (rotation transmission portions) are formed on the outer peripheral surface 532a of the rotating portion 532 and aligned along the circumferential direction d1 centered on the central axis C1. The plurality of gear grooves 532b are, for example, equally spaced around the entire circumference of the outer peripheral surface 532a in the circumferential direction d1. Each gear groove 532b has, for example, a rectangular shape in a cross section perpendicular to the central axis C1. The cross-sectional shape of each gear groove 532b is not limited to a rectangular shape and may be other shapes.

[0048] Each gear groove 532b meshes with a gear connected to the motor 55 and transmits the rotational driving force of the motor 55 to the rotating unit 532. The method of transmitting the rotational driving force of the motor 55 is not limited to the method using gears. For example, the rotational driving force of the motor 55 may be transmitted to the rotating unit 532 using a rubber band. Any other transmission method may be used as long as it is capable of transmitting the rotational driving force of the motor 55 to the rotating unit 532. The rotating unit 532 receives the rotational driving force transmitted from the motor 55 via the multiple gear grooves 532b and rotates integrally with the holder unit 531 around the central axis C1. The rotation angle of the input fiber F1 held in the holder unit 531 is adjusted in accordance with this rotation. The "rotational transmission unit" in the present disclosure is not necessarily limited to the gear grooves 532b. For example, when a rubber band is used to transmit the rotational driving force of the motor to the rotating unit, the "rotational transmission unit" may be a simple flat surface or a groove that matches the thickness of the rubber band.

[0049] The rotation support portion 533 includes a first rotation guide portion 541 and a second rotation guide portion 542. The first rotation guide portion 541 is, for example, disposed on the opposite side of the rotating portion 532 from the holder portion 531 and is connected to the rotating portion 532 in the X direction. The first rotation guide portion 541 is, for example, cylindrical and has a larger outer diameter than the rotating portion 532. When a rotational driving force is transmitted from the motor to the rotating portion 532, the rotation support portion 533 rotates integrally with the rotating portion 532 around the central axis C1. In this embodiment, the holder portion 531, the rotating portion 532, and the rotation support portion 533 are arranged in this order along the X direction, but the order of the holder portion 531, the rotating portion 532, and the rotation support portion 533 can be changed as needed, and other orders may also be used.

[0050] The second rotation guide unit 542 includes a guide hole 542a into which the first rotation guide unit 541 is inserted. The guide hole 542a includes an inner peripheral surface 542b that surrounds the outer peripheral surface 541a of the first rotation guide unit 541. The inner peripheral surface 542b faces the outer peripheral surface 541a of the first rotation guide unit 541 with a gap therebetween. The gap is provided so that rotation of the first rotation guide unit 541 is permitted and so that the central axis C1 of the incident fiber F1 does not significantly deviate from the central axis C2 of the measurement target fiber F2 when the first rotation guide unit 541 is inserted into the guide hole 542a. Grease may be provided in the gap to reduce frictional resistance between the inner peripheral surface 542b and the outer peripheral surface 541a. To improve sliding between the inner peripheral surface 542b and the outer peripheral surface 541a, for example, a bearing may be formed by arranging multiple balls in the gap.

[0051] A slit 53a for setting the incident fiber F1 is formed in the holder 53. The slit 53a is formed in one location of the holder 53 along the circumferential direction d1, and extends from the rotation support portion 533 to the rotating portion 532. The slit 53a is not formed in the holder portion 531, but is formed only in the rotating portion 532 and the rotation support portion 533. The slit 53a passes through the rotating portion 532 and the rotation support portion 533, and extends linearly in the radial direction d2 perpendicular to the central axis C1 from the outer surface 542c of the second rotation guide portion 542 to a position through which the incident fiber F1 passes. For example, when the holder 53 is viewed along the X direction in which the central axis C1 extends, the slit 53a extends from the outer surface 542c of the second rotation guide portion 542, through the second rotation guide portion 542, the first rotation guide portion 541, and the rotating portion 532 in which the multiple gear grooves 532b are formed, to a position where it reaches the input fiber F1. In the example shown in FIG. 3, the radial direction d2 coincides with the Z direction.

