Optical connector and optical connection structure

Abstract

An optical connector and an optical connection structure are provided that can reduce losses due to bending of an optical fiber. [Solution] The optical connector 1A includes a ferrule 10 having a plurality of fiber holes 11 and an introduction hole, and a plurality of optical fibers 20 inserted from the introduction hole into the fiber hole 11. The introduction hole has a rear end opening on a rear end face 10b of the ferrule 10 opposite the connecting end face 10a. The plurality of optical fibers 20 include a plurality of optical fiber groups 40 each having a plurality of optical fibers 20. The plurality of optical fiber groups 40 are introduced into the introduction hole from the rear end opening and inserted into the fiber holes 11, respectively. The fiber holes 11 are formed at different positions in the first direction X on the connecting end face 10a. Two or more of the plurality of optical fibers 20 included in the optical fiber group 40 are positioned at different positions in the second direction Y at the rear end opening.

Description

[Technical Field]

[0001] The present invention relates to an optical connector and an optical connection structure. [Background technology]

[0002] With an increase in transmission capacity in communication networks using optical fibers, the use of multi-core fibers is expected. In order to apply multi-core fibers to existing communication networks that use single-core fibers, a structure in which a multi-core fiber and a single-core fiber are connected is used (for example, see Patent Document 1).

[0003] A fan-in / fan-out (FIFO) device is sometimes used to connect a multicore fiber to a single-core fiber. A FIFO device is a conversion device between a multicore fiber and a single-core fiber.

[0004] The FIFO device includes, for example, a first optical connector for a single-core fiber and a second optical connector for a multi-core fiber. The first optical connector has a structure in which a plurality of optical fibers, which are single-core fibers, are inserted into a fiber hole of a ferrule. By connecting the first optical connector to the second optical connector for the multi-core fiber, it is possible to connect a plurality of optical fibers (single-core fibers) to the multi-core fiber. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-125195 Summary of the Invention [Problem to be solved by the invention]

[0006] To achieve higher density, it is conceivable to use a multi-core optical connector using a plurality of multi-core fibers as the optical connector (second optical connector) on the multi-core fiber side. However, as the number of multi-core fibers increases, the number of optical fibers in the optical connector (first optical connector) on the single-core fiber side also increases. When many optical fibers are inserted into the ferrule in the first optical connector, some of the optical fibers may bend significantly, resulting in increased loss.

[0007] An object of one aspect of the present invention is to provide an optical connector and an optical connection structure that can reduce loss due to bending of an optical fiber. [Means for solving the problem]

[0008] An optical connector according to a first aspect of the present invention comprises a ferrule having a plurality of fiber holes opening at a connection end face and introduction holes communicating with the fiber holes, and a plurality of optical fibers inserted into the fiber holes from the introduction holes, wherein the introduction holes have a rear end opening at a rear end face opposite the connection end face of the ferrule, the plurality of optical fibers include a plurality of optical fiber groups each having a plurality of the optical fibers, the plurality of optical fiber groups being introduced into the introduction holes from the rear end opening and inserted into the fiber holes, the fiber holes are formed at different positions in a first direction at the connection end face, a direction perpendicular to the first direction along a plane perpendicular to the longitudinal direction of the fiber holes is a second direction, and two or more of the plurality of optical fibers included in the optical fiber groups have different positions in the second direction at the rear end opening.

[0009] According to the first aspect of the present invention, the dimensions of the plurality of optical fibers in the first direction can be reduced. Therefore, compared to when the plurality of optical fibers are arranged side by side in the first direction, the bending applied to the optical fibers positioned on the outer side in the first direction can be reduced. Therefore, the loss due to bending of the optical fibers can be suppressed.

[0010] A second aspect of the present invention is the optical connector of the first aspect, wherein the optical fibers included in the optical fiber group are positioned differently in the second direction in the rear end opening.

[0011] A third aspect of the present invention is the optical connector according to the first or second aspect, wherein the optical fibers included in the optical fiber group are aligned in the second direction at the rear end opening.

