Optical connection assembly, optical waveguide component, and method for manufacturing optical connection assembly

Abstract

This optical connection assembly according to the present invention comprises an optical waveguide component, a plurality of optical fiber members each including a plurality of cores, and a plurality of single core fibers. The plurality of optical fiber members include a first optical fiber member and a second optical fiber member. The plurality of single core fibers include a first single core fiber and a second single core fiber. The plurality of optical waveguides include a first optical waveguide optically coupled to a first core of the first optical fiber member and optically coupled to the first single core fiber, and a second optical waveguide optically coupled to a second core of the second optical fiber member and optically coupled to the second single core fiber. The arrangement of the plurality of cores referenced to the center axis of each of the plurality of optical fiber members is the same for each of the plurality of optical fiber members.

Description

Optical connection assembly, optical waveguide component, method for manufacturing optical connection assembly

[0001] This disclosure relates to optical connection assemblies, optical waveguide components, and methods for manufacturing optical connection assemblies. This application claims priority under Japanese application No. 2024-213758, filed on 6 December 2024, incorporating all the provisions of the said Japanese application.

[0002] As an example of optical waveguide components, FIFO (Fan-in / Fan-out) devices are known that convert the pitch between multiple waveguides along the direction of light propagation (see, for example, Patent Documents 1 and 2). Such FIFO devices make it possible to connect two optical components with different minimum core pitches to each other with low loss. For example, a FIFO device makes it possible to connect each core of multiple single-core fibers to the corresponding cores of a multi-core fiber or bundled fiber with low loss.

[0003] International Publication No. 2008 / 155548, U.S. Patent Application Publication No. 2022 / 0373732, Specification

[0004] The optical connection assembly of the present disclosure includes an optical waveguide component including a first surface, a second surface different from the first surface, and a plurality of optical waveguides extending from the first surface to the second surface; a plurality of cores arranged in N stages (where N is an integer of 1 or more) in a first direction along the first surface, each of the plurality of cores being connected to the first surface such that the plurality of cores are optically coupled to the plurality of optical waveguides; a plurality of optical fiber members arranged along a second direction intersecting the first direction; and a plurality of single-core fibers arranged along the second direction and connected to the second surface such that each of the plurality of single-core fibers is optically coupled to the plurality of optical waveguides. The plurality of optical fiber members include a first optical fiber member and a second optical fiber member different from the first optical fiber member. The plurality of single-core fibers include a first single-core fiber and a second single-core fiber different from the first single-core fiber. The plurality of optical waveguides include a first optical waveguide optically coupled to a first core that is one of the plurality of cores of the first optical fiber member and optically coupled to the first single-core fiber, and a second optical waveguide optically coupled to a second core different from the first core among the plurality of cores of the second optical fiber member and optically coupled to the second single-core fiber. The arrangement of the plurality of cores with respect to the central axis of each of the plurality of optical fiber members is the same in each of the plurality of optical fiber members.

[0005] Figure 1 is a perspective view showing an optical connection assembly of one embodiment. Figure 2 is a perspective view showing an optical connection assembly with the multicore fiber array and single-core fiber array separated from the optical waveguide substrate. Figure 3 is a plan view showing the optical connection assembly of Figure 1. Figure 4 is a side view showing the optical connection assembly of Figure 1. Figure 5 is a front view showing the multicore fiber array of Figure 1. Figure 6 is a front view showing the single-core fiber array of Figure 1. Figure 7 is a front view showing the optical waveguide substrate of Figure 1. Figure 8 is a rear view showing the optical waveguide substrate of Figure 1. Figure 9 is a diagram illustrating the connection relationship between the multicore fiber array, the optical waveguide substrate and the single-core fiber array. Figure 10 is a diagram showing the relationship between the arrangement of multiple cores in the first multicore fiber and the second multicore fiber and the arrangement of multiple optical waveguides in the optical waveguide substrate. Figure 11 is a diagram showing the manufacturing process of an optical connection assembly of one embodiment. Figure 12 is a diagram showing the subsequent process after Figure 11. Figure 13 is a diagram illustrating the problem of the optical connection assembly of Reference Example 1. Figure 14 is a diagram illustrating the problem of the optical connection assembly in Reference Example 2. Figure 15 is a diagram illustrating the problem of the optical connection assembly in Reference Example 3. Figure 16 is a diagram showing the relationship between the arrangement of multiple cores in the first multicore fiber and the second multicore fiber and the arrangement of multiple optical waveguides on the optical waveguide substrate in the optical connection assembly of Modification Example 1. Figure 17 is a diagram showing the relationship between the arrangement of multiple cores in the first bundle fiber and the second bundle fiber and the arrangement of multiple optical waveguides on the optical waveguide substrate in the optical connection assembly of Modification Example 2. Figure 18 is a diagram showing the relationship between the arrangement of multiple cores in the first multicore fiber and the second multicore fiber and the arrangement of multiple optical waveguides on the optical waveguide substrate in the optical connection assembly of Modification Example 3. Figure 19 is a diagram showing the relationship between the arrangement of multiple cores in the first multicore fiber and the second multicore fiber and the arrangement of multiple optical waveguides on the optical waveguide substrate in the optical connection assembly of Modification Example 4. Figure 20 shows the relationship between the arrangement of multiple cores in the first multicore fiber and the second multicore fiber, and the arrangement of multiple optical waveguides in the optical waveguide substrate, in the optical connection assembly of modified example 5.Figure 21 shows the relationship between the arrangement of multiple cores in the first and second multicore fibers and the arrangement of multiple optical waveguides on the optical waveguide substrate in the optical connection assembly of Modified Example 6. Figure 22 shows the relationship between the arrangement of multiple cores in the first and second multicore fibers and the arrangement of multiple optical waveguides on the optical waveguide substrate in the optical connection assembly of Modified Example 7. Figure 23 shows the relationship between the arrangement of multiple cores in the first and second multicore fibers and the arrangement of multiple optical waveguides on the optical waveguide substrate in the optical connection assembly of Modified Example 8. Figure 24 is a diagram illustrating the problem of the optical connection assembly in Reference Example 4. Figure 25 is a diagram illustrating the problem of the optical connection assembly in Reference Example 5. Figure 26 shows the relationship between the arrangement of multiple cores in the first and second multicore fibers and the arrangement of multiple optical waveguides on the optical waveguide substrate in the optical connection assembly of Modified Example 9. Figure 27 is a diagram illustrating the problem of the optical connection assembly in Reference Example 6.

[0006] To achieve higher capacity in optical transmission, development of multicore fibers with multiple cores is progressing. Even after multicore fibers are put into practical use, it is thought that FIFO devices will be needed to connect each core of the multicore fiber to a single-core fiber within the optical transmission path. One type of FIFO device is the optical waveguide type, and it is conceivable to use a FIFO device that integrates more optical waveguides to optically connect more optical fibers. However, as the number of optical fibers to be connected increases, the amount of optical fiber alignment work required for the FIFO device may increase. To put such FIFO devices into practical use, it is important to improve the efficiency of the alignment work.

[0007] This disclosure provides an optical connection assembly that facilitates alignment work, an optical waveguide component, and a method for manufacturing an optical connection assembly.

[0008] According to this disclosure, the alignment process becomes easier.

[0009] Embodiments of optical connection assemblies, optical waveguide components, and methods for manufacturing optical connection assemblies described herein are explained.

[0010] (1) An optical connection assembly of one embodiment includes an optical waveguide component including a first surface, a second surface different from the first surface, and a plurality of optical waveguides extending from the first surface to the second surface; a plurality of optical fiber members each containing a plurality of cores arranged in N stages (where N is an integer of 1 or more) in a first direction along the first surface, connected to the first surface so as to be optically coupled to the plurality of optical waveguides, and arranged along a second direction intersecting the first direction; and a plurality of single-core fibers connected to the second surface so as to be optically coupled to the plurality of optical waveguides, and arranged along the second direction. The plurality of optical fiber members include a first optical fiber member and a second optical fiber member different from the first optical fiber member. The plurality of single-core fibers include a first single-core fiber and a second single-core fiber different from the first single-core fiber. The plurality of optical waveguides include a first optical waveguide that is optically coupled to a first core, which is one of the plurality of cores of a first optical fiber member, and is optically coupled to a first single-core fiber, and a second optical waveguide that is optically coupled to a second core, which is different from the first core among the plurality of cores of a second optical fiber member, and is optically coupled to a second single-core fiber. The arrangement of the plurality of cores with respect to the central axis of each of the plurality of optical fiber members is the same in each of the plurality of optical fiber members.

[0011] In the optical connection assembly described above, the first single-core fiber and the second single-core fiber are optically coupled to the first optical waveguide and the second optical waveguide of the optical waveguide component, respectively. The first optical waveguide is optically coupled to the first core of the first optical fiber member, and the second optical waveguide is optically coupled to the second core of the second optical fiber member. In this case, when manufacturing the optical connection assembly, for example, if alignment light is input to the first single-core fiber and the second single-core fiber, that light passes through the first optical waveguide and the second optical waveguide and is output from the first core of the first optical fiber member and the second core of the second optical fiber member. When the intensity of that light is at its maximum, the first single-core fiber and the second single-core fiber, as well as the first core of the first optical fiber member and the second core of the second optical fiber member, are aligned with respect to the first optical waveguide and the second optical waveguide. Since the arrangement of multiple cores relative to the central axis of each optical fiber member is the same for each optical fiber member, if the first core of the first optical fiber member and the second core of the second optical fiber member are aligned, all remaining cores and all remaining single-core fibers corresponding to them can also be aligned. In other words, in the optical connection assembly described above, once the alignment work of the first single-core fiber and the second single-core fiber, and the first core of the first optical fiber member and the second core of the second optical fiber member is performed, all cores of all optical fiber members and all single-core fibers can be aligned together, eliminating the need to align each core of each optical fiber member and each single-core fiber one by one. Therefore, with the optical connection assembly described in (1) above, alignment work can be easily performed even if the number of optical fiber members and single-core fibers increases. As a result, more optical waveguides can be integrated into optical waveguide components, and more optical fiber members and single-core fibers can be easily optically coupled, thus easily achieving higher capacity in optical transmission.

