Optical fiber holding component, optical fiber assembly, optical connector, and optical coupling device

Abstract

An optical fiber holding component (310) of the present disclosure, which is fixed to a ferrule (200), comprises a first end surface (310a) and a second end surface (310b), a plurality of through-holes (315), a first flat surface (311), and a pair of corner parts (319). The first flat surface (311) has a width (L2) equal to or less than the width (L1) of a ferrule flat surface (242), and the maximum width (L3) of the optical fiber holding component (310) is greater than the width (L1) of the ferrule flat surface (242).

Description

Optical fiber holding components, optical fiber assemblies, optical connectors, and optical coupling devices

[0001] The present disclosure relates to an optical fiber holding component, an optical fiber assembly, an optical connector, and an optical coupling device. This application claims priority from Japanese Patent Application No. 2023-093169, filed on June 6, 2023, the contents of which are relied upon and incorporated herein by reference in their entirety.

[0002] Patent Document 1 discloses an MT connector for optically connecting multiple optical fibers to multiple other optical fibers at once. The MT connector in Patent Document 1 uses multiple multi-core optical fibers (hereinafter referred to as "MCFs"), each containing multiple cores, as optical fibers. Therefore, the multiple MCFs, which are aligned by rotating them around their fiber axes, are temporarily held by multiple fiber holding components that maintain the aligned state for each fiber or pair of fibers. By inserting these multiple optical fiber holding components into ferrules, an MT connector is obtained in which the aligned state of the multiple MCFs is maintained.

[0003] International Publication No. WO2016 / 031678A1

[0004] The holding equipment for optical fiber of the present disclosure holds a plurality of optical fibers in a ferrule and is fixed with at least a portion inserted into a storage space of the ferrule. The ferrule has a front end face provided with a plurality of fiber holes into which the tip portions of the plurality of optical fibers are respectively inserted, a rear end face provided with an opening defined by an open end of a plurality of recessed corners each chamfered, and a storage space extending from the rear end face to the front end face and having the same cross-sectional shape as the opening. The holding equipment for optical fiber also has a first end face and a second end face, a plurality of through holes, a first flat surface, and a pair of projected corners. The first end face and the second end face are arranged along a first direction from the front end face to the rear end face of the ferrule. The plurality of through holes have a shape extending from the first end face along the first direction and are arranged along a second direction perpendicular to the first direction, and pass corresponding optical fibers of the plurality of optical fibers from the second end face to the first end face. The first flat surface directly faces the flat surface of the ferrule. The ferrule flat surface is an installation reference surface that is a part of the inner wall surface that defines the storage space of the ferrule, and is a flat surface sandwiched between a pair of adjacent corners among multiple corners. The pair of corners are arranged to sandwich the first flat surface along the second direction. Also, each of the pair of corners is chamfered so that a non-contact state with the pair of corners is maintained when the ferrule flat surface and the first flat surface are in contact. In particular, in the width of holding equipment for optical fiber of the present disclosure, the width of the first flat surface is set to be equal to or less than the width of the ferrule flat surface with respect to the width of the ferrule along the second direction, and the maximum width of holding equipment for optical fiber satisfies the relationship that the width of the first flat surface is set to be greater than the width of the ferrule flat surface.

[0005] Fig. 1 is a diagram showing an example of an assembly process of an optical coupling device of the present disclosure. Fig. 2 is a diagram showing an example of the structure of a ferrule applicable to an optical connector of the present disclosure. Fig. 3 is a diagram showing an example of the structure of an optical fiber assembly of the present disclosure and holding equipment for optical fiber of the present disclosure. Fig. 4 is a diagram for explaining an inserted state of holding equipment for optical fiber of the present disclosure. Fig. 5 is a diagram for explaining a change in shape of an optical fiber after inserting an optical fiber assembly into a ferrule. Fig. 6 is a diagram showing the structure of a modified example of holding equipment for optical fiber of the present disclosure.

[0006] [Problems to be Solved by the Present Disclosure] As a result of examining the above-mentioned conventional techniques, the inventors have found the following problems. That is, in the assembly process of the MT connector of Patent Document 1, a plurality of holding equipment for optical fiber is prepared to hold MCFs aligned one by one or two by two. These plurality of holding equipment for optical fiber are inserted into the ferrule one by one. In this case, since it is necessary to bond each inserted holding equipment for optical fiber to the ferrule, there is a problem that it takes a long time to mount a plurality of holding equipment for optical fiber into the ferrule.

[0007] Furthermore, the MT connector of Patent Document 1 has a problem in that the positioning mechanism for the ferrules and holding components for optical fiber becomes complicated. This is because, due to the structural characteristics of the MCF, all of the holding components for optical fiber must be individually positioned with high precision not only in the horizontal and vertical directions but also in the rotational direction.

[0008] Furthermore, when adhesively fixing multiple holding equipment for optical fiber to a ferrule, a clearance for injecting adhesive is required between the ferrule and multiple holding equipment for optical fiber. On the other hand, the clearance causes the multiple holding equipment for optical fiber to become unstable when fixed in the ferrule. In particular, if the posture of each of the multiple holding equipment for optical fiber when fixed in the ferrule is not stable, there is a possibility that each holding equipment for optical fiber will be misaligned with the fiber hole of the ferrule that holds the tip part of the MCF. In such a situation, even if multiple MCFs are inserted into the fiber hole of the ferrule, unnecessary stress will be applied to the part of the held MCF that is exposed from each holding equipment for optical fiber, which may cause damage to the MCF.

[0009] The present disclosure has been made to solve the above-mentioned problems, and aims to provide an optical fiber holding component, an optical fiber assembly, an optical connector, and an optical coupling device that are easily fixed to a ferrule and have a structure for limiting posture fluctuations before being fixed to the ferrule.

[0010] [Effects of the present disclosure] According to the holding equipment for optical fiber of the present disclosure, it is easy to fix it to the ferrule, and it is possible to limit the change in posture before it is fixed to the ferrule.

[0011] [Description of Embodiments of the Present Disclosure] First, the contents of the embodiments of the present disclosure will be individually listed and described.

[0012] (1) The holding equipment for optical fiber of the present disclosure is a component that holds multiple optical fibers in a ferrule and is fixed in a state where at least a part of the optical fibers is inserted into the storage space of the ferrule. For example, if each optical fiber is an MCF having multiple cores, the holding equipment for optical fiber also functions as a component that maintains the alignment state of each MCF.

