Multi-core optical fiber aligning device, multi-core optical fiber ribbon manufacturing device, multi-core optical fiber unit manufacturing device, multi-core optical fiber aligning method, multi-core optical fiber ribbon manufacturing method, multi-core optical fiber unit manufacturing method, multi-core optical fiber ribbon inspection device, and multi-core optical fiber ribbon inspection method

Abstract

An aligning device (4) for a multi-core optical fiber (1) is provided with: an optical fiber rotating unit (41) that changes the rotation angle of the axis center of the multi-core optical fiber (1); an optical fiber bending section (42) that bends the multi-core optical fiber (1), the rotation angle of which has changed, in a predetermined direction; a time lag measurement unit (40) that causes light to enter the pair of cores (11, 13) of the multi-core optical fiber (1), receives each of the light emitted from the pair of cores (11, 13), and measures a time lag value (S) for each of the light; and a control unit (49) that controls the optical fiber rotation unit (41) to adjust the rotation angle of the multi-core optical fiber (1) so that the time lag value (S) becomes a predetermined value.

Description

Technical Field

[0001] The present invention relates to a centering device for a multi-core optical fiber, a manufacturing device for a multi-core optical fiber ribbon, a manufacturing device for a multi-core optical fiber unit, a centering method for a multi-core optical fiber, a manufacturing method for a multi-core optical fiber ribbon, a manufacturing method for a multi-core optical fiber unit, an inspection device for a multi-core optical fiber ribbon, and an inspection method for a multi-core optical fiber ribbon. Background Art

[0002] It is known that a multi-core optical fiber is used in which the outer periphery of multiple cores is surrounded by a cladding, and multiple signals are transmitted by light propagating in each core. When connecting multi-core optical fibers to each other, it is necessary to perform centering of the axial center of the multi-core optical fibers to be connected in the rotation direction so that the cores of each multi-core optical fiber are opposite to each other.

[0003] In Patent Document 1, a multi-core optical fiber is bent while light is propagated in a predetermined core to detect the amount of light leaking from the core, and the multi-core optical fiber is rotated about an axis so that the amount of light becomes approximately constant, thereby aligning the rotation direction of the multi-core optical fiber.

[0004] Patent Document 1: Japanese Patent No. 6046311

[0005] Patent Document 2: Japanese Patent No. 6226905

[0006] However, in the alignment method described in Patent Document 1, even if the multi-core optical fiber is rotated about the axis, the amount of leaked light changes only slightly. Therefore, it is difficult to detect the alignment deviation of the multi-core optical fiber in the rotation direction of the axis center, and it is difficult to align the optical fiber with high precision. Summary of the invention

[0007] Therefore, the object of the present invention is to provide a multi-core optical fiber centering device capable of accurately centering the multi-core optical fiber in the rotational direction, a multi-core optical fiber ribbon manufacturing device, a multi-core optical fiber unit manufacturing device, a multi-core optical fiber centering method, a multi-core optical fiber ribbon manufacturing method, a multi-core optical fiber unit manufacturing method, and a multi-core optical fiber ribbon inspection device and a multi-core optical fiber ribbon inspection method capable of accurately detecting the centering deviation of the multi-core optical fiber in the rotational direction.

[0008] Mode 1 of the present invention is a centering device for a multi-core optical fiber, characterized in that it comprises: an optical fiber rotating unit, which changes the rotation angle of the axial center of the multi-core optical fiber; an optical fiber bending unit, which bends the multi-core optical fiber with the changed rotation angle in a specified direction; a time delay measuring unit, which measures the time delay value of light propagating in a pair of cores of the multi-core optical fiber; and a control unit, which controls the optical fiber rotating unit to adjust the rotation angle of the multi-core optical fiber so that the time delay value becomes a specified value.

[0009] When the multi-core optical fiber is rotated about an axis in a state where the multi-core optical fiber is bent in a predetermined direction, the arrangement direction of a pair of cores relative to the bending direction changes, and the time delay value of light propagating in the pair of cores changes. Therefore, by adjusting the rotation angle so that the time delay value becomes a predetermined value, the arrangement direction of a pair of cores relative to the bending direction can be made into a predetermined direction. Compared with the change of leakage light, the change of the time delay value relative to the rotation angle can be measured more accurately, so compared with the centering of the multi-core optical fiber described in Patent Document 1, the centering of the rotation direction can be performed with high precision.

[0010] Mode 2 of the present invention is achieved based on the multi-core optical fiber centering device of Mode 1, and is characterized in that the control unit adjusts the rotation angle so that the skew value becomes a maximum value or a minimum value.

[0011] In this case, the absolute value of the skew value is large, so the resolution can be improved and the centering can be performed more accurately than when the skew value is adjusted to a value that is not the maximum or minimum. In addition, when the arrangement direction of the pair of cores is along the bending direction, the skew value becomes the maximum or minimum.

[0012] In aspect 1 or 2, it is preferable that the pair of cores is a pair of cores which are most distant from each other among the plurality of cores of the multi-core optical fiber.

[0013] Mode 3 of the present invention is a manufacturing device for a multi-core optical fiber ribbon, characterized in that it comprises: a delivery section for delivering one or more multi-core optical fibers; a multi-core optical fiber centering device of mode 1 or 2 for centering the orientation in the rotation direction of at least one of the multi-core optical fibers delivered from the above-mentioned delivery section; and a ribbonizing section for converting a plurality of optical fiber ribbons including the multi-core optical fibers centered by the above-mentioned centering device.

[0014] According to this multi-core optical fiber ribbon manufacturing apparatus, it is possible to manufacture a multi-core optical fiber ribbon in which the rotational direction of the multi-core optical fibers is aligned with high accuracy.

[0015] A fourth aspect of the present invention is a manufacturing device for a multi-core optical fiber unit, characterized in that it comprises: the centering device of the first or second aspect; and a connecting portion for connecting the multi-core optical fiber aligned by the centering device to another optical component.

[0016] According to the manufacturing device of the multi-core optical fiber unit, the rotation direction of the multi-core optical fiber is adjusted with high precision, so that the multi-core optical fiber can be connected with other optical components in a state where the rotation direction is properly adjusted. Therefore, a multi-core optical fiber unit in which the multi-core optical fiber with the rotation direction properly adjusted is connected with other optical components can be manufactured.

[0017] Mode 5 of the present invention is a method for aligning a multi-core optical fiber, characterized in that it includes: an optical fiber rotation step, which changes the rotation angle of the axial center of the multi-core optical fiber; an optical fiber bending step, which bends the multi-core optical fiber with the changed rotation angle in a specified direction; and a time delay measurement step, which measures the time delay value of light propagating in a pair of cores of the multi-core optical fiber; in the optical fiber rotation step, the rotation angle of the multi-core optical fiber is adjusted so that the time delay value becomes a specified value.

[0018] According to this aspect, similarly to aspect 1, the centering of the multi-core optical fiber in the rotational direction can be performed with high accuracy.

[0019] Mode 6 of the present invention is achieved based on the multi-core optical fiber centering method of Mode 5, and is characterized in that in the above-mentioned optical fiber rotation step, the above-mentioned rotation angle is adjusted so that the above-mentioned time lag value becomes a maximum value or a minimum value.

[0020] According to this aspect, similar to aspect 2, centering can be performed with higher accuracy.

[0021] Mode 7 of the present invention is achieved based on the centering method of a multi-core optical fiber according to Mode 5 or 6, and is characterized in that the pair of cores is a pair of cores that are farthest from each other among the multiple cores of the multi-core optical fiber.

[0022] If the arrangement direction of a pair of cores relative to the bending direction of the multi-core optical fiber is constant, the time lag value of the light propagating in the most distant core pair becomes the largest, and if the rotation angle of the multi-core optical fiber is offset, the change in the time lag value becomes larger. Therefore, according to this method, the time lag value can be measured with higher accuracy, and the rotation direction of the multi-core optical fiber can be adjusted with higher accuracy.

[0023] Mode 8 of the present invention is a method for manufacturing a multi-core optical fiber ribbon, characterized in that it comprises: a feeding step of feeding out one or more multi-core optical fibers; an alignment step of aligning the orientation of at least one of the multi-core optical fibers fed out in the feeding step in the rotational direction by using any one of the multi-core optical fiber alignment methods of modes 5 to 7; and a ribbonizing step of ribbonizing the plurality of multi-core optical fibers aligned in the alignment step.

[0024] According to this aspect, similarly to aspect 3, a multi-core optical fiber ribbon in which the rotational direction of the multi-core optical fiber is aligned with high accuracy can be manufactured.

[0025] Mode 9 of the present invention is a method for manufacturing a multi-core optical fiber unit, characterized in that it comprises: an alignment step, in which the orientation of the multi-core optical fiber in the rotation direction is aligned by the multi-core optical fiber alignment method of any one of Modes 5 to 7; and a connecting step, in which the multi-core optical fiber aligned in the above-mentioned alignment step is connected to other optical components.