[0012] (2) In the optical connection assembly described in (1) above, the first optical fiber member and the second optical fiber member may be positioned at the furthest distance from each other in the second direction among the plurality of optical fiber members. The first single core fiber and the second single core fiber may be positioned at the furthest distance from each other in the second direction among the plurality of single core fibers. In this case, the alignment accuracy of the plurality of single core fibers and plurality of optical fiber members with respect to the optical waveguide component can be improved.

[0013] (3) In the optical connection assembly described in (1) or (2) above, the first surface may include a first end in the second direction and a second end located opposite to the first end in the second direction. When the first surface is viewed from multiple optical fiber members, the first core may be positioned closest to the first end among two or more cores arranged in the nth row (where n is 1 or more and N or less) of the multiple cores of the first optical fiber member, and the second core may be positioned closest to the second end among two or more cores arranged in a different row from the nth row of the multiple cores of the second optical fiber member. When the centering light from the first single core fiber and the second single core fiber passes through the first core and the second core, if each core of each optical fiber member is positioned on the first surface of the optical waveguide component at a position corresponding to each optical waveguide, then all cores of all optical fiber members can be optically coupled to all single core fibers. However, even if each core of each optical fiber component is positioned offset from the position corresponding to each optical waveguide, there is still a possibility that alignment light from the first single-core fiber and the second single-core fiber will be input to the first and second cores. In this case, cores that are not optically coupled to the single-core fiber may occur. In contrast, with the configuration of (3) above, when alignment light from the first single-core fiber and the second single-core fiber passes through the first and second cores, the position of each core relative to the arrangement of each optical waveguide is more easily determined uniquely, thus reducing the possibility that each core of each optical fiber component is positioned offset from the position corresponding to each optical waveguide. As a result, each core of each optical fiber component can be reliably optically coupled to each single-core fiber.

[0014] (4) In the optical connection assembly described in any one of (1) to (3) above, the first core and the second core may be positioned at the furthest distances from each other in the second direction. In this case, the alignment accuracy of the multiple single-core fibers and multiple optical fiber members with respect to the optical waveguide component can be improved.

[0015] (5) In the optical connection assembly described in (3) or (4) above, at least one of the first core and the second core may be positioned in the first or Nth stage among a plurality of N-stage cores. In this case, when light from the first single-core fiber and the second single-core fiber passes through the first and second cores, the possibility that each core of each optical fiber member is positioned off-center from the position corresponding to each optical waveguide can be more reliably reduced. As a result, each core of each optical fiber member can be optically coupled more reliably to each single-core fiber.

[0016] (6) In the optical connection assembly described in any one of (3) to (5) above, the first surface includes a third end in the first direction and a fourth end located opposite to the third end in the first direction, and when the first surface is viewed from multiple optical fiber members, the first core may be positioned closer to the third end than the fourth end with respect to the central axis of the first optical fiber member in the first direction, and the second core may be positioned in a region closer to the fourth end than the third end with respect to the central axis of the second optical fiber member in the first direction. In this case, when light from the first single-core fiber and the second single-core fiber passes through the first core and the second core, the possibility that each core of each optical fiber member is positioned off-center from the position corresponding to each optical waveguide can be more reliably reduced. As a result, each core of each optical fiber member can be optically coupled more reliably to each single-core fiber.

[0017] (7) In the optical connection assembly described in any one of (1) to (6) above, each of the multiple optical fiber members may be a multicore fiber or a bundled fiber. In this case, since multiple cores can be arranged at high density, high capacity in optical transmission can be easily achieved.

[0018] (8) An optical waveguide component of one embodiment comprises a first surface, a second surface different from the first surface, and a plurality of optical waveguides extending from the first surface to the second surface. The first surface is connected to a plurality of optical fiber members, each containing a plurality of cores arranged in N stages (where N is an integer of 1 or more) in a first direction along the first surface, such that the plurality of cores are optically coupled to the plurality of optical waveguides, with the plurality of optical fiber members arranged in a second direction intersecting the first direction. The second surface is connected to a plurality of single-core fibers such that the plurality of single-core fibers arranged along the second direction are optically coupled to the plurality of optical waveguides. The plurality of optical fiber members includes a first optical fiber member and a second optical fiber member different from the first optical fiber member. The plurality of single-core fibers includes a first single-core fiber and a second single-core fiber different from the first single-core fiber. The multiple optical waveguides include a first optical waveguide that is optically coupled to a first core, which is one of the multiple cores of a first optical fiber member, and is optically coupled to a first single-core fiber, and a second optical waveguide that is optically coupled to a second core, which is different from the first core among the multiple cores of a second optical fiber member, and is optically coupled to a second single-core fiber. The arrangement of the multiple cores with respect to the central axis of each of the multiple optical fiber members is the same for each of the multiple optical fiber members. The optical waveguide component described in (8) above provides the same effect as described in (1) above.

[0019] (9) A method for manufacturing an optical connection assembly according to one embodiment is a method for manufacturing an optical connection assembly according to any one of (1) to (7) above, comprising the steps of: arranging a plurality of optical fiber members at a position facing the first surface of an optical waveguide component, and arranging a plurality of single-core fibers at a position facing the second surface of an optical waveguide component; inputting light into at least the first single-core fiber and the second single-core fiber among the plurality of single-core fibers, and aligning the plurality of optical fiber members and the plurality of single-core fibers with respect to the optical waveguide component so that the intensity of light output from the first core of the first optical fiber member and the second core of the second optical fiber member through the first optical waveguide and the second optical waveguide is maximized; and fixing the aligned plurality of optical fiber members and the plurality of single-core fibers to the first surface and the second surface of the optical waveguide component, respectively. According to the method for manufacturing an optical connection assembly according to (9) above, the same effects as those described in (1) above can be obtained.

[0020] [Details of Embodiments of the Disclosure] Specific examples of optical connection assemblies, optical waveguide components, and methods for manufacturing optical connection assemblies according to embodiments of the Disclosure will be described below with reference to the drawings. The Disclosure is not limited to the following examples, but is as indicated by the claims and is intended to include all modifications within the scope equivalent to the claims. In the description of the drawings, the same or equivalent elements are denoted by the same reference numerals, and redundant descriptions are omitted where appropriate. The drawings may be simplified or exaggerated in part for ease of understanding, and dimensional ratios, etc., are not limited to those shown in the drawings.

[0021] Figure 1 is a perspective view showing the optical connection assembly 1 of this embodiment. As shown in Figure 1, the optical connection assembly 1 includes, for example, a multicore fiber array 10, a single-core fiber array 20, and an optical waveguide substrate 30 (optical waveguide component). Figure 2 is a perspective view showing the optical connection assembly 1 with the single-core fiber array 20 and the multicore fiber array 10 separated from the optical waveguide substrate 30. Figure 3 is a plan view showing the optical connection assembly 1. Figure 4 is a side view showing the optical connection assembly 1.

[0022] As shown in Figures 1 to 4, the multicore fiber array 10 is positioned facing the single-core fiber array 20 with an optical waveguide substrate 30 in between. The optical waveguide substrate 30 is positioned between the multicore fiber array 10 and the single-core fiber array 20. The optical waveguide substrate 30 optically couples the single-core fiber array 20 and the multicore fiber array 10 to each other. The optical waveguide substrate 30 distributes and aggregates optical signals between the single-core fiber array 20 and the multicore fiber array 10. The optical waveguide substrate 30 functions as a FIFO (Fan-In / Fan-Out).

[0023] As shown in Figures 1 and 2, the multicore fiber array 10 comprises, for example, a plurality (e.g., two) of multicore fibers M and a first holding component 2 that holds the plurality of multicore fibers M. In the following description, the direction in which each of the plurality of multicore fibers M extends will be referred to as the connection direction D1, the direction in which the plurality of multicore fibers M are aligned will be referred to as the left-right direction D2 (second direction), and the direction perpendicular to both the connection direction D1 and the left-right direction D2 will be referred to as the up-down direction D3 (first direction).

[0024] Multiple multicore fibers M extend along the connection direction D1 and are arranged in a line along the left-right direction D2. The multiple multicore fibers M are arranged at equal intervals along the left-right direction D2, for example. The multiple multicore fibers M include a first multicore fiber M1 and a second multicore fiber M2 that are located furthest apart from each other in the left-right direction D2. The first multicore fiber M1 is located at the first end of the multiple multicore fibers M in the left-right direction D2 (for example, the left end when viewed along the direction from the multicore fiber array 10 toward the optical waveguide substrate 30). The second multicore fiber M2 is located at the second end of the multiple multicore fibers M in the left-right direction D2 (for example, the right end when viewed along the direction from the multicore fiber array 10 toward the optical waveguide substrate 30).