[0013] The ferrule, into which at least a portion of the optical fiber holding component is inserted, comprises a front end face provided with a plurality of fiber holes into which the tip portions of a plurality of optical fibers are respectively inserted, a rear end face provided with an opening defined by an opening end with a plurality of corners each chamfered, and a storage space extending from the rear end face toward the front end face and having the same cross-sectional shape as the opening.

[0014] On the other hand, holding equipment for optical fiber is a component fixed to the ferrule in a state in which it holds a plurality of optical fibers, and a part of it is inserted into the storage space from the opening. The holding equipment for optical fiber comprises a first end face and a second end face, a plurality of through holes, a first flat surface, and a pair of corners. The first end face and the second end face are arranged along a first direction from the front end face to the rear end face of the ferrule. The plurality of through holes have a shape extending from the first end face along the first direction, are arranged along a second direction perpendicular to the first direction, and pass corresponding optical fibers among the plurality of optical fibers from the second end face to the first end face. The first flat surface is an installation reference surface that is a part of the inner wall surface that defines the storage space of the ferrule, and directly faces the ferrule flat surface sandwiched between a pair of adjacent corners among the multiple corners. The pair of corners are arranged to sandwich the first flat surface along the second direction. Furthermore, each of the pair of corners is chamfered so that a non-contact state with the pair of corners is maintained when the ferrule flat surface and the first flat surface are in contact.

[0015] In particular, in the optical fiber holding equipment of the present disclosure, the width of the optical fiber holding equipment along the second direction satisfies the relationship that the width of the first flat surface is set to be equal to or less than the width of the ferrule flat surface relative to the width of the ferrule along the second direction, and the maximum width of the optical fiber holding equipment is longer than the width of the ferrule flat surface.

[0016] Incidentally, like the above-mentioned "ferrule flat surface" and "first flat surface," the "flat surface" disclosed in this specification means a surface having a curvature of 0.1 (1 / mm) or less. A "corner" and a "corner" mean a portion sandwiched between a pair of adjacent "flat surfaces," and the pair of "flat surfaces" are adjacent to the "corner" or "corner" and are continuous with each other. Also, the "chamfering" of the corner of the opening end at the rear end face of the ferrule and the "chamfering" of the corner of the holding equipment for optical fiber include "C-chamfering," which processes the edge portion into a surface inclined at 45 degrees from the flat surface, and "R-chamfering," which processes the surface of the edge portion smoothly.

[0017] As described above, the rear end face of the ferrule into which holding equipment for optical fiber is inserted and fixed has an opening defined by an open end with multiple chamfered corners. Meanwhile, the corners of holding equipment for optical fiber are also chamfered so as not to come into contact with the corners. In addition, the width of the first flat face of holding equipment for optical fiber is set to be equal to or smaller than the width of the ferrule flat face which serves as the installation reference face. Meanwhile, the maximum width of holding equipment for optical fiber is set to be longer than the width of the ferrule flat face. With this configuration, holding equipment for optical fiber can be inserted and fixed into the ferrule with high precision, and the positional fluctuation of holding equipment for optical fiber before fixing inside the ferrule can be effectively restricted. Furthermore, since holding equipment for optical fiber holds multiple optical fibers, these optical fibers can be mounted into the ferrule all at once.

[0018] (2) In the above (1), the width of the first flat surface sandwiched between a pair of corners may be equal to the width of the ferrule flat surface. The corners of the opening end at the rear end face of the ferrule are chamfered, and the corners of holding equipment for optical fiber are also chamfered. Therefore, when the width of the first flat surface and the width of the ferrule flat surface are equal, the movement of holding equipment for optical fiber along the second direction is automatically limited. In other words, once the first flat surface and the ferrule flat surface come into contact, the posture of holding equipment for optical fiber before fixing inside the ferrule is stable.

[0019] (3) In the above (1) or (2), the plurality of through holes arranged on the first end face may include a plurality of row forming groups each defined by one or more through holes arranged along the second direction, and the plurality of row forming groups are arranged along a third direction perpendicular to both the first direction and the second direction. In this way, by arranging the plurality of through holes two-dimensionally on the first end face, the holding equipment for optical fiber can hold more optical fibers. Furthermore, when a plurality of optical fibers are arranged not only in the second direction but also in the third direction, it is possible to significantly increase the number of optical fibers held by the holding equipment for optical fiber, and as a result, the workability of mounting a plurality of optical fibers to ferrules is significantly improved.

[0020] (4) In any of the above (1) to (3), the first flat surface may be a surface parallel to both the first direction and the second direction. Also, the first flat surface may be a surface parallel to both the first direction and the third direction. The third direction is a direction perpendicular to each of the first direction and the second direction. When the first flat surface is a surface parallel to both the first direction and the second direction, it becomes possible to use a large surface parallel to multiple optical fibers in terms of the structure of holding equipment for optical fiber and ferrule. Therefore, it becomes possible to more stabilize the posture of holding equipment for optical fiber in the ferrule. On the other hand, when the first flat surface is a surface parallel to both the first direction and the third direction, in addition to stabilizing the posture of holding equipment for optical fiber in the ferrule, it becomes easier to position holding equipment for optical fiber with respect to the second direction, which is the arrangement direction of fiber holes in the ferrule.

[0021] (5) In any of the above (1) to (4), holding equipment for optical fiber may have a second flat surface parallel to the first flat surface. By providing the first flat surface and the second flat surface parallel to each other in this way, handling of holding equipment for optical fiber becomes easy, and as a result, workability of mounting ferrules to a plurality of optical fibers can be improved.

[0022] (6) In any of the above (1) to (5), holding equipment for optical fiber may have a third flat surface formed continuously from one of a pair of corners to the first flat surface. In this case, the first flat surface and the third flat surface may be perpendicular. By making the first flat surface and the third flat surface perpendicular, it becomes possible to position holding equipment for optical fiber in both the second direction which is the arrangement direction of the fiber holes of the ferrule and the third direction perpendicular thereto. As a result, it becomes easy to mount the ferrule to multiple optical fibers.