[0052] The slit 53a includes a slit 542d formed in the second rotation guide portion 542, a slit 541b formed in the first rotation guide portion 541, and a slit 532c formed in the rotating portion 532. The slit 542d extends in the radial direction d2 from the outer surface 542c of the second rotation guide portion 542 to the inner circumferential surface 542b. The slit 541b is formed on an extension line of the slit 542d in the first rotation guide portion 541. The slit 541b extends in the radial direction d2 from the outer circumferential surface 541a of the first rotation guide portion 541 to the center.

[0053] The slit portion 532c is formed at a position overlapping in the X direction with the slit portion 541b formed in the first rotation guide portion 541. The slit portion 532c extends along the radial direction d2 from the outer peripheral surface 532a of the rotating portion 532 to the center of the rotating portion 532. An incident fiber F1 extending from the holder portion 531 is disposed at the center of the rotating portion 532 and the center of the first rotation guide portion 541. The width of the slit 53a in the circumferential direction d1 is larger than the outer diameter of the incident fiber F1. The width of the slit 53a in the circumferential direction d1 is, for example, constant at each position along the radial direction d2 along which the slit 53a extends. The incident fiber F1 extending from the holder portion 531 passes through the slit portion 532c. The incident fiber F1 is separated from the inner surface of the slit portion 532c without contacting it.

[0054] When setting the incident fiber F1 in the holder 53, with the lid 535 of the holder unit 531 removed, the incident fiber F1 is moved along the slit 53a to the center of the rotating unit 532 and placed in a V-groove 536 formed in the support base 534. With the incident fiber F1 placed in the V-groove 536, the incident fiber F1 is positioned at the center of the rotating unit 532. In this state, the central axis C1 of the incident fiber F1 coincides with the center of the rotating unit 532. Thereafter, the lid 535 presses the incident fiber F1 against the support base 534, thereby holding the incident fiber F1 in the holder unit 531 so as not to be rotated out of position relative to the holder unit 531. The rotating unit 532, which is connected to the holder unit 531, rotates by receiving the rotational driving force of the motor 55. As a result, the input fiber F1 rotates together with the rotating portion 532, the first rotation guide portion 541, and the holder portion 531 around the central axis C1.

[0055] The controller 57 shown in FIG. 1 is communicatively connected to the motor 55 and the imaging unit 59. The imaging unit 59 is a camera capable of capturing an image of the end face 2 a of the measurement target fiber F2. The imaging unit 59 is movable relative to the measurement target fiber F2. The movement of the imaging unit 59 is controlled by, for example, the controller 57. The imaging unit 59 moves to a position facing the end face 2 a of the measurement target fiber F2 along the X direction. Then, with the measurement target fiber F2 irradiated with observation light, the imaging unit 59 captures an image of the end face 2 a of the measurement target fiber F2. The imaging unit 59 outputs an imaging signal S2 indicating an image of the end face 2 a to the controller 57.

[0056] After capturing an image of the end face 2 a of the measurement target fiber F2, the image capturing unit 59 moves to a position facing the end face 2 a of the next measurement target fiber F2 and outputs an image capturing signal S2 indicating an image of the end face 2 a to the controller 57. By repeating this operation, the image capturing unit 59 outputs image capturing signals S2 indicating images of the end faces 2 a of all measurement target fibers F2 included in the multi-core optical fiber 12 to the controller 57. The image capturing unit 59 may be disposed in a position facing the end face 2 a in an oblique direction inclined from the X direction, and may capture an image of the end face 2 a from that position. The image capturing unit 59 may be moved to a position facing the end face 1 a of the input fiber F1 and may capture an image of the end face 1 a.

[0057] The controller 57 receives an imaging signal S2 from the imaging unit 59 and generates a control signal S3 that controls the rotation angle of the motor 55. The controller 57 physically includes hardware such as one or more processors, a main memory device, an auxiliary memory device, an input device, an output device, and a communication device. The controller 57 is one or more computers that include this hardware and software such as a program. The controller 57 may be communicatively connected to at least one of a stage on which the support mechanism 52 is placed and a stage on which the holder 53 is placed, and may control the three-dimensional position of the incident fiber F1 relative to the measurement target fiber F2.