[0025] The first retaining component 2 includes, for example, a base 3 and a lid 4. The base 3 is, for example, a rectangular parallelepiped with the connection direction D1 as its longitudinal direction. As shown in Figures 2 and 4, the base 3 includes, for example, an end face 3a, an upper surface 3b, and a stepped surface 3c. The end face 3a faces the optical waveguide substrate 30 along the connection direction D1. The end face 3a may be inclined with respect to a plane perpendicular to the connection direction D1. The upper surface 3b is located at the upper end of the base 3 in the vertical direction D3. The upper surface 3b is connected to the end face 3a and extends from the end face 3a along the connection direction D1. The stepped surface 3c forms a recess relative to the upper surface 3b. The stepped surface 3c is positioned opposite the end face 3a, with the upper surface 3b in between, in the connection direction D1.

[0026] Figure 5 is a front view showing the multicore fiber array 10. As shown in Figure 5, a plurality (for example, two) of V-grooves 3d are formed on the upper surface 3b. The plurality of V-grooves 3d extend along the connection direction D1 and are arranged in a row along the left-right direction D2. A plurality of multicore fibers M are placed on each of the plurality of V-grooves 3d. For example, as shown in Figure 2, the portions of the plurality of multicore fibers M with the coating removed are placed on each of the plurality of V-grooves 3d, and the coated portions of the plurality of multicore fibers M are placed on the stepped surface 3c. The base portion 3 may have a plurality of circular holes instead of a plurality of V-grooves 3d.

[0027] As shown in Figure 5, each of the multiple multicore fibers M contains multiple (e.g., four) cores C. The multiple cores C are positioned offset from the central axis X of each of the multiple multicore fibers M. For example, the multiple cores C are arranged at equal intervals along the circumferential direction centered on the central axis X. The arrangement of the multiple cores C with respect to the central axis X is the same for each of the multiple multicore fibers M. That is, when the central axis X of the first multicore fiber M1 is aligned with the central axis X of the second multicore fiber M2, the position of each core C of the first multicore fiber M1 coincides with the center position of each core C of the second multicore fiber M2. In this case, for example, the center position of each core C of the first multicore fiber M1 may coincide with the center position of each core C of the second multicore fiber M2. The center position of each core C of the first multicore fiber M1 does not necessarily have to perfectly coincide with the center position of each core C of the second multicore fiber M2; it may be slightly offset within the manufacturing tolerance. The four cores C of each multicore fiber M are, for example, located at the four vertices of a square centered on the central axis X within each multicore fiber M.

[0028] As shown in Figures 1 and 2, the lid 4 is, for example, a rectangular plate. As shown in Figure 5, the lid 4 is positioned to face the upper surface 3b of the base 3, sandwiching the multiple multicore fibers M in the vertical direction D3. The lid 4 is fixed to the upper surface 3b of the base 3 by, for example, adhesive A. The multiple multicore fibers M are sandwiched between the base 3 and the lid 4 and fixed to the base 3 and the lid 4 by adhesive A.

[0029] As shown in Figures 1 and 2, the single-core fiber array 20 comprises, for example, a plurality (e.g., eight) of single-core fibers S and a second holding component 5 that holds the plurality of single-core fibers S.

[0030] Multiple single-core fibers S extend along the connection direction D1 and are arranged in a line along the left-right direction D2. For example, the multiple single-core fibers S are arranged at equal intervals along the left-right direction D2. The multiple single-core fibers S include a first single-core fiber S1 and a second single-core fiber S2 that are located furthest apart from each other in the left-right direction D2. The second single-core fiber S2 is located at the first end of the multiple single-core fibers S in the left-right direction D2 (for example, the right end when viewed along the direction from the single-core fiber array 20 toward the optical waveguide substrate 30). The first single-core fiber S1 is located at the second end of the multiple single-core fibers S in the left-right direction D2 (for example, the left end when viewed along the direction from the single-core fiber array 20 toward the optical waveguide substrate 30).

[0031] The second retaining component 5 includes, for example, a base 6 and a lid 7. The base 6 is, for example, a rectangular parallelepiped with the connection direction D1 as its longitudinal direction. As shown in Figures 2 and 4, the base 6 includes, for example, an end face 6a, an upper surface 6b, and a stepped surface 6c. The end face 6a faces the optical waveguide substrate 30 along the connection direction D1. The end face 6a may be inclined with respect to a plane perpendicular to the connection direction D1. The upper surface 6b is located at the upper end of the base 6 in the vertical direction D3. The upper surface 6b is connected to the end face 6a and extends from the end face 6a along the connection direction D1. The stepped surface 6c forms a recess relative to the upper surface 6b. The stepped surface 6c is positioned opposite the end face 6a in the connection direction D1, with the upper surface 6b in between.

[0032] Figure 6 is a front view showing the end face 6a of the base 6. As shown in Figure 6, a plurality (for example, eight) of V-grooves 6d are formed on the upper surface 6b. The plurality of V-grooves 6d extend along the connection direction D1 and are arranged in a row along the left-right direction D2. A plurality of single-core fibers S are placed on each of the plurality of V-grooves 6d. For example, the portions of the plurality of single-core fibers S from which the coating has been removed are placed on each of the plurality of V-grooves 6d, and the coated portions of the plurality of single-core fibers S are placed on the stepped surface 6c. Each of the plurality of single-core fibers S contains one core C. The core C of each single-core fiber S is positioned on the central axis of each single-core fiber S. The base 6 may have a plurality of circular holes instead of a plurality of V-grooves 6d.

[0033] As shown in Figures 1 and 2, the lid 7 is, for example, a rectangular plate. As shown in Figure 6, the lid 7 is positioned facing the base 6 in the vertical direction D3, sandwiching a plurality of single-core fibers S. The lid 7 is fixed to the upper surface 6b of the base 6 by, for example, adhesive A. The plurality of single-core fibers S are sandwiched between the base 6 and the lid 7 and fixed to the base 6 and the lid 7 by adhesive A.

[0034] The optical waveguide substrate 30 shown in Figures 1 to 4 is, for example, a glass substrate on which a three-dimensional optical waveguide is formed. Therefore, the optical waveguide substrate 30 is formed from, for example, a glass material. The optical waveguide substrate 30 comprises, for example, a substrate body 31, a first lid 33, and a second lid 35.

[0035] The substrate body 31 is, for example, a rectangular parallelepiped with the connection direction D1 as its longitudinal direction. The substrate body 31 includes, for example, a first end face 31a (first face), a second end face 31b (second face), and a top surface 31c. The first end face 31a is an end face located at the first end of the substrate body 31 in the connection direction D1. The first end face 31a faces the multicore fiber array 10 along the connection direction D1. The first end face 31a is connected to a plurality of multicore fibers M by, for example, being fixed to the end face 3a of the multicore fiber array 10. The first end face 31a may be inclined with respect to a plane perpendicular to the connection direction D1. In this specification, the connection of a first element (e.g., the first end face 31a) to a second element (e.g., a plurality of multicore fibers M) includes the first element being directly connected to the second element and the first element being indirectly connected to the second element with another element (e.g., adhesive) in between.

[0036] The second end face 31b is an end face located at the second end of the substrate body 31 in the connection direction D1. The second end face 31b faces opposite to the first end face 31a in the connection direction D1. The second end face 31b faces the single-core fiber array 20 along the connection direction D1. The second end face 31b is connected to the single-core fiber S by, for example, being fixed to the end face 6a of the single-core fiber array 20. The second end face 31b may be inclined with respect to a plane perpendicular to the connection direction D1.

[0037] The upper surface 31c is an end face located at the upper end of the substrate body 31 in the vertical direction D3. The upper surface 31c extends along the connection direction D1 from the first end face 31a to the second end face 31b. The first lid 33 and the second lid 35 are placed on the upper surface 31c. Each of the first lid 33 and the second lid 35 is, for example, a rectangular plate with the left-right direction D2 as its longitudinal direction. The first lid 33 is located at the end of the upper surface 31c closest to the first end face 31a. The first lid 33 is fixed to the lid 4 of the multicore fiber array 10. The second lid 35 is located at the end of the upper surface 31c closest to the second end face 31b. The second lid 35 is fixed to the lid 7 of the single-core fiber array 20.

[0038] For fixing the multicore fiber array 10 to the optical waveguide substrate 30, and for fixing the single-core fiber array 20 to the optical waveguide substrate 30, for example, an ultraviolet-curing adhesive is used.

[0039] The substrate body 31 contains a plurality (e.g., eight) of optical waveguides W internally. In this embodiment, the substrate body 31 includes a first optical waveguide group G1 containing a plurality (e.g., four) of optical waveguides W corresponding to a plurality (e.g., four) of cores C of a first multicore fiber M1, and a second optical waveguide group G2 containing a plurality (e.g., four) of optical waveguides W corresponding to a plurality (e.g., four) of cores C of a second multicore fiber M2. The first optical waveguide group G1 corresponds to the first multicore fiber M1, and the second optical waveguide group G2 corresponds to the second multicore fiber M2.

[0040] Multiple optical waveguides W are formed, for example, by drawing them on the substrate body 31 with a laser. The multiple optical waveguides W are, for example, high refractive index regions where the glass has been altered by multiphoton absorption. The multiple optical waveguides W extend from the first end face 31a to the second end face 31b and are aligned along the left-right direction D2.

[0041] Figure 7 is a front view showing the optical waveguide substrate 30. As shown in Figure 7, the multiple optical waveguides W are exposed on the first end face 31a of the optical waveguide substrate 30. Each optical waveguide W is arranged along the left-right direction D2 and the up-down direction D3 on the first end face 31a. Each optical waveguide W is positioned to face each core C (see Figure 5) of each multicore fiber M on the first end face 31a and is optically coupled to each core C of each multicore fiber M.