[0023] (7) In any of the above (1) to (6), the first end face may have a square shape. When the whole of holding equipment for optical fiber is inserted into the storage space of the ferrule, both the first end face and the second end face will be located in the storage space. On the other hand, when a part of holding equipment for optical fiber is inserted into the storage space of the ferrule, only the first end face will be located in the storage space. In either case, handling of holding equipment for optical fiber becomes easy, and high-precision positioning of holding equipment for optical fiber in the ferrule becomes possible.

[0024] (8) The optical fiber assembly of the present disclosure comprises holding equipment for optical fiber having the structure described in any one of (1) to (7) above, and a plurality of optical fibers. The plurality of optical fibers are fixed in each of a plurality of through holes of holding equipment for optical fiber. The tip portions of each of a plurality of optical fibers inserted into a plurality of fiber holes arranged on the front end face of the ferrule have the resin coating covering the glass portion removed. Therefore, the portion of the optical fiber held in each of a plurality of through holes of holding equipment for optical fiber may be the portion from which the resin coating has been removed, or may be the portion covered with the resin coating. In this way, when holding equipment for optical fiber of the present disclosure disclosed in any one of (1) to (7) above is applied, an optical fiber assembly that is easy to handle can be obtained.

[0025] (9) An optical connector of the present disclosure comprises the optical fiber assembly according to (8) above and a ferrule. As described above, at least a part of the optical fiber assembly is inserted into the storage space of the ferrule. In this configuration, the posture of holding equipment for optical fiber in the storage space of the ferrule is maintained with a part of holding equipment for optical fiber in contact with the flat surface of the ferrule. Tip portions of multiple optical fibers are inserted into multiple fiber holes of the ferrule while being fixed in multiple through holes of holding equipment for optical fiber. In this case, an optical connector is obtained that maintains high rotational alignment accuracy for each of the multiple optical fibers.

[0026] (10) In the above (9), a clearance is maintained between the inner wall surface of the ferrule and holding equipment for optical fiber, so that the angle formed between the ferrule flat surface and the first flat surface is 0° or more and 1° or less when a part of holding equipment for optical fiber is in contact with the ferrule flat surface. With this configuration, movement of holding equipment for optical fiber along the ferrule flat surface is limited.

[0027] (11) An optical coupling device according to the present disclosure includes a first optical connector and a second optical connector that function as the optical connector described in (9) or (10). The relative positions of the first optical connector and the second optical connector are fixed such that the front end face of the first optical connector faces the front end face of the second optical connector. In this case, an optical coupling device that enables optical coupling with low connection loss is obtained.

[0028] As described above, each aspect listed in the [Description of Embodiments of the Present Disclosure] section can be applied to all of the remaining aspects individually or to all combinations of these remaining aspects.

[0029] [Details of the embodiments of the present disclosure] Specific examples of holding equipment for optical fiber, optical fiber assembly, optical connector, and optical coupling device according to the present disclosure will be described in detail below with reference to the accompanying drawings. Note that the present disclosure is not limited to these examples, but is indicated by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims. In addition, in the description of the drawings, the same elements are given the same symbols, and duplicate explanations will be omitted.

[0030] Fig. 1 is a diagram showing an example of an assembly process for an optical coupling device of the present disclosure. The optical coupling device 1 shown in Fig. 1 includes a pair of optical connectors 100 optically connected by a connecting part 400. Note that Fig. 1 shows optical connectors 100A and 100B having the same structure as the pair of optical connectors 100 to be optically coupled. The connecting part 400 includes a through hole 410 for directly facing the optical connector 100A and the optical connector 100B, and guide pins 450A and 450B for fixing the relative positions of the optical connector 100A and the optical connector 100B.

[0031] The optical connector 100A includes a ferrule 200 and an optical fiber assembly 300. The ferrule 200 has a front end face 210a with a plurality of fiber holes 230, a rear end face 210b with an opening 210c, and a storage space 240 provided between the front end face 210a and the rear end face 210b. The storage space 240 communicates with the outside of the ferrule 200 through the opening 210c in the rear end face 210b and an injection port 241 for injecting adhesive provided on the upper end face of the optical connector 100A. The optical connector 100A also has guide holes 220a and 220b into which guide pins 450A and 450B held by the connecting part 400 are inserted, respectively.

[0032] The optical fiber assembly 300 comprises a plurality of optical fibers 320 and holding equipment for optical fiber 310 for holding the plurality of optical fibers 320. The plurality of optical fibers 320 include glass optical fibers 321 and resin coatings 322 that cover the outer peripheries of the glass optical fibers 321. The holding equipment for optical fiber 310 comprises a first end face 310a and a second end face 310b arranged along a first direction from the front end face 210a to the rear end face 210b of the ferrule 200. Moreover, the holding equipment for optical fiber 310 holds the plurality of optical fibers 320 in a state where the tip portions of the plurality of optical fibers 320, from which a part of the resin coating 322 has been removed, are exposed from the first end face 310a. Furthermore, the holding equipment for optical fiber 310 is inserted from the first end face 310a through the opening 210c into the storage space 240 of the ferrule 200, and then adhesively fixed to the ferrule 200 while maintaining its orientation in the storage space 240.

[0033] The optical connector 100B also has a structure similar to that of the optical connector 100A. The connecting part 400 is fixed to the front end face 210a of the optical connector 100A by inserting first ends of the guide pins 450A and 450B of the connecting part 400 into the guide holes 220a and 220b, respectively. Meanwhile, the connecting part 400 is fixed to the front end face 210a of the optical connector 100B by inserting second ends of the guide pins 450A and 450B of the connecting part 400 into the guide holes 220a and 220b, respectively. In this way, the relative positions of the optical connectors 100A and 100B are fixed by the connecting part 400, thereby obtaining the optical coupling device 1.

[0034] As mentioned above, the optical connector 100 of the present disclosure is an MT connector, and a single holding equipment for optical fiber 310 is mounted on the ferrule 200. That is, in the optical connector 100 of the present disclosure, a single holding equipment for optical fiber 310 can mount a plurality of optical fibers 320 in all of the fiber holes 230 of the ferrule 200. Although the specific structure will be described later, according to the optical connector 100 of the present disclosure, the cooperation of the ferrule 200 and holding equipment for optical fiber 310 does not require a complicated mechanism or a special insertion method, and a structure that allows control of the installation position and rotation angle of holding equipment for optical fiber 310 relative to the ferrule 200 can also be obtained.

