Connection method and connection device

Abstract

The connection method of the present disclosure includes: a step of preparing a first optical fiber member including a target element to be rotationally aligned at a position deviated from the central axis on the end face, and a plurality of second optical fiber members each including a target element to be rotationally aligned at a position deviated from the central axis on the end face; a step of 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 that the deviation amount of the target element included in the first optical fiber member with respect to the target element included in one of the plurality of second optical fiber members arranged side by side is reduced; and a step of connecting the end face of the first optical fiber member to the end face of one second optical fiber member. In the step of performing rotational alignment, one second optical fiber member is not rotated.

Description

Technical Field

[0001] The present disclosure relates to a connection method and a connection device. This application claims priority based on Japanese Application No. 2024-032323 filed on March 4, 2024, and incorporates all the descriptions described in the above Japanese application.

Background Art

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

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] A connection method according to an embodiment of the present disclosure includes: preparing a first optical fiber member including a target element to be rotationally centered at a position deviated from the central axis on an end face, and a plurality of second optical fiber members each including a target element to be rotationally centered at a position deviated from the central axis on an end face; rotating the first optical fiber member by a predetermined rotation angle around the central axis of the first optical fiber member so that the deviation amount of the target element included in the first optical fiber member with respect to the target element included in one of the plurality of second optical fiber members arranged side by side decreases, and performing rotational centering; and connecting the end face of the first optical fiber member to the end face of one of the second optical fiber members. In the step of performing rotational centering, one of the second optical fiber members is not rotated.

Brief Description of the Drawings

[0005]

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

[0007] When inspecting a multi-core MCF as described above instead of a multi-core SCF, it is assumed that an operation of connecting the multi-core MCF to the single-core MCF connected to the measuring instrument is performed. In this operation, in addition to adjusting the three-dimensional position of the multi-core MCF with respect to the single-core MCF in order to align the core positions of the multi-core MCF with the core position of the single-core MCF, rotational centering for adjusting the rotational position between the single-core MCF and the multi-core MCF is required. In this case, it is assumed that an operation of dividing the multi-core MCF into a plurality of single-core MCFs occurs in order to adjust the rotational position of the multi-core MCF. The occurrence of such an operation can reduce the efficiency of the operation of connecting the single-core MCF and the multi-core MCF. It is also assumed that an operation of rotating each of the plurality of divided single-core MCFs occurs. This operation can also reduce the efficiency of the operation of connecting the single-core MCF and the multi-core MCF.

[0008] The present disclosure provides a connection method and a connection device capable of improving the efficiency of the operation.

[0009] [Effects of the Present Disclosure] According to the connection method and the connection device of the present disclosure, the efficiency of the operation can be improved.

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

[0011] (1) The connection method according to an embodiment of the present disclosure includes a first optical fiber member including a target element to be rotationally centered at a position deviated from the central axis on the end face, and a plurality of second optical fiber members each including a target element to be rotationally centered at a position deviated from the central axis on the end face. Preparing steps, and rotating the first optical fiber member by a predetermined rotation angle around the central axis of the first optical fiber member so that the deviation amount of the target element included in the first optical fiber member with respect to the target element included in one of the plurality of second optical fiber members arranged side by side is reduced. A step of performing rotational centering by rotating, and a step of connecting the end face of the first optical fiber member to the end face of one second optical fiber member. In the step of performing rotational centering, one second optical fiber member is not rotated.

[0012] For example, when inspecting a plurality of second optical fiber members bundled together, in order to input measurement light into one of the plurality of second optical fiber members, an operation of connecting a first optical fiber member that can be connected to a measuring instrument to the second optical fiber member occurs. In order to connect the first optical fiber member and the second optical fiber member, a rotational centering operation of adjusting the rotational positions of the first optical fiber member and the second optical fiber member occurs. In the above connection method, by rotating only the first optical fiber member by a predetermined rotational angle without rotating the second optical fiber member, the rotational position of the first optical fiber member with respect to the second optical fiber member is adjusted. When only the first optical fiber member is rotationally centered in this way, even when a plurality of second optical fiber members are bundled, it is not necessary to separate the plurality of second optical fiber members one by one. Therefore, compared with the case of rotationally centering a plurality of second optical fiber members, the labor required for the rotational centering operation can be reduced. Further, when only the first optical fiber member is rotationally centered in this way, it is not necessary to rotate each of the plurality of second optical fiber members. Therefore, compared with the case of rotationally centering a plurality of second optical fiber members, the labor required for the rotational centering operation can be reduced. Thereby, it becomes possible to improve the efficiency of the operation when connecting the first optical fiber member to the second optical fiber member.

[0013] (2) The connection method described in (1) above may further include a step of imaging an end face of one second optical fiber member, a step of detecting a rotational position of a target element included in one second optical fiber member using an image of the end face of one second optical fiber member, and a step of calculating, as a predetermined rotational angle, a deviation in the rotational position of a target element included in the first optical fiber member with respect to the rotational position of a target element included in one second optical fiber member. In this case, since the operation of calculating the rotational angle of the first optical fiber member can be automated, the efficiency of the operation of rotationally centering the first optical fiber member can be improved.