[0026] According to this aspect, similarly to aspect 4, a multi-core optical fiber unit can be manufactured in which a multi-core optical fiber whose rotational direction is appropriately aligned is connected to other optical components.

[0027] Mode 10 of the present invention is a multi-core optical fiber ribbon inspection device, characterized in that it comprises: an optical fiber bending section, which bends the multi-core optical fiber by bending the multi-core optical fiber ribbon having more than one multi-core optical fiber; a time delay measuring section, which measures the time delay value of light propagating in a pair of cores of at least one of the multi-core optical fibers; and a determination section, which determines when the time delay value of at least one of the multi-core optical fibers is outside a specified range.

[0028] According to this method, in the portion bent by the optical fiber bending portion, the centering deviation of the multi-core optical fiber can be detected with high accuracy by detecting the case where the time delay value is outside the specified range. In addition, when detecting the centering deviation interval in the rotation direction of the multi-core optical fiber, the interval can be detected with high accuracy by sequentially feeding the multi-core optical fiber to the optical fiber bending portion.

[0029] In aspect 10, it is preferable that the pair of cores is arranged perpendicularly to an arrangement direction of the plurality of multi-core optical fibers.

[0030] Mode 11 of the present invention is a method for inspecting a multi-core optical fiber ribbon, characterized in that it comprises: an optical fiber bending step, bending the multi-core optical fiber by bending the multi-core optical fiber ribbon having more than one multi-core optical fiber; a time delay measuring step, measuring the time delay value of light propagating in a pair of cores of at least one of the multi-core optical fibers; and a judgment step, judging whether the time delay value of at least one of the multi-core optical fibers is outside a specified range.

[0031] According to this aspect, similarly to aspect 10, it is possible to detect the misalignment of the multi-core optical fiber with high accuracy.

[0032] Mode 12 of the present invention is completed based on the inspection method of the multi-core optical fiber ribbon of Mode 11, and is characterized in that the multi-core optical fiber ribbon has a plurality of optical fibers arranged side by side including the multi-core optical fibers, and the pair of cores are arranged perpendicular to the arrangement direction of the optical fibers.

[0033] The multi-core optical fiber ribbon is usually bent in a direction perpendicular to the arrangement direction of the optical fibers. In addition, when the arrangement direction of a pair of cores is along the bending direction, the skew value becomes maximum or minimum. Therefore, according to this method, the absolute value of the skew value is large, so the resolution of the skew value can be improved, and the centering deviation can be detected with higher accuracy.

[0034] As described above, according to the present invention, there are provided a multi-core optical fiber centering device capable of accurately centering the multi-core optical fiber in the rotational direction, a multi-core optical fiber ribbon manufacturing device, a multi-core optical fiber unit manufacturing device, a multi-core optical fiber centering method, a multi-core optical fiber ribbon manufacturing method, a multi-core optical fiber unit manufacturing method, and a multi-core optical fiber ribbon inspection device and a multi-core optical fiber ribbon inspection method capable of accurately detecting the centering deviation of the multi-core optical fiber in the rotational direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a diagram showing an example of a cross-sectional view of a multi-core optical fiber.

[0036] Figure 2 Yes means Figure 1 A diagram of how a multi-core optical fiber bends.

[0037] Figure 3 Yes means Figure 1 , Figure 2 A graph showing the relationship between the bending radius of a multi-core optical fiber and the time lag value per unit length of light propagating in a pair of cores.

[0038] Figure 4 This is a diagram showing the relationship between the angle between the arrangement direction of a pair of cores and the direction in which the multi-core optical fiber is bent, and the skew value per unit length.

[0039] Figure 5 This is a diagram showing an example of a multi-core optical fiber ribbon according to the first embodiment of the present invention.

[0040] Figure 6 It is a diagram showing a manufacturing apparatus for a multi-core optical fiber ribbon.

[0041] Figure 7 It is a diagram showing the appearance of the optical fiber rotation unit.

[0042] Figure 8 This is a flow chart showing a method for manufacturing a multi-core optical fiber ribbon.

[0043] Fig. 9 It is a diagram showing an example of a multi-core optical fiber unit according to a second embodiment of the present invention.

[0044] Fig.10 Yes means Fig. 9 Figure 2. A diagram of a manufacturing apparatus for a multi-core optical fiber unit.

[0045] Fig.11 This is a flowchart showing a method for manufacturing a multi-core optical fiber unit.

[0046] Fig.12 It is a diagram showing a multi-core optical fiber ribbon inspection device according to a third embodiment of the present invention.

[0047] Fig.13 This is a flowchart showing a method for inspecting a multi-core optical fiber ribbon.

[0048] Fig.14 It is a diagram showing a modified example of the multi-core optical fiber ribbon. DETAILED DESCRIPTION

[0049] Hereinafter, preferred embodiments of the centering device for the multi-core optical fiber, the manufacturing device for the multi-core optical fiber ribbon, the manufacturing device for the multi-core optical fiber unit, the centering method for the multi-core optical fiber, the manufacturing method for the multi-core optical fiber ribbon, the manufacturing method for the multi-core optical fiber unit, the inspection device for the multi-core optical fiber ribbon, and the inspection method for the multi-core optical fiber ribbon involved in the present invention will be described in detail with reference to the accompanying drawings. The embodiments illustrated below are intended to facilitate the understanding of the present invention and are not intended to limit the interpretation of the present invention. The present invention can be changed and improved according to the embodiments without departing from its main purpose. In addition, for ease of understanding, there are cases where the proportions recorded in the various figures are different from the proportions recorded in the following description.

[0050] (First Embodiment)

[0051] First, the time skew of the multi-core optical fiber will be described. Figure 1 FIG. 1 is a diagram showing an example of a cross-sectional view of a multi-core optical fiber. Figure 1 As shown, the multi-core optical fiber 1 in this description includes: a plurality of cores 10 to 16; a cladding 18 that surrounds the outer peripheral surface of each core 10 to 16 without a gap; and a protective layer 19 that covers the outer peripheral surface of the cladding 18. The refractive index of each core 10 to 16 is higher than the refractive index of the cladding 18. Each core 10 to 16 and the cladding 18 are composed of glass to which a dopant is added as needed. The protective layer 19 is composed of a resin, and may also be composed of a plurality of layers with different hardnesses.

[0052] In this description, the number of cores is 7 in total, one core 10 is arranged along the central axis of the cladding 18, and a plurality of cores 11 to 16 are arranged at equal intervals around the core 10. In addition, when no twist is applied to the multi-core optical fiber 1 and the cladding 18 is formed in a straight line, the plurality of cores 10 to 16 are in a straight line.

[0053] Figure 2 Yes means Figure 1 This is a diagram showing how a multi-core optical fiber 1 is bent. Figure 2 The protective layer 19 is omitted. Here, starting from the center of the cladding 18, a predetermined radial direction is set as the x-axis, a radial direction orthogonal to the x-axis is set as the y-axis, and an angle between the bending direction of the multi-core optical fiber 1 and the x-axis is set as θ. Figure 1 , Figure 2In the example, the straight line passing through core 10, core 11, and core 14 is the x-axis, core 11 is the outer side of the bend, and core 14 is the inner side of the bend. If the x-axis, y-axis, and angle θ are defined in this way, then Figure 2 In the case where the multi-core optical fiber 1 is bent, the angle θ is 180°.

[0054] When a pair of cores among the cores 10 to 16 of the multi-core optical fiber 1 is set as core m and core n, the group delay difference between the light propagating in core m and the light propagating in core n, that is, the hysteresis value S, is as described in detail in Patent Document 2 and is expressed by the following formula with i being set to m or n.

[0055]

[0056] F=-B2C 12 -B1(C 12 +C 11 )

[0057] G i =x i cosθ-y i sinθ

[0058] C 11 =E(1-v) / |(1+v)(1-2v)]

[0059] C 12 =Ev / [(1+v(1-2v)]

[0060] Where L is the length of the fiber, c is the speed of light in a vacuum, and N 1m is the group refractive index of the core m, N 1n is the group refractive index of the core n, R b is the bending radius of the multi-core optical fiber, B1 is the photoelastic coefficient of each core relative to the ordinary light, B2 is the photoelastic coefficient of each core relative to the extraordinary light, and x m ,y m is the coordinate position of the core m based on the center of the cladding 18, x n ,y n is the coordinate position of the core n based on the center of the cladding 18, E is the Young's modulus of the core, and ν is the Poisson's ratio of the core.