[0035] Next, the assembly process of the optical connector 100 when an MCF is used as an example of the optical fiber 320 will be described.

[0036] When multiple optical fibers 320 are inserted, rotated, aligned, and fixed one by one, first one MCF is placed in holding equipment for optical fiber 310. In this state, the MCF is rotated in the direction indicated by arrow S to perform rotation alignment, and then the rotated and aligned MCF is fixed to holding equipment for optical fiber 310 with adhesive. A series of steps of inserting, rotating, aligning, and fixing are repeated for all multiple optical fibers to obtain an optical fiber assembly 300. Finally, the holding equipment for optical fiber 310 of the obtained optical fiber assembly 300 is inserted into the storage space 240 of the ferrule 200 through the opening 210c, and then the holding equipment for optical fiber 310 is fixed to the ferrule 200 in a predetermined position and posture to obtain an optical connector 100.

[0037] On the other hand, when multiple optical fibers 320 are inserted, rotated, and fixed at the same time, all MCFs are placed in the holding equipment for optical fiber 310. In this state, rotational alignment is performed by rotating each MCF in the direction indicated by the arrow S. If necessary, the MCFs after rotational alignment may be temporarily fixed using a jig that grips the resin coating 322. After that, all MCFs after rotational alignment are adhesively fixed to the holding equipment for optical fiber 310 at once, and the optical fiber assembly 300 is obtained. Finally, the holding equipment for optical fiber 310 of the obtained optical fiber assembly 300 is inserted into the storage space 240 of the ferrule 200 through the opening 210c, and then the holding equipment for optical fiber 310 is adhesively fixed to the ferrule 200 in a predetermined position and posture, and the optical connector 100 is obtained.

[0038] FIG. 2 is a diagram showing an example of a ferrule structure applicable to the optical connector of the present disclosure (denoted as "ferrule" in FIG. 2). The left column of FIG. 2 (denoted as "single-row arrangement" in FIG. 2) shows an example of a ferrule 200 in which fiber holes 230 for holding the tip portions of optical fibers 320 are arranged in a single row, and the right column of FIG. 2 (denoted as "double-row arrangement" in FIG. 2) shows an example of a ferrule 200A in which fiber holes 230 for holding the tip portions of optical fibers 320 are arranged in two rows. The upper part of FIG. 2 (denoted as "cross-sectional structure" in FIG. 2) shows the cross-sectional structures of the ferrules 200 and 200A taken along line II shown in FIG. 1. The middle part of FIG. 2 (denoted as "front end face" in FIG. 2) shows the front end faces 210a of the ferrules 200 and 200A. The lower part of FIG. 2 (denoted as "rear end face" in FIG. 2) shows the rear end faces 210b of the ferrules 200 and 200A.

[0039] The "single-row" ferrule 200 shown in the upper left column of Fig. 2 comprises a front end face 210a with a plurality of fiber holes 230, a rear end face 210b with openings 210c, and a storage space 240 provided between the front end face 210a and the rear end face 210b. The plurality of fiber holes 230 extend along a first direction from the front end face 210a to the rear end face 210b, and are arranged in a row along a second direction perpendicular to the first direction, as shown in the middle left column of Fig. 2. Between each fiber hole 230 and the storage space 240, there are provided tapered portions 231 for smoothly guiding the tip portions of the plurality of optical fibers 320 into the fiber holes 230, and stoppers 232 for positioning the holding equipment for optical fiber 310 in the first direction. The storage space 240 is connected to the outside of the ferrule 200 through openings 210c provided in the rear end face 210b and an injection port 241 for injecting adhesive resin. Moreover, the storage space 240 has a cross-sectional shape that substantially matches the shape of the opening 210c, and between the stopper 232 and the opening 210c there is a ferrule flat surface 242 that is a part of the inner wall that defines the storage space 240. The curvature of this ferrule flat surface 242 is 0.1 (1 / mm) or less, and the ferrule flat surface 242 functions as an installation reference surface for holding equipment for optical fiber 310.

[0040] The "two-row" ferrule 200A shown in the upper right column of Fig. 2 has the same structure as the above-described ferrule 200, except for the arrangement of the multiple fiber holes 230. That is, in the ferrule 200A, as shown in the middle right column of Fig. 2, two rows of optical fibers 320 arranged along the second direction are provided along a third direction perpendicular to both the first and second directions. Each row defines a row-forming group including one or more fiber holes 230.

[0041] As shown in the lower left and right columns of FIG. 2 , the rear end face 210b of the "single-row" ferrule 200 and the rear end face 210b of the "double-row" ferrule 200A have the same structure. That is, the rear end face 210b has an opening 210c defined by an open end with each corner 211 chamfered. As shown in FIG. 2 , a rounded chamfer is suitable for the "chamfering" of each corner 211, considering the structure of the surrounding area defining the opening 210c and the ease of processing. In the following description and related drawings, an example is shown in which the corners 211 of the open end defining the opening 210c are rounded. Furthermore, a ferrule flat surface 242 is disposed between a pair of adjacent corners 211, and the width of the ferrule flat surface 242 along the second direction is L1. Therefore, the cross-sectional shape of the storage space 240 perpendicular to the first direction matches the shape of the opening 210c. The curvature of the R-chamfered corner 211 is 1 / R (1 / mm). R is the radius of curvature, and specifically, the radius of curvature R may be 0.05 mm or more and 0.5 mm or less.

[0042] Fig. 3 is a diagram showing an example of the structure of the optical fiber assembly 300 of the present disclosure including holding equipment for optical fiber 310 of the present disclosure (marked as "optical fiber assembly" in Fig. 3). The upper part of Fig. 3 (marked as "assembly process" in Fig. 3) shows a diagram for explaining the assembly process of the optical fiber assembly 300. The middle part of Fig. 3 (marked as "cross-sectional structure" in Fig. 3) shows the cross-sectional structure of holding equipment for optical fiber 310, which is a part of the optical fiber assembly 300, taken along line II-II shown in the upper part of Fig. 3. The lower part of Fig. 3 (marked as "planar structure" in Fig. 3) shows the planar structure of holding equipment for optical fiber 310 when looking at the second end face 310b.