[0058] 4 is a diagram showing the functional components of the controller 57. The controller 57 includes, as functional components, a detection unit 571, a calculation unit 572, a storage unit 573, and an output unit 574. Each functional component of the controller 57 is implemented by executing a program on the hardware of the computer described above.

[0059] The detector 571 acquires an imaging signal S2 from the imaging unit 59. The detector 571 acquires the imaging signal S2 from the imaging unit 59 each time the imaging unit 59 captures an image of the measurement target fiber F2. The detector 571 detects the rotational position of the captured measurement target fiber F2 from the image of the end face 2a of the measurement target fiber F2 indicated by the imaging signal S2. For example, the detector 571 detects the core 21a of the measurement target fiber F2 as the target element to be rotationally aligned, and acquires the rotational position of the core 21a of the measurement target fiber F2. The detector 571 may detect an element other than the core 21a of the measurement target fiber F2 as the target element to be rotationally aligned. The detector 571 passes detection data D2 indicating the position of the core 21a of the measurement target fiber F2 to the calculator 572. The detector 571 may store the detection data D2 in the memory unit 573.

[0060] The storage unit 573 stores position data D1 indicating, for example, the position of the core 31a as a target element to be rotationally aligned for the incident fiber F1. The position data D1 can be acquired from an image of the end face 1a of the incident fiber F1 captured using, for example, the imaging unit 59 or another imaging unit. The storage unit 573 passes the position data D1 to the calculation unit 572. The calculation unit 572 uses the position data D1 and the detection data D2 to calculate the rotation angle (rotation amount) of the incident fiber F1 required to align the position of the core 31a of the incident fiber F1 with the position of the core 21a of the measurement target fiber F2.

[0061] Fig. 5A is a diagram showing the end face 1a of the incident fiber F1. Fig. 5B is a diagram showing the end face 2a of the measurement target fiber F2. Fig. 5C is a diagram for explaining the rotation angle of the incident fiber F1 required for rotational alignment. In Fig. 5A, four cores 31a (see Fig. 2B) exposed from the end face 1a of the incident fiber F1 are distinguished by being referred to as core N1 to core N4. In Fig. 5B, four cores 21a (see Fig. 2A) exposed from the end face 2a of the measurement target fiber F2 are distinguished by being referred to as core n1 to core n4.

[0062] In FIG. 5A, a line passing through the central axis C1 and the center of core N1 is defined as a reference line L1. The deviation from the reference line L1 in a first direction is represented by "+θ," and the deviation from the reference line L1 in a second direction, which is opposite to the first direction, is represented by "-θ." In this case, the deviation of the center position of core N1 from the reference line L1 is zero (θ = 0). In FIG. 5B, a line passing through the central axis C2 and the center of core n1 is shown as a reference line L2. The reference line L1 described above is also shown in FIG. 5B. The position of core n1 of the measurement target fiber F2 can be represented by θt (θ = θt), which is the deviation of the reference line L2 from the reference line L1.

[0063] 5C , by rotating the incident fiber F1 by a rotation angle θt in the "+θ" direction relative to the measurement target fiber F2, the positions of cores N1 to N4 of the incident fiber F1 can be made to coincide with cores n1 to n4 of the measurement target fiber F2. In this case, the calculation unit 572 shown in FIG. 1 calculates the rotation angle of the incident fiber F1 required to align the position of core 21a of the measurement target fiber F2 with the position of core 31a of the incident fiber F1 as θt. The calculation unit 572 passes rotation angle data D3 indicating the rotation angle θt to the output unit 574.

[0064] The output unit 574 outputs a control signal S3 to the motor 55 to rotate the incident fiber F1 by a rotation angle θt. In response to the control signal S3, the motor 55 rotates an angle required to rotate the incident fiber F1 by the rotation angle θt. In response to this rotation of the motor 55, the incident fiber F1 held by the holder 53 rotates around the central axis C1 by the rotation angle θt. This performs rotational alignment of the incident fiber F1 with respect to the measurement target fiber F2. Thereafter, the end face 1a of the rotationally aligned incident fiber F1 is connected to the end face 2a of the measurement target fiber F2.