[0012] A fourth aspect of the present invention is an optical connector according to any one of the first to third aspects, wherein the pitch of the fiber holes in the connection end face is smaller than the pitch of the optical fibers when the optical fibers are arranged in the first direction without any gaps.

[0013] A fifth aspect of the present invention is the optical connector according to any one of the first to fourth aspects, wherein the number of optical fibers included in one optical fiber group is four.

[0014] An optical connection structure according to a sixth aspect of the present invention comprises an optical connector according to any one of the first to fifth aspects and a second optical connector connected to the optical connector, wherein the second optical connector has a second ferrule having a second connection end face abutting the connection end face and a second fiber hole opening into the second connection end face, and a multi-core fiber inserted into the second fiber hole and connected to a plurality of the optical fibers. [Effects of the Invention]

[0015] According to one aspect of the present invention, it is possible to provide an optical connector and an optical connection structure that can reduce loss due to bending of an optical fiber. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a perspective view of an optical connector according to a first embodiment. [Figure 2] 1 is a cross-sectional view of the optical connector according to the first embodiment, taken along line II in FIG. [Figure 3]FIG. 1 is a plan view of an optical connector according to a first embodiment. [Figure 4] 1 is a perspective view of an optical fiber used in the optical connector according to the first embodiment. [Figure 5] 3 is a schematic diagram showing the arrangement of optical fibers in the rear end opening of the ferrule in the optical connector according to the first embodiment. FIG. [Figure 6] 1 is a front view of a portion of a connection end face of an optical connector according to a first embodiment. [Figure 7] 2 is a cross-sectional view of an optical fiber inserted into a fiber hole of the optical connector according to the first embodiment. FIG. [Figure 8] FIG. 2 is a perspective view of a second optical connector. [Figure 9] FIG. 4 is a front view of a portion of a second connection end face of the second optical connector. [Figure 10] FIG. 2 is a front view of the multi-core fiber at the second connection end face of the second optical connector. [Figure 11] FIG. 1 is a plan view of an optical connection structure according to an embodiment. [Figure 12] 1 is a cross-sectional view of an optical connection structure according to an embodiment. [Figure 13] FIG. 10 is a perspective view of an optical connector according to a second embodiment. [Figure 14] FIG. 10 is a perspective view of an optical fiber used in the optical connector according to the second embodiment. [Figure 15] 10 is a schematic diagram showing the arrangement of optical fibers in the rear end opening of the ferrule in the optical connector according to the second embodiment. FIG. [Figure 16] 10 is a schematic diagram showing the arrangement of optical fibers in the rear end opening of the ferrule in the optical connector according to the third embodiment. FIG. [Figure 17] 10 is a schematic diagram showing the arrangement of optical fibers in the rear end opening of the ferrule in the optical connector according to the fourth embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, an optical connector and an optical connection structure according to an embodiment of the present invention will be described with reference to the drawings.

[0018] [Optical Connector] (First Embodiment) FIG. 1 is a perspective view of an optical connector 1A according to a first embodiment. FIG. 2 is a cross-sectional view of the optical connector 1A. FIG. 2 is a cross-sectional view taken along line II in FIG. 1. FIG. 3 is a plan view of the optical connector 1A. FIG. 4 is a perspective view of an optical fiber 20 used in the optical connector 1A. FIG. 5 is a schematic diagram showing the arrangement of the optical fiber 20 in the rear end opening 10c of the ferrule 10. FIG. 6 is a front view of a portion of the connection end face 10a of the optical connector 1A. FIG. 7 is a cross-sectional view of a bare fiber 21 inserted into a fiber hole 11.

[0019] As shown in FIG. 1, the optical connector 1A includes a ferrule 10 and a plurality of optical fibers 20.

[0020] The ferrule 10 has a connection end face 10a, a rear end face 10b, a fiber hole 11, two positioning holes 13, and an introduction hole 14 (see FIG. 2). The connection end face 10a is the surface that is butted against another connector or the like when the optical connector 1A is connected to another connector or the like. The rear end face 10b is the surface of the ferrule 10 opposite the connection end face 10a. The fiber hole 11 and the two positioning holes 13 open to the connection end face 10a.