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

[0015] (4) A connection device for implementing the connection method according to any one of (1) to (3) above, comprising: a support mechanism that supports a plurality of second optical fiber members arranged side by side; and a rotational alignment mechanism that supports a first optical fiber member arranged to face one second optical fiber member and rotatably holds the first optical fiber member around the central axis of the first optical fiber member. The first optical fiber member is held by the rotational alignment mechanism in a state of being rotated by a predetermined rotation angle, and the end face of the first optical fiber member is connected to the end face of one second optical fiber member. According to this connection device, by rotating only the first optical fiber member without rotating the second optical fiber member, rotational alignment of the first optical fiber member with respect to the second optical fiber member can be performed. When performing rotational alignment only on the first optical fiber member in this way, even when a plurality of second optical fiber members are bundled, it is not necessary to separate the plurality of second optical fiber members one by one. Therefore, compared with the case of performing rotational alignment on a plurality of second optical fiber members, the labor required for the rotational alignment operation can be reduced. Also, when performing rotational alignment only on the first optical fiber member in this way, it is not necessary to rotate each of the plurality of second optical fiber members. Therefore, compared with the case of performing rotational alignment on a plurality of second optical fiber members, the labor required for the rotational alignment operation can be reduced. As a result, it becomes possible to improve the efficiency of the operation when connecting the first optical fiber member to the second optical fiber member.

[0016] (5) In the connecting device according to (4) above, 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 a support mechanism, and the front portions of the plurality of second optical fiber members may be bundled by a resin material. In this configuration, when aligning the second optical fiber members by rotation, it is necessary to separate the plurality of second optical fiber members one by one, so the above-described effects can be fully exhibited.

[0017] (6) In the connecting device according to (4) above, 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 a support mechanism, and the rear portions of the plurality of second optical fiber members may be bundled by a resin material. In this configuration, when aligning the second optical fiber members by rotation, it is necessary to separate the plurality of second optical fiber members one by one, so the above-described effects can be fully exhibited.

[0018] (7) In the connecting device according to (4) above, 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 a support mechanism, and the front portions and rear portions of the plurality of second optical fiber members may be bundled by a resin material. In this configuration, when aligning the second optical fiber members by rotation, it is necessary to separate the plurality of second optical fiber members one by one, so the above-described effects can be fully exhibited.

[0019] (8) In the connecting device according to any one of (4) to (7) above, the rotation alignment mechanism may include a holder that holds the first optical fiber member, a motor connected to the holder, and a controller that is communicably 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 a predetermined rotation angle can be automated, so the efficiency of the operation of aligning the first optical fiber member by rotation can be improved.

[0020] (9) In the connecting device according to (8) above, the rotary alignment mechanism may further include an imaging unit that images the end face of one second optical fiber member, and the controller uses the image of the end face of one second optical fiber member to detect the rotational position of the target element of the second optical fiber member. A detection unit, a calculation unit that calculates the deviation between the rotational position of the target element included in the first optical fiber member and the rotational position of the target element included in the second optical fiber member as a predetermined rotational angle, and a control signal that rotates the holder by the predetermined rotational angle. And an output unit that outputs to the motor. In this case, since the operation of calculating the rotation angle of the first optical fiber member can be automated, the efficiency of the operation of rotationally aligning the first optical fiber member can be further improved.

[0021] (10) In the connecting device according to (8) or (9) above, 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 the rotation of the motor, and a motor. It may include a driving force transmission unit that transmits the rotational driving force to the rotating unit, and a rotational support unit that rotatably supports the rotating unit. In this case, a configuration in which the first optical fiber member is automatically rotated by a predetermined rotation angle around the central axis can be easily implemented.

[0022] (11) In the connecting device according to (10) above, the holder portion may include a support base formed with a V-groove for supporting the first optical fiber member, and a lid placed on the support base so as to cover the first optical fiber member. In this case, the first optical fiber member can be easily set in the holder portion.

[0023] (12) In the connecting device according to (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. In this case, a configuration in which the first optical fiber member is rotated by a predetermined rotation angle around the central axis using a motor can be more reliably implemented.

[0024] (13) In the connecting device described in (12) above, the rotation support portion includes a columnar first rotation guide portion that is connected to the rotation portion and is rotatable about the central axis together with the rotation portion, and a second rotation guide portion that includes a guide hole into which the first rotation guide portion is inserted. A gap may be provided between the inner peripheral surface of the guide hole and the outer peripheral surface of the first rotation guide portion. In this case, while allowing the first rotation guide portion to rotate with respect to the second rotation guide portion, it is possible to reduce the risk that the rotation center of the first rotation guide portion deviates significantly from the central axis of the first optical fiber member. As a result, a configuration in which the first optical fiber member is rotated by a predetermined rotation angle about the central axis using a motor can be more reliably implemented.

[0025] (14) In the connecting device described in (13) above, the holder is formed across the rotation portion and the rotation support portion, and includes a slit that extends along a direction intersecting the direction in which the first optical fiber member extends. A portion of the first optical fiber member that extends from the holder portion to the rotation support portion 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 connecting device according to any one of (4) to (14) above, the support mechanism may include a support base portion in which a plurality of V-grooves for respectively supporting the plurality of second optical fiber members are formed, and a support base housing portion in which a housing recess for housing the support base portion is formed. In this case, by removing the support base portion from the support base housing portion, it is possible to replace it with another support base portion in which a plurality of other V-grooves having an arrangement pitch and size different from those of the plurality of V-grooves are formed. 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, if a plurality of types of support base portions in which V-grooves are formed in accordance with the arrangement pitch and outer diameter of the plurality of types of second optical fiber members are prepared, it is possible to correspond to the plurality of types of second optical fiber members only by replacing the support base portion.

[0027] (16) In the connecting device according to any one of (4) to (15) above, 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 connecting 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-described effects can be fully exhibited.