[0065] A connection method performed using the above-described connection device 5 will be described with reference to Fig. 6 to Fig. 8. Fig. 6 is a flowchart showing each step for performing the connection method of this embodiment. Fig. 7 is a plan view showing the connection device 5 performing step S11 of Fig. 6. Fig. 8 is a plan view showing the connection device 5 performing step S14 of Fig. 6.

[0066] First, the above-described incident fiber F1 and multiple measurement target fibers F2 are prepared (step S10 in FIG. 6). The multiple measurement target fibers F2 are supported by a support mechanism 52, and the incident fiber F1 is supported by a rotation alignment mechanism 51 (see FIG. 1). Then, the three-dimensional position of the holder 53 relative to the support mechanism 52 is adjusted so that the end face 1a of the incident fiber F1 faces the end face 2a of one of the measurement target fibers F2.

[0067] Next, the imaging unit 59 images the end face 2 a of the first measurement target fiber F2 (step S11 in FIG. 6 ). At this time, for example, as shown in FIG. 7 , the imaging unit 59 images the end face 2 a of the first measurement target fiber F2, then moves to a position facing the end face 2 a of the second measurement target fiber F2, and images the end face 2 a of the second measurement target fiber F2. By repeating this operation, the imaging unit 59 images the end face 2 a of each measurement target fiber F2 in sequence. The imaging unit 59 outputs an imaging signal S2 indicating the image of the end face 2 a to the controller 57. After the imaging unit 59 images the end face 2 a of the first measurement target fiber F2, the operation of the imaging unit 59 to image the end faces 2 a of the remaining measurement target fibers F2 may be performed simultaneously in parallel with the next steps S12 to S15 being performed on the first measurement target fiber F2. The image capturing section 59 does not have to capture the image of the end face 2a of each measurement target fiber F2 in sequence, but may capture the image of the end faces 2a of all measurement target fibers F2 simultaneously.

[0068] Next, the controller 57 detects the rotational position of the imaged first fiber to be measured F2 (step S12 in FIG. 6). For example, the detector 571 of the controller 57 detects the rotational position of the core 21 a of the fiber to be measured F2 from the end face 2 a of the fiber to be measured F2 indicated by the image signal S2.

[0069] Next, the controller 57 calculates the rotation angle of the incident fiber F1 required to align the rotational position of the incident fiber F1 with the detected rotational position of the first measurement target fiber F2 (step S13 in FIG. 6). For example, the calculation unit 572 of the controller 57 calculates θt, which is the amount of deviation of the reference line L2 indicating the position of the core n1 of the measurement target fiber F2 from the reference line L1 indicating the position of the core N1 of the incident fiber F1, as the rotation angle of the incident fiber F1 required for rotational alignment (see FIG. 5C).

[0070] Next, the controller 57 rotationally aligns the incident fiber F1 (step S14 in FIG. 6 ). For example, as shown in FIG. 8 , the output unit 574 of the controller 57 outputs a control signal S3 to the motor 55 to rotate the incident fiber F1 by a rotation angle θt. In response to the control signal S3, the motor 55 rotates an angle required to rotate the incident fiber F1 by the rotation angle θt. In response to this rotation of the motor 55, the incident fiber F1 rotates around the central axis C1 by the rotation angle θt. As a result, the position of the core 31a of the incident fiber F1 coincides with the position of the core 21a of the first measurement target fiber F2, and the incident fiber F1 is rotationally aligned with respect to the core 21a of the first measurement target fiber F2. The multiple measurement target fibers F2, including the first measurement target fiber F2, remain stationary without being rotationally aligned. Therefore, in this embodiment, of the incident fiber F1 and the measurement target fibers F2, only the incident fiber F1 is rotationally aligned.