[0021] (direction definition) In this specification, the direction parallel to the central axis O of the fiber hole 11 is referred to as the longitudinal direction Z. The direction from the rear end face 10b of the ferrule 10 toward the connection end face 10a along the longitudinal direction Z is referred to as the +Z direction, forward, or tip side. The direction opposite to the +Z direction is referred to as the -Z direction, rear, or base side. A direction perpendicular to the longitudinal direction Z is referred to as the first direction X. The first direction X is the direction in which the two positioning holes 13 are aligned. A direction perpendicular to both the longitudinal direction Z and the first direction X is referred to as the second direction Y, up-down direction, or height direction. One direction of the second direction Y is referred to as the +Y direction or upward. The direction opposite to the +Y direction is referred to as the -Y direction or downward. The second direction Y is perpendicular to the X direction along a plane perpendicular to the longitudinal direction Z.

[0022] In the connection end face 10a, the plurality of fiber holes 11 are arranged between two positioning holes 13. The plurality of fiber holes 11 are formed at different positions in the first direction X. The plurality of fiber holes 11 are formed side by side in the first direction X. The plurality of fiber holes 11 may be formed at intervals in the first direction X, or may be formed without any intervals.

[0023] 1 is a female optical connector, and the relative positions of the optical connector 1A and the other optical connector are determined by inserting a positioning pin of the other optical connector into the positioning hole 13. However, the optical connector 1A may also be a male optical connector. In other words, the optical connector 1A may have a positioning pin instead of the positioning hole 13.

[0024] 2, the introduction hole 14 opens to the rear end face 10b. The opening of the introduction hole 14 formed in the rear end face 10b is a rear end opening 10c. The introduction hole 14 communicates with the fiber hole 11.

[0025] When viewed from the first direction X, the connection end face 10a is inclined with respect to an imaginary plane P that is perpendicular to the longitudinal direction Z. The inclined connection end face 10a is formed, for example, by polishing the end face of the ferrule 10. The angle between the connection end face 10a and the imaginary plane P is, for example, 8°. However, this angle can be changed. By inclining the connection end face 10a in this way, the amount of light reflected at the connection point can be reduced. However, the connection end face 10a does not have to be inclined.

[0026] The ferrule 10 is made of, for example, resin, ceramic, etc. Examples of resin include polyether ether ketone resin (PEEK), polyarylene sulfide resin (PAS) (e.g., polyphenylene sulfide resin (PPS)), polyether sulfone resin (PES), polyether imide resin (PEI), and liquid crystal resin (LCP) (melting point of 300°C or higher). Examples of ceramic include zirconia.

[0027] As shown in Fig. 4, the optical fiber 20 has a bare fiber 21 and a coating 22. The bare fiber 21 is made of, for example, quartz glass or the like. The coating 22 partially covers the bare fiber 21. The coating 22 is made of, for example, a resin or the like. For example, the material of the coating 22 may be a UV-curable resin. The bare fiber 21 is exposed in a portion including the tip of the optical fiber 20.

[0028] The bare fiber 21 has a small diameter portion 21a, a large diameter portion 21b, and a tapered portion 21c. The small diameter portion 21a is the portion that includes the tip of the bare fiber 21. The outer diameter of the small diameter portion 21a is smaller than the outer diameter of the large diameter portion 21b. The tapered portion 21c is located between the small diameter portion 21a and the large diameter portion 21b. The tapered portion 21c has an outer diameter that gradually decreases toward the tip. The small diameter portion 21a and the tapered portion 21c can be formed by thinning the bare fiber 21 by etching or the like.

[0029] 7, the optical fiber 20 is a single-core fiber. The bare fiber 21 has a core 21d and a cladding 21e surrounding the core 21d.