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

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

[0030] The measuring device 3 is a device that measures the optical characteristics of the multi-core optical fiber 12 to be measured. The measuring device 3 measures the optical characteristics of the multi-core optical fiber 12 using, for example, the OTDR (Optical Time Domain Reflectometer) method. In this case, the measuring device 3 makes the measurement light Lm incident on the 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 that returns to the end face 2a. Then, the measuring device 3 measures optical characteristics such as the optical loss or crosstalk generated in the single-core optical fiber F2 based on the intensity of the received light. The measuring device 3 may measure the optical characteristics of the single-core optical fiber F2 based on the intensity of the light emitted from another end face (not shown) of the single-core optical fiber F2 located on the side opposite to the end face 2a, with the measurement light Lm incident on the single-core optical fiber F2 from the end face 2a. The end face 2a is the 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 described as the "measured fiber F2" (second optical fiber member).

[0031] FIG. 2A is a cross-sectional view of a plurality of measured fibers F2 along the line IIa-IIa in FIG. 1. As shown in FIG. 2A, each of the plurality of measured fibers F2 extends along the X direction and is arranged side by side along the Y direction orthogonal to the X direction. Each measured fiber F2 is an optical fiber member that requires rotational alignment. In the present embodiment, as an optical fiber member that requires rotational alignment, the case where the measured fiber F2 is a MCF is exemplified. The measured 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 a plurality of cores 21a and a cladding 21b. The cladding 21b is a common cladding that surrounds the plurality of cores 21a.

[0032] The plurality of cores 21a are arranged at positions shifted from the central axis C2 in a cross-section perpendicular to the central axis C2 of the fiber under measurement F2. In FIG. 2A, four cores 21a are shown, and an example is illustrated in which all of the cores 21a are arranged at positions shifted from the central axis C2. The number and arrangement of the cores included in the fiber under measurement F2 are not limited to the example shown in FIG. 2A and can be changed as appropriate. The fiber under measurement F2 may include, for example, 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 fiber under measurement F2 may be 2 or may be 5 or more.

[0033] The plurality of cores 21a are refractive index changing portions having refractive indices different from that of the cladding 21b. When the fiber under measurement F2 has a refractive index changing portion arranged at a position shifted from the central axis C2, the fiber under measurement F2 needs to be rotationally aligned around the central axis C2. Examples of the optical fiber member that requires rotational alignment include, in addition to MCF, for example, a bundle fiber and a polarization maintaining fiber. The polarization maintaining fiber includes a core arranged on the central axis of the polarization maintaining fiber and a stress applying portion arranged at a position shifted from the central axis. In the bundle fiber, a plurality of SMFs are bundled, and the core of at least one SMF is arranged at a position shifted from the central axis of the bundle fiber. The core of the bundle fiber and the stress applying portion of the polarization maintaining fiber are each a refractive index changing portion having a refractive index different from that of the cladding. Therefore, when the core and the stress applying portion are refractive index changing portions, the optical fiber member that requires rotational alignment includes a refractive index changing portion at a position shifted from its central axis.

[0034] As shown in FIG. 1, the measuring device 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 emit measurement light Lm onto the end face 2a of the fiber under measurement F2 and measures the light returning to the end face 2a. Connected to the FIFO device 35 are a single-core optical fiber F1 connected to the fiber under measurement F2 and a single-core optical fiber F3 connected to the measuring instrument 33. The single-core optical fiber F1 is, for example, an MCF for incidence for emitting the measurement light Lm onto the fiber under measurement F2. Hereinafter, the single-core optical fiber F1 will be described as the "incidence fiber F1" (first optical fiber member).

[0035] The end face 1a of the incidence fiber F1 faces the end face 2a of the fiber under measurement F2 along the X direction. The incidence fiber F1 has the same outer diameter as the outer diameter of the fiber under measurement F2. The end face 1a of the incidence fiber F1 faces and is connected to the end face 2a of the fiber under measurement F2. The fact that the end face 1a is connected to the end face 2a includes both the case where the end face 1a is directly connected to the end face 2a and the case where the end face 1a is indirectly connected to the end face 2a with another member sandwiched therebetween.

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

[0037] The input fiber F1 includes, for example, four cores 31a corresponding to the four cores 21a of the fiber F2 to be measured. And all of these cores 31a are arranged at positions deviated from the central axis C1. The number and arrangement of the cores included in the input fiber F1 are not limited to the example shown in FIG. 2B and can be changed as appropriate. The input fiber F1 may include, for example, a central core arranged on the central axis C1 in addition to the peripheral cores arranged around the central axis C1. The number of cores included in the input fiber F1 may be 2 or may be 5 or more. The input fiber F1 may be an optical fiber member including a refractive index changing portion at a position deviated from the central axis, similar to the fiber F2 to be measured, and may be, for example, a bundle fiber or a polarization maintaining fiber.

[0038] As shown in FIG. 1, the single-mode optical fiber F3 connected to the measuring instrument 33 is, for example, an SCF. The single-mode optical fiber F3 is optically connected to the core 31a (see FIG. 2B) corresponding to the core 21a to be measured of the fiber F2 to be measured among the plurality of cores 31a of the input fiber F1. The measurement light Lm emitted from the measuring instrument 33 and received by the single-mode optical fiber F3 enters the end face 2a of the fiber F2 to be measured through the input fiber F1. Then, the light that has passed through the fiber F2 to be measured and returned from the fiber F2 to be measured to the end face 2a is received by the measuring instrument 33 through the input fiber F1 and the single-mode optical fiber F3. The measuring instrument 33 measures the optical characteristics of the fiber F2 to be measured based on the received light.