[0071] Next, the splicing device 5 splices the rotationally aligned incident fiber F1 to the first measurement target fiber F2 (step S15 in FIG. 6 ). For example, while maintaining the rotational position of the incident fiber F1, the splicing device 5 adjusts the three-dimensional position of the incident fiber F1 relative to the first measurement target fiber F2 so that the end face 1 a of the incident fiber F1 is butted against the end face 2 a of the first measurement target fiber F2. As a result, the end face 1 a of the incident fiber F1 is spliced ​​to the end face 2 a of the first measurement target fiber F2, and the core 31 a of the incident fiber F1 is optically connected to the core 21 a of the first measurement target fiber F2. Steps S12 to S15 are then repeatedly performed for the remaining measurement target fibers F2, thereby sequentially splicing the incident fibers F1 to the remaining measurement target fibers F2.

[0072] When inspecting the measurement target fiber F2, the measurement device 3 measures the optical characteristics of the measurement target fiber F2 by irradiating the measurement light Lm from the incident fiber F1 to the measurement target fiber F2 after step S15. The measurement device 3 measures the optical characteristics of a plurality of measurement target fibers F2 by performing the above measurement each time steps S12 to S15 are repeated.

[0073] The effects obtained by the connection method and connection device 5 according to this embodiment described above will now be described.

[0074] In this embodiment, rotational alignment of the incident fiber F1 with respect to the measurement target fiber F2 is performed by rotating only the incident fiber F1 without rotating the measurement target fiber F2. In this case, even if multiple measurement target fibers F2 are bundled with the resin material 13, there is no need to separate the multiple measurement target fibers F2 one by one for rotational alignment, which reduces the effort required for the rotational alignment compared to rotating and aligning multiple measurement target fibers F2 one by one. Furthermore, when rotational alignment of only the incident fiber F1 is performed in this manner, there is no need to rotate each of the multiple measurement target fibers F2, which reduces the effort required for the rotational alignment compared to rotating and aligning multiple measurement target fibers F2. These factors improve the efficiency of the operation when splicing the incident fiber F1 to the measurement target fiber F2.

[0075] As in this embodiment, the rear portions P22 of the plurality of measurement target fibers F2 may be bundled with the resin material 13. In this configuration, when the plurality of measurement target fibers F2 are rotationally aligned, the plurality of measurement target fibers F2 does not have to be separated one by one, and therefore the above-described effects can be fully exhibited.

[0076] As in the present embodiment, the rotational alignment mechanism 51 may include a holder 53 that holds the incident fiber F1, a motor 55 that is connected to the holder 53, and a controller 57 that is communicatively connected to the motor 55 and controls the rotation angle of the motor 55 so that the holder 53 rotates by a predetermined rotation angle θt. In this case, the operation of rotating the incident fiber F1 by the predetermined rotation angle θt can be automated, thereby improving the efficiency of the operation of rotational aligning the incident fiber F1.

[0077] As in the present embodiment, the controller 57 may include a detection unit 571 that detects the rotational position of the core 21 a of the end face 2 a of the measurement target fiber F2 using an image of the end face 2 a of the measurement target fiber F2, a calculation unit 572 that calculates, as a predetermined rotation angle θt, the deviation of the rotational position of the core 31 a of the end face 1 a of the incident fiber F1 from the rotational position of the core 21 a of the end face 2 a of the measurement target fiber F2, and an output unit 574 that outputs a control signal S3 to the motor 55 to rotate the holder 53 by the predetermined rotation angle θt. In this case, the operation of calculating the rotation angle θt of the incident fiber F1 can be automated, thereby further improving the efficiency of the operation of rotationally aligning the incident fiber F1.

[0078] As in the present embodiment, the holder 53 may include a holder portion 531 that holds the incident fiber F1, a rotating portion 532 that is connected to the holder portion 531 and is rotatable around the central axis C1 of the incident fiber F1 in response to rotation of the motor 55, a plurality of gear grooves 532b that transmit the rotational driving force of the motor 55 to the rotating portion 532, and a rotation support portion 533 that rotatably supports the rotating portion 532. In this case, it is possible to easily implement a configuration that automatically rotates the incident fiber F1 by a predetermined rotation angle θt around the central axis C1.