[0030] 1 and 5, the plurality of optical fibers 20 includes a plurality of optical fiber groups 40. Each optical fiber group 40 has a plurality of optical fibers 20. In this embodiment, the number of optical fiber groups 40 is four. Each optical fiber group 40 has four optical fibers 20.

[0031] 2, the optical fibers 20 included in the optical fiber group 40 are aligned in a row in the second direction Y at the rear end opening 10c. The optical fibers 20 included in the optical fiber group 40 may be arranged at intervals in the second direction Y, or may be arranged without any intervals.

[0032] As shown in FIG. 5, the multiple optical fibers 20 included in the optical fiber group 40 are all positioned differently in the second direction Y at the rear end opening 10c. In this embodiment, of the four optical fibers 20, the first optical fiber 20A is at the highest position. The second optical fiber 20B is at the second highest position. The third optical fiber 20C is at the third highest position. The fourth optical fiber 20D is at the lowest position. The four optical fibers 20 do not overlap when viewed from the first direction X. It is sufficient that two or more of the multiple optical fibers 20 included in the optical fiber group 40 are positioned differently in the second direction Y at the rear end opening 10c.

[0033] The optical fiber groups 40 are formed in the rear end opening 10c and aligned in the first direction X. The optical fiber groups 40 may be arranged at intervals in the first direction X, or may be arranged without any intervals. In this embodiment, four optical fiber groups 40 are aligned in the first direction X, and therefore the optical fibers 20 are arranged in a rectangular lattice pattern (matrix pattern) of 4 rows and 4 columns in the rear end opening 10c.

[0034] As shown in FIG. 2, the optical fiber group 40 is introduced into the introduction hole 14 from the rear end opening 10c. The bare fibers 21 of the optical fibers 20 belonging to the optical fiber group 40 are bundled together and inserted into the fiber hole 11. The bare fibers 21 are inserted into one fiber hole 11 at the small diameter portion 21a. As shown in FIG. 6, the tip surfaces of the bare fibers 21 are exposed at the splicing end face 10a. In this embodiment, at the splicing end face 10a, four bare fibers 21 belonging to one optical fiber group 40 are arranged in a rectangular lattice pattern (matrix pattern) of 2 rows and 2 columns.

[0035] As shown in Fig. 3, the multiple optical fiber groups 40 are inserted into different fiber holes 11. In this embodiment, of the four optical fiber groups 40, a first optical fiber group 40A is inserted into a first fiber hole 11A of the four fiber holes 11. A second optical fiber group 40B is inserted into a second fiber hole 11B. A third optical fiber group 40C is inserted into a third fiber hole 11C. A fourth optical fiber group 40D is inserted into a fourth fiber hole 11D.

[0036] 2, the adhesive 30 functions to fix the optical fibers 20 to the ferrule 10. The adhesive 30 fills the gap between the inner surface of the fiber hole 11 and the outer peripheral surface of the optical fiber 20. For example, a thermosetting resin can be used as the adhesive 30. The adhesive 30 may also be an epoxy resin.

[0037] As shown in FIG. 3, the pitch P1 of the fiber holes 11 in the splicing end face 10a is compared with the pitch P2 of the optical fibers 20 when the optical fibers 20 having the coating 22 are arranged without gaps in the first direction X. The relationship between the pitch P1 and the pitch P2 is not particularly limited. The pitch P1 may be smaller than the pitch P2. The pitch P1 may be equal to the pitch P2. The pitch P1 may be larger than the pitch P2. The pitch P2 is, for example, the pitch at the rear end opening 10c. The pitch P2 is, for example, equal to the outer diameter of the coating 22.

[0038] [Optical connector assembly method] The optical connector 1A is assembled, for example, in the following manner.

[0039] A plurality of optical fibers 20 are prepared. The coating 22 of the optical fibers 20 is partially removed to expose the bare fibers 21. The diameter of the exposed bare fibers 21 is reduced by etching or the like. By adjusting the time for which the bare fibers 21 are immersed in the etching solution for each position in the longitudinal direction, the small diameter portions 21a and the tapered portions 21c can be formed (see FIG. 4).