[0061] The skew value S can be obtained for all combinations of a pair of cores among the cores 10 to 16 of the multi-core optical fiber 1 . Figure 3 Yes means Figure 1 , Figure 2 A graph showing the relationship between the bending radius of the multi-core optical fiber 1 and the time delay value S per unit length of light propagating in a pair of cores. Figure 3, the skew value S between the core 11 and the core 14, the skew value S between the core 11 and the core 13, and the skew value S between the core 11 and the core 12 of the multi-core optical fiber 1 are shown. Figure 3 When the bending direction is the x-axis direction, that is, θ = 180°. In addition, the group refractive index N of a pair of cores is 1m 、N 1n That is, when the multi-core optical fiber 1 is in a straight line state, the skew value S is zero. Figure 3 It can be seen that the smaller the bending radius, the larger the skew value S is, and the skew value S increases rapidly in a region with a small bending radius.

[0062] Figure 4 : is a diagram showing the relationship between the angle θ between the arrangement direction of a pair of cores and the bending direction of the multi-core optical fiber 1, and the skew value S per unit length. Figure 4 In the figure, the bending radius R is shown. b The time delay value S of the light propagating in two of the cores 10, 11, and 14 by bending the multi-core optical fiber 1. Figure 4 In the example, the group refractive index of each core is made the same value. Figure 4 , when θ=90°, 270°, that is, when bending in the direction of the y-axis, the skew value S is 0, and when θ=0°, 180°, that is, when bending in the direction of the x-axis, the skew value S is maximum or minimum. That is, the absolute value of the skew value S when a pair of cores are arranged along the bending direction is greater than the skew value S when a pair of cores are not arranged along the bending direction. In addition, the absolute value of the skew value S of core 11-core 14 is greater than the absolute value of the skew value S of core 11-core 10 and the absolute value of the skew value S of core 14-core 10. That is, when the arrangement direction of a pair of cores relative to the bending direction is constant, the absolute value of the skew value S of the pair of cores with a larger inter-core distance is greater. This is because, when a multi-core optical fiber is bent, the difference in curvature radius between the core located on the inner circumference of the bend and the core located on the outer circumference becomes larger than when a pair of cores are arranged along the bend direction and the distance between the cores of the pair of cores is large, and the difference in transmission path length and effective group refractive index between the pair of cores caused by the bend becomes larger. In addition, for example, Figure 2 In this way, when the multi-core optical fiber 1 is bent, the skew value S of the core 12 - core 15 is equal to the skew value S of the core 11 - core 14 at θ=-60° (θ=300°).

[0063] Next, the multi-core optical fiber ribbon will be described.

[0064] Figure 5 FIG. 1 is a diagram showing an example of a multi-core optical fiber ribbon according to the present embodiment. Figure 5In the example of FIG. 1 , the multi-core optical fiber ribbon 2 of the present embodiment includes a plurality of multi-core optical fibers 1 and a ribbon-shaped coating 21 . In the example of FIG.

[0065] The multi-core optical fibers 1 are arranged side by side. Figure 5 In the example, the multi-core optical fiber 1 and Figure 1 The multi-core optical fiber 1 of the embodiment has four cores 11 to 14, and the cores 11 to 14 are arranged at the vertices of a square centered at the center of the cladding 18. In addition, in this example, a pair of cores 11 and 13 are arranged in a direction perpendicular to the arrangement direction of the plurality of multi-core optical fibers 1. The pair of cores 11 and 13 are the most distant core pairs together with the cores 12 and 14 among the core pairs of the cores of the multi-core optical fiber 1. The pair of cores 12 and 14 are arranged along the arrangement direction of the plurality of multi-core optical fibers 1.

[0066] The ribbon coating 21 covers the outer peripheral surface of the multi-core optical fiber 1 to make each multi-core optical fiber 1 integrated. The ribbon coating 21 is a flat shape with the main surface along the arrangement direction of the plurality of multi-core optical fibers 1. Therefore, the multi-core optical fiber ribbon 2 is in the shape of a flat rope. In this example, the shape of the cross section perpendicular to the length direction is roughly an elliptical track shape. The ribbon coating 21 is made of resin. The resin of the ribbon coating 21 can be the same type of resin as the protective layer 19, or a different type of resin.

[0067] Next, the production of the multi-core optical fiber ribbon 2 will be described.

[0068] Figure 6 2 is a diagram showing a manufacturing apparatus for a multi-core optical fiber ribbon 2. Figure 6 As shown, the manufacturing device 3 of the multi-core optical fiber ribbon 2 of the present embodiment includes a feeding unit 31, a winding unit 32, an aligning device 4, and a tape forming unit 33 as main components.

[0069] The delivery portion 31 is composed of, for example, a reel, and one end side of a plurality of multi-core optical fibers 1 is wound side by side. The delivery portion 31 can deliver the plurality of multi-core optical fibers 1 by rotating. The delivery portion 31 is, for example, a structure in which a plurality of reels are arranged side by side. One end of each multi-core optical fiber 1 is optically connected to the same number of multi-core optical fibers 31F as the multi-core optical fiber 1 through an optical rotary joint assembled in the delivery portion 31. The optical rotary joint is a joint component between optical fibers that can ensure optical connection between the multi-core optical fiber 1 and the multi-core optical fiber 31F even if the delivery portion 31 rotates. The delivery portion 31 can also be composed of a plurality of reels arranged side by side.

[0070] The centering device 4 is a device for aligning the direction of the axis center of the multi-core optical fiber 1 delivered from the delivery portion 31 in the rotation direction. The details of the centering device 4 will be described later.

[0071] The tape forming unit 33 tapes the plurality of multi-core optical fibers 1 aligned by the centering device 4. The tape forming unit 33 is composed of, for example, a die (dice) for applying uncured resin, which will become the tape coating 21, on the outer peripheral surface of each multi-core optical fiber 1, and a curing unit for curing the resin applied to the multi-core optical fiber 1 that has passed through the die. The resin applied to each multi-core optical fiber 1 is integrated when being sent out from the die, thereby forming a plurality of multi-core optical fibers 1 into a tape. Figure 5 The multi-core optical fiber ribbon 2 shown. In addition, examples of the resin that forms the ribbon-shaped coating 21 include ultraviolet curable resins, thermosetting resins, and thermoplastic resins.

[0072] The winding section 32 is composed of, for example, a reel, and can be rotated to wind up the multi-core optical fiber ribbon 2. The other ends of the multi-core optical fibers 1 of the multi-core optical fiber ribbon 2 are optically connected to the same number of multi-core optical fibers 32F as the multi-core optical fibers 1 through optical rotary joints assembled in the winding section 32. Therefore, even if the winding section 32 rotates, the optical connection between the multi-core optical fibers 1 and the multi-core optical fibers 32F can be maintained.

[0073] The centering device 4 includes a fiber rotating unit 41, a fiber bending unit 42, a skew measuring unit 40, and a control unit 49 as main components. The skew measuring unit 40 of this example includes a network analyzer 43, channel selectors 44 and 47, a fan-in device 45, a fan-out device 46, and a computing unit 48 as main components.

[0074] The optical fiber rotating unit 41 changes the rotation angle of the axial center of the multi-core optical fiber 1 . Figure 7 FIG. 4 is a diagram showing an example of the optical fiber rotating unit 41. Figure 7 As shown, the optical fiber rotating part 41 has a pulley 41P, a pulley shaft 41A and a driving part 41D as main structures. The pulley 41P is a disc-shaped component with a V-groove on the side. The multi-core optical fiber 1 sent out from the delivery part 31 is clamped by the V-groove. A through hole is formed in the center of the pulley 41P along the thickness direction, and the pulley shaft 41A is inserted into the through hole. Therefore, the pulley 41P can rotate around the pulley shaft 41A. One end of the pulley shaft 41A is connected to the driving part 41D. The driving part 41D is configured to include, for example, a stepping motor, etc., which can make the angle of the pulley shaft 41A in the length direction as shown in FIG. Figure 7 By changing the angle of the pulley shaft 41A, the angle of the pulley 41P changes as shown by the dotted line, and the rotation angle of the axial center of the multi-core optical fiber 1 clamped by the groove of the pulley 41P changes as shown by the dotted line.

[0075] exist Figure 7 , a structure for changing the rotation angle of one multi-core optical fiber 1 is shown, but the optical fiber rotating part 41 has the same number as the number of multi-core optical fibers 1. Figure 7The structure can make the rotation angles of multiple multi-core optical fibers 1 change independently. In addition, the groove of the pulley 41P is not limited to a V-shaped groove. For example, from the perspective of increasing the contact area between the multi-core optical fiber 1 and the pulley 41P to make it easier for the multi-core optical fiber 1 to rotate around the axis center, it is preferred that the bottom of the groove is formed into a curved surface, and the curvature radius of the bottom is roughly the same as the radius of the multi-core optical fiber 1. U-shaped groove.