[0079] As in this embodiment, the holder part 531 may include a support base 534 having a V-shaped groove 536 for supporting the incident fiber F1, and a lid 535 that is placed on the support base 534 so as to cover the incident fiber F1. In this case, the incident fiber F1 can be easily set in the holder part 531.

[0080] As in the present embodiment, a plurality of gear grooves 532b may be formed on the outer circumferential surface 532a of the rotating portion 532. In this case, it is possible to more reliably implement a configuration in which the input fiber F1 is rotated by the predetermined rotation angle θt around the central axis C1 using the motor 55.

[0081] As in the present embodiment, a gap may be formed between the outer peripheral surface 541a of the first rotation guide part 541 and the inner peripheral surface 542b of the guide hole 542a. In this case, it is possible to reduce the risk that the center of rotation of the first rotation guide part 541 will be significantly misaligned from the central axis C1 of the incident fiber F1 while allowing rotation of the first rotation guide part 541 relative to the second rotation guide part 542. As a result, it is possible to more reliably implement a configuration in which the incident fiber F1 is rotated by the predetermined rotation angle θt around the central axis C1 using the motor 55.

[0082] As in the present embodiment, the holder 53 includes a slit 53a formed across the rotating portion 532, the first rotation guide portion 541, and the second rotation guide portion 542, and extending along the radial direction d2 intersecting the incident fiber F1, and a portion of the incident fiber F1 extending from the holder portion 531 to the rotation support portion 533 may be disposed in the slit 53a. In this case, the incident fiber F1 can be easily set in the holder 53 by moving the incident fiber F1 along the slit 53a.

[0083] As in this embodiment, the input fiber F1 and the measurement target fiber F2 may each be an MCF. In this case, when connecting the end face 1a of the input fiber F1 to the end face 2a of the measurement target fiber F2, rotational alignment of the input fiber F1 with respect to the measurement target fiber F2 is required, so the above-mentioned effects can be fully exerted.

[0084] The connection method and connection device 5 of the present disclosure are not limited to the above-described embodiment, and may be modified within the scope of the claims.

[0085] FIG. 9 is a cross-sectional view showing a modified example of the support mechanism 52 that supports the measurement target fiber F2. The support mechanism 52A shown in FIG. 9 includes a support base 52a and a support base housing 52b that houses the support base 52a. The support base 52a is a base member in which the above-mentioned multiple V-grooves 521 are formed. The support base housing 52b is a housing member formed separately from the support base 52a. The support base housing 52b includes a housing recess 52d that can house the support base 52a. The housing recess 52d is recessed in the Z direction from the upper surface 52c of the support base housing 52b. The bottom surface 52e of the support base 52a is placed in the housing recess 52d. The support base 52a is detachable from the support base housing 52b. Even with this configuration, the same effects as those of the above-described embodiment can be obtained.

[0086] Furthermore, by using the support mechanism 52A shown in FIG. 9 , the support base 52a can be removed from the support base housing 52b. In this case, the support base 52a removed from the support base housing 52b can be replaced with another support base on which a different plurality of V-grooves having an arrangement pitch and size different from the above-described plurality of V-grooves 521 are formed. In this way, by replacing the support base 52a with a different support base, the arrangement pitch and size of the multiple V-grooves can be freely adjusted. Therefore, by preparing multiple types of support bases on which V-grooves are formed to match the arrangement pitches and outer diameters of multiple types of measurement target fibers, multiple types of measurement target fibers F2 can be accommodated simply by replacing the support base.

[0087] The present disclosure is not limited to the above-described embodiments and modifications, and various other modifications are possible. In the above-described embodiments and modifications, the case where the input fiber F1 and the measurement target fiber F2 are each an "MCF" has been described. However, the "first optical fiber member" and the "second optical fiber member" of the present disclosure may be other optical fiber members that require rotational alignment, such as a "polarization-maintaining fiber" or a "bundle fiber." When at least one of the "first optical fiber member" and the "second optical fiber member" is defined as a "bundle fiber," the "bundle fiber" formed by bundling multiple SCFs does not correspond to each of the multiple SCFs included in the "bundle fiber" as an "optical fiber member."