[0043] As a structure of holding equipment for optical fiber 310, for example, it has through holes for holding glass optical fibers 321 from which resin coating 322 has been removed among a plurality of optical fibers 320. A flat surface is provided in holding equipment for optical fiber 310, and a positioning structure is adopted that enables smooth mounting of optical fibers 320 by bringing this flat surface into contact with the ferrule flat surface 242. In addition, the corners of holding equipment for optical fiber 310 close to the ferrule 200 are chamfered to enable accurate surface alignment. One or more rows of through holes are provided in holding equipment for optical fiber 310, and the number of these through holes is the same as the number of fiber holes 230 in the ferrule 200.

[0044] Specifically, as shown in the upper part of Fig. 3, holding equipment for optical fiber 310 is a part of the optical fiber assembly 300, and is a part that is fixed to the ferrule 200 in a state where it holds a plurality of optical fibers 320. A part of it is inserted into the storage space 240 from the opening 210c of the ferrule 200 in a state where it holds a plurality of optical fibers 320. Incidentally, the axis AX1 shown in the upper part of Fig. 3 is an axis that indicates the first direction, the axis AX2 is an axis that indicates the second direction, and the axis AX3 is an axis that indicates the third direction.

[0045] 3, the holding equipment for optical fiber 310 comprises a first end face 310a and a second end face 310b, a plurality of through holes 315, a flat surface 311, and a pair of corners 319. The first end face 310a and the second end face 310b are arranged along an axis AX1 indicating a first direction. The plurality of through holes 315 have a shape extending from the first end face 310a along the axis AX1, are arranged along an axis AX2 perpendicular to the axis AX1, and pass corresponding optical fibers of the plurality of optical fibers 320 from the second end face 310b to the first end face 310a. The flat surface 311 directly faces the ferrule flat surface 242 which is a reference installation surface that is a part of the inner wall surface defining the storage space 240 of the ferrule 200. The pair of corners 319 are arranged to sandwich the flat surface 311 along the axis AX2. Furthermore, a tapered section 316 is provided between the through hole 315 and the second end face 310b to facilitate the insertion of each optical fiber 320, and an introduction section 317 and a groove 318 into which a section covered with a resin coating 322 is inserted are provided to stabilize the posture of each optical fiber 320. Although the groove 318 shown in the figure is a V-groove, a U-groove with a curvature radius larger than the inner diameter of the through hole 315 may be used instead of the V-groove. In manufacturing the optical fiber assembly 300, the optical fiber 320 may be fixed to the holding equipment for optical fiber 310 by, for example, ultraviolet curing, heat curing, anaerobic adhesive, or laser welding. Suitable materials for the holding equipment for optical fiber 310 include glass, resin, etc. that transmit ultraviolet light with a wavelength of 200 nm to 400 nm and visible light with a wavelength of 400 nm to 800 nm.

[0046] Each of the pair of corners 319 is chamfered so as to maintain a non-contact state with the pair of R-chamfered corners 211 when the ferrule flat surface 242 and the flat surface 311 are in contact. As an example, the pair of corners 319 shown in the lower part of FIG. 3 are R-chamfered so that the curvature is 1 / r (1 / mm), where r is the radius of curvature, and the relationship r<R is satisfied. Furthermore, since it is sufficient for the pair of corners 319 to maintain a non-contact state with the pair of R-chamfered corners 211 when the ferrule flat surface 242 and the flat surface 311 are in contact, they may be C-chamfered, for example, as shown in the lower part of FIG.

[0047] Moreover, the width of holding equipment 310 for optical fiber along axis AX2 satisfies the relationship that the width L2 of the flat surface 311 is set to be equal to or less than the width L1 of the ferrule flat surface 242 with respect to the width of the ferrule 200 along axis AX2, and the maximum width L3 of holding equipment 310 is longer than the width L1 of the ferrule flat surface 242. As a result, when holding equipment 310 for optical fiber is inserted into the storage space 240 of the ferrule 200, even if the ferrule flat surface 242 and the flat surface 311 are not in contact with each other, it is possible to minimize the risk of breakage of the tip portion of the optical fiber 320. "Insertion state where the ferrule flat surface 242 and the flat surface 311 are not in contact" means a state where the flat surface 311 of holding equipment for optical fiber 310 is not in contact with the ferrule flat surface 242 inside the storage space 240 of the ferrule 200, that is, a state where a gap of angle θ is generated between the ferrule flat surface 242 and the flat surface 311 by inserting holding equipment for optical fiber 310 into the storage space 240 in a state where it is shifted along the axis AX2. More specifically, this will be explained using Fig. 5 and Fig. 6.

[0048] In addition, the width L2 of the flat surface 311 sandwiched between a pair of corners 319 may ideally be equal to the width L1 of the ferrule flat surface. The corners of the opening end at the rear end face 210b of the ferrule 200 are R-chamfered, and the corners 319 of holding equipment for optical fiber 310 are also R-chamfered. Therefore, when the width L2 of the flat surface 311 and the width L1 of the ferrule flat surface 242 are equal, the movement of holding equipment for optical fiber 310 along the axis AX2 is automatically limited. In other words, once the flat surface 311 and the ferrule flat surface 242 come into contact, the posture of holding equipment for optical fiber 310 before fixing inside the ferrule 200 is stabilized.

[0049] 3, a plurality of through holes 315 are arranged in a row along the axis AX2 on the first end face 310a. However, as shown in FIG. 6 described later, the plurality of through holes 315 may be arranged in two or more rows extending along the axis AX2 along the axis AX3. In this way, by arranging a plurality of through holes 315 two-dimensionally on the first end face 310a, the holding equipment for optical fiber 310 can hold more optical fibers 320. When a plurality of optical fibers 320 are arranged not only along the axis AX2 but also along the axis AX3, the number of optical fibers 320 held by the holding equipment for optical fiber 310 can be significantly increased, and as a result, the workability of mounting a plurality of optical fibers 320 to ferrules is significantly improved.