[0076] The optical fiber bending portion 42 bends the multi-core optical fiber 1 whose rotation angle has changed in a predetermined direction. The optical fiber bending portion 42 of the present embodiment is composed of a pair of pulleys 42a and 42b. The pulleys 42a and 42b are, for example, structures in which the same number of pulleys as the pulley 41P are overlapped. Therefore, the optical fiber bending portion 42 can bend each multi-core optical fiber 1 under the same conditions. The diameters of the pulleys 42a and 42b may also be different from each other. The bending radius of the multi-core optical fiber 1 is preferably greater than 5 mm and less than 30 mm. The multiple multi-core optical fibers 1 sent out from the optical fiber rotating portion 41 are bent 360° by the pulleys 42a and 42b in the optical fiber bending portion 42. In addition, each multi-core optical fiber 1 may be wound on the pulleys 42a and 42b multiple times to be bent more than 360°. In addition, the radii of the pulleys 42a and 42b may also be different from each other, and the multi-core optical fiber 1 is bent with different radii of curvature.

[0077] In addition, in this embodiment, the multi-core optical fiber 1 is Figure 5 The arrangement direction of the cores 11 and 13 of the multi-core optical fiber 1 is wound around the pulleys 42a and 42b in the optical fiber bending portion 42 in a manner substantially along the radial direction of the pulleys 42a and 42b. That is, in this embodiment, Figure 5 The arrangement direction of the cores 11 and 13 of the multi-core optical fiber 1 is approximately along Figure 1 The x direction, Figure 2 The bending direction of the multi-core optical fiber 1 shown is along the x direction. The structure of winding the multi-core optical fiber 1 around the pulleys 42a and 42b in this way will be described later.

[0078] The network analyzer 43 is connected to the same number of optical fibers 43a and 43b as the number of the multi-core optical fibers 1 to be aligned. One optical fiber 43a and one optical fiber 43b correspond to one multi-core optical fiber 1. When light of a specified wavelength is emitted to each optical fiber 43a and the light is incident from the optical fiber 43b corresponding to each optical fiber 43a via a specified path, the network analyzer 43 measures the group delay of each light. The network analyzer 43 outputs a signal representing the measured group delay. In this embodiment, the light emitted from the network analyzer 43 to each optical fiber 43a propagates in any one of the cores 11 and 13 of each multi-core optical fiber 1. In addition, the network analyzer 43 can also be configured as a single-channel network analyzer that uses the same number of optical fibers 1 as the multi-core optical fibers 1 to connect one optical fiber 43a to one optical fiber 43b.

[0079] The channel selector 44 is connected to a plurality of the above-mentioned optical fibers 43a and a plurality of optical fibers 44a and 44b for output. The number of optical fibers 44a and 44b is the same as that of the multi-core optical fiber 1, and a pair is formed by one optical fiber 44a and one optical fiber 44b, and one pair corresponds to one multi-core optical fiber 1 and one optical fiber 43a. In addition, the optical fiber 44a and the optical fiber 44b are optical fibers with the same characteristics and the same length. Light incident from one optical fiber 43a is incident on any one of the pair of optical fibers 44a and 44b. The channel selector 44 switches in each pair which of the optical fibers 44a and 44b the light incident from the optical fiber 43a is output to. A fan-in device 45 is connected between each optical fiber 44a, 44b and the multi-core optical fiber 31F of the optical rotary joint of the delivery section 31. The fan-in device 45, for example, has a plurality of waveguides and a plurality of optical fibers respectively connected to each waveguide. In this embodiment, each optical fiber 44a is optically connected to the core 11 of each multi-core optical fiber 1 via the fan-in device 45 and the multi-core optical fiber 31F, and each optical fiber 44b is optically connected to the core 13 of each multi-core optical fiber 1 via the fan-in device 45 and the multi-core optical fiber 31F.

[0080] With the above configuration, light incident on each optical fiber 43 a from the network analyzer 43 enters each of the cores 11 and 13 of each multi-core optical fiber 1 via the channel selector 44 , the fan-in device 45 , and the multi-core optical fiber 31F.

[0081] The channel selector 47 has the same structure as the channel selector 44. However, the same number of optical fibers 43b for output are connected to the channel selector 47 instead of the multiple optical fibers 43a, and the same number of pairs of optical fibers 47a, 47b for input are connected instead of the multiple pairs of optical fibers 44a, 44b. The optical fiber 47a and the optical fiber 47b are optical fibers with the same characteristics and the same length. Light incident from any one of a pair of optical fibers 47a, 47b is incident on one optical fiber 43b. The channel selector 47 switches in each pair to make the light emitted to the optical fiber 43b become the light incident from which optical fiber 47a, 47b. A fan-out device 46 is connected between the multiple multi-core optical fibers 32F of the optical rotary joint of the winding section 32 and each optical fiber 47a, 47b. The fan-out device 46 has the same structure as the fan-in device 45, for example. In this embodiment, each optical fiber 47 a is optically connected to the core 11 of the multi-core optical fiber 1 via the multi-core optical fiber 32F and the fan-out device 46 , and each optical fiber 47 b is optically connected to the multi-core optical fiber 32F and the core 13 via the fan-out device 46 .

[0082] According to the above configuration, light emitted from any one of the cores 11 and 13 of each multi-core optical fiber 1 enters the network analyzer 43 via the multi-core optical fiber 32F, the fan-out device 46 , and the channel selector 47 .

[0083] The network analyzer 43 is electrically connected to the operation unit 48, and the signal indicating the group delay output by the network analyzer 43 is input to the operation unit 48. The operation unit 48 is composed of an operation device having a differential circuit. The operation unit 48 calculates the skew value S based on the signal indicating the group delay of each light input from the network analyzer 43. The skew value S is calculated for each of the multi-core optical fibers 1. The signal indicating the skew value S calculated by the operation unit 48 is output to the control unit 49.

[0084] The skew measurement unit 40 having the above configuration measures the skew value S of the light propagating through the pair of cores 11 and 13 of the multi-core optical fiber 1 .

[0085] The control unit 49 is composed of, for example, a microcontroller, an integrated circuit such as an IC (Integrated Circuit), an LSI (Large-scale Integrated Circuit), an ASIC (Application Specific Integrated Circuit), or an NC (Numerical Control) device. In addition, when the control unit 49 uses an NC device, a machine learning machine may be used or not. The control unit 49 controls the optical fiber rotation unit 41 based on a signal representing the lag value S output from the operation unit 48. Specifically, the control unit 49 controls the optical fiber rotation unit 41 to adjust the rotation angle of the axial center of the multi-core optical fiber 1 so that the lag value S becomes a specified value. In the present embodiment, the control unit 49 adjusts the rotation angle of the multi-core optical fiber 1 so that the lag value S becomes a maximum value.

[0086] Next, a method for manufacturing the multi-core optical fiber ribbon 2 will be described.

[0087] Figure 8 FIG. 2 is a flow chart showing a method for manufacturing a multi-core optical fiber ribbon 2. Figure 8 As shown, the manufacturing method of the multi-core optical fiber ribbon 2 of this embodiment comprises a feeding step S1, a centering step S2, and a ribbonizing step S3. In addition, the centering step S2 comprises an optical fiber rotating step S21, an optical fiber bending step S22, and a time delay measuring step S23. The centering step S2 constitutes a centering method for centering the direction of rotation of the multi-core optical fiber 1.

[0088] (Sending step S1)

[0089] This step is a step of feeding out a plurality of multi-core optical fibers 1. Specifically, the winding section 32 is rotated by a driving section (not shown) to wind up the multi-core optical fiber ribbon 2, thereby pulling each multi-core optical fiber 1, and feeding out the plurality of multi-core optical fibers 1 wound on the feeding section 31. In addition, a ribbon pulling machine may be provided before the winding section 32, and the multi-core optical fiber ribbon 2 may be pulled by the ribbon pulling machine.

[0090] (Optical Fiber Rotation Step S21)

[0091] This step is a step of changing the rotation angle of the axis center of the multi-core optical fiber 1. The plurality of multi-core optical fibers 1 delivered from the delivery unit 31 are delivered to the optical fiber rotating unit 41. In the optical fiber rotating unit 41, as shown in FIG. Figure 7 As described above, the multi-core optical fiber 1 enters the groove of the pulley 41P. If the inclination of the pulley 41P changes, the rotation angle of the axial center of the multi-core optical fiber 1 changes accordingly with the change in the inclination. The inclination of the pulley 41P changes appropriately according to the instruction from the control unit 49. Therefore, the rotation angle of the multi-core optical fiber 1 also changes appropriately according to the instruction from the control unit 49. The multiple multi-core optical fibers 1 with changed rotation angles are sent out from the optical fiber rotating unit 41 with the rotation angles roughly unchanged.