[0042] The arrangement of multiple optical waveguides W with respect to the extension of the central axis X of the multicore fiber M is the same for both the first optical waveguide group G1 and the second optical waveguide group G2. In other words, when the extension of the central axis X of the first multicore fiber M1, XL, is taken as the center of the first optical waveguide group G1 at the first end face 31a, and the extension of the central axis X of the second multicore fiber M2, XL, is taken as the center of the second optical waveguide group G2 at the first end face 31a, when the center of the first optical waveguide group G1 coincides with the center of the second optical waveguide group G2 at the first end face 31a, the position of each optical waveguide W of the first optical waveguide group G1 at the first end face 31a coincides with the position of each optical waveguide W of the second optical waveguide group G2 at the first end face 31a. In this case, for example, the center position of each optical waveguide W in the first optical waveguide group G1 may coincide with the center position of each optical waveguide W in the second optical waveguide group G2. However, the center position of each optical waveguide W in the first optical waveguide group G1 does not necessarily have to perfectly coincide with the center position of each optical waveguide W in the second optical waveguide group G2, and may be slightly off within the manufacturing tolerance. The four optical waveguides W in the first optical waveguide group G1 and the second optical waveguide group G2 are arranged, for example, at the four vertices of a square centered on the respective centers of the first optical waveguide group G1 and the second optical waveguide group G2.

[0043] Figure 8 is a rear view showing the optical waveguide substrate 30. As shown in Figure 8, multiple optical waveguides W are exposed on the second end face 31b. Each optical waveguide W is arranged in a line along the left-right direction D2 on the second end face 31b. Each optical waveguide W is positioned to face each single-core fiber S on the second end face 31b. Each optical waveguide W is optically coupled to the core C of each single-core fiber S. The spacing between each optical waveguide W in the left-right direction D2 decreases as it approaches the first end face 31a from the second end face 31b. In this way, each optical waveguide W optically couples each single-core fiber S with each core C of each multi-core fiber M.

[0044] FIG. 9 is a diagram for explaining the connection relationship among the multi-core fiber array 10, the optical waveguide substrate 30, and the single-core fiber array 20. In FIG. 9, the path indicated by the thick black line shows the path of the light L from when the light L is input to the first single-core fiber S1 and the second single-core fiber S2 until the light L is output from the first multi-core fiber M1 and the second multi-core fiber M2 through the optical waveguide substrate 30.

[0045] As shown in FIG. 9, the plurality of optical waveguides W includes, for example, eight optical waveguides W11, W12, W13, W14, W21, W22, W23, and W24. The four optical waveguides W11, W12, W13, and W14 are included in the first optical waveguide group G1 (see FIG. 1), and the four optical waveguides W21, W22, W23, and W24 are included in the second optical waveguide group G2 (see FIG. 1). The four optical waveguides W11, W12, W13, and W14 are optically coupled to the first multi-core fiber M1 at the first end face 31a. The four optical waveguides W21, W22, W23, and W24 are optically coupled to the second multi-core fiber M2 at the first end face 31a.

[0046] The plurality of cores C of the first multi-core fiber M1 includes four cores C11, C12, C13, and C14. The four cores C11, C12, C13, and C14 are arranged to correspond to the four optical waveguides W11, W12, W13, and W14 respectively at the first end face 31a, and are optically coupled to the four optical waveguides W11, W12, W13, and W14 respectively. The plurality of cores C of the second multi-core fiber M2 includes four cores C21, C22, C23, and C24. The four cores C21, C22, C23, and C24 are arranged to correspond to the four optical waveguides W21, W22, W23, and W24 respectively at the first end face 31a, and are optically coupled to the four optical waveguides W21, W22, W23, and W24 respectively.

[0047] The eight optical waveguides W11, W12, W13, W14, W21, W22, W23, and W24 are arranged in this order along the left - right direction D2 at the second end face 31b. The eight optical waveguides W11, W12, W13, W14, W21, W22, W23, and W24 are arranged so as to face the eight single - core fibers S respectively, and are optically coupled to the eight single - core fibers S respectively.

[0048] Among the plurality of optical waveguides W, the optical waveguide W12 (the first optical waveguide) and the optical waveguide W24 (the second optical waveguide) are arranged at positions that are the farthest from each other in the left - right direction D2 at the second end face 31b. The optical waveguide W12 is arranged so as to correspond to the first single - core fiber S1 at the second end face 31b, and is optically coupled to the first single - core fiber S1. The optical waveguide W12 is arranged so as to correspond to the core C12 (the first core) of the first multi - core fiber M1 at the first end face 31a, and is optically coupled to the core C12. The optical waveguide W24 is arranged so as to correspond to the second single - core fiber S2 at the second end face 31b, and is optically coupled to the second single - core fiber S2. The optical waveguide W24 is arranged so as to correspond to the core C24 (the second core) of the second multi - core fiber M2 at the first end face 31a, and is optically coupled to the core C24.

[0049] Therefore, the first single - core fiber S1 and the second single - core fiber S2, which are the farthest from each other in the left - right direction D2, are optically coupled to the first multi - core fiber M1 and the second multi - core fiber M2, which are the farthest from each other in the left - right direction D2, through the optical waveguides W12 and W24 of the optical waveguide substrate 30 respectively. That is, the first single - core fiber S1 is optically coupled to the core C12 of the first multi - core fiber M1, and the second single - core fiber S2 is optically coupled to the core C24 of the second multi - core fiber M2. Therefore, when light L is input to the first single - core fiber S1 and the second single - core fiber S2, the light L passes through the optical waveguides W12 and W24 and is input to the core C12 of the first multi - core fiber M1 and the core C24 of the second multi - core fiber M2.

[0050] Figure 10 shows the relationship between the arrangement of multiple cores C in the first multicore fiber M1 and the second multicore fiber M2, and the arrangement of multiple optical waveguides W in the optical waveguide substrate 30. In Figure 10, the optical waveguides W12 and W24 through which light L from the first single-core fiber S1 and the second single-core fiber S2 passes are filled in black. The arrangement relationship of cores C12 and C24 corresponding to these optical waveguides W12 and W24 will be explained in detail below. In the following explanation, the arrangement relationship of cores C12 and C24 will be explained based on the view from the first end face 31a of the first multicore fiber M1 and the second multicore fiber M2 as shown in Figure 10.

[0051] As shown in Figure 10, the first end face 31a includes a first end E1 (left end) in the left-right direction D2, a second end E2 (right end) located opposite to the first end E1 in the left-right direction D2, a third end E3 (upper end) in the up-down direction D3, and a fourth end E4 (lower end) located opposite to the third end E3 in the up-down direction D3. The first multicore fiber M1 is positioned closest to the first end E1 in the left-right direction D2, and the second multicore fiber M2 is positioned closest to the second end E2 in the left-right direction D2.

[0052] The four cores C11, C12, C13, and C14 of the first multicore fiber M1 are arranged adjacent to each other along the left-right direction D2 and the up-down direction D3. The four cores C11, C12, C13, and C14 are arranged in N rows in the up-down direction D3, where N is an integer greater than or equal to 2. For example, two cores C12 and C13 are arranged in two rows (N=2) relative to two cores C11 and C14. Cores C11 and C14 are adjacent to each other in the left-right direction D2, and cores C12 and C13 are also adjacent to each other in the left-right direction D2. Cores C12 and C13 are adjacent to cores C11 and C14 in the up-down direction D3, respectively. Among the four cores C11, C12, C13, and C14, if cores C11 and C14, which are located closest to the fourth end E4 in the vertical direction D3, are designated as the first stage (n=1), then cores C12 and C13 can be said to be located in the second stage (n=2). Here, n is an integer less than or equal to N.

[0053] The arrangement of the four cores C21, C22, C23, and C24 in the second multicore fiber M2 is the same as the arrangement of the four cores C11, C12, C13, and C14 in the first multicore fiber M1. The four cores C21, C22, C23, and C24 in the second multicore fiber M2 are arranged adjacent to each other along the left-right direction D2 and the up-down direction D3. The four cores C21, C22, C23, and C24 are arranged in N rows along the up-down direction D3. For example, two cores C22 and C23 are arranged in two rows (N=2) relative to two cores C21 and C24. Cores C21 and C24 are adjacent to each other in the left-right direction D2, and cores C22 and C23 are also adjacent to each other in the left-right direction D2. Cores C22 and C23 are adjacent to cores C21 and C24 in the up-down direction D3, respectively. Among the four cores C21, C22, C23, and C24, if we consider cores C21 and C24, which are located closest to the fourth end E4 in the vertical direction D3, as the first stage (n=1), then cores C22 and C23 can be said to be located in the second stage (n=2).

[0054] The first-stage cores C21 and C24 are positioned to be aligned with the first-stage cores C11 and C14 along the left-right direction D2. In other words, the first-stage cores C21 and C24 are at the same height as the first-stage cores C11 and C14 in the up-down direction D3. The second-stage cores C22 and C23 are positioned to be aligned with the second-stage cores C12 and C13 along the left-right direction D2. In other words, the second-stage cores C22 and C23 are at the same height as the second-stage cores C12 and C13 in the up-down direction D3.