[0050] 3, the flat surface 311 of holding equipment for optical fiber 310 is shown as the surface directly facing the ferrule flat surface 242. However, the installation reference surface in the ferrule 200 may be an inner wall surface other than the ferrule flat surface 242. In such a case, the flat surface of holding equipment for optical fiber 310 may be a surface parallel to both the axis AX1 and the axis AX2, for example, like the flat surface 311 or the flat surface 312. Also, the flat surface of holding equipment for optical fiber 310 may be a surface parallel to both the axis AX1 and the axis AX3, for example, like the flat surface 313 or the flat surface 314. When the flat surface 311 or the flat surface 312 parallel to both the axis AX1 and the axis AX2 is adopted as the flat surface of holding equipment for optical fiber 310, it becomes possible to use a large surface parallel to multiple optical fibers 320 in the structure of holding equipment for optical fiber 310 and ferrule 200. Therefore, it becomes possible to make the posture of holding equipment for optical fiber 310 inside the ferrule 200 more stable. On the other hand, when the flat surface 313 or 314 parallel to both the axis AX1 and the axis AX3 is adopted as the flat surface of the optical fiber holding equipment 310, the position of the optical fiber holding equipment 310 inside the ferrule 200 is stabilized, and the positioning of the optical fiber holding equipment 310 along the axis AX2 indicating the arrangement direction of the fiber holes 230 of the ferrule 200 becomes easy.

[0051] By providing holding equipment for optical fiber 310 with flat surfaces 311 and 312 parallel to each other, it becomes easy to handle holding equipment for optical fiber 310, and as a result, it becomes possible to improve the workability of ferrule mounting to multiple optical fibers 320. The flat surfaces 313 and 314 of holding equipment for optical fiber 310 are surfaces formed continuously from one of a pair of corners 319 to the flat surface 311. In this case, the flat surfaces 311 and 313, or the flat surfaces 311 and 314 may be perpendicular. By making the flat surfaces 313 and 314 perpendicular to the flat surface 311, it becomes possible to position holding equipment for optical fiber 310 along both the axis AX2 which is the arrangement direction of the fiber holes 230 of the ferrule 200, and the axis AX3 which is perpendicular thereto. As a result, it becomes easy to mount ferrules to multiple optical fibers 320.

[0052] Furthermore, the first end face 310a of the first end face 310a and the second end face 310b may have a square or oval shape. When the whole of holding equipment for optical fiber 310 is inserted into the storage space 240 of the ferrule 200, both the first end face 310a and the second end face 310b will be located inside the storage space 240. On the other hand, when a part of holding equipment for optical fiber 310 is inserted into the storage space 240 of the ferrule 200, only the first end face 310a will be located inside the storage space 240. In either case, handling of holding equipment for optical fiber 310 becomes easy, and high accuracy positioning of holding equipment for optical fiber 310 inside the ferrule 200 becomes possible.

[0053] Fig. 4 is a diagram for explaining the inserted state of holding equipment for optical fiber 310 of the present disclosure (marked as "inserted state of holding equipment for optical fiber" in Fig. 4). The upper part of Fig. 4 (marked as "horizontal position" in Fig. 4) shows the position of holding equipment for optical fiber 310 inserted into the ferrule 200 with the ferrule flat surface 242 and the flat surface 311 in contact. The middle part of Fig. 4 (marked as "inclined position" in Fig. 4) shows the position of holding equipment for optical fiber 310 inserted into the ferrule 200 with the flat surface 311 inclined to the ferrule flat surface 242. The lower part of Fig. 4 (marked as "modified corner" in Fig. 4) shows modified chamfering of the corner 319 of holding equipment for optical fiber 310.

[0054] When holding equipment for optical fiber 310 is stored in the storage space 240 of the ferrule 200 through the opening 210c, the flat surface 311 of holding equipment for optical fiber 310 and the ferrule flat surface 242 come into contact with each other. That is, as shown in the upper part of Fig. 4, the holding equipment for optical fiber 310 takes a horizontal position. Usually, when holding equipment for optical fiber 310 is adhesively fixed to the ferrule 200, a clearance for injecting adhesive is required between the ferrule 200 and holding equipment for optical fiber 310. Therefore, the clearance causes instability of the position of holding equipment for optical fiber 310 when fixed inside the ferrule 200. However, in the optical connector 100 of this disclosure, the ferrule flat surface 242 is sandwiched between a pair of R-chamfered corners 211, and the existence of these pair of corners 211 reduces the fluctuation of holding equipment for optical fiber 310 itself along the axis AX2.

[0055] In the example of Fig. 4, the width L1 of the ferrule flat surface 242 and the width L2 of the flat surface 311 of the holding equipment for optical fiber 310 are the same, and when the ferrule flat surface 242 and the flat surface 311 are in contact, the R-chamfered corner 319 is kept in a non-contact state with the similarly R-chamfered corner 211.

[0056] On the other hand, when holding equipment 310 for optical fiber is stored in storage space 240 of ferrule 200 from opening 210c, if flat surface 311 of holding equipment 310 is tilted by angle θ (°) with respect to flat surface 242 of ferrule, that is, if holding equipment 310 is shifted along axis AX2, holding equipment 310 will be inclined as shown in the middle of Fig. 4. At this time, in the optical connector 100 of this disclosure, corner part 319 of holding equipment 310 for optical fiber is placed on corner part 211 of ferrule 200, and movement of holding equipment 310 for optical fiber along axis AX2 is restricted. In order to restrict the movement of the optical fiber holding equipment 310 along the axis AX2, the optical connector 100 of the present disclosure maintains a clearance between the inner wall surface of the ferrule 200 and the optical fiber holding equipment 310, so that the angle formed between the ferrule flat surface 242 and the flat surface 311 is between 0° and 1° when a part of the optical fiber holding equipment 310 is in contact with the ferrule flat surface 242, restricting the posture fluctuation of the optical fiber holding equipment 310 caused by the position shift along the axis AX2.

[0057] The above-mentioned effect of posture restriction is obtained by the following: the width L2 of the flat surface 311 is set equal to or shorter than the width L1 of the ferrule flat surface 242; the maximum width L3 of the second end face 310b of holding equipment for optical fiber 310 is set longer than the width L1 of the ferrule flat surface 242; and a non-contact state is maintained between the corner 319 and the corner 211 when the flat surface 311 and the ferrule flat surface 242 are in contact. Thus, according to the optical connector 100 of the present disclosure, the insertion and fixation of holding equipment for optical fiber 310 into the ferrule 200 can be performed with high precision, and posture fluctuation of holding equipment for optical fiber 310 before fixation inside the ferrule 200 can be effectively restricted. In addition, since holding equipment for optical fiber 310 holds multiple optical fibers 320, these optical fibers 320 can be mounted into the ferrule 200 all at once.