[0092] (Optical Fiber Bending Step S22)

[0093] This step is a step of bending the multi-core optical fiber 1 whose rotation angle has changed in a predetermined direction. The multi-core optical fiber 1 fed from the optical fiber rotating section 41 is fed into the optical fiber bending section 42. In the optical fiber bending section 42, the multi-core optical fiber 1 is bent by the pulleys 42a and 42b as described above. Therefore, a time delay is generated in the light propagating in the pair of cores 11 and 13 of the multi-core optical fiber 1. Figure 4 As described above, the time delay value S changes according to the relationship between the arrangement direction of the pair of cores 11 and 13 and the bending direction of the multi-core optical fiber 1. In this embodiment, the multi-core optical fiber 1 is bent by the pulleys 42a and 42b in such a manner that the bending direction of the multi-core optical fiber 1 is consistent with the arrangement direction of the cores 11 and 13. That is, the optical fiber rotating unit 41 changes the rotation angle of the multi-core optical fiber 1 so that the multi-core optical fiber 1 is bent by the pulleys 42a and 42b in this way. In this case, Figure 4 The angle θ between the bending direction in the fiber cores 11 and 13 and the arrangement direction is approximately 0°, and the time lag value S is approximately the maximum. In addition, as described above, if each multi-core optical fiber 1 is wound on the pulleys 42a and 42b multiple times, the time lag value S becomes larger, so it is preferred. Each multi-core optical fiber 1 is sent out from the optical fiber bending portion 42 after being bent by the optical fiber bending portion 42.

[0094] (Time Lag Measurement Step S23)

[0095] This step is a step of causing light to be incident on a pair of cores 11 and 13 of the multi-core optical fiber 1 and receiving each light emitted from the pair of cores 11 and 13 to measure the time delay value S of each light. The network analyzer 43 injects light of a specified wavelength into each optical fiber 43a. In the channel selector 44, for example, the channel is first set in such a way that the light from the optical fiber 43a propagates to the optical fiber 44a. Therefore, the light emitted from the network analyzer 43 is incident on the core 11 of each multi-core optical fiber 1 via the channel selector 44 and the fan-in device 45. The light propagating in the core 11 generates a group delay. The light emitted from the core 11 of each multi-core optical fiber 1 is incident on the network analyzer 43 via the fan-out device 46 and the channel selector 47. In the network analyzer 43, the group delay of each light is measured, and a signal including the group delay of each light is output to the operation unit 48. Next, the channel selector 44 sets the channel in such a way that the light from the optical fiber 43a propagates to each optical fiber 44b. Therefore, each light is incident on the core 13 of each multi-core optical fiber 1. The light propagating in the core 13 generates a group delay, and the group delay of each light incident on the network analyzer 43 is measured, and a signal including the group delay of each light is output to the operation unit 48. The group delay changes according to the radius of curvature of the propagating core. Therefore, in the optical fiber bending portion 42, the group delay of the light propagating in the core 11 and the light propagating in the core 13 are different according to the radius of curvature of the cores 11 and 13 determined by the pulleys 42a and 42b. The operation unit 48 calculates the skew value S based on the two group delays propagating in the cores 11 and 13. In this way, the skew value S of each multi-core optical fiber 1 is measured for each multi-core optical fiber 1. The signal including the calculated skew value S is output to the control unit 49.

[0096] The control unit 49 controls the optical fiber rotating unit 41 based on the signal including the skew value S input from the calculation unit 48 so that the skew value S becomes a predetermined value. That is, in the optical fiber rotation step S21, the rotation angle of the multi-core optical fiber 1 is adjusted so that the skew value S becomes a predetermined value. In the present embodiment, the optical fiber rotating unit 41 is controlled so that the skew value S becomes the maximum. When the skew value S becomes smaller, the control unit 49 controls the driving unit 41D of the optical fiber rotating unit 41, for example, to change the rotation angle of the multi-core optical fiber 1 in a manner such that the arrangement direction of the cores 11 and 13 moves toward the +θ side. At this time, when the skew value S becomes further smaller, the rotation angle of the multi-core optical fiber 1 is changed in a manner such that the arrangement direction of the cores 11 and 13 moves toward the -θ side. Therefore, in the present embodiment, as described above, the multi-core optical fiber 1 is bent by the pulleys 42a and 42b in a manner such that the bending direction of the multi-core optical fiber 1 is along the arrangement direction of the cores 11 and 13. In this way, the direction of the rotation direction of the axial center of each multi-core optical fiber 1 is aligned.

[0097] (Taping Step S3)

[0098] This step is a step of forming a plurality of multi-core optical fibers 1 that have been aligned in the alignment step S2 into a tape. Through the alignment step S2, the orientation of each multi-core optical fiber 1 in the rotational direction is aligned, and the multi-core optical fiber 1 is fed from the optical fiber bending section 42 to the tape forming section 33. In the tape forming section 33, the outer circumference of each multi-core optical fiber 1 is covered with an uncured resin that becomes a tape coating 21, and the resin is cured, thereby forming a plurality of multi-core optical fibers 1 into a tape. Figure 5 The multi-core optical fiber ribbon 2 is shown.

[0099] The multi-core optical fiber ribbon 2 is wound up by the winding unit 32 .

[0100] As described above, in the centering device 4 of the multi-core optical fiber 1 and the centering method of the multi-core optical fiber 1 of the present embodiment, the rotation angle of the axial center of the multi-core optical fiber 1 is changed, and the multi-core optical fiber 1 with the changed rotation angle is bent in a specified direction, and the time delay value S of the light propagating in a pair of cores 11 and 13 of the multi-core optical fiber 1 is measured. When the multi-core optical fiber 1 is rotated, the rotation angle of the multi-core optical fiber 1 is adjusted in such a way that the time delay value S becomes a specified value. By adjusting the rotation angle in such a way that the time delay value S becomes a specified value, the arrangement direction of the pair of cores can be made into a specified direction relative to the bending direction. Compared with the change of the leakage light, the change of the time delay value S relative to the rotation angle can be measured more accurately, so according to the centering device 4 of the multi-core optical fiber 1 and the centering method of the multi-core optical fiber 1 of the present embodiment, the centering in the rotation direction can be performed with high precision.

[0101] In addition, in the centering device 4 of the multi-core optical fiber 1 and the centering method of the multi-core optical fiber 1 of the present embodiment, the rotation angle is adjusted in such a way that the skew value S becomes the maximum value. In addition, the rotation angle can also be adjusted in such a way that the skew value S becomes the minimum value. In these cases, compared with adjusting the rotation angle in such a way that the skew value S becomes a specified value between the maximum value and the minimum value, the absolute value of the skew value S is large, the resolution of the skew value S can be improved, and the centering can be performed with higher accuracy. In addition, in the case where the arrangement direction of a pair of cores 11 and 13 is along the bending direction, the skew value S becomes the maximum or minimum. Therefore, the arrangement direction of a pair of cores 11 and 13 is along the bending direction, and the arrangement direction of a pair of cores 11 and 13 can be easily grasped, and the multi-core optical fiber 1 that has been aligned can be easily handled. In addition, unlike the present embodiment, in the centering device 4 of the multi-core optical fiber 1 and the centering method of the multi-core optical fiber 1, the rotation angle can also be adjusted in such a way that the skew value S becomes a specified value that is not the maximum. In this case, the arrangement direction of the cores 11 and 13 is along a direction other than the direction perpendicular to the arrangement direction of the multi-core optical fiber 1 in the multi-core optical fiber ribbon 2. For example, the rotation angle may be adjusted so that the skew value S becomes zero. In this case, the arrangement direction of the cores 11 and 13 is along the arrangement direction of the multi-core optical fiber 1. Alternatively, the rotation angle may be adjusted so that the skew value S becomes 45 degrees relative to the arrangement direction of the multi-core optical fiber 1.

[0102] In addition, in the centering device 4 of the multi-core optical fiber 1 and the centering method of the multi-core optical fiber 1 of the present embodiment, the pair of cores 11 and 13 whose skew value S is measured is the pair of cores that are farthest from each other among the plurality of cores 11 to 14 in the multi-core optical fiber 1. Therefore, if the rotation angle of the multi-core optical fiber 1 is offset, the change in the skew value S becomes larger. Therefore, the skew value S can be measured with higher accuracy, so that the centering can be performed with higher accuracy. In addition, the pair of cores whose skew value S is measured may not be the pair of cores that are farthest from each other. For example, the skew value S of the light propagating in the cores 11 and 12 may be measured. In this case, as long as the rotation angle is adjusted in such a way that the skew value S becomes the maximum value, the cores 11 and 12 are arranged in a direction perpendicular to the arrangement direction of the multi-core optical fiber 1, and the cores 11 and 13 are arranged in a direction that is 45° relative to the direction perpendicular to the arrangement direction of the multi-core optical fiber 1.