[0055] Core C12 of the first multicore fiber M1 is located in the second stage of cores C11, C12, C13, and C14, which are arranged in two stages. Core C12 in the second stage is located closest to the third end E3 in the vertical direction D3. Core C24 of the second multicore fiber M2 is located in a different stage than core C12, which is located in the second stage (n=2). Specifically, core C24 is located in the first stage (n=1) of cores C11, C12, C13, and C14, which are arranged in two stages. Therefore, with respect to the central axis X of the first multicore fiber M1 and the second multicore fiber M2, core C12 is located closer to the third end E3 than to the fourth end E4 in the vertical direction D3, and core C24 is located closer to the fourth end E4 than to the third end E3 in the vertical direction D3. In other words, cores C12 and C24 are located in opposite regions with respect to the central axis X in the vertical direction D3.

[0056] Core C12 is positioned closest to the first end E1 in the left-right direction D2 among the first-stage cores C12 and C13. Core C24 is positioned closest to the second end E2 in the left-right direction D2 among the second-stage cores C21 and C24. As a result, cores C12 and C24 are positioned furthest apart from each other in the left-right direction D2.

[0057] An example of a manufacturing method for the optical connection assembly 1 of this embodiment will be described with reference to Figures 11 and 12. Figure 11 is a diagram showing the manufacturing process of the optical connection assembly 1. Figure 12 is a diagram showing the subsequent process after Figure 11.

[0058] First, as shown in Figure 11, the multicore fiber array 10 is brought close to the first end face 31a of the optical waveguide substrate 30, and the singlecore fiber array 20 is brought close to the second end face 31b of the optical waveguide substrate 30. Next, the position of the multicore fiber array 10 relative to the optical waveguide substrate 30 is adjusted so that each core C of each multicore fiber M faces each optical waveguide W at the first end face 31a of the optical waveguide substrate 30. The position of the singlecore fiber array 20 relative to the optical waveguide substrate 30 is adjusted so that each core C of each singlecore fiber S faces each optical waveguide W at the second end face 31b of the optical waveguide substrate 30.

[0059] Next, as shown in Figure 12, a light L for alignment is input to the first single-core fiber S1 and the second single-core fiber S2, which are furthest apart from each other in the left-right direction D2. The light L passes through the optical waveguides W12 and W24 of the optical waveguide substrate 30 and is output from the core C12 of the first multi-core fiber M1 and the core C24 of the second multi-core fiber M2. Next, the intensity of the light L output from the cores C12 and C24 is measured using a power meter. The rotation angles of the multi-core fiber array 10 and the single-core fiber array 20 relative to the optical waveguide substrate 30 are adjusted so that the intensity of the light L is maximized.

[0060] This aligns the three components: the multicore fiber array 10, the singlecore fiber array 20, and the optical waveguide substrate 30. The positions of the first singlecore fiber S1 and the second singlecore fiber S2 relative to the optical waveguides W12 and W24 of the optical waveguide substrate 30 are adjusted, and the positions of the core C12 of the first multicore fiber M1 and the core C24 of the second multicore fiber M2 relative to the optical waveguides W12 and W24 of the optical waveguide substrate 30 are adjusted. As a result, the first singlecore fiber S1 and the second singlecore fiber S2 are optically coupled to the core C12 of the first multicore fiber M1 and the core C24 of the second multicore fiber M2, respectively.

[0061] As a result of the above alignment, the remaining single-core fibers S positioned inside the first single-core fiber S1 and the second single-core fiber S2 are also aligned with the remaining optical waveguides W11, W13, W14, W21, W22, and W23, and are optically coupled to the remaining cores C11, C13, C14, C21, C22, and C23, respectively. Subsequently, the optical waveguide substrate 30, the multi-core fiber array 10, and the single-core fiber array 20 are fixed to each other using an ultraviolet-curing adhesive to obtain the optical connection assembly 1. This completes the series of steps in the manufacturing method of the optical connection assembly 1.

[0062] The advantages obtained from the optical connection assembly 1 and the method for manufacturing the optical connection assembly 1 described above will be explained along with the problems of the prior art.

[0063] As background technology, the use of multicore fibers, which house multiple cores in a single fiber, has attracted attention as an optical fiber to cope with the increasing traffic volume of optical fiber networks in recent years, and development of spatial division transmission technology using multicore fibers is progressing. In transmission line systems using multicore fibers, FIFO devices are used to separate multiple cores of a multicore fiber into multiple single-core fibers, or to couple multiple single-core fibers into multiple cores of a multicore fiber.

[0064] For example, it is difficult to amplify the intensity of light output from multiple cores of a multicore fiber to the same level simultaneously (i.e., with a single excitation light) using an optical amplifier. Therefore, a FIFO device is sometimes used to separate the transmission paths of multiple cores and amplify the light individually in each branched transmission path. In the case of an optical transmitter or receiver for a single-core fiber, a FIFO device may be used to separate the optical transmission paths and send and receive light individually. As such a FIFO device, for example, an optical waveguide substrate is known in which a three-dimensional optical waveguide is formed inside a glass material by laser writing. This optical waveguide substrate can optically couple multiple cores contained in one multicore fiber to multiple single-core fibers, respectively.

[0065] To achieve high capacity in optical transmission, it is conceivable to use an optical waveguide substrate that optically couples multiple cores contained in two or more multicore fibers to multiple single-core fibers. As the number of multicore fibers and single-core fibers connected to the optical waveguide device increases, the alignment work of the multicore fibers and single-core fibers may increase. To put such optical waveguide devices into practical use, it is important to improve the efficiency of the alignment work.

[0066] In the optical connection assembly 1 of this embodiment, when alignment light L is input to the first single-core fiber S1 and the second single-core fiber S2, the light L passes through the optical waveguides W12 and W24 and is output from the core C12 of the first multi-core fiber M1 and the core C24 of the second multi-core fiber M2. When the intensity of the light L reaches its maximum, the first single-core fiber S1 and the second single-core fiber S2, as well as the core C12 of the first multi-core fiber M1 and the core C24 of the second multi-core fiber M2, are aligned with respect to the optical waveguides W12 and W24. In this embodiment, the arrangement of the multiple cores C with respect to the central axis X of each multi-core fiber M is the same for each multi-core fiber M. Therefore, if the core C12 of the first multi-core fiber M1 and the core C24 of the second multi-core fiber M2 are aligned, all the remaining cores C and all the remaining single-core fibers S corresponding to them can also be aligned. In other words, in the optical connection assembly of this embodiment, by performing the alignment operation once to align the first single-core fiber S1 and the second single-core fiber S2, and the core C12 of the first multi-core fiber M1 and the core C24 of the second multi-core fiber M2, all the cores C of all the multi-core fibers M and all the single-core fibers S can be aligned together, eliminating the need to align each core C of each multi-core fiber M and each single-core fiber S individually. Therefore, with the optical connection assembly 1 of this embodiment, the alignment operation can be easily performed even when the number of multi-core fibers M and single-core fibers S increases. As a result, more optical waveguides W can be integrated into the optical waveguide substrate 30, and more multi-core fibers M and single-core fibers S can be easily connected to each other, thus easily achieving higher capacity in optical transmission.

[0067] As in this embodiment, the first multicore fiber M1 and the second multicore fiber M2 may be positioned at the furthest distances from each other in the left-right direction D2 among the multiple multicore fibers M. The first singlecore fiber S1 and the second singlecore fiber S2 may be positioned at the furthest distances from each other in the left-right direction D2 among the multiple singlecore fibers S. In this case, the alignment accuracy of the multiple singlecore fibers S and the multiple multicore fibers M with respect to the optical waveguide substrate 30 can be improved.

[0068] As in this embodiment, when viewing the first end face 31a from multiple multicore fibers M, core C12 may be positioned closest to the first end E1 among two or more cores C arranged in the nth row of the multiple cores C of the first multicore fiber M1, and core C24 may be positioned closest to the second end E2 among two or more cores C arranged in a different row from the nth row of the multiple cores C of the second multicore fiber M2. When the aligning light L from the first single-core fiber S1 and the second single-core fiber S2 passes through cores C12 and C24, if each core C of each multicore fiber M is positioned at a location corresponding to each optical waveguide W on the first end face 31a of the optical waveguide substrate 30, then all cores C of all multicore fibers M can be optically coupled to all single-core fibers S. However, even if each core C of each multicore fiber M is positioned offset from the position corresponding to each optical waveguide W, the aligning light L from the first single-core fiber S1 and the second single-core fiber S2 may be input to one of the cores C. In this case, a core C that is not optically coupled to the single-core fiber S will be created.

[0069] Figure 13 is a diagram illustrating the problem of the optical connection assembly 100 in Reference Example 1. In the optical connection assembly 100, optical waveguides W12 and W23 are optically coupled to the first single-core fiber S1 and the second single-core fiber S2, respectively, and are optically coupled to the core C12 of the first multi-core fiber M1 and the core C23 of the second multi-core fiber M2, respectively. In this case, the light L for alignment is input from the optical waveguides W12 and W23 to the cores C12 and C23, respectively. Both cores C12 and C23 are located in the same stage (specifically, the second stage (n=2)) within the multiple cores C of the first multi-core fiber M1 and the second multi-core fiber M2, respectively.

[0070] In this case, as shown in Figure 13, when the position of each core C in the first multicore fiber M1 and the second multicore fiber M2 is shifted upward relative to the position of each corresponding optical waveguide W, the light L is input to cores C11 and C24 instead of cores C12 and C23. In this case, cores C12, C13, C22 and C23 are not optically coupled to the optical waveguide W, so it is not possible to optically couple all cores C to all single-core fibers S.