[0088] In the above-described embodiment and modified examples, the "core 31 a" of the input fiber F1 and the "core 21 a" of the measurement target fiber F2 are described as the "target element to be rotationally aligned" of the present disclosure. However, the "target element to be rotationally aligned" of the present disclosure does not have to be the "core" of the optical fiber member. For example, it may be a "marker" formed on the end face of the optical fiber member, or a "stress-applying portion" if the optical fiber member is a polarization-maintaining fiber. In the above-described embodiment and modified examples, the connection device 5 applied to the measurement system 1 has been described. However, the "connection device" of the present disclosure is not limited to the measurement system 1 and may be applied to other systems.

[0089] In the above-described embodiment and modified example, steps S11 to S15 in FIG. 6 are automatically performed by the connection device 5. However, for example, steps S10, S14, and S15 may be performed manually. In this case, steps S11 to S13 may be omitted. For example, with the end face 1 a of the incident fiber F1 facing the end face 2 a of the measurement object fiber F2, while the measurement light is incident from the incident fiber F1 to the measurement object fiber F2, rotation of only the incident fiber F1 may be performed to maximize the optical coupling efficiency between the incident fiber F1 and the measurement object fiber F2.

[0090] 1... Measurement system 1a, 2a... End face 3... Measurement device 5... Connection device 12... Multi-core optical fiber 13... Resin material 21, 31... Glass fiber 21a, 31a, N1, N2, N3, N4, n1, n2, n3, n4... Core (target element) 21b, 31b... Cladding 22, 32... Coating resin 33... Measuring instrument 35... FIFO device 51... Rotational alignment mechanism 52, 52A... Support mechanism 52a... Support base portion 52b... Support base storage portion 52c... Top surface 52d... Storage recess 52e... Bottom surface 522... Support surface 53... Holder 53a... Slit 55... Motor 57... Controller 59... Imaging unit 521, 536... V-groove 531... Holder portion 532... Rotating portion 532a, 541a...Outer surface 532b...Gear groove (rotation transmission part) 532c, 541b, 542d...Slit part 533...Rotation support part 534...Support base 534a...Support surface 535...Lid 535a...Inner surface of lid 536a...Inner surface 541...First rotation guide part 542b...Inner peripheral surface 542...Second rotation guide part 542a...Guide hole 542c...Outer surface 571...Detection part 572...Calculation part 573...Storage part 574...Output part C1, C2...Central axis d1...Circumferential direction d2...Radial direction D1...Position data D2...Detection data D3...Rotation angle data F1...Input fiber (first optical fiber member) F2...Measurement target fiber (second optical fiber member) F3...Single-core optical fiber Lm...Measurement light L1, L2...reference lines P21...front portion P22...rear portion S2...image pickup signal S3...control signal θt...rotation angle

Claims

1. A splicing method comprising the steps of: preparing a first optical fiber member including a target element to be rotationally aligned at a position offset from the central axis on its end face; and preparing a plurality of second optical fiber members, each including a target element to be rotationally aligned at a position offset from the central axis on its end face; performing rotational alignment by rotating the first optical fiber member by a predetermined rotation angle around the central axis of the first optical fiber member so as to reduce the amount of deviation of the target element included in one second optical fiber member among the plurality of second optical fiber members arranged side by side; and connecting the end face of the first optical fiber member to the end face of the one second optical fiber member, wherein the one second optical fiber member is not rotated in the rotational alignment step.

2. The connection method described in claim 1, further comprising the steps of: capturing an image of the end face of the one second optical fiber member; detecting the rotational position of the target element included in the one second optical fiber member using the image of the end face of the one second optical fiber member; and calculating the deviation of the rotational position of the target element included in the first optical fiber member relative to the rotational position of the target element included in the one second optical fiber member as the specified rotation angle.

3. A connection method according to claim 1 or claim 2, wherein in the step of performing rotational alignment, a holder that holds the first optical fiber member is rotated by the predetermined rotation angle by a motor.