[0039] The connecting device 5 is a device for connecting the input fiber F1 to the fiber under measurement F2. The connecting device 5 connects the end face 1a of the input fiber F1 to the end face 2a of the fiber under measurement F2 in a state where the end face 1a of the input fiber F1 faces the end face 2a of the fiber under measurement F2. In a state where the end face 1a is connected to the end face 2a, the central axis C1 of the input fiber F1 coincides with the central axis C2 of the fiber under measurement F2, and each core 21a of the input fiber F1 is optically connected to each core 31a of the fiber under measurement F2 (see FIGS. 2A and 2B). The connecting device 5 may connect the end face 1a to the end face 2a by simply butting the end face 1a of the input fiber F1 against the end face 2a of the fiber under measurement F2.

[0040] The connecting device 5 includes a rotary alignment mechanism 51 that supports the input fiber F1 and a support mechanism 52 that supports a plurality of fibers under measurement F2. The rotary alignment mechanism 51 holds the input fiber F1 so that the input fiber F1 can be rotationally aligned. That is, the rotary alignment mechanism 51 holds the input fiber F1 so as to be rotatable around the central axis C1. The support mechanism 52 is, for example, a resin support base on which a plurality of fibers under measurement F2 are placed. The support mechanism 52 only needs to have at least the function of supporting a plurality of fibers under measurement F2, and it is not necessary to hold each fiber under measurement F2 so as to be rotatable around the central axis C2. For example, each fiber under measurement F2 may be arranged on the support mechanism 52 so as not to rotate around the central axis C2. For example, each fiber under measurement F2 may be fixed to the support mechanism 52 with an adhesive, or each fiber under measurement F2 may be fixed to the support mechanism 52 by pressing each fiber under measurement F2 against the support mechanism 52 using an upper lid. Thus, the connecting device 5 may be configured to rotationally align only the input fiber F1 among the input fiber F1 and the fibers under measurement F2.

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

[0042] As shown in FIG. 2A, the support mechanism 52 includes, for example, a support surface 522 in which a plurality of V-grooves 521 are formed. The support surface 522 is a plane extending along the X and Y directions, for example. The plurality of V-grooves 521 extend in the X direction and are arranged side by side along the Y direction corresponding to the plurality of fibers F2 to be measured. The plurality of fibers F2 to be measured are respectively placed in the plurality of V-grooves 521.

[0043] As shown in FIG. 1, the rotary alignment mechanism 51 includes a holder 53, a motor 55, a controller 57, and an imaging unit 59. The holder 53 holds the input fiber F1. The holder 53 is placed on a stage movable along the X, Y, and Z directions. Therefore, the three-dimensional position of the input fiber F1 can be adjusted. The holder 53 is connected to the motor 55 and rotates around the central axis C1 under the rotational driving force of the motor 55. The holder 53 rotates around the central axis C1 while holding the input fiber F1. Thereby, the rotation angle of the input fiber F1 around the central axis C1 is adjusted. That is, the rotary alignment of the input 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 integrally with the holder portion 531, for example. The rotating portion 532 rotates around the central axis C1 integrally with the holder portion 531 in response to the 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 rotatably supports the rotating portion 532 around the central axis C1.

[0045] As shown in FIG. 2B, the holder portion 531 includes a support base 534 that supports the input fiber F1 and a lid 535 that is placed on the support base 534 so as to cover the input fiber F1. The support base 534 includes a support surface 534a in which one V-groove 536 is formed. The support surface 534a is a plane extending along the X direction and the Y direction, for example. The V-groove 536 extends along the X direction on the support surface 534a. The input fiber F1 is placed in the V-groove 536. In a state where the input fiber F1 is placed in the V-groove 536, the three-dimensional position of the holder 53 with respect to the support mechanism 52 is adjusted so that the central axis C1 of the input fiber F1 coincides with the central axis C2 of the fiber under measurement F2.

[0046] The lid 535 includes an inner lid surface 535a facing the support surface 534a. In a state where the input fiber F1 is placed in the V-groove 536, the input fiber F1 is in contact with the inner lid surface 535a and the inner surface 536a of the V-groove 536. The input fiber F1 is held by the holder portion 531 so as not to be displaced with respect to the holder portion 531 by being sandwiched between the lid 535 and the support base 534. As shown in FIG. 1, in a state where the input fiber F1 is held by the holder portion 531, the end face 1a of the input fiber F1 protrudes in the X direction from the holder 53. The end face 1a of the input fiber F1 protruding from the holder 53 faces the end face 2a of the fiber under measurement F2 along the X direction.