[0071] Figure 14 is a diagram illustrating the problem of the optical connection assembly 200 in Reference Example 2. In the optical connection assembly 200, optical waveguides W13 and W22 are optically coupled to the first single-core fiber S1 and the second single-core fiber S2, respectively, and are optically coupled to the core C13 of the first multi-core fiber M1 and the core C22 of the second multi-core fiber M2, respectively. In this case, the light L for alignment is input from the optical waveguides W13 and W22 to the cores C13 and C22, respectively. The cores C13 and C22 are located in the same stage (specifically, the second stage (n=2)) within the multiple cores C of the first multi-core fiber M1 and the second multi-core fiber M2, and are located at the closest possible positions to each other in the left-right direction D2.

[0072] In this case, as shown in Figure 14, when the position of each core C in the first multicore fiber M1 and the second multicore fiber M2 is shifted upward relative to the position of each corresponding optical waveguide W, the light L is input to cores C14 and C21 instead of cores C13 and C22. In this case, cores C12, C13, C22 and C23 are not optically coupled to the optical waveguide W, so it is not possible to optically couple all cores C to all single-core fibers S.

[0073] Figure 15 is a diagram illustrating the problem of the optical connection assembly 300 in Reference Example 3. In the optical connection assembly 300, optical waveguides W14 and W23 are optically coupled to the first single-core fiber S1 and the second single-core fiber S2, respectively, and are optically coupled to the core C14 of the first multi-core fiber M1 and the core C23 of the second multi-core fiber M2, respectively. In this case, the light L for alignment is input from the optical waveguides W14 and W23 to the cores C14 and C23, respectively. Both cores C14 and C23 are located in the position closest to the second end E2 in the left-right direction D2 among the multiple cores C of the first multi-core fiber M1 and the second multi-core fiber M2, respectively.

[0074] In this case, as shown in Figure 15, when the position of each core C in the first multicore fiber M1 and the second multicore fiber M2 is shifted to the right with respect to the position of each corresponding optical waveguide W, the light L is input to cores C11 and C22 instead of cores C14 and C23. In this case, cores C13, C14, C23, and C24 are not optically coupled to the optical waveguide W, so it is not possible to optically couple all cores C to all single-core fibers S.

[0075] In contrast, as shown in Figure 10, if the core C12 optically coupled to the first single-core fiber S1 is positioned closest to the first end E1 among two or more cores C arranged in the nth stage of the multiple cores C of the first multi-core fiber M1, and the core C24 optically coupled to the second single-core fiber S2 is positioned closest to the second end E2 among two or more cores C arranged in a different stage from the nth stage of the multiple cores C of the second multi-core fiber M2, then when the aligning light L from the first single-core fiber S1 and the second single-core fiber S2 passes through cores C12 and C24, the arrangement of each core C relative to the arrangement of each optical waveguide W is easily uniquely determined, thus reducing the possibility that each core C of each multi-core fiber M is positioned off-center from the position corresponding to each optical waveguide W. As a result, each core C of each multi-core fiber M can be reliably optically coupled by each single-core fiber S.

[0076] As in this embodiment, cores C12 and C24 may be positioned at the furthest possible locations from each other in the left-right direction D2. In this case, the alignment accuracy of the multiple single-core fibers S and multiple multi-core fibers M relative to the optical waveguide substrate 30 can be improved.

[0077] As in this embodiment, core C12 may be positioned in the Nth stage among a plurality of N stages of core C, and core C24 may be positioned in the 1st stage among a plurality of N stages of core C. In this case, when light L from the first single-core fiber S1 and the second single-core fiber S2 passes through core C12 and core C24, the possibility that each core C of each multi-core fiber M is positioned off-center from the position corresponding to each optical waveguide W can be more reliably reduced. As a result, each core C of each multi-core fiber M can be optically coupled more reliably by each single-core fiber S.

[0078] As in this embodiment, when viewing the first end face 31a from multiple multicore fibers M, core C12 may be positioned closer to the third end E3 than the fourth end E4 with respect to the central axis X of the first multicore fiber M1 in the vertical direction D3, and core C24 may be positioned closer to the fourth end E4 than the third end E3 with respect to the central axis X of the second multicore fiber M2 in the vertical direction D3. In this case, when light L from the first single-core fiber S1 and the second single-core fiber S2 passes through core C12 and core C24, the possibility that each core C of each multicore fiber M is positioned off-center from the position corresponding to each optical waveguide W can be more reliably reduced. As a result, each core C of each multicore fiber M can be optically coupled more reliably by each single-core fiber S.

[0079] Embodiments of the optical connection assembly and the method for manufacturing the optical connection assembly have been described above. This disclosure is not limited to the embodiments described above. It will be readily apparent to those skilled in the art that various modifications and changes are possible within the scope of the gist of the claims. That is, the shape, size, number, material and arrangement of the parts of the optical connection assembly can be appropriately modified within the scope of the gist described above.

[0080] <Modification Example 1> Figure 16 shows the relationship between the arrangement of multiple cores C in the first multicore fiber M1A and the second multicore fiber M2A, and the arrangement of multiple optical waveguides W in the optical waveguide substrate 30, in the optical connection assembly 1A of Modification Example 1. In the optical connection assembly 1A, the optical waveguide W13 (first optical waveguide) and the optical waveguide W21 (second optical waveguide) are optically coupled to the first single-core fiber S1 and the second single-core fiber S2, respectively, and are optically coupled to the core C13 of the first multicore fiber M1 and the core C21 of the second multicore fiber M2, respectively. In this case, the light L for alignment is input from the optical waveguides W13 and W21 to the cores C13 and C21, respectively.

[0081] Core C13 (first core) is positioned closest to the second end E2 (first end) in the left-right direction D2 among the second-stage cores C12 and C13. Core C21 (second core) is positioned closest to the first end E1 (second end) in the left-right direction D2 among the first-stage cores C21 and C24. With respect to the central axis X of the first multicore fiber M1A and the second multicore fiber M2A, core C13 is positioned closer to the third end E3 than the fourth end E4 in the up-down direction D3, and core C21 is positioned closer to the fourth end E4 than the third end E3 in the up-down direction D3. Even with such an optical connection assembly 1A, the same effects as in the embodiment described above can be obtained.

[0082] <Modification 2> Figure 17 shows the relationship between the arrangement of multiple cores C in the first bundle fiber M1B and the second bundle fiber M2B, and the arrangement of multiple optical waveguides W in the optical waveguide substrate 30, in the optical connection assembly 1B of Modification 2. In the optical connection assembly 1B, the first bundle fiber M1B (first optical fiber member) and the second bundle fiber M2B (second optical fiber member) are used instead of the first multicore fiber M1 and the second multicore fiber M2. Each of the first bundle fiber M1B and the second bundle fiber M2B is formed by bundling multiple single-core fibers. Even with such an optical connection assembly 1B, the same effects as in the embodiment described above can be obtained.

[0083] <Modification 3> Figure 18 shows the relationship between the arrangement of multiple cores CA in the first multicore fiber M1C and the second multicore fiber M2C in the optical connection assembly 1C of Modification 3, and the arrangement of multiple optical waveguides WA in the optical waveguide substrate 30. In the optical connection assembly 1C, the multiple cores CA are arranged in four rows (N=4) in the vertical direction D3. Each core CA is arranged to be adjacent to one another along the vertical direction D3 and the horizontal direction D2.

[0084] In the first multicore fiber M1C, the core CA1 (first core) located in the third stage (n=3) of the four layers of cores CA is optically coupled to the first singlecore fiber S1 through the optical waveguide WA1 (first optical waveguide). Among the four cores CA located in the third stage, core CA1 is positioned closest to the first end E1 in the left-right direction D2.

[0085] In the second multicore fiber M2C, the core CA2 (second core), located in the second stage (n=2) of the four layers of cores CA, is optically coupled to the second singlecore fiber S2 through the optical waveguide WA2 (second optical waveguide). Among the four cores CA located in the second stage, core CA2 is positioned closest to the second end E2 in the left-right direction D2. Cores CA1 and CA2 are positioned furthest from each other in the left-right direction D2.

[0086] With respect to the central axis X of the first multicore fiber M1C and the second multicore fiber M2C, core CA1 is positioned closer to the third end E3 than to the fourth end E4 in the vertical direction D3, and core CA2 is positioned closer to the fourth end E4 than to the third end E3 in the vertical direction D3. Even with such an optical connection assembly 1C, the same effects as in the embodiment described above can be obtained.

[0087] <Modification 4> Figure 19 shows the relationship between the arrangement of multiple cores CA in the first multicore fiber M1C and the second multicore fiber M2C and the arrangement of multiple optical waveguides WA in the optical waveguide substrate 30 in the optical connection assembly 1D of Modification 4. In the optical connection assembly 1D, the arrangement of multiple cores CA in the first multicore fiber M1C and the second multicore fiber M2C is the same as the arrangement of multiple cores CA shown in Figure 18.

[0088] In the first multicore fiber M1C, the core CA1 (first core) located in the third stage (n=3) of the four layers of cores CA is optically coupled to the first singlecore fiber S1 through the optical waveguide WA1 (first optical waveguide). Among the four cores CA located in the third stage, core CA1 is positioned closest to the first end E1 in the left-right direction D2.

[0089] In the second multicore fiber M2C, the core CA2 (second core) located in the first stage (n=1) of the multiple cores CA in the fourth stage is optically coupled to the second singlecore fiber S2 through the optical waveguide WA2 (second optical waveguide). Among the two cores CA located in the first stage, core CA2 is positioned closest to the second end E2 in the left-right direction D2.