[0040] As shown in Figure 2, multiple optical fibers 20 are introduced into the introduction hole 14 of the ferrule 10 from the rear end opening 10c, and bare fibers 21 are inserted into the fiber holes 11. An uncured adhesive 30 is injected into the internal space of the ferrule 10. The adhesive 30 may be actively forced into the fiber holes 11 by suctioning the fiber holes 11 from the opening of the connection end face 10a. The adhesive 30 may also be forced into the fiber holes 11 by capillary force generated within the fiber holes 11.

[0041] The optical fiber 20 is fixed to the ferrule 10 by curing the adhesive 30. For example, if the adhesive 30 is a thermosetting resin such as epoxy resin, the adhesive 30 is heated to a temperature equal to or higher than its curing temperature. For example, if the adhesive 30 is a UV-curable resin, the adhesive 30 is cured by irradiating it with UV light. This results in the optical connector 1A shown in FIG. 1 etc.

[0042] [Second optical connector and optical connection structure C] Fig. 8 is a perspective view of the second optical connector 100 of the optical connection structure C according to the embodiment. Fig. 9 is a front view of a portion of the second connection end face 110a of the second optical connector 100. Fig. 10 is a front view of the multi-core fiber 120 at the second connection end face 110a. Fig. 11 is a plan view of the optical connection structure C according to the embodiment. Fig. 12 is a cross-sectional view of the optical connection structure C according to the embodiment.

[0043] 8, the second optical connector 100 includes a second ferrule 110 and a plurality of multi-core fibers 120. The second ferrule 110 has a second connection end face 110a, a plurality of second fiber holes 111 opening into the second connection end face 110a, two positioning pins 113, and an introduction hole 114 (see FIG. 12).

[0044] In the second connecting end face 110a, the plurality of second fiber holes 111 are arranged between two positioning pins 113. The second fiber holes 111 open to the second connecting end face 110a. The plurality of second fiber holes 111 are formed side by side in the first direction X. The plurality of second fiber holes 111 may be formed at intervals in the first direction X, or may be formed without any intervals. The pitch of the second fiber holes 111 is equal to the pitch of the fiber holes 11 of the optical connector 1A (see FIG. 1).

[0045] 11 and 12, the second connecting end face 110a is abutted against the connecting end face 10a of the optical connector 1A. The second connecting end face 110a abuts against the connecting end face 10a. As shown in FIG. 12, the introduction hole 114 opens to the rear end face of the second ferrule 110 (the face opposite to the second connecting end face 110a). The introduction hole 114 communicates with the second fiber hole 111.

[0046] The second ferrule 110 is made of, for example, resin, ceramic, etc. Examples of resin include PEEK, PAS (for example, PPS), PES, PEI, LCP (melting point of 300° C. or higher), etc. Examples of ceramic include zirconia.

[0047] The multi-core fiber 120 has bare fibers 121 and a coating 122. The bare fibers 121 are exposed at a portion including the tip of the multi-core fiber 120. The multi-core fiber 120 is inserted into the second fiber hole 111 through the introduction hole 114. As shown in Fig. 9, the tip surface of the bare fibers 121 is exposed at the second connection end face 110a.

[0048] 10, the bare fiber 121 has a plurality of cores 121d and a cladding 121e surrounding the cores 121d. In this embodiment, the multi-core fiber 120 has four cores 121d. The four cores 121d are arranged in a rectangular lattice pattern (matrix pattern) of 2 rows and 2 columns.

[0049] 11, the multiple multi-core fibers 120 are arranged side by side in the first direction X. The multiple multi-core fibers 120 may be arranged at intervals in the first direction X, or may be arranged without any intervals. In this embodiment, the number of multi-core fibers 120 is four.

[0050] As shown in FIG. 12, the adhesive 130 is injected into the second ferrule 110 to fix the multi-core fiber 120 to the second ferrule 110 .

