JP2023085697A - Optical fiber array and optical connection structure - Google Patents

Abstract

To provide an optical fiber array capable of suppressing bending loss and breaking of an optical fiber, and an optical connection structure.SOLUTION: A first diameter part, a second diameter part and a third diameter part of a plurality of optical fibers of an optical fiber array are positioned in order. The second diameter part has a diameter larger than that of the first diameter part. The third diameter part has a diameter larger than that of the second diameter part. A positioning part positions the first diameter part of the plurality of optical fibers. A support part is connected to the positioning part and supports the plurality of optical fibers. The support part includes a first surface and a second surface. The first surface extends along the second diameter part and supports the second diameter part. The second surface is positioned closer to the third diameter part than the first diameter part. The second surface is connected to the first surface in a position overlapping the second diameter part when viewed from a direction perpendicular to the first surface. The second surface extends in a direction perpendicular to the first surface and away from the second diameter part.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to optical fiber arrays and optical connection structures.

Patent Document 1 discloses an optical fiber array in which a plurality of optical fibers are fixed to a base member. Each of the plurality of optical fibers includes portions having diameters different from each other. The base member includes a locator for locating each optical fiber.

JP 2009-198649 A JP-A-2000-147296 JP 2008-76795 A

In an optical fiber array such as that disclosed in Patent Document 1, it is conceivable to fix a plurality of optical fibers to a base member with a resin member such as an adhesive. In this case, each of the plurality of optical fibers includes portions having different diameters, and the resin member is positioned between the base member and each optical fiber. The resin member may expand or contract depending on curing of the resin member, changes in environmental temperature, and environmental humidity. When the resin member expands or contracts, stress is applied to the optical fiber. The greater the amount of the resin member, the greater the stress applied to the optical fiber according to the expansion and contraction of the resin member. If the optical fiber bends due to the stress, bending loss may occur and the optical fiber may break.

An object of the present disclosure is to provide an optical fiber array and an optical connection structure capable of suppressing bending loss and breakage of optical fibers.

An optical fiber array according to the present disclosure includes multiple optical fibers, a base member, and a resin member. Each of the plurality of optical fibers includes a first diameter, a second diameter and a third diameter. The first diameter, the second diameter, and the third diameter are positioned in order. The second diameter portion has a diameter larger than the diameter of the first diameter portion. The third diameter portion has a diameter larger than the diameter of the second diameter portion. A base member supports a plurality of optical fibers. The resin member fixes the plurality of optical fibers to the base member. The base member includes a positioning portion and a support portion. The positioning portion positions the first diameter portions of the plurality of optical fibers. The support portion is connected to the positioning portion and supports the plurality of optical fibers. The support includes a first surface and a second surface. The first surface extends along and supports the second diameter. The second surface is located closer to the third diameter than to the first diameter. The second surface is connected to the first surface at a position overlapping the second diameter portion when viewed in a direction perpendicular to the first surface. The second surface intersects the first surface and extends away from the second diameter.

An optical connection structure according to the present disclosure includes the above optical fiber array and multicore fibers. A multicore fiber includes multiple cores and a cladding covering the multiple cores. At least one of the multiple cores included in the multicore fiber and at least one core of the multiple optical fibers are optically coupled.

According to the present disclosure, it is possible to provide an optical fiber array and an optical connection structure capable of suppressing bending loss and breakage of optical fibers.

FIG. 1 is a perspective view showing an optical connection structure according to an embodiment. FIG. 2 is a perspective view of an optical fiber holder. FIG. 3 is a perspective view of an optical fiber array. FIG. 4 is an end view of an optical fiber array. FIG. 5 is a plan view of an optical fiber. FIG. 6 is a perspective view of a support; FIG. 7 is a side view of an optical fiber array. FIG. 8 is a perspective view of an optical fiber array in a modification of the embodiment;

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

An optical fiber array according to an embodiment of the present disclosure includes multiple optical fibers, a base member, and a resin member. Each of the plurality of optical fibers includes a first diameter, a second diameter and a third diameter. The first diameter, the second diameter, and the third diameter are positioned in order. The second diameter portion has a diameter larger than the diameter of the first diameter portion. The third diameter portion has a diameter larger than the diameter of the second diameter portion. A base member supports a plurality of optical fibers. The resin member fixes the plurality of optical fibers to the base member. The base member includes a positioning portion and a support portion. The positioning portion positions the first diameter portions of the plurality of optical fibers. The support portion is connected to the positioning portion and supports the plurality of optical fibers. The support includes a first surface and a second surface. The first surface extends along and supports the second diameter. The second surface is located closer to the third diameter than to the first diameter. The second surface is connected to the first surface at a position overlapping the second diameter portion when viewed in a direction perpendicular to the first surface. The second surface intersects the first surface and extends away from the second diameter.