[0090] With respect to the central axis X of the first multicore fiber M1C and the second multicore fiber M2C, core CA1 is positioned closer to the third end E3 than to the fourth end E4 in the vertical direction D3, and core CA2 is positioned closer to the fourth end E4 than to the third end E3 in the vertical direction D3. Even with such an optical connection assembly 1D, the same effects as in the embodiment described above can be obtained.

[0091] <Modification 5> Figure 20 shows the relationship between the arrangement of multiple cores CB in the first multicore fiber M1D and the second multicore fiber M2D in the optical connection assembly 1E of Modification 5, and the arrangement of multiple optical waveguides WB in the optical waveguide substrate 30. In the optical connection assembly 1E, the multiple cores CB are arranged in five rows (N=5) in the vertical direction D3. Each core CB is arranged adjacent to one another along the vertical direction D3 and the left-right direction D2. One of the multiple cores CB is positioned along the central axis X of the multicore fiber M, and the remaining six cores CB are arranged at equal intervals along the circumferential direction with respect to the central axis X.

[0092] In the first multicore fiber M1D, the core CB1 (first core) located in the fourth stage (n=4) of the multiple core CBs in the five stages is optically coupled to the first singlecore fiber S1 through the optical waveguide WB1 (first optical waveguide). Among the two core CBs located in the fourth stage, core CB1 is positioned closest to the first end E1 in the left-right direction D2.

[0093] In the second multicore fiber M2D, the core CB2 (second core), located in the second stage (n=2) of the multiple cores CB in the five stages, is optically coupled to the second single-core fiber S2 through the optical waveguide WB2 (second optical waveguide). Among the two cores CB located in the second stage, core CB2 is positioned closest to the second end E2 in the left-right direction D2. Cores CB1 and CB2 are positioned furthest from each other in the left-right direction D2.

[0094] With respect to the central axis X of the first multicore fiber M1D and the second multicore fiber M2D, core CB1 is positioned closer to the third end E3 than to the fourth end E4 in the vertical direction D3, and core CB2 is positioned closer to the fourth end E4 than to the third end E3 in the vertical direction D3. Even with such an optical connection assembly 1E, the same effects as in the embodiment described above can be obtained.

[0095] <Modification 6> Figure 21 is a diagram showing the relationship between the arrangement of multiple core CBs in the first multicore fiber M1D and the second multicore fiber M2D in the optical connection assembly 1F of Modification 6, and the arrangement of multiple optical waveguides WB in the optical waveguide substrate 30. In the optical connection assembly 1F, the arrangement of multiple core CBs in the first multicore fiber M1D and the second multicore fiber M2D is the same as the arrangement of multiple core CBs shown in Figure 20.

[0096] In the first multicore fiber M1D, the core CB1 (first core) located in the fourth stage (n=4) of the multiple core CBs in the five stages is optically coupled to the first singlecore fiber S1 through the optical waveguide WB1 (first optical waveguide). Among the two core CBs located in the fourth stage, core CB1 is positioned closest to the first end E1 in the left-right direction D2.

[0097] In the second multicore fiber M2D, the core CB2 (second core) located in the first stage (n=1) of the multiple cores CB in the five stages is optically coupled to the second singlecore fiber S2 through the optical waveguide WB2 (second optical waveguide). Within the first stage, core CB2 is located closest to the second end E2 in the left-right direction D2.

[0098] With respect to the central axis X of the first multicore fiber M1D and the second multicore fiber M2D, core CB1 is positioned closer to the third end E3 than to the fourth end E4 in the vertical direction D3, and core CB2 is positioned closer to the fourth end E4 than to the third end E3 in the vertical direction D3. Even with such an optical connection assembly 1F, the same effects as in the embodiment described above can be obtained.

[0099] <Modification 7> Figure 22 shows the relationship between the arrangement of multiple cores CC in the first multicore fiber M1E and the second multicore fiber M2E, and the arrangement of multiple optical waveguides WC in the optical waveguide substrate 30, in the optical connection assembly 1G of Modification 7. In the optical connection assembly 1G, the multiple cores CC are arranged in four rows (N=4) in the vertical direction D3. Each core CC is arranged to be adjacent to one another along the vertical direction D3 and the horizontal direction D2.

[0100] In the first multicore fiber M1E, the core CC1 (first core) located in the third stage (n=3) of the multiple cores CC in the four stages is optically coupled to the first singlecore fiber S1 through the optical waveguide WC1 (first optical waveguide). Among the three cores CC located in the third stage, core CC1 is positioned closest to the first end E1 in the left-right direction D2.

[0101] In the second multicore fiber M2E, the core CC2 (second core), located in the second stage (n=2) of the four-stage core CCs, is optically coupled to the second single-core fiber S2 via the optical waveguide WC2 (second optical waveguide). Among the three core CCs located in the second stage, core CC2 is positioned closest to the second end E2 in the left-right direction D2. Cores CC1 and CC2 are positioned furthest apart from each other in the left-right direction D2.

[0102] With respect to the central axis X of the first multicore fiber M1E and the second multicore fiber M2E, core CC1 is positioned closer to the third end E3 than to the fourth end E4 in the vertical direction D3, and core CC2 is positioned closer to the fourth end E4 than to the third end E3 in the vertical direction D3. Even with such an optical connection assembly 1G, the same effects as in the embodiment described above can be obtained.

[0103] <Modification 8> Figure 23 shows the relationship between the arrangement of multiple cores CD in the first multicore fiber M1F and the second multicore fiber M2F, and the arrangement of multiple optical waveguides WD in the optical waveguide substrate 30, in the optical connection assembly 1H of Modification 8. In the optical connection assembly 1H, the multiple cores CD are arranged in four rows (N=4) in the vertical direction D3. Each core CD is arranged to be adjacent to one another along the vertical direction D3 and the horizontal direction D2.

[0104] In the first multicore fiber M1F, the core CD1 (first core) located in the third stage (n=3) of the four layers of core CDs is optically coupled to the first singlecore fiber S1 through the optical waveguide WD1 (first optical waveguide). Among the four core CDs located in the third stage, core CD1 is positioned closest to the first end E1 in the left-right direction D2.

[0105] In the second multicore fiber M2F, the core CD2 (second core), located in the first stage (n=1) of the multiple cores CD in the four stages, is optically coupled to the second single-core fiber S2 through the optical waveguide WD2 (second optical waveguide). Among the two cores CD located in the first stage, core CD2 is positioned closest to the second end E2 in the left-right direction D2. Cores CD1 and CD2 are positioned furthest apart from each other in the left-right direction D2.

[0106] With respect to the central axis X of the first multicore fiber M1F and the second multicore fiber M2F, core CD1 is positioned closer to the third end E3 than to the fourth end E4 in the vertical direction D3, and core CD2 is positioned closer to the fourth end E4 than to the third end E3 in the vertical direction D3. Even with such an optical connection assembly 1H, the same effects as in the embodiment described above can be obtained.

[0107] Figure 24 is a diagram illustrating the problem of the optical connection assembly 400 in Reference Example 4. In the optical connection assembly 400, the arrangement of the multiple cores CD in the first multicore fiber M1F and the second multicore fiber M2F is the same as the arrangement of the multiple cores CD shown in Figure 23. In the optical connection assembly 400, with respect to the central axis X of the first multicore fiber M1F and the second multicore fiber M2F, both cores CD1 and CD2 are positioned closer to the third end E3 than to the fourth end E4 in the vertical direction D3.

[0108] In this case, as shown in Figure 24, when the positions of each core CD in the first multicore fiber M1F and the second multicore fiber M2F are shifted diagonally upward and to the left relative to the positions of the corresponding optical waveguides WD, the light L is input to a core CD other than core CD1 or CD2. In this case, a core CD that is not optically coupled to the optical waveguide W is created, and therefore it is not possible to optically couple all core CDs to all single-core fibers S.

[0109] Figure 25 is a diagram illustrating the problem of the optical connection assembly 500 in Reference Example 5. In the optical connection assembly 500, the arrangement of the multiple cores CD in the first multicore fiber M1F and the second multicore fiber M2F is the same as the arrangement of the multiple cores CD shown in Figure 23. In the optical connection assembly 500, with respect to the central axis X of the first multicore fiber M1F and the second multicore fiber M2F, both cores CD1 and CD2 are positioned closer to the third end E3 than to the fourth end E4 in the vertical direction D3.

[0110] In this case, as shown in Figure 25, when the positions of each core CD in the first multicore fiber M1F and the second multicore fiber M2F are shifted diagonally upward and to the right relative to the positions of the corresponding optical waveguides WD, the light L is input to a core CD other than core CD1 or CD2. In this case, a core CD that is not optically coupled to the optical waveguide W is created, and therefore it is not possible to optically couple all core CDs to all single-core fibers S.

[0111] <Modification 9> Figure 26 shows the relationship between the arrangement of multiple cores CE of the first multicore fiber M1G and the second multicore fiber M2G in the optical connection assembly 1J of Modification 9 and the arrangement of multiple optical waveguides WD of the optical waveguide substrate 30. In the optical connection assembly 1J, the multiple cores CE are arranged at equal intervals along the circumferential direction with respect to the central axis X. The multiple cores CE are arranged in five rows (N=5) in the vertical direction D3.

[0112] Among the five stages of multiple cores CE in the first multicore fiber M1G, core CE1 (first core), located in the fourth stage (n=4), is optically coupled to the first single-core fiber S1 through the optical waveguide WE1 (first optical waveguide). Core CE1 is located in the position closest to the first end E1 in the left-right direction D2 among the two cores CE located in the fourth stage.