4. A connection device for carrying out the connection method described in any one of claims 1 to 3, comprising: a support mechanism for supporting the plurality of second optical fiber members arranged side by side; and a rotary alignment mechanism for supporting the first optical fiber member arranged so as to face one of the second optical fiber members and for rotatably holding the first optical fiber member around the central axis of the first optical fiber member, wherein the first optical fiber member is held by the rotary alignment mechanism in a state rotated by the predetermined rotation angle, and the end face of the first optical fiber member is connected to the end face of the one of the second optical fiber members.

5. A connection device as described in claim 4, wherein each of the plurality of second optical fiber members includes a front portion including an end face and a rear portion excluding the front portion, the front portion of each of the plurality of second optical fiber members is supported by the support mechanism, and the front portion of each of the plurality of second optical fiber members is bundled with a resin material.

6. A connection device as described in claim 4, wherein each of the plurality of second optical fiber members includes a front portion including an end face and a rear portion excluding the front portion, the front portion of each of the plurality of second optical fiber members is supported by the support mechanism, and the rear portion of each of the plurality of second optical fiber members is bundled with a resin material.

7. A connection device as described in claim 4, wherein each of the plurality of second optical fiber members includes a front portion including an end face and a rear portion excluding the front portion, the front portion of each of the plurality of second optical fiber members is supported by the support mechanism, and the front portion and the rear portion of each of the plurality of second optical fiber members are bundled together with a resin material.

8. A connection device as described in any one of claims 4 to 7, wherein the rotation alignment mechanism includes: a holder that holds the first optical fiber member; a motor connected to the holder; and a controller that is communicatively connected to the motor and controls the rotation angle of the motor so that the holder rotates by the predetermined rotation angle.

9. A connection device as described in claim 8, wherein the rotation alignment mechanism further includes an imaging unit that images the end face of the one second optical fiber member, and the controller includes: a detection unit that detects the rotational position of the target element of the second optical fiber member using an image of the end face of the one second optical fiber member; a calculation unit that calculates the deviation of the rotational position of the target element included in the first optical fiber member relative to the rotational position of the target element included in the one second optical fiber member as the specified rotation angle; and an output unit that outputs a control signal to the motor to rotate the holder by the specified rotation angle.

10. A connection device as described in claim 8 or claim 9, wherein the holder includes: a holder portion that holds the first optical fiber member; a rotating portion that is connected to the holder portion and is rotatable around the central axis of the first optical fiber member in response to rotation of the motor; a driving force transmission portion that transmits the rotational driving force of the motor to the rotating portion; and a rotation support portion that rotatably supports the rotating portion.

11. A connection device as described in claim 10, wherein the holder portion includes: a support base having a V-groove formed therein for supporting the first optical fiber member; and a lid that is placed on the support base so as to cover the first optical fiber member.

12. A connection device according to claim 10 or 11, wherein the driving force transmission portion is a plurality of gear grooves formed on the outer peripheral surface of the rotating portion.

13. A connection device as described in claim 12, wherein the rotation support portion includes a cylindrical first rotation guide portion connected to the rotating portion and rotatable around the central axis together with the rotating portion, and a second rotation guide portion including a guide hole into which the first rotation guide portion is inserted, and a gap is provided between the inner surface of the guide hole and the outer surface of the first rotation guide portion.

14. A connection device as described in claim 13, wherein the holder includes a slit formed across the rotating portion and the rotation support portion and extending in a direction intersecting the direction in which the first optical fiber member extends, and a portion of the first optical fiber member extending from the holder portion to the rotation support portion is disposed in the slit.

15. A connection device as described in any one of claims 4 to 14, wherein the support mechanism includes a support base portion having a plurality of V-grooves formed therein that support each of the plurality of second optical fiber members, and a support base accommodating portion having an accommodating recess formed therein that accommodates the support base portion.

16. A connection device according to any one of claims 4 to 15, wherein each of the first optical fiber member and the plurality of second optical fiber members is one of a multi-core optical fiber, a polarization-maintaining fiber, and a bundle fiber.

Images