In this optical fiber array configuration, the support portion of the base member includes a first surface and a second surface. The first surface extends along and supports the second diameter. The second surface is connected to the first surface at a position overlapping the second diameter portion when viewed in a direction orthogonal to the first surface, and extends in a direction that intersects the first surface and separates from the second diameter portion. ing. In this case, the amount of the resin member located between the first diameter portion and the second diameter portion and the base member can be reduced. Therefore, the expansion or contraction of the resin member can reduce the stress applied to the optical fiber. Therefore, bending loss and breakage of the optical fiber can be suppressed.

As one embodiment of the fiber optic array, the locator may include a plurality of grooves. The plurality of grooves may extend in the first direction and be arranged in a second direction intersecting the first direction. The first diameters of the plurality of optical fibers may each be arranged in corresponding grooves of the plurality of grooves. In this case, the first diameter portions of the plurality of optical fibers can be easily arranged by the base member.

As an embodiment of the optical fiber array, the optical fiber array may further include a lid covering at least part of the groove. A first diameter portion of each of the plurality of optical fibers may be located between the lid portion and the groove. In this case, the first diameter portions of the plurality of optical fibers can be easily and reliably fixed.

As one embodiment of the optical fiber array, the support may further include a third surface and a fourth surface. The third surface may extend along and support the first diameter. The fourth surface may be located closer to the second diameter than the positioning portion. The fourth surface may be connected to the third surface at a position overlapping the first diameter portion when viewed in a direction perpendicular to the third surface. The fourth surface may intersect the third surface and extend away from the first diameter. In this case, the amount of the resin member located between the first diameter portion and the base member can be further reduced. Therefore, the expansion or contraction of the resin member can further reduce the stress applied to the optical fiber.

As an embodiment of the optical fiber array, the fourth surface may connect the third surface and the first surface and form a step between the first surface and the third surface. In this case, the amount of the resin member positioned between the first diameter portion and the second diameter portion and the base member can be further reduced.

In one embodiment of the optical fiber array, the first diameter, second diameter, and third diameter may include a core and a cladding. The shortest distance between the third surface and the core may be smaller than the shortest distance between the first surface and the core. In this case, the amount of the resin member located between the first diameter portion and the base member can be further reduced.

As one embodiment of the optical fiber array, the third diameter portion may further include a coating film covering the cladding. In this case, the structure can suppress damage to the optical fiber, and bending loss and breakage of the optical fiber can be suppressed.

As one embodiment of the optical fiber array, each of the plurality of optical fibers may further include a tapered portion. The tapered portion may include a tapered surface and connect the first diameter portion and the second diameter portion by the tapered surface. The fourth surface connects the first surface and the third surface, and may be inclined with respect to the first surface and the third surface along the tapered portion. In this case, concentration of stress between the first diameter portion and the second diameter portion of the optical fiber can be suppressed, and the amount of the resin member located between the tapered portion and the base member can be reduced.

In one embodiment of the fiber optic array, the support may further include a base surface extending along the third diameter. In this case, the amount of the resin member located between the third diameter portion and the base member can be reduced while the plurality of optical fibers are more firmly supported by the base member.

An optical connection structure according to the present disclosure includes the above optical fiber array and multicore fibers. A multicore fiber includes multiple cores and a cladding covering the multiple cores. At least one of the multiple cores included in the multicore fiber and at least one core of the multiple optical fibers are optically coupled. In this case, bending loss and breakage of the optical fiber can be suppressed in the optical connection structure.
[Details of the embodiment of the present disclosure]

Specific examples of embodiments of the present disclosure will be described below with reference to the drawings. The present invention 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 of equivalents to the scope of the claims. In the description of the drawings, the same elements are denoted by the same reference numerals, and overlapping descriptions are omitted.

FIG. 1 is a perspective view showing an optical connection structure according to one embodiment. As shown in FIG. 1, the optical connection structure 1 includes an optical fiber holder 10 and an optical fiber array 20. As shown in FIG. The optical fiber array 20 corresponds to a so-called fine fanout device. FIG. 2 is a perspective view of an optical fiber holder. FIG. 3 is a perspective view of an optical fiber array. The X-axis, Y-axis and Z-axis intersect each other. In this embodiment, the X-axis direction, the Y-axis direction, and the Z-axis direction are orthogonal to each other.