[0047] Figure 3 is a cross-sectional view of the holder 53 taken along line III-III of Figure 1. In Figure 3, the rotating portion 532 of the holder 53 is shown in cross-section. As shown in Figure 3, the rotating portion 532 is, for example, in the shape of a disk centered on the central axis C1. On the outer peripheral surface 532a of the rotating portion 532, a plurality of gear grooves 532b (rotation transmission portions) arranged along the circumferential direction d1 centered on the central axis C1 are formed. The plurality of gear grooves 532b are, for example, arranged at equal intervals over the entire circumference in the circumferential direction d1 on the outer peripheral surface 532a. Each gear groove 532b is, for example, rectangular 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 each gear connected to the motor 55 and transmits the rotational driving force of the motor 55 to the rotating portion 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 portion 532 using a rubber band. As long as it is a method capable of transmitting the rotational driving force of the motor 55 to the rotating portion 532, other transmission methods may be used. The rotating portion 532 receives the rotational driving force transmitted from the motor 55 through the plurality of gear grooves 532b and rotates around the central axis C1 integrally with the holder portion 531. In response to this rotation, the rotation angle of the incident fiber F1 held by the holder portion 531 is adjusted. The "rotation transmission portion" of the present disclosure is not necessarily limited to the gear groove 532b. For example, when transmitting the rotational driving force of the motor using a rubber band, the "rotation transmission portion" may be a simple plane or a groove adapted to 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 disposed, for example, on the side opposite to the holder portion 531 with the rotation portion 532 interposed therebetween, and is connected to the rotation portion 532 in the X direction. The first rotation guide portion 541 is, for example, cylindrical with an outer diameter larger than that of the rotation portion 532. When a rotational driving force is transmitted from the motor to the rotation portion 532, the rotation support portion 533 rotates integrally with the rotation portion 532 around the central axis C1. In the present embodiment, a case where the holder portion 531, the rotation portion 532, and the rotation support portion 533 are arranged in this order along the X direction is illustrated. However, the arrangement order of the holder portion 531, the rotation portion 532, and the rotation support portion 533 can be appropriately changed as needed, and other arrangement orders may be used.

[0050] The second rotation guide portion 542 includes a guide hole 542a into which the first rotation guide portion 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 portion 541. The inner peripheral surface 542b faces the outer peripheral surface 541a of the first rotation guide portion 541 with a gap therebetween. In a state where the first rotation guide portion 541 is inserted into the guide hole 542a, a gap is provided so that the rotation of the first rotation guide portion 541 is allowed and the central axis C1 of the incident fiber F1 does not deviate significantly from the central axis C2 of the fiber under measurement F2. Grease for reducing the frictional resistance between the inner peripheral surface 542b and the outer peripheral surface 541a may be provided in the gap. From the viewpoint of improving the sliding between the inner peripheral surface 542b and the outer peripheral surface 541a, for example, a bearing may be formed by arranging a plurality of balls in the gap.

[0051] The holder 53 is formed with a slit 53a for setting the incident fiber F1. The slit 53a is formed at one location of the holder 53 along the circumferential direction d1 and extends from the rotation support portion 533 to the rotation portion 532. The slit 53a is not formed in the holder portion 531 and is formed only in the rotation portion 532 and the rotation support portion 533. The slit 53a passes through the rotation portion 532 and the rotation support portion 533 and linearly extends along the radial direction d2 orthogonal to the central axis C1 from the outer surface 542c of the second rotation guide portion 542 to the position where the incident fiber F1 passes in a cross section perpendicular to the central axis C1. 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 rotation portion 532 in which a plurality of gear grooves 532b are formed to the position reaching the incident 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 portion 542d formed in the second rotation guide portion 542, a slit portion 541b formed in the first rotation guide portion 541, and a slit portion 532c formed in the rotation portion 532. The slit portion 542d extends along the radial direction d2 from the outer surface 542c to the inner circumferential surface 542b of the second rotation guide portion 542. The slit portion 541b is formed on the extension line of the slit portion 542d in the first rotation guide portion 541. The slit portion 541b extends along the radial direction d2 from the outer peripheral surface 541a to the central portion of the first rotation guide portion 541.

[0053] The slit portion 532c is formed at a position overlapping with the slit portion 541b formed in the first rotation guide portion 541 in the X direction. The slit portion 532c extends along the radial direction d2 from the outer peripheral surface 532a of the rotating portion 532 to the central portion of the rotating portion 532. At the central portion of the rotating portion 532 and the central portion of the first rotation guide portion 541, the incident fiber F1 extending from the holder portion 531 is disposed. 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 in 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 contact.

[0054] When setting the incident fiber F1 in the holder 53, with the lid 535 of the holder portion 531 removed, the incident fiber F1 is moved along the slit 53a to the central portion of the rotating portion 532, and the incident fiber F1 is placed on the V-groove 536 formed in the support base 534. In a state where the incident fiber F1 is placed on the V-groove 536, the incident fiber F1 is disposed at the central portion of the rotating portion 532. In this state, the central axis C1 of the incident fiber F1 coincides with the center of the rotating portion 532. Thereafter, by pressing the incident fiber F1 against the support base 534 with the lid 535, the incident fiber F1 is held by the holder portion 531 so as not to rotate and shift with respect to the holder portion 531. The rotating portion 532 connected to the holder portion 531 rotates by receiving the rotational driving force of the motor 55. Thereby, the incident fiber F1 rotates around the central axis C1 together with the rotating portion 532, the first rotation guide portion 541, and the holder portion 531.

[0055] The controller 57 shown in FIG. 1 is communicably connected to the motor 55 and the imaging unit 59. The imaging unit 59 is a camera capable of imaging the end face 2a of the fiber F2 to be measured. The imaging unit 59 is movable relative to the fiber F2 to be measured. The movement operation 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 2a of the fiber F2 to be measured along the X direction. Then, in a state where the observation light is irradiated on the fiber F2 to be measured, the imaging unit 59 images the end face 2a of the fiber F2 to be measured. The imaging unit 59 outputs an imaging signal S2 indicating an image of the end face 2a to the controller 57.