[0051] As shown in FIGS. 11 and 12, the optical connection structure C includes an optical connector 1A (see FIG. 1), a second optical connector 100 (see FIG. 8), and an adapter 2.

[0052] The optical connector 1A and the second optical connector 100 are connected with the connection end face 10a and the second connection end face 110a butting against each other. The positioning pin 113 shown in FIG. 8 is inserted into the positioning hole 13 (see FIG. 1) of the ferrule 10 of the optical connector 1A, thereby determining the relative positions of the second optical connector 100 and the optical connector 1A.

[0053] The adapter 2 has the function of keeping the connection end surface 10a of the optical connector 1A and the second connection end surface 110a of the second optical connector 100 in contact with each other at an appropriate position. The adapter 2 has a through hole 2a that passes through the adapter 2 in the longitudinal direction Z. The optical connector 1A and the second optical connector 100 are inserted into the through hole 2a, respectively.

[0054] The tip faces (see FIG. 6) of the optical fibers 20 of the plurality of optical fiber groups 40 of the optical connector 1A are respectively butted against the tip faces (see FIG. 9) of the plurality of multi-core fibers 120 of the second optical connector 100. The cores 21d (see FIG. 7) of the optical fibers 20 are optically connected to the cores 121d (see FIG. 10) of the multi-core fibers 120, respectively.

[0055] [Effects of the optical connector 1A and optical connection structure C according to this embodiment] In the optical connector 1A according to this embodiment (see FIG. 1), two or more of the optical fibers 20 included in the optical fiber group 40 are positioned at different positions in the second direction Y in the rear end opening 10c. This allows the dimensions of the optical fibers 20 in the first direction X to be reduced. Therefore, compared to when the optical fibers 20 are arranged side by side in the first direction X, the bending applied to the optical fibers 20 positioned outside in the first direction X can be reduced. This allows the loss due to bending of the optical fibers 20 to be reduced.

[0056] In the optical connector 1A (see FIG. 1), the multiple optical fibers 20 included in the optical fiber group 40 are positioned differently in the second direction Y at the rear end opening 10c. In the example shown in FIG. 5, all four optical fibers 20 included in one optical fiber group 40 are positioned differently in the second direction Y. This allows the size of the multiple optical fibers 20 in the first direction X to be reduced. This allows the loss due to bending of the optical fibers 20 to be reduced.

[0057] In the optical connector 1A (see FIG. 1), the optical fibers 20 included in the optical fiber group 40 are aligned in the second direction Y at the rear end opening 10c. This allows the size of the optical fibers 20 in the first direction X to be reduced. This allows the loss due to bending of the optical fibers 20 to be reduced.

[0058] As shown in FIG. 3, the pitch P1 of the fiber holes 11 is set equal to the pitch P2 of the optical fibers 20 when the optical fibers 20 are arranged in the first direction X without any gaps. That's all In this case, the optical connector 1A can particularly enhance the effect of reducing loss due to bending of the optical fibers 20 for the following reason: When the pitch P1 is smaller than the pitch P2, the pitch of the optical fibers 20 at the rear end of the ferrule 10 is larger than that at the front end, and therefore the bending applied to the optical fibers 20 is likely to be large. In contrast, in the optical connector 1A, the dimension of the multiple optical fibers 20 in the first direction X at the rear end of the ferrule 10 can be made smaller, and therefore the bending of the optical fibers 20 can be made smaller, and loss can be reduced.

[0059] Since the number of optical fibers 20 included in the optical fiber group 40 is four, the dimension of the optical fiber group 40 in the second direction Y can be reduced. Therefore, the dimension of the ferrule 10 in the second direction Y can be reduced. Therefore, the thickness dimension of the optical connector 1A can be reduced.

[0060] The optical connection structure C according to this embodiment includes an optical connector 1A and a second optical connector 100. Therefore, in the optical connector 1A, the dimension of the plurality of optical fibers 20 in the first direction X can be reduced. As a result, loss due to bending of the optical fibers 20 can be reduced.