The optical fiber holder 10 includes a multi-core fiber 12 (hereinafter also referred to as “MCF 12”) and a ferrule 14. As shown in FIG. The optical fiber array 20 includes multiple optical fibers 22 , a base member 24 , a lid portion 26 and a resin member 28 . The optical fiber array 20 has an optical fiber array. The optical connection structure 1 further includes the optical fiber holder 10 and the optical fiber array 20 such that the optical axis of each core of the MCF 12 of the optical fiber holder 10 is aligned with the optical axis of each core of the plurality of optical fibers 22 . and may be provided with a member that holds and aligns from the outside.

The MCF 12 extends, for example, in the Z-axis direction. That is, the Z-axis direction corresponds to the longitudinal direction of the MCF 12 . As shown in FIG. 2, the MCF 12 has a plurality of cores 12a extending in the Z-axis direction, a clad 12b extending in the Z-axis direction and collectively covering the plurality of cores 12a, and a tip surface 12c. . The tip of MCF 12 and the end face of ferrule 14 are shown in FIG. The tip surface 12c is composed of tips of a plurality of cores 12a and tips of the clads 12b. The core 12a may be made of silica glass doped with a dopant such as germanium to increase the refractive index, and the clad 12b may be made of silica glass doped with a dopant such as fluorine to lower the refractive index. , materials and dopants can be selected as appropriate. In such an MCF 12, each core 12a can propagate an optical signal of a predetermined wavelength.

In the MCF 12, multiple cores 12a are arranged in the X-axis direction. In the example shown in FIG. 2, a pair of cores 12a are arranged in a row in the X-axis direction. The number of cores 12a in the MCF 12 is not limited to this. The mode field diameter of each core 12a may be, for example, 15 μm or less, 5 μm or less, or 1 μm or more. The core pitch of each core 12a may be, for example, 20 μm or more and 50 μm or less. The “core pitch” corresponds to the distance between core centers in a cross section orthogonal to the Z-axis direction. The diameter of the clad 12b may be, for example, 200 μm or less, 125 μm or less, 100 μm or less, 80 μm or less, or 50 μm or more.

The ferrule 14 is a tubular member that holds the tip portion of the MCF 12 , and has an inner hole 14 a that is a through hole for accommodating the tip portion of the MCF 12 and an end face 14 b of the ferrule 14 . The ferrule 14 fixes the tip portion of the MCF 12 to the inner hole 14a so that the tip face 12c of the MCF 12 is exposed inside the end face 14b. The inner diameter of the inner hole 14a is the same as or slightly larger than the outer diameter of the MCF 12, and the tip portion of the MCF 12 is fitted by being inserted into the inner hole 14a. The length of the ferrule 14 in the Z-axis direction is, for example, 6 mm or more and 11 mm or less. Ferrule 14 is composed of a ceramic material such as zirconia or a glass material.

Next, the structure of the optical fiber array 20 in this embodiment will be described in detail with reference to FIGS. 3 to 7. FIG. FIG. 4 is an end view of an optical fiber array. FIG. 5 is a plan view of an optical fiber. FIG. 6 is a perspective view of a support; FIG. 7 is a side view of an optical fiber array.

A plurality of optical fibers 22 of the optical fiber array 20 are optical fibers optically connected to the MCF 12 . Each optical fiber 22 has, as shown in FIG. 4, a core 22a extending in the Z-axis direction, a clad 22b extending in the Z-axis direction and covering the core 22a, and a tip surface 22c. The tip surface 22c is composed of the tip of the core 22a and the tip of the clad 22b. The core 22a may be made of silica glass doped with a dopant such as germanium to increase the refractive index, and the clad 22b may be made of silica glass doped with a dopant such as fluorine to lower the refractive index. , a combination of materials, dopants, and the like can be appropriately selected. In such an optical fiber 22, an optical signal with a predetermined wavelength is propagated through each core 22a. Each of the plurality of optical fibers 22 is a single-core optical fiber having one core.

The mode field diameter of each core 22a is, for example, 15 μm or less. The mode field diameter of each core 22a may be, for example, 5 μm or more or 1 μm or less. The core pitch of each core 22a on the tip surface 22c is, for example, 20 μm or more and 50 μm or less. The diameter of the clad 22b on the tip surface 22c is, for example, 80 μm or more and 125 μm or less.