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

[0057] Receiving the imaging signal S2 from the imaging unit 59, the controller 57 generates a control signal S3 for controlling the rotation angle of the motor 55. Physically, the controller 57 includes hardware such as one or more processors, a main storage device, an auxiliary storage device, an input device, an output device, and a communication device. The controller 57 is one or more computers including these hardware and software such as programs. The controller 57 may be communicably connected to at least one of the stage on which the support mechanism 52 is placed and the stage on which the holder 53 is placed, and may control the three-dimensional position of the input fiber F1 with respect to the fiber F2 to be measured.

[0058] FIG. 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 a program being executed on the hardware of the computer described above.

[0059] The detection unit 571 acquires the imaging signal S2 from the imaging unit 59. The detection unit 571 acquires the imaging signal S2 from the imaging unit 59 each time the imaging unit 59 images the measurement target fiber F2. The detection unit 571 detects the rotational position of the imaged 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 detection unit 571 detects the core 21a of the measurement target fiber F2 as the target element to be rotationally centered, and acquires the rotational position of the core 21a of the measurement target fiber F2. The detection unit 571 may detect an element other than the core 21a of the measurement target fiber F2 as the target element to be rotationally centered. The detection unit 571 passes the detection data D2 indicating the position of the core 21a of the measurement target fiber F2 to the calculation unit 572. The detection unit 571 may store the detection data D2 in the storage unit 573.

[0060] The storage unit 573 stores, as the target element to be rotationally centered of the input fiber F1, for example, position data D1 indicating the position of the core 31a. The position data D1 can be obtained, for example, from an image of the end face 1a of the input fiber F1 imaged using 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 calculates the rotation angle (rotation amount) of the input fiber F1 necessary to align the position of the core 31a of the input fiber F1 with the position of the core 21a of the measurement target fiber F2 using the position data D1 and the detection data D2.

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

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

[0063] Therefore, as shown in FIG. 5C, by rotating the input fiber F1 by the rotation angle θt in the “+θ” direction with respect to the fiber F2 to be measured, the positions of the cores N1 to N4 of the input fiber F1 can be made to coincide with the cores n1 to n4 of the fiber F2 to be measured. In this case, the arithmetic unit 572 shown in FIG. 1 calculates the rotation angle θt of the input fiber F1 required to make the position of the core 21a of the fiber F2 to be measured coincide with the position of the core 31a of the input fiber F1. The arithmetic unit 572 passes the 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 for rotating the input fiber F1 by a rotation angle θt. The motor 55 rotates by an angular rotation necessary for the input fiber F1 to rotate by the rotation angle θt in response to the control signal S3. In response to the rotation of the motor 55, the input fiber F1 held by the holder 53 rotates by the rotation angle θt around the central axis C1. Thereby, rotational alignment of the input fiber F1 with respect to the measurement target fiber F2 is performed. Thereafter, the end face 1a of the rotationally aligned input fiber F1 is connected to the end face 2a of the measurement target fiber F2.

[0065] Referring to FIGS. 6 to 8, a connection method implemented using the above-described connection device 5 will be described. FIG. 6 is a flowchart showing each step for implementing the connection method of the present embodiment. FIG. 7 is a plan view showing the connection device 5 for implementing step S11 of FIG. 6. FIG. 8 is a plan view showing the connection device 5 for implementing step S14 of FIG. 6.

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

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

[0068] Next, the controller 57 detects the rotational position of the imaged first measurement target fiber F2 (step S12 in FIG. 6). For example, the detection unit 571 of the controller 57 detects the rotational position of the core 21a of the measurement target fiber F2 from the end face 2a of the measurement target fiber F2 indicated by the imaging signal S2.

[0069] Next, the controller 57 calculates the rotational angle of the incident fiber F1 necessary 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 arithmetic unit 572 of the controller 57 calculates, as the rotational angle of the incident fiber F1 necessary for rotational alignment, θt which is the deviation amount between the reference line L2 indicating the position of the core n1 of the measurement target fiber F2 and the reference line L1 indicating the position of the core N1 of the incident fiber F1 (see FIG. 5C).

[0070] Next, the controller 57 rotates and 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. The motor 55 rotates by an angular rotation necessary for the incident fiber F1 to rotate by the rotation angle θt in response to the control signal S3. In response to the rotation of the motor 55, the incident fiber F1 rotates by the rotation angle θt around the central axis C1. 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. A plurality of measurement target fibers F2 including the first measurement target fiber F2 maintain a stationary state without being rotationally aligned. Therefore, in the present embodiment, only the incident fiber F1 among the incident fiber F1 and the measurement target fiber F2 is rotationally aligned.

[0071] Next, the connection device 5 connects the rotationally aligned incident fiber F1 to the first measurement target fiber F2 (step S15 in FIG. 6). For example, the connection device 5 adjusts the three-dimensional position of the incident fiber F1 with respect to the first measurement target fiber F2 so that the end face 1a of the incident fiber F1 abuts against the end face 2a of the first measurement target fiber F2 while maintaining the rotational position of the incident fiber F1. Thereby, the end face 1a of the incident fiber F1 is connected to the end face 2a of the first measurement target fiber F2, and the core 31a of the incident fiber F1 is optically connected to the core 21a of the first measurement target fiber F2. Then, steps S12 to S15 are repeatedly performed for the remaining measurement target fibers F2, whereby the connection of the incident fiber F1 to the remaining measurement target fibers F2 is sequentially performed.