[0061] [Optical Connector] (Second Embodiment) Next, an optical connector 1B according to a second embodiment will be described. The basic configuration of the optical connector 1B is the same as that of the optical connector 1A (see FIG. 1). Therefore, the same components as those in the optical connector 1A will be assigned the same reference numerals, and their description will be omitted, with only the differences being described.

[0062] Fig. 13 is a perspective view of the optical connector 1B. Fig. 14 is a perspective view of an optical fiber 20 used in the optical connector 1B. Fig. 15 is a schematic diagram showing the arrangement of the optical fiber 20 in the rear end opening 210c of the ferrule 10 of the optical connector 1B.

[0063] As shown in FIG. 13, the optical connector 1B includes a ferrule 10 and a plurality of optical fibers 20. 14, the optical fibers 20 constitute a plurality of optical fiber groups 240. Each optical fiber group 240 includes a plurality of optical fibers 20. In this embodiment, the number of optical fiber groups 240 is four. Each optical fiber group 240 includes four optical fibers 20.

[0064] 15, the four optical fibers 20 belonging to one optical fiber group 240 are arranged in a rectangular lattice pattern (matrix pattern) of 2 rows and 2 columns in the rear end opening 210c. The four optical fibers 20 belonging to the optical fiber group 240 are arranged in the second direction Y, for example, as a first group consisting of a plurality of optical fibers 20E, 20F arranged in the first direction X, and a second group consisting of a plurality of optical fibers 20G, 20H arranged in the first direction X. Therefore, it can be said that two or more of the four optical fibers 20 are positioned at different positions in the second direction Y in the rear end opening 210c.

[0065] The multiple optical fiber groups 240 are formed in the rear end opening 210c aligned in the first direction X. In this embodiment, four optical fiber groups 240 are aligned in the first direction X, and therefore the multiple optical fibers 20 are arranged in a rectangular lattice pattern (matrix pattern) of 2 rows and 8 columns in the rear end opening 210c.

[0066] In the optical connector 1B according to this embodiment, two or more of the optical fibers 20 included in the optical fiber group 240 are positioned at different positions in the second direction Y in the rear end opening 210c. This allows the dimensions of the optical fibers 20 in the first direction X to be reduced. Therefore, compared to when the optical fibers 20 are arranged side by side in the first direction X, the bending applied to the optical fibers 20 positioned outside in the first direction X can be reduced. This allows the loss due to bending of the optical fibers 20 to be reduced.

[0067] [Optical Connector] (Third Embodiment) Next, an optical connector according to a third embodiment will be described. The same components as those in the optical connector 1A will be given the same reference numerals, and the description thereof will be omitted, and only the differences will be described.

[0068] FIG. 16 is a schematic diagram showing the arrangement of the optical fiber 20 in the rear end opening 310c of the ferrule. 16, the four optical fibers 20 belonging to one optical fiber group 340 are arranged in the rear end opening 310c along a straight line that slopes upward toward the first direction X (to the right in FIG. 16). Therefore, it can be said that two or more of the four optical fibers 20 are positioned differently in the second direction Y in the rear end opening 310c. The multiple optical fiber groups 340 are formed side by side in the first direction X in the rear end opening 310c.

[0069] In the optical connector according to this embodiment, two or more of the optical fibers 20 included in the optical fiber group 340 are positioned at different positions in the second direction Y in the rear end opening 310c. This allows the dimensions of the optical fibers 20 in the first direction X to be reduced. Therefore, compared to when the optical fibers 20 are arranged side by side in the first direction X, the bending applied to the optical fibers 20 positioned outside in the first direction X can be reduced. This allows the loss due to bending of the optical fibers 20 to be reduced.

[0070] [Optical Connector] (Fourth Embodiment) Next, an optical connector according to a fourth embodiment will be described. The same components as those in the optical connector 1A will be given the same reference numerals, and the description thereof will be omitted, and only the differences will be described.