In the optical fiber array 20, multiple optical fibers 22 are arranged in the X-axis direction. In the examples shown in FIGS. 3 and 5, two optical fibers 22 are arranged in a row in the X-axis direction. The number of optical fibers 22 in the optical fiber array 20 is not limited to this.

In this embodiment, each optical fiber 22 is, for example, a single-mode optical fiber. Each optical fiber 22 has a unimodal refractive index distribution profile. As a modification of this embodiment, each optical fiber 22 has a layer with a lower refractive index than the clad 22b between the core 22a and the clad 22b, and has a trench-type refractive index distribution profile. may As a modification of this embodiment, each optical fiber 22 may be a multimode optical fiber.

The total number and arrangement of the cores of the optical fibers 22 of the optical fiber array 20 correspond to the number and arrangement of the multiple cores 12a of the MCF 12 of the optical fiber holder 10 . In other words, the arrangement of the cores of the multiple optical fibers 22 matches the arrangement of the multiple cores 12 a of the MCF 12 . However, the total number and arrangement of cores of the plurality of optical fibers 22 do not have to completely match the number and arrangement of cores of the MCF 12, and a part may not be optically connected.

In the optical connection structure 1, at least one of the multiple cores 12a included in the MCF 12 and at least one core of the multiple optical fibers 22 are optically coupled. For example, when the optical fiber 22 is a single-core optical fiber, the optical fiber 22 and the core 12a of the MCF 12 of the optical fiber holder 10 are in one-to-one correspondence. For example, when the optical fiber 22 is a multi-core optical fiber, multiple cores of one optical fiber 22 correspond to multiple cores 12a of the MCF 12 of the optical fiber holder 10 .

Each optical fiber 22 is, for example, configured to have an optical loss of 0.15 dB or less when light having a wavelength of 1.550 μm is incident in a state in which the optical fiber 22 is wound in an annular shape with a radius of curvature of 5 mm or less. there is Each optical fiber 22 is configured so that the optical loss is 0.45 dB or less when light having a wavelength of 1.625 μm is incident in a state in which the optical fiber 22 is wound into a ring having a radius of curvature of 5 mm or less. Each optical fiber 22 may have both the above characteristics for light having a wavelength of 1.550 μm and the above characteristics for light having a wavelength of 1.625 μm, or may have either one of the characteristics. may be

As shown in FIG. 5, each of the plurality of optical fibers 22 includes a first diameter portion 31, a second diameter portion 32, a tapered portion 33, and a third diameter portion . The first diameter portion 31, the second diameter portion 32, the taper portion 33, and the third diameter portion 34 are positioned in order in the Z-axis direction. The first diameter portion 31, the second diameter portion 32, the tapered portion 33, and the third diameter portion 34 each include a core 22a and a clad 22b. The third diameter portion 34 further includes a coating film that covers the clad 22b.

The first diameter portion 31 includes the tip portion 22 d of each optical fiber 22 . The first diameter portion 31 corresponds to a small-diameter optical fiber portion, and has a smaller diameter than a general outer diameter. The first diameter portion 31 is formed, for example, by a thinning process using an etching treatment using hydrofluoric acid water or the like. The second diameter portion 32 corresponds to a portion having a general outer diameter. The second diameter portion 32 has a larger diameter than the diameter of the first diameter portion 31 . The tapered portion 33 includes a tapered surface 33a whose outer diameter in a plane orthogonal to the Z-axis direction decreases toward the tip portion 22d. The tapered portion 33 connects the first diameter portion 31 and the second diameter portion 32 with a tapered surface 33a. The third diameter portion 34 corresponds to a portion having a general outer shape covered with a coating film. The third diameter portion 34 has a larger diameter than the diameter of the second diameter portion 32 .

The diameter of the first diameter portion 31 is, for example, 20 μm or more and 80 μm or less. The diameter of the second diameter portion 32 is, for example, 50 μm or more and 200 μm or less. The diameter of the third diameter portion 34 is, for example, 170 μm or more and 260 μm or less.