[0072] When inspecting the fiber F2 to be measured, after step 15, the measuring device 3 measures the optical characteristics of the fiber F2 to be measured by injecting the measuring light Lm from the input fiber F1 into the fiber F2 to be measured. The measuring device 3 measures the optical characteristics of a plurality of fibers F2 to be measured by performing the above measurement each time steps S12 to S15 are repeated.

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

[0074] In the present embodiment, by rotating only the input fiber F1 without rotating the fiber F2 to be measured, rotational alignment of the input fiber F1 with respect to the fiber F2 to be measured is performed. In this case, even when a plurality of fibers F2 to be measured are bundled by the resin material 13, it is not necessary to separate the plurality of fibers F2 to be measured one by one for rotational alignment. Therefore, compared with the case of performing rotational alignment on each of the plurality of fibers F2 to be measured one by one, the labor required for the rotational alignment operation can be reduced. Further, when only the input fiber F1 is rotationally aligned in this way, it is not necessary to rotate each of the plurality of fibers F2 to be measured. Therefore, compared with the case of performing rotational alignment on the plurality of fibers F2 to be measured, the labor required for the rotational alignment operation can be reduced. As a result, it is possible to improve the efficiency of the operation when connecting the input fiber F1 to the fiber F2 to be measured.

[0075] As in the present embodiment, the rear portions P22 of the plurality of fibers F2 to be measured may be bundled by the resin material 13. In this configuration, when performing rotational alignment on the plurality of fibers F2 to be measured, labor is required to separate the plurality of fibers F2 to be measured one by one. Therefore, the above-described effects can be fully exhibited.

[0076] As in this embodiment, the rotation alignment mechanism 51 may include a holder 53 that holds the input fiber F1, a motor 55 connected to the holder 53, and a controller 57 that is communicably 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, since the operation of rotating the input fiber F1 by the predetermined rotation angle θt can be automated, the efficiency of the operation of rotationally aligning the input fiber F1 can be improved.

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

[0078] As in this embodiment, the holder 53 may include a holder portion 531 that holds the input fiber F1, a rotating portion 532 that is connected to the holder portion 531 and is rotatable around the central axis C1 of the input fiber F1 in response to the 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, a configuration for automatically rotating the input fiber F1 by a predetermined rotation angle θt around the central axis C1 can be easily implemented.

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

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

[0081] As in this embodiment, a gap may be formed between the outer peripheral surface 541a of the first rotation guide portion 541 and the inner peripheral surface 542b of the guide hole 542a. In this case, while allowing the rotation of the first rotation guide portion 541 with respect to the second rotation guide portion 542, the risk that the rotation center of the first rotation guide portion 541 deviates greatly from the central axis C1 of the incident fiber F1 can be reduced. As a result, a configuration in which the incident fiber F1 is rotated by a predetermined rotation angle θt around the central axis C1 using the motor 55 can be more reliably implemented.

[0082] As in this embodiment, the holder 53 is formed across the rotating portion 532, the first rotation guide portion 541, and the second rotation guide portion 542, and includes a slit 53a extending along the radial direction d2 intersecting the incident fiber F1. 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, each of the incident fiber F1 and the measurement target fiber F2 may be an MCF. In this case, when connecting the end face 1a of the incident fiber F1 to the end face 2a of the measurement target fiber F2, rotational alignment of the incident fiber F1 with respect to the measurement target fiber F2 is required, so the above-described effects can be fully exhibited.

[0084] The connection method and the connection device 5 of the present disclosure are not limited to the above-described embodiments, and can be modified without departing from the spirit of the claims.

[0085] FIG. 9 is a cross-sectional view showing a modified example of the support mechanism 52 that supports the fiber F2 to be measured. The support mechanism 52A shown in FIG. 9 includes a support base portion 52a and a support base housing portion 52b that houses the support base portion 52a. The support base portion 52a is a base member in which the plurality of V-grooves 521 described above are formed. The support base housing portion 52b is a housing member formed separately from the support base portion 52a. The support base housing portion 52b includes a housing recess 52d that can house the support base portion 52a. The housing recess 52d is recessed in the Z direction from the upper surface 52c of the support base housing portion 52b. The bottom surface 52e of the support base portion 52a is placed in the housing recess 52d. The support base portion 52a is removable from the support base housing portion 52b. Even in such a form, 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 portion 52a can be removed from the support base housing portion 52b. In this case, the support base portion 52a removed from the support base housing portion 52b can be replaced with another support base portion in which another plurality of V-grooves having an array pitch and size different from those of the above-described plurality of V-grooves 521 are formed. In this way, by replacing the support base portion 52a with another support base portion, the array pitch and size of the plurality of V-grooves can be freely adjusted. Therefore, if a plurality of types of support base portions in which V-grooves are formed according to the array pitch and outer diameter of a plurality of types of fibers to be measured are prepared, it is possible to correspond to a plurality of types of fibers F2 to be measured only by replacing the support base portion.

[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 incident fiber F1 and the fiber under measurement F2 are both "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 "polarization-maintaining fibers" or "bundle fibers". When at least one of the "first optical fiber member" and the "second optical fiber member" is a "bundle fiber", each of the plurality of SCFs included in the "bundle fiber" does not correspond to the "optical fiber member", but the "bundle fiber" formed by bundling the plurality of SCFs corresponds to the "optical fiber member".