[0103] In addition, the manufacturing device 3 of the multi-core optical fiber ribbon 2 and the manufacturing method of the multi-core optical fiber ribbon 2 of the present embodiment feed out a plurality of multi-core optical fibers 1, perform the centering of the rotation direction of the fed multi-core optical fibers 1 by the above-mentioned centering, and form the aligned plurality of multi-core optical fibers 1 into a ribbon. According to such a manufacturing device 3 and manufacturing method of the multi-core optical fiber ribbon 2, a multi-core optical fiber ribbon 2 in which the rotation direction of each multi-core optical fiber 1 is highly precisely aligned can be manufactured.

[0104] Furthermore, in the present embodiment, the rotational direction of the plurality of multi-core optical fibers 1 included in the multi-core optical fiber ribbon 2 is adjusted. However, the rotational direction of a portion of the multi-core optical fibers 1 included in the multi-core optical fiber ribbon 2 may be adjusted without adjusting the rotational direction of the other portion of the multi-core optical fibers 1. In this case, only the multi-core optical fibers 1 that are adjusted are fed from the delivery section 31 to the ribbonizing section 33 via the adjustment device 4, and the other portion of the multi-core optical fibers 1 that are not adjusted are fed from the delivery section 31 to the ribbonizing section 33 without passing through the adjustment device 4. In this case, the optical fiber rotating section 41, the optical fiber bending section 42, and the time-delay measuring section 40 may be configured to adjust the multi-core optical fiber 1 to be adjusted.

[0105] (Second Embodiment)

[0106] Next, refer to Figures 9-11 The second embodiment of the present invention will be described in detail. Components that are the same as or equivalent to those in the first embodiment are denoted by the same reference numerals, and duplicate descriptions are omitted unless otherwise specified.

[0107] Fig. 9 is a diagram showing a multi-core optical fiber unit 100 according to this embodiment. Fig. 9 In the example, the multi-core optical fiber unit 100 includes a multi-core optical fiber 1 and a multi-core optical fiber 101 as another optical component, and the multi-core optical fiber 1 and the multi-core optical fiber 101 are connected. In this example, the cores 11 to 14 of the multi-core optical fiber 1 are connected to the cores 111 to 114 of the multi-core optical fiber 101, respectively. Fig. 9 , the configuration of each core is schematically shown, and the protective layer 19 is omitted.

[0108] Fig.10 1 is a diagram showing a manufacturing apparatus for the multi-core optical fiber unit 100 according to the present embodiment. Fig.10 As shown, the manufacturing device 5 of the multi-core optical fiber unit 100 of the present embodiment includes a feeding section 31 , a winding section 32 , an aligning device 4 , and a connecting section 50 as main components.

[0109] The manufacturing device 5 of this embodiment connects the cores 11 to 14 of one multi-core optical fiber 1 to the cores 111 to 114 of another multi-core optical fiber 101, respectively, thereby manufacturing the multi-core optical fiber unit 100. Therefore, one multi-core optical fiber 1 is wound in the delivery section 31, and one multi-core optical fiber 1 is wound in the winding section 32. Therefore, in the centering device 4, the centering of one multi-core optical fiber 1 in the rotation direction is performed.

[0110] The connecting portion 50 connects the multi-core optical fiber 1 that has been aligned by the centering device 4 to another multi-core optical fiber 101. The connecting portion 50 of the present embodiment includes a pulley 51, an optical fiber rotation and fixing moving portion 52, an optical fiber cutting portion 53, and a fusion splicing portion 54. The pulley 51, for example, has the same structure as the pulley 41P. The optical fiber cutting portion 53, for example, has an optical fiber cutter that can cut the multi-core optical fiber 1. The optical fiber rotation and fixing moving portion 52, for example, has a structure that can clamp the outer peripheral surface of the multi-core optical fiber 1 from three directions, and can switch the rotation of the axial center of the multi-core optical fiber 1 between fixed and non-fixed. The optical fiber rotation and fixing moving portion 52 can move the end of the multi-core optical fiber 1 formed by cutting after the optical fiber cutting portion 53 is cut in a state where the rotation of the multi-core optical fiber 1 is fixed, as shown by the dotted line, to the fusion splicing portion 54.

[0111] The end of the multi-core optical fiber 101 is placed in the fusion splice 54. The cores 111 to 114 of the multi-core optical fiber 101 are as follows. Fig. 9 As described above, the cores 11 to 14 are arranged symmetrically with each other and can be opposed to the cores 11 to 14, respectively.

[0112] The fusion splice 54 includes, for example, a pair of discharge electrodes that are opposed to each other with the end of the multi-core optical fiber 1 and the end of the multi-core optical fiber 101 sandwiched therebetween, and the end of the multi-core optical fiber 1 and the end of the multi-core optical fiber 101 are fused together by heating based on discharge from the discharge electrodes. The fusion splice 54 may also be fused by other methods.

[0113] Next, a method for manufacturing the multi-core optical fiber unit 100 will be described.

[0114] Fig.11 1 is a flow chart showing a method for manufacturing the multi-core optical fiber unit 100 according to the present embodiment. Fig.11 As shown, the manufacturing method of the multi-core optical fiber unit 100 involved in this embodiment includes a centering step S2 and a connection step S4. In this embodiment, the centering step S2 also constitutes a centering method for centering the orientation of the multi-core optical fiber 1 in the rotation direction, and includes a fiber rotation step S21, a fiber bending step S22, and a time delay measurement step S23. The connection step S4 is a step of connecting the cores 11 to 14 of the multi-core optical fiber 1 that has been centered in the centering step S2 to other waveguides. The connection step S4 of this embodiment includes a fiber cutting step S41, a fiber moving step S42, and a fusion splicing step S43.

[0115] (Centering step S2)

[0116] First, similarly to the alignment step S2 of the first embodiment, the rotational direction alignment of the multi-core optical fiber 1 is performed. However, in the present embodiment, only one multi-core optical fiber 1 is aligned.

[0117] (Optical Fiber Cutting Step S41)

[0118] This step is a step of cutting the multi-core optical fiber 1. If the portion of the multi-core optical fiber 1 whose rotational direction has been adjusted by the adjustment step S2 is moved to the optical fiber cutting section 53 via the pulley 51, the winding section 32 stops the winding of the multi-core optical fiber 1, and accordingly, the delivery section 31 stops the delivery of the multi-core optical fiber 1. In the state where the movement of the multi-core optical fiber 1 has stopped, the optical fiber rotation fixing moving section 52 fixes the rotation of the multi-core optical fiber 1 in such a manner that the multi-core optical fiber 1 does not rotate. Then, the optical fiber cutting section 53 cuts the multi-core optical fiber 1. The end of the multi-core optical fiber 1 formed by the cutting is in a state where the rotational direction is adjusted.

[0119] (Optical Fiber Moving Step S42)

[0120] This step is a step of moving the end of the multi-core optical fiber 1 to the fusion splice 54. The optical fiber rotation fixing moving part 52 moves the end of the multi-core optical fiber 1 to the fusion splice 54 while maintaining the rotation state of the multi-core optical fiber 1. At this time, in order to suppress the change of the tension applied to the multi-core optical fiber 1, the optical fiber rotation fixing moving part 52 is rotated, for example, approximately 90 degrees.

[0121] (Welding Step S43)

[0122] This step is a step of fusing the multi-core optical fiber 1 with the multi-core optical fiber 101. The cores 11 to 14 of the moved multi-core optical fiber 1 are opposed to the cores 111 to 114 of the multi-core optical fiber 101. In addition, in the centering step S2, after the optical fiber moving step S42, the centering is performed in a manner in which the cores 11 to 14 and the cores 111 to 114 are opposed to each other. In this step, the end of the multi-core optical fiber 1 and the end of the multi-core optical fiber 101 are melted, for example, by discharge, so that the respective ends are brought into contact, thereby performing fusion splicing. At this time, the cores 11 to 14 and the cores 111 to 114 are opposed to each other, so that the cores 11 to 14 and the cores 111 to 114 are fused to each other. In this way, the multi-core optical fiber 1 and the multi-core optical fiber 101 are connected to produce. Fig. 9 The multi-core optical fiber unit 100 is shown.

[0123] In the manufacturing device 5 of the multi-core optical fiber unit 100 and the connection method of the multi-core optical fiber unit 100 of the present embodiment, the cores 11 to 14 of the multi-core optical fiber 1 that have been aligned by the alignment device 4 and the above-mentioned alignment method are connected to other optical components. Therefore, the multi-core optical fiber 1 is connected in a state where the rotation direction is aligned with high precision, so that the multi-core optical fiber unit 100 in which the multi-core optical fiber 1 whose rotation direction is properly aligned is connected to the multi-core optical fiber 101 as another optical component can be manufactured. Therefore, in the multi-core optical fiber unit 100 of this example, the cores 11 to 14 and the cores 111 to 114 can be appropriately opposed to each other, so that the leakage of light at the connection portion can be suppressed.