[0058] In the examples shown in the upper and middle sections of Fig. 4, the corners 319 of holding equipment for optical fiber 310 are R-chamfered, but the corners 319 may be C-chamfered as shown in the lower section of Fig. 4. In this case too, with the ferrule flat surface 242 and the flat surface 311 in contact, the C-chamfered corners 319 are kept in a non-contact state with the R-chamfered corners 211.

[0059] Fig. 5 is a diagram for explaining the shape change of the optical fiber 320 after the optical fiber assembly 300 is inserted into the ferrule 200 (marked as "shape change of optical fiber" in Fig. 5). The upper part of Fig. 5 (marked as "horizontal position" in Fig. 5) shows the shape change of the tip part of the optical fiber 320 in the horizontal position of holding equipment for optical fiber 310 shown in the upper part of Fig. 4. The lower part of Fig. 5 (marked as "tilted position" in Fig. 5) shows the shape change of the tip part of the optical fiber 320 in the tilted position of holding equipment for optical fiber 310 shown in the middle part of Fig. 4.

[0060] When holding equipment for optical fiber 310 housed in the housing space 240 of the ferrule 200 is in a horizontal position as shown in the upper part of Fig. 4, the first end face 310a of holding equipment for optical fiber 310 and the tapered part 231 connected to the fiber hole 230 of the ferrule 200 are in a state of directly facing each other as shown in the upper part of Fig. 5. In the horizontal position, the tip part of the optical fiber located between the tapered part 231 and the first end face 310a, that is, the glass optical fiber 321 exposed from the first end face 310a, maintains a linear shape.

[0061] On the other hand, even when holding equipment 310 for optical fiber housed in the housing space 240 of the ferrule 200 is in a tilted position as shown in the middle of Fig. 4, the first end face 310a of holding equipment for optical fiber 310 and the tapered part 231 connected to the fiber hole 230 of the ferrule 200 are in a directly facing state as shown in the bottom of Fig. 5. However, in the tilted position, the row of through holes 315 on the first end face 310a of holding equipment for optical fiber 310 is in a tilted state by an angle θ (°) with respect to the axis AX2. In other words, the position of the through holes 315 on the first end face 310a is deviated from the arrangement direction of the fiber holes 230, i.e., the direction along the axis AX2. In such a tilted position, the glass optical fiber 321 exposed from the first end face 310a is guided to the fiber hole 230 by the function of the tapered part 231, but unnecessary bending stress is applied to the glass optical fiber 321 exposed between the first end face 310a and the tapered part 231. If this bending stress becomes large, that is, if the angle θ (°) becomes large, the transmission loss increases and breakage occurs. Therefore, in the optical connector 100 of the present disclosure, a clearance is provided so that the angle formed by the flat surface 311 of the holding equipment for optical fiber 310 and the flat surface 242 of the ferrule is between 0° and 1°.

[0062] Fig. 6 is a diagram showing a structure of a modified example of holding equipment for optical fiber 310 of the present disclosure (marked as "holding equipment for optical fiber" in Fig. 6). The left column of Fig. 6 (marked as "outline" in Fig. 6) shows a perspective view of each of holding equipment for optical fiber 310A, 310B, 310C according to the modified example, and the right column of Fig. 6 (marked as "cross-sectional structure" in Fig. 6) shows a cross-sectional structure of each of holding equipment for optical fiber 310A, 310B, 310C according to the modified example. The upper part of Fig. 6 (marked as "Modification 1" in Fig. 6) shows a perspective view of holding equipment for optical fiber 310A according to the first modified example and a cross-sectional structure taken along line III-III shown in the perspective view. The middle part of Fig. 6 (marked as "Modification 2" in Fig. 6) shows a perspective view of holding equipment for optical fiber 310B according to the second modified example and a cross-sectional structure taken along line IV-IV shown in the perspective view. The lower part of Fig. 6 (marked as "Modification 3" in Fig. 6) shows a perspective view of holding equipment for optical fiber 310C according to the third modification and a cross-sectional structure along the line VV shown in the perspective view.

[0063] 6, a first modification of holding equipment for optical fiber 310A is provided with an introduction part 317 at the opposite side of the first end face 310a in the through hole 315, which holds a tapered part 316 and a section of a resin coating 322 of an optical fiber 320. Also, a groove 318 extending from the introduction part 317 to the second end face 310b is provided in the holding equipment for optical fiber 310A. The introduction part 317 has an inner diameter larger than that of the through hole 315. The groove 318 may be a V-groove or a U-groove with a curvature radius larger than that of the through hole 315. Also, the introduction part 317 and the groove 318 are areas where the resin coating 322 is placed at a lower position than the through hole 315 so that unnecessary bending of the inserted optical fiber 320 does not occur. This holding equipment for optical fiber 310A has a structure that allows a plurality of optical fibers 320 to be arranged in two rows. Therefore, in order to facilitate the insertion of the optical fiber 320, in this optical fiber holding component 310A, the longitudinal positions of the introduction section 317, the groove section 318 that holds the resin coating 322 of the optical fiber 320, or both, are different for each row of the optical fiber 320.

[0064] 6 shows a second modified example of holding equipment for optical fiber 310B. The through hole 315 has an introduction part 317 at the opposite side of the first end face 310a to hold the tapered part 316 and the section of the resin coating 322 of the optical fiber 320. After one row of optical fibers 320 is inserted into the holding equipment for optical fiber 310B, the holding equipment for optical fiber 310B is turned over to insert the next row of optical fibers 320. The holding equipment for optical fiber 310B has a U-shaped groove 318 with a curvature radius larger than the inner diameter of the through hole 315. The introduction part 317 and the groove 318 are areas where the resin coating 322 is placed at a lower position than the through hole 315 to prevent unnecessary bending of the inserted optical fibers 320. The introduction part 317 has an inner diameter larger than the inner diameter of the through hole 315. The holding equipment for optical fiber 310B has a structure that allows multiple optical fibers 320 to be arranged in two rows. Moreover, the longitudinal positions of the introduction parts 317, the groove parts 318, or both of them are aligned with each other for the rows of the optical fibers 320. In this way, in the holding equipment for optical fiber 310B, the introduction parts 317, the groove parts 318 that hold the resin coating, or both of them have symmetry with respect to any plane to facilitate the insertion of the optical fibers 320.