[0088] In the above-described embodiments and modifications, the case where the "core 31a" of the incident fiber F1 and the "core 21a" of the fiber under measurement F2 are the "target elements to be rotationally aligned" of the present disclosure has been described. However, the "target elements to be rotationally aligned" of the present disclosure do not necessarily have to be the "cores" of the optical fiber members, and may be, for example, "markers" formed on the end faces of the optical fiber members, or "stress-applying portions" when the optical fiber members are polarization-maintaining fibers. In the above-described embodiments and modifications, 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 embodiments and modified examples, the case where steps S11 to S15 in FIG. 6 are automatically performed by the connection device 5 has been described. However, for example, steps S10, S14, and S15 may be performed manually. In this case, steps S11 to S13 may be omitted. For example, while the end face 1a of the incident fiber F1 is facing the end face 2a of the fiber under measurement F2, while measuring light is being incident from the incident fiber F1 to the fiber under measurement F2, by rotating only the incident fiber F1 so that the optical coupling efficiency between the incident fiber F1 and the fiber under measurement F2 becomes maximum, rotational alignment of the incident fiber F1 with respect to the fiber under measurement F2 may be performed.

Explanation of Signs

[0090] 1…Measurement system 1a, 2a…End faces 3…Measuring device 5…Connection device 12…Multicore optical fiber 13…Resin material 21, 31…Glass fibers 21a, 31a, N1, N2, N3, N4, n1, n2, n3, n4…Cores (target elements) 21b, 31b…Claddings 22, 32…Coating resins 33…Measuring instrument 35…FIFO device 51…Rotational alignment mechanism 52, 52A…Support mechanisms 52a…Support base part 52b…Support base housing part 52c…Upper surface 52d…Housing recess 52e…Bottom surface 522…Support surface 53…Holder 53a…Slit 55…Motor 57…Controller 59…Imaging unit 521, 536…V-grooves 531…Holder part 532…Rotating part 532a, 541a... Outer peripheral surface 532b... Gear groove (rotation transmission part) 532c, 541b, 542d... Slit part 533... Rotation support part 534... Support base 534a... Support surface 535... Cover 535a... Inner surface of the cover 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... Memory 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... Incident fiber (first optical fiber member) F2... Fiber to be measured (second optical fiber member) F3... Single-core optical fiber Lm... Measurement light L1, L2... Reference line P21... Front part P22... Rear part S2... Imaging signal S3... Control signal θt... Rotation angle

Claims

1. preparing a first optical fiber member including a target element to be rotationally aligned at a position offset from the central axis on an 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 an 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 that a deviation amount of the target element included in one second optical fiber member among the plurality of second optical fiber members arranged side by side is reduced with respect to the target element included in the first optical fiber member; and connecting the end face of the first optical fiber member to the end face of one of the second optical fiber members; In the step of performing rotational alignment, the one second optical fiber member is not rotated. How to connect.

2. imaging the end face of the one second optical fiber member; detecting a rotational position of the target element included in the one second optical fiber member using an image of the end face of the one second optical fiber member; calculating a deviation of a rotational position of the target element included in the first optical fiber member relative to a rotational position of the target element included in the one second optical fiber member as the predetermined rotation angle; Further comprising: The connection method according to claim 1 .

3. 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; The connection method according to claim 1 .

4. A connection device for implementing the connection method according to any one of claims 1 to 3, a support mechanism for supporting the plurality of second optical fiber members arranged side by side; a rotation alignment mechanism that supports the first optical fiber member arranged to face one of the second optical fiber members and holds the first optical fiber member rotatably around the central axis of the first optical fiber member; Equipped with the first optical fiber member is held by the rotation 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 one of the second optical fiber members; Connection device.

5. 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; the front portions of the second optical fiber members are bundled together with a resin material; The connection device according to claim 4 .

6. 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; the rear portions of the second optical fiber members are bundled together with a resin material; The connection device according to claim 4 .

7. 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; the front portion and the rear portion of each of the plurality of second optical fiber members are bundled together by a resin material; The connection device according to claim 4 .

8. The rotation alignment mechanism includes: a holder for holding the first optical fiber member; a motor coupled to the holder; a controller communicatively connected to the motor and configured to control a rotation angle of the motor so that the holder rotates by the predetermined rotation angle; The connection device according to claim 4 .

9. The rotation alignment mechanism includes: an imaging unit configured to image the end surface of the one second optical fiber member; The controller a detection unit that detects a 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 a deviation of a rotational position of the target element included in the first optical fiber member relative to a rotational position of the target element included in the one second optical fiber member as the predetermined rotation angle; an output unit that outputs a control signal to the motor to rotate the holder by the predetermined rotation angle, The connection device according to claim 8.

10. The holder is a holder portion for holding the first optical fiber member; a rotating part connected to the holder part and rotatable around the central axis of the first optical fiber member in response to rotation of the motor; a driving force transmission unit that transmits the rotational driving force of the motor to the rotating unit; A rotation support portion that rotatably supports the rotating portion, The connection device according to claim 8.

11. The holder portion is a support base having a V-groove formed therein for supporting the first optical fiber member; a lid placed on the support base so as to cover the first optical fiber member, The connection device according to claim 10.

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

13. The rotation support portion is a cylindrical first rotation guide portion coupled to the rotating portion and rotatable together with the rotating portion around the central axis; a second rotation guide portion including a guide hole into which the first rotation guide portion is inserted, A gap is provided between the inner peripheral surface of the guide hole and the outer peripheral surface of the first rotation guide portion. The connection device according to claim 12.

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

15. The support mechanism includes: a support base portion having a plurality of V-grooves formed therein for supporting the plurality of second optical fiber members, respectively; A support base accommodating portion having an accommodating recess formed therein for accommodating the support base portion, The connection device according to claim 4 .

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

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