[0124] In addition, in the present embodiment, the connection part 50 has a pulley 51, an optical fiber rotation and fixing moving part 52, an optical fiber cutting part 53 and a fusion splicing part 54, but they are not essential, as long as the cores 11 to 14 of the multi-core optical fiber 1 that has been aligned by the aligning device 4 can be connected to other optical components. For example, in the present embodiment, an example of a connection based on fusion is shown, but a connection based on crimping can also be used. In this case, the connection part 50 has a crimping part instead of the fusion splicing part 54, and the connection step S4 has a crimping step instead of the fusion splicing step S43. Moreover, as in the above-mentioned embodiment, after the end of the multi-core optical fiber 1 is moved in the optical fiber moving step S42, a crimping step is performed, and in the crimping step, the crimping part crimps the end of the multi-core optical fiber 1 to the end of the multi-core optical fiber 101.

[0125] In addition, in this embodiment, the multi-core optical fiber 101 is used as an example for explanation as an optical component. However, the optical component can be any component connected to the multi-core optical fiber 1, and it does not need to be the multi-core optical fiber 101. As an optical component, for example, it can be a waveguide substrate, a fan-in-fan-out device, or a multi-core optical connector. In addition, the optical component can also be optically connected to only a part of the cores 11 to 14 of the multi-core optical fiber 1.

[0126] In addition, the optical component only needs to be a component connected to the multi-core optical fiber 1 such as a ferrule, and may not be optically coupled to the cores 11 to 14. For example, in the case where the optical component is a ferrule, the connecting portion 50 has an insertion portion instead of the fusion portion 54, and the connecting step S4 has an insertion step instead of the fusion step S43. Moreover, as in the above-mentioned embodiment, after the end of the multi-core optical fiber 1 is moved in the optical fiber moving step S42, an insertion step is performed. In the insertion step, the insertion portion relatively moves the multi-core optical fiber 1 and the ferrule in such a way that the end of the multi-core optical fiber 1 is inserted into the ferrule, thereby connecting the multi-core optical fiber 1 to the ferrule. Therefore, a multi-core optical fiber unit is manufactured in which the multi-core optical fiber 1 and the ferrule are connected in a state where the centering of the rotation direction of the multi-core optical fiber 1 is highly accurately aligned. When the ferrule is accommodated in the housing of the optical fiber connector, the optical fiber connector becomes a multi-core optical fiber unit.

[0127] In addition, in this embodiment, an example of connecting a multi-core optical fiber 1 to an optical component is used for explanation. However, it is also possible to perform centering of a plurality of multi-core optical fibers 1 in the rotational direction and connect the plurality of multi-core optical fibers 1 to the optical component. The centering of the plurality of multi-core optical fibers 1 can be performed, for example, by the centering device 4 in the first embodiment.

[0128] (Third Embodiment)

[0129] Next, refer to Fig.12 ,13 The third embodiment of the present invention will be described in detail. Components that are the same as or equivalent to those in the first embodiment are denoted by the same reference numerals, and duplicate descriptions are omitted unless otherwise specified.

[0130] Fig.12 2 is a diagram showing an inspection device for a multi-core optical fiber ribbon 2 according to the present embodiment. Fig.12 As shown, the inspection device 6 for the multi-core optical fiber ribbon 2 of the present embodiment has a delivery section 31, an optical fiber bending section 42, a winding section 33, a network analyzer 43, channel selectors 44, 47, a fan-in device 45, a fan-out device 46, a calculation section 48 and a determination section 60 as main structures.

[0131] The multi-core optical fiber ribbon 2 is wound on the delivery section 31 of the present embodiment. As in the first embodiment, one end of each multi-core optical fiber 1 of the multi-core optical fiber ribbon 2 is optically connected to the same number of multi-core optical fibers 31F as the multi-core optical fibers 1. The width of the groove of the pulleys 42a, 42b of the optical fiber bending section 42 of the present embodiment is larger than the width in the arrangement direction of the multi-core optical fibers 1 of the multi-core optical fiber ribbon 2, and the bottom of the groove is formed to be flat. Therefore, the multi-core optical fiber ribbon 2 can be bent in a direction perpendicular to the arrangement direction of the multi-core optical fibers 1.

[0132] The calculation unit 48 of this embodiment outputs the calculated skew value S to the determination unit 60. The determination unit 60 has, for example, the same structure as the control unit 49, and determines whether the skew value S is outside the predetermined range. Figure 5 As shown, the arrangement direction of the cores 11 and 13 of the multi-core optical fiber 1 is perpendicular to the arrangement direction of the multi-core optical fiber 1 of the multi-core optical fiber ribbon 2. As in the first embodiment, the skew value of the light propagating in the cores 11 and 13 of each multi-core optical fiber 1 is measured. In this case, the above-mentioned prescribed range is, for example, from the maximum value of the skew value S to a value as low as 1% of the maximum value. When the skew value S of any multi-core optical fiber 1 is outside the prescribed range, the determination unit 60 outputs which position in the length direction of which multi-core optical fiber 1 is outside the prescribed range.

[0133] Next, a method for inspecting the multi-core optical fiber ribbon 2 will be described.

[0134] Fig.13 FIG. 2 is a flow chart showing a method for inspecting the multi-core optical fiber ribbon 2 according to the present embodiment. Fig.13 As shown, the inspection method of the multi-core optical fiber ribbon 2 according to the present embodiment includes a feeding step S1, an optical fiber bending step S22, a skew measuring step S23, and a determination step S5.

[0135] (Sending step S1)

[0136] In this step, the multi-core optical fiber ribbon 2 including the plurality of multi-core optical fibers 1 is fed out from the feeding portion 31 .

[0137] (Optical Fiber Bending Step S22)

[0138] In this step, each multi-core optical fiber 1 is bent by bending the multi-core optical fiber ribbon 2. The multi-core optical fiber ribbon 2 delivered from the delivery section 31 is delivered to the optical fiber bending section 42, and is bent in a predetermined direction by each pulley 42a, 42b. At this time, in this embodiment, the optical fiber bending section 42 bends the multi-core optical fiber ribbon 2 in the thickness direction thereof. This direction is a direction perpendicular to the arrangement direction of the multi-core optical fibers 1, and is the arrangement direction of the fiber cores 11, 13.

[0139] (Time Lag Measurement Step S23)

[0140] This step is a step of causing light to enter the pair of cores 11 and 13 of each multicore optical fiber 1 and receiving each light emitted from the pair of cores 11 and 13 of each multicore optical fiber 1 to measure the skew value S of each light for each multicore optical fiber 1. In this embodiment, the skew value S is measured in the same manner as in the first embodiment.

[0141] (Determination step S5)

[0142] This step is a step of determining whether the skew value S of at least one multi-core optical fiber 1 is outside the prescribed range. If the skew value S is input from the operation unit 48, the determination unit 60 determines whether the skew value S is outside the prescribed range. When the skew value S is within the prescribed range, for example, no signal is output. When the skew value S is outside the prescribed range, a signal indicating that the multi-core optical fiber 1 has a skew value S outside the prescribed range and a signal indicating the position of the multi-core optical fiber 1 in the longitudinal direction where the skew value S is outside the prescribed range are output.

[0143] In the inspection device 6 and the inspection method of the multi-core optical fiber ribbon 2 of the present embodiment, in the portion bent by the optical fiber bending portion 42, the time lag value S is used outside the prescribed range to detect the centering offset of the multi-core optical fiber 1, thereby being able to detect the centering offset of the multi-core optical fiber 1 with high precision.

[0144] In addition, in the present embodiment, the multi-core optical fiber ribbon 2 is fed sequentially to the optical fiber bending portion 42, so that the centering deviation of the multi-core optical fiber 1 can be detected along the length direction. Therefore, the interval of the centering deviation in the rotation direction of the multi-core optical fiber 1 can be detected with high precision. In addition, the feeding of the multi-core optical fiber ribbon 2 to the optical fiber bending portion 42 is not a necessary configuration. For example, if the rotation direction of the multi-core optical fiber 1 hardly changes in the length direction, the multi-core optical fiber 1 in the multi-core optical fiber ribbon 2 is bent by the optical fiber bending portion 42, and the time lag value S is measured, thereby determining the multi-core optical fiber 1 that has produced the centering deviation in the rotation direction.