[0113] In the second multicore fiber M2G, the core CE2 (second core) located in the first stage (n=1) of the multiple cores CE in the five stages is optically coupled to the second singlecore fiber S2 through the optical waveguide WE2 (second optical waveguide). Within the first stage, core CE2 is located closest to the second end E2 in the left-right direction D2.

[0114] With respect to the central axis X of the first multicore fiber M1G and the second multicore fiber M2G, core CE1 is positioned closer to the third end E3 than to the fourth end E4 in the vertical direction D3, and core CE2 is positioned closer to the fourth end E4 than to the third end E3 in the vertical direction D3. Even with such an optical connection assembly 1J, the same effects as in the embodiment described above can be obtained.

[0115] Figure 27 is a diagram illustrating the problem of the optical connection assembly 600 in Reference Example 6. In the optical connection assembly 600, the arrangement of multiple cores CE in the first multicore fiber M1G and the second multicore fiber M2G is the same as the arrangement of multiple cores CE shown in Figure 26. In the optical connection assembly 600, neither core CE1 nor CE2 is located in either the first stage (n=1) or the fourth stage (n=4).

[0116] In this case, as shown in Figure 27, when the position of each core CE of the first multicore fiber M1G and the second multicore fiber M2G is shifted diagonally upward and to the right relative to the position of each corresponding optical waveguide WE, the light L is input to a core CE other than core CE1 and CE2. In this case, a core CE that is not optically coupled to the optical waveguide WE is created, so it is not possible to optically couple all core CEs to all single-core fibers S.

[0117] This disclosure is not limited to the embodiments and variations described above, and various other modifications are possible. For example, the embodiments and variations described above may be combined with each other in a consistent manner, depending on the required purpose and effect. In the embodiments described above, a case was described in which alignment light L is input to two single-core fibers S (specifically, the first single-core fiber S1 and the second single-core fiber S2) among a plurality of single-core fibers S. The number of single-core fibers to which alignment light is input is not limited to two, but may be three, four, or five or more.

[0118] The above-described embodiment explains the case where two multicore fibers M (specifically, a first multicore fiber M1 and a second multicore fiber M2) are connected to the optical waveguide substrate 30. The number of multicore fibers connected to the optical waveguide component is not limited to two, but may be three, four, or five or more. In this case, the number of optical waveguide groups corresponding to the multicore fibers is not limited to two, but may be three, four, or five or more. The number of single-core fibers is not limited to eight, but may be seven or fewer, or nine or more.

[0119] In the embodiments described above, a case was explained in which a multicore fiber M is placed in each of the multiple V-grooves 3d of the first retaining component 2, and a single-core fiber S is placed in each of the multiple V-grooves 6d of the second retaining component 5. A dummy fiber that is not optically coupled to the single-core fiber S may be placed in at least one of the multiple V-grooves 3d, and a dummy fiber may also be placed in at least one of the multiple V-grooves 6d. In this case, the core of the dummy fiber does not correspond to the "first core" and "second core" of this disclosure.

[0120] 1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1J... Optical connection assembly 2... First retaining part 3, 6... Base 3a, 6a... End face 3b, 6b, 31c... Top surface 3c, 6c... Stepped surface 3d, 6d... V-groove 4, 7... Lid 5... Second retaining part 10... Multicore fiber array 20... Single core fiber array 30... Optical waveguide substrate (optical waveguide component) 31... Substrate body 31a... First end face (first surface) 31b... Second end face (second surface) 33... First lid 35... Second lid A... Adhesive C, C14, C22, C23, CA, CB, CC, CD, CE... Core C11, C12, C13, CA1, CB1, CC1, CD1, CE1... Core (First Core) C21, C24, CA2, CB2, CC2, CD2, CE2... Core (Second Core) D1... Connection Direction D2... Left-right Direction (Second Direction) D3... Up-down Direction (First Direction) E1... First End E2... Second End E3... Third End E4... Fourth End G1... First Optical Waveguide Group G2... Second Optical Waveguide Group L... Optical M... Multicore Fiber M1, M1A, M1C, M1D, M1E, M1F, M1G... First Multicore Fiber (First Optical Fiber Component) M2, M2A, M2C, M2D, M2E, M2F, M2G... Second Multicore Fiber (Second Optical Fiber Component) M1B...First bundle fiber (first optical fiber component) M2B...Second bundle fiber (second optical fiber component) S...Single core fiber S1...First single core fiber S2...Second single core fiber W, W14, W22, W23, WA, WB, WC, WD, WE...Optical waveguides W11, W12, W13, WA1, WB1, WC1, WD1, WE1...Optical waveguide (first optical waveguide) W21, W24, WA2, WB2, WC2, WD2, WE2...Optical waveguide (second optical waveguide) X...Central axis

Claims

1. An optical waveguide component including a first surface, a second surface different from the first surface, and a plurality of optical waveguides extending from the first surface to the second surface; a plurality of optical fiber members each containing a plurality of cores arranged in N stages (where N is an integer of 1 or more) in a first direction along the first surface, the plurality of cores connected to the first surface so as to be optically coupled to the plurality of optical waveguides, and arranged along a second direction intersecting the first direction; a plurality of single-core fibers connected to the second surface so as to be optically coupled to the plurality of optical waveguides, and arranged along the second direction, wherein the plurality of optical fiber members include a first optical fiber member and a second optical fiber member different from the first optical fiber member; the plurality of single-core fibers include a first single-core fiber and a second single-core fiber different from the first single-core fiber; and the plurality of optical waveguides include a first optical waveguide optically coupled to a first core which is one of the plurality of cores of the first optical fiber member and optically coupled to the first single-core fiber. An optical connection assembly comprising: a second optical waveguide optically coupled to a second core of the second optical fiber member that is different from the first core among the plurality of cores of the second optical fiber member, and optically coupled to the second single-core fiber, wherein the arrangement of the plurality of cores with respect to the central axis of each of the plurality of optical fiber members is the same in each of the plurality of optical fiber members.

2. The optical connection assembly according to claim 1, wherein the first optical fiber member and the second optical fiber member are arranged at the furthest positions from each other in the second direction among the plurality of optical fiber members, and the first single core fiber and the second single core fiber are arranged at the furthest positions from each other in the second direction among the plurality of single core fibers.

3. The optical connection assembly according to claim 1 or claim 2, wherein the first surface includes a first end in the second direction and a second end located opposite to the first end in the second direction, and when the first surface is viewed from the plurality of optical fiber members, the first core is located closest to the first end among two or more cores arranged in the nth row (where n is 1 or more and N or less) of the plurality of cores of the first optical fiber member, and the second core is located closest to the second end among two or more cores arranged in a different row from the nth row of the plurality of cores of the second optical fiber member.

4. The optical connection assembly according to any one of claims 1 to 3, wherein the first core and the second core are positioned at the furthest distances from each other in the second direction.

5. The optical connection assembly according to claim 3 or 4, wherein at least one of the first core and the second core is located in the first or Nth stage among the N-stage plurality of cores.

6. The optical connection assembly according to any one of claims 3 to 5, wherein the first surface includes a third end in the first direction and a fourth end located opposite to the third end in the first direction, and when the first surface is viewed from the plurality of optical fiber members, the first core is positioned closer to the third end than the fourth end with respect to the central axis of the first optical fiber member in the first direction, and the second core is positioned closer to the fourth end than the third end with respect to the central axis of the second optical fiber member in the first direction.

7. The optical connection assembly according to any one of claims 1 to 6, wherein each of the plurality of optical fiber members is a multicore fiber or a bundled fiber.

8. The device comprises a first surface, a second surface different from the first surface, and a plurality of optical waveguides extending from the first surface to the second surface, wherein the first surface is connected to the plurality of optical fiber members, each containing a plurality of cores arranged in N stages (where N is an integer of 1 or more) in a first direction along the first surface, such that the plurality of cores are optically coupled to the plurality of optical waveguides, and the plurality of optical fiber members are arranged in a second direction intersecting the first direction, the plurality of single core fibers are connected to the plurality of single core fibers, such that the plurality of single core fibers arranged along the second direction are optically coupled to the plurality of optical waveguides, the plurality of optical fiber members include a first optical fiber member and a second optical fiber member different from the first optical fiber member, the plurality of single core fibers include a first single core fiber and a second single core fiber different from the first single core fiber, and the plurality of optical waveguides are An optical waveguide component comprising: a first optical waveguide optically coupled to a first core which is one of the plurality of cores of the first optical fiber member and optically coupled to the first single-core fiber; and a second optical waveguide optically coupled to a second core which is different from the first core among the plurality of cores of the second optical fiber member and optically coupled to the second single-core fiber, wherein the arrangement of the plurality of cores with respect to the central axis of each of the plurality of optical fiber members is the same in each of the plurality of optical fiber members.

9. A method for manufacturing an optical connection assembly according to any one of claims 1 to 7, comprising the steps of: arranging the plurality of optical fiber members at a position facing the first surface of the optical waveguide component, and arranging the plurality of single-core fibers at a position facing the second surface of the optical waveguide component; inputting light into at least the first single-core fiber and the second single-core fiber among the plurality of single-core fibers, and aligning the plurality of optical fiber members and the plurality of single-core fibers with respect to the optical waveguide component such that the intensity of light output from the first core of the first optical fiber member and the second core of the second optical fiber member through the first optical waveguide and the second optical waveguide is maximized; and fixing the aligned plurality of optical fiber members and the plurality of single-core fibers to the first surface and the second surface of the optical waveguide component, respectively.

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