[0065] 6 shows a third modified example of holding equipment for optical fiber 310C. It has the same structure as holding equipment for optical fiber 310A of the first modified example, but is different in that injection holes H1 and H2 for bonding the optical fiber 320 are provided in the through hole 315. The through hole 315 has an introduction part 317 at the position opposite to the first end face 310a, which holds the tapered part 316 and a section of the resin coating 322 of the optical fiber 320. The holding equipment for optical fiber 310C also has a groove 318 extending from the introduction part 317 to the second end face 310b. The introduction part 317 has an inner diameter larger than the inner diameter of the through hole 315. The groove 318 may be a V-groove or a U-groove with a curvature radius larger than the inner diameter of the through hole 315. The introduction part 317 and the groove 318 are areas where the resin coating 322 is placed at a lower position than the through hole 315 to prevent unnecessary bending of the inserted optical fiber 320. Furthermore, holding equipment for optical fiber 310C has a structure that can arrange a plurality of optical fibers 320 in two rows. Therefore, in order to make it easy to insert the optical fibers 320, in this holding equipment for optical fiber 310A, the longitudinal positions of the introduction part 317, the groove part 318 that holds the resin coating 322 of the optical fiber 320, or both of them are different for each row of the optical fibers 320.

[0066] In addition, for the above-mentioned holding equipment for optical fiber 310A, 310B, 310C, for example, ultraviolet curing, heat curing, anaerobic adhesive, or laser welding may be applied to fix the optical fiber 320. Also, for the material of each of these holding equipment for optical fiber 310A, 310B, 310C, for example, glass, resin, etc. that transmits ultraviolet light with a wavelength of 200nm or more and 400nm or less, or visible light with a wavelength of 400nm or more and 800nm ​​or less are suitable.

[0067] 1...optical coupling device 100, 100A, 100B...optical connector 200, 200A...ferrule 210a...front end face 210b...rear end face 210c...opening 211...corner 220a, 220b...guide hole 230...fiber hole 231...tapered portion 232...stopper 240...storage space 241...inlet 242...ferrule flat surface 300...optical fiber assembly 310, 310A, 310B, 310C...optical fiber holding component 310a...first end face 310b...second end face 311, 312, 313, 314...flat surface 315...through hole 316...tapered portion 317...introduction portion 318...groove portion 319...corner 320...optical fiber 321...glass optical fiber 322...Resin coating 400...Connecting part 410...Through hole 450A, 450B...Guide pin AX1, AX2, AX3...Axis S...Arrow L1, L2...Width L3...Maximum width H1, H2...Injection hole θ...Angle

Claims

1. An optical fiber holding equipment for a ferrule having a front end face provided with a plurality of fiber holes into which tip portions of a plurality of optical fibers are respectively inserted, a rear end face provided with an opening defined by an opening end with a plurality of corners each chamfered, and a storage space extending from the rear end face to the front end face and having a cross-sectional shape that matches the shape of the opening, wherein the equipment holds the plurality of optical fibers and is fixed in a state where at least a part of the optical fibers is inserted into the storage space, a first end face and a second end face arranged along a first direction from the front end face toward the rear end face of the ferrule; a plurality of through holes each having a shape extending from the first end face along the first direction, arranged along a second direction perpendicular to the first direction, and allowing corresponding optical fibers among the plurality of optical fibers to pass through from the second end face toward the first end face; a first flat surface that is a part of an inner wall surface that defines the storage space of the ferrule and that directly faces a ferrule flat surface that is sandwiched between a pair of adjacent corners among the plurality of corners; a pair of corner portions arranged to sandwich the first flat surface along the second direction, the corner portions being chamfered so as to maintain a non-contact state with the pair of corner portions when the ferrule flat surface and the first flat surface are in contact with each other; Equipped with The width of said holding equipment for optical fiber along said second direction satisfies the relationship that the width of said first flat surface is set to be less than the width of said ferrule flat surface, and the maximum width of said holding equipment for optical fiber is longer than the width of said ferrule flat surface, Optical fiber holding parts.

2. a width of the first flat surface sandwiched between the pair of corner portions is equal to a width of the ferrule flat surface; 2. Holding equipment for optical fiber according to claim 1.

3. the plurality of through holes arranged on the first end surface include a plurality of row-forming groups each defined by one or more through holes arranged along the second direction, and the plurality of row-forming groups are arranged along a third direction perpendicular to both the first direction and the second direction; 2. Holding equipment for optical fiber according to claim 1.

4. the first flat surface is any one of a surface parallel to both the first direction and the second direction, and a surface parallel to both the first direction and a third direction perpendicular to each of the first direction and the second direction; 2. Holding equipment for optical fiber according to claim 1.

5. a second flat surface parallel to the first flat surface; 2. Holding equipment for optical fiber according to claim 1.

6. a third flat surface formed continuously from one of the pair of corner portions to the first flat surface, and the first flat surface and the third flat surface are perpendicular to each other; 2. Holding equipment for optical fiber according to claim 1.

7. The first end surface has a quadrangular shape.

2. Holding equipment for optical fiber according to claim 1.

8. Holding equipment for optical fiber according to any one of claims 1 to 7, the plurality of optical fibers fixed in the plurality of through holes of the holding equipment for optical fiber; Equipped with Fiber optic assembly.

9. The optical fiber assembly of claim 8; the ferrule, at least a portion of which is inserted into the receiving space; Equipped with The posture of said holding equipment for optical fiber in said storage space of said ferrule is maintained in a state where a part of said holding equipment for optical fiber is in contact with said flat surface of said ferrule, The tip portions of the plurality of optical fibers are inserted into the plurality of fiber holes of the ferrule in a state where they are fixed to the plurality of through holes of the holding equipment for optical fiber. Optical connector.

10. Between the inner wall surface of the ferrule and holding equipment for optical fiber, a clearance is maintained to limit the positional fluctuation of holding equipment for optical fiber caused by a position shift along the second direction, so that the angle formed by the ferrule flat surface and the first flat surface is 0° or more and 1° or less when a part of holding equipment for optical fiber is in contact with the ferrule flat surface.

10. The optical connector according to claim 9.

11. a first optical connector and a second optical connector according to claim 9; The relative positions of the first optical connector and the second optical connector are fixed in a state where a front end face of the first optical connector and a front end face of the second optical connector face each other. Optical coupling device.