[0145] Furthermore, in the present embodiment, the above-mentioned prescribed range may also be a value from the minimum value of the skew value S to a value up to 1% of the minimum value. In addition, the pair of cores for measuring the skew value S may not be arranged along the thickness direction of the multi-core optical fiber ribbon 2. However, the arrangement of the pair of cores along the thickness direction of the multi-core optical fiber ribbon 2 increases the value of the skew value S, and can detect the centering deviation in the rotation direction of the multi-core optical fiber 1 with higher accuracy, which is preferred.

[0146] Furthermore, in the present embodiment, the centering offset of the plurality of multi-core optical fibers 1 included in the multi-core optical fiber ribbon 2 is detected. However, the centering offset of a portion of the multi-core optical fibers 1 included in the multi-core optical fiber ribbon 2 may be detected without detecting the centering offset of another portion of the multi-core optical fibers 1. In this case, it is sufficient that only the multi-core optical fibers 1 for which the centering offset is detected are connected to the time-delay measuring unit 40. In this case, the time-delay measuring unit 40 only needs to have a structure capable of measuring the time-delay value of the multi-core optical fiber 1 for which the centering offset is detected.

[0147] As mentioned above, although the present invention has been described by taking the embodiments as examples, the present invention is not limited to these.

[0148] For example, the number and arrangement of the cores of the multi-core optical fiber 1 may be different from those in the above-described embodiment. The cores of the multi-core optical fiber 1 may be arranged in a straight line, an annular ring, or a lattice.

[0149] In addition, the structure of the multi-core optical fiber ribbon 2 can also be Figure 5 The structure shown is different. For example, the number of multi-core optical fibers 1 constituting the multi-core optical fiber ribbon 2 can be appropriately changed. In addition, it is not necessary for all optical fibers constituting the multi-core optical fiber ribbon 2 to be multi-core optical fibers 1. The multi-core optical fiber ribbon 2 only needs to include at least one multi-core optical fiber 1. Therefore, for example, the multi-core optical fiber ribbon 2 may also have more than one multi-core optical fiber 1 and more than one single-core optical fiber. In this case, the centering device 4 is used to perform centering of the rotation direction of at least one multi-core optical fiber 1.

[0150] Fig.14 2 is a diagram showing a modified example of the multi-core optical fiber ribbon 2. Fig.14As shown, a plurality of mutually adjacent multi-core optical fibers 1 may be fixed to each other by a fixing resin 22 to form a multi-core optical fiber ribbon 2. Fig.14 In the figure, the case where there are two multi-core optical fibers 1 is shown, but the multi-core optical fibers 1 may be three or more. In addition, the fixing resin 22 may be provided intermittently along the length direction of the multi-core optical fiber 1. When such a fixing resin 22 is used, Figure 5 Compared with the multi-core optical fiber ribbon 2 shown in the figure, the multi-core optical fiber 1 is easily offset in the rotation direction. Therefore, in the third embodiment, when inspecting the multi-core optical fiber ribbon 2, it is preferred to increase the tension. In addition, in this modified example, the multi-core optical fiber ribbon 2 may also include more than one multi-core optical fiber 1 and more than one single-core optical fiber.

[0151] In the first and third embodiments, the plurality of optical fibers 43a and 43b are respectively connected to the network analyzer 43, but one of the optical fibers 43a and 43b may be connected to the network analyzer 43. In this case, the channel selector 44 switches the optical path so that light is sequentially propagated to the plurality of multi-core optical fibers 1, and the channel selector 47 switches the optical path so that light incident from any one of the plurality of optical fibers 47a and 47b is emitted to the optical fiber 43b.

[0152] In addition, the centering device 4 may also include a memory having a table indicating the relationship between the angle θ formed by the direction in which a pair of cores are arranged and the bending direction and the skew value S. In this case, the control unit 49 may refer to the memory and perform calculations based on the measured skew value S and the table to adjust the rotation angle of the multi-core optical fiber 1 at the optical fiber rotating unit 41.

[0153] In addition, the delivery part and the winding part may not use a reel. For example, the multi-core optical fiber 1 may be drawn out from a folded state or a coiled state within a range without being damaged, and may be drawn out in the same state instead of winding.

[0154] In addition, the skew measuring unit 40 may have other configurations as long as it can measure the skew value S of the light propagating through the pair of cores of the multi-core optical fiber 1 .

[0155] As described above, according to the present invention, there are provided a centering device for a multi-core optical fiber that can accurately center the multi-core optical fiber in the rotational direction, a manufacturing device for a multi-core optical fiber ribbon, a connecting device for a multi-core optical fiber, a centering method for a multi-core optical fiber, a manufacturing method for a multi-core optical fiber ribbon, and a connecting method for a multi-core optical fiber, as well as an inspection device for a multi-core optical fiber ribbon and an inspection method for a multi-core optical fiber ribbon that can accurately detect the centering deviation in the rotational direction of the multi-core optical fiber, which can be used in the fields of optical communications and the like.

Claims

1. A centering device for a multi-core optical fiber, characterized in that: have: An optical fiber rotating unit changes the rotation angle of the axis center of the multi-core optical fiber; an optical fiber bending portion for bending the multi-core optical fiber whose rotation angle has changed in a predetermined direction; a time skew measuring unit that measures a time skew value of light propagating through a pair of cores of the multi-core optical fiber; and The control unit controls the optical fiber rotating unit to adjust the rotation angle of the multi-core optical fiber so that the skew value becomes a predetermined value.

2. The centering device for a multi-core optical fiber according to claim 1, characterized in that: The control unit adjusts the rotation angle so that the time lag value becomes a maximum value or a minimum value.

3. A manufacturing device for a multi-core optical fiber ribbon, characterized in that: have: A sending part, sending out one or more multi-core optical fibers; The multi-core optical fiber centering device according to claim 1 or 2, which performs centering of the orientation in the rotation direction of at least one of the multi-core optical fibers delivered from the delivery portion; as well as The tape forming unit forms a plurality of optical fibers including the multi-core optical fiber aligned by the alignment device into a tape.

4. A manufacturing device for a multi-core optical fiber unit, characterized in that: have: The centering device according to claim 1 or 2; and The connection portion connects the multi-core optical fiber aligned by the alignment device to another optical component.

5. A method for aligning a multi-core optical fiber, characterized in that: have: An optical fiber rotating step to change the rotation angle of the axis center of the multi-core optical fiber; an optical fiber bending step of bending the multi-core optical fiber with the changed rotation angle in a predetermined direction; as well as a time lag measuring step of measuring a time lag value of light propagating in a pair of cores of the multi-core optical fiber, In the optical fiber rotating step, the rotation angle of the multi-core optical fiber is adjusted so that the skew value becomes a predetermined value.

6. The method for aligning a multi-core optical fiber according to claim 5, characterized in that: In the optical fiber rotating step, the rotation angle is adjusted so that the time lag value becomes a maximum value or a minimum value.

7. The method for aligning a multi-core optical fiber according to claim 5 or 6, characterized in that: The pair of cores is a pair of cores that are most distant from each other among the plurality of cores of the multi-core optical fiber.

8. A method for manufacturing a multi-core optical fiber ribbon, characterized in that: have: A sending out step, sending out one or more multi-core optical fibers; an alignment step of adjusting the orientation of at least one of the multi-core optical fibers fed out in the feeding step in a rotational direction by using the multi-core optical fiber alignment method according to any one of claims 5 to 7; as well as The step of forming a tape is to form a plurality of the multi-core optical fibers aligned in the step of aligning into a tape.

9. A method for manufacturing a multi-core optical fiber unit, characterized in that: have: an alignment step of performing alignment of the multi-core optical fiber in a rotational direction by using the multi-core optical fiber alignment method according to any one of claims 5 to 7; and The connecting step is to connect the multi-core optical fiber aligned in the alignment step to another optical component.

10. An inspection device for a multi-core optical fiber ribbon, characterized in that: have: an optical fiber bending section that bends a multi-core optical fiber by bending a multi-core optical fiber ribbon having one or more multi-core optical fibers; a time lag measuring unit for measuring a time lag value of light propagating in a pair of cores of at least one of the multi-core optical fibers; as well as The determination unit determines that the skew value of at least one of the multi-core optical fibers is outside a predetermined range.

11. A method for inspecting a multi-core optical fiber ribbon, characterized in that: have: an optical fiber bending step of bending the multi-core optical fiber by bending a multi-core optical fiber ribbon having more than one multi-core optical fiber; a time lag measuring step of measuring a time lag value of light propagating in a pair of cores of at least one of the multi-core optical fibers; as well as The step of determining whether the skew value of at least one of the multi-core optical fibers is outside a prescribed range.

12. The method for inspecting a multi-core optical fiber ribbon according to claim 11, characterized in that: The multi-core optical fiber ribbon includes a plurality of optical fibers arranged in parallel including the multi-core optical fiber. The pair of fiber cores are arranged perpendicular to the arrangement direction of the optical fibers.

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