[0071] FIG. 17 is a schematic diagram showing the arrangement of the optical fiber 20 in the rear end opening 410c of the ferrule. As shown in FIG. 17, the four optical fibers 20 belonging to one optical fiber group 440 are arranged in the rear end opening 410c in a configuration in which a first group consisting of optical fibers 20I and 20J and a second group consisting of multiple optical fibers 20J and 20K arranged in the first direction X are arranged in the second direction Y. The optical fibers 20I and 20J of the first group are arranged along a straight line that slopes downward toward the first direction X (to the right in FIG. 17). The optical fibers 20K and 20L of the second group are arranged along a straight line that slopes downward toward the first direction X (to the right in FIG. 17). Therefore, it can be said that two or more of the four optical fibers 20 are positioned differently in the second direction Y in the rear end opening 210c. The multiple optical fiber groups 440 are formed arranged in the first direction X in the rear end opening 410c.

[0072] In the optical connector according to this embodiment, two or more of the optical fibers 20 included in the optical fiber group 440 are positioned at different positions in the second direction Y in the rear end opening 410c. This allows the dimensions of the optical fibers 20 in the first direction X to be reduced. Therefore, compared to when the optical fibers 20 are arranged side by side in the first direction X, the bending applied to the optical fibers 20 positioned outside in the first direction X can be reduced. This allows the loss due to bending of the optical fibers 20 to be reduced.

[0073] The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

[0074] For example, the number of optical fiber groups 40 in the optical connector is not particularly limited. The number of optical fiber groups 40 may be multiple (any number greater than or equal to 2). The number of optical fibers 20 constituting the optical fiber group 40 is not particularly limited. The number of optical fibers 20 constituting the optical fiber group 40 may be multiple (any number greater than or equal to 2).

[0075] In addition, it is possible to replace the components in the above-described embodiments with well-known components as appropriate, and the above-described embodiments and variations may be combined as appropriate, without departing from the spirit of the present invention. [Explanation of symbols]

[0076] DESCRIPTION OF SYMBOLS 1A, 1B...Optical connector 10, 210...Ferrule 10a...Connection end face 10b...Rear end face 10c, 210c, 310c, 410c...Rear end opening 11...Fiber hole 14...Introduction hole 20, 20A to 20L...Optical fiber 40, 240, 340, 440...Optical fiber group 100...Second optical connector 110...Second ferrule 110a...Second connection end face 111...Second fiber hole 120...Multi-core fiber C...Optical connection structure X...First direction Y...Second direction

Claims

1. a ferrule having a plurality of fiber holes opening at a connection end surface and introduction holes communicating with the fiber holes; a plurality of optical fibers inserted into the fiber holes from the introduction holes; Equipped with the introduction hole has a rear end opening on a rear end surface of the ferrule opposite to the connection end surface, the plurality of optical fibers includes a plurality of optical fiber groups each having four or more of the optical fibers; the plurality of optical fiber groups are introduced into the introduction hole from the rear end opening and inserted into the fiber holes, respectively; the fiber holes are formed at different positions in a first direction on the connection end face, a second direction perpendicular to the first direction along a plane perpendicular to the longitudinal direction of the fiber hole; two or more of the optical fibers included in the optical fiber group are positioned at different positions in the second direction in the rear end opening, two or more of the optical fibers included in the optical fiber group are positioned at different positions in the first direction in the rear end opening; the optical fibers included in the optical fiber group are positioned at different positions in the second direction in the rear end opening; Optical connector.

2. a pitch of the fiber holes in the connection end face is equal to or greater than a pitch of the optical fibers when the optical fibers are arranged in the first direction without any gaps; 2. The optical connector according to claim 1.

3. The number of the optical fibers included in one optical fiber group is four.

2. The optical connector according to claim 1.

4. The optical connector according to any one of claims 1 to 3, a second optical connector to be connected to the optical connector; Equipped with The second optical connector comprises: a second ferrule having a second connection end surface abutting the connection end surface and a second fiber hole opening into the second connection end surface; a multi-core fiber inserted into the second fiber hole and connected to the plurality of optical fibers; having Optical connection structure.

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