A base member 24 supports a plurality of optical fibers 22 . A base member 24 extends along the plurality of optical fibers 22 . The base member 24 and the first diameter portion 31, the second diameter portion 32, the tapered portion 33, and the third diameter portion 34 of each optical fiber 22 overlap each other when viewed from the Y-axis direction. The first diameter portion 31, the second diameter portion 32, and the tapered portion 33 are positioned within the region where the base member 24 is positioned when viewed from the Y-axis direction. The base member 24 has a rectangular shape when viewed from the Y-axis direction and extends in the Z-axis direction. The longitudinal direction of the base member 24 corresponds to the Z-axis direction, and the lateral direction of the base member 24 corresponds to the X-axis direction. The base member 24 is made of, for example, silicon or glass material.

The base member 24 includes a positioning portion 41 and a support portion 42 . The positioning portion 41 positions the first diameter portions 31 of the plurality of optical fibers 22 . The support portion 42 is connected to the positioning portion 41 and supports the plurality of optical fibers 22 . The positioning portion 41 and the support portion 42 are continuous with each other. For example, the positioning portion 41 and the support portion 42 are integrally formed. For example, the positioning portion 41 and the support portion 42 may be formed separately.

As shown in FIG. 4, the positioning portion 41 positions the tip portions 22d of the plurality of optical fibers 22 so that the tip surfaces 22c of the plurality of optical fibers 22 are exposed at the end surface 24b of the base member 24. As shown in FIG. The positioning portion 41 includes a plurality of grooves D, for example. The multiple grooves D each extend in the first direction. A plurality of grooves D are arranged in a second direction that intersects with the first direction.

In this embodiment, the first direction corresponds to the Z-axis direction, and the second direction corresponds to the X-axis direction. The first diameter portions 31 of the plurality of optical fibers 22 are arranged in corresponding grooves D among the plurality of grooves D, respectively. Each of the plurality of first diameter portions 31 is fitted in a different groove D and extends along each groove D. As shown in FIG. The length of the groove D is greater than the diameter of the first diameter portion 31 fitted in the groove D in the X-axis direction. The groove D has, for example, a V shape. The shape of the groove D is not limited to this. For example, groove D may be U-shaped.

As a modification of this embodiment, the positioning portion 41 may include a plurality of holes extending in the Z-axis direction instead of the plurality of grooves D. In this case, the first diameter portions 31 of the plurality of optical fibers 22 may be arranged inside corresponding holes among the plurality of holes.

The positioning portion 41 includes a top surface 41a and a wall surface 41b. An end surface 24 b of the base member 24 is formed by a positioning portion 41 . The top surface 41a extends, for example, along the XZ-axis plane. The wall surface 41b is connected to the top surface 41a. The wall surface 41b is arranged at a position facing the end surface 24b. The wall surface 41b extends in a direction intersecting the top surface 41a. A step is formed by the top surface 41a and the wall surface 41b. In this embodiment, the wall surface 41b is orthogonal to the top surface 41a. The wall surface 41b extends, for example, along the XY-axis plane.

The top surface 41a has, for example, a rectangular shape when viewed from the Y-axis direction. When viewed from the Y-axis direction, the plurality of grooves D are arranged within the region where the top surface 41a is located. The wall surface 41b has, for example, a rectangular shape when viewed from the Z-axis direction. When viewed from the Z-axis direction, the plurality of grooves D are arranged within the region where the wall surface 41b is located. The plurality of grooves D pass through the positioning portion 41 in the Z-axis direction. A plurality of grooves D penetrate between the end surface 24b and the wall surface 41b. The plurality of grooves D are open to the top surface 41a.

The support portion 42 includes a first support portion 51 , a second support portion 52 and a third support portion 53 . The first support portion 51 includes a support surface 51a and a wall surface 51b. The support surface 51 a extends along the first diameter portion 31 and supports the first diameter portion 31 . The support surface 51a extends, for example, along the XZ-axis plane. The wall surface 51b is positioned closer to the second diameter portion 32 than the positioning portion 41 is. The wall surface 51b is connected to the support surface 51a at a position overlapping the first diameter portion 31 when viewed from the direction perpendicular to the support surface 51a. The wall surface 51b may be connected to the support surface 51a at a position overlapping the tapered portion 33 when viewed from the direction perpendicular to the support surface 51a. In this embodiment, the direction perpendicular to the support surface 51a corresponds to the Y-axis direction. The top surface 41a and the support surface 51a are connected by a wall surface 41b, and a step is formed between the top surface 41a and the support surface 51a. The wall surface 51b intersects with the support surface 51a and extends in a direction away from the first diameter portion 31 . In this embodiment, the wall surface 51b extends in the Y-axis direction. The wall surface 51b extends, for example, along the YZ-axis plane. The support surface 51a and the wall surface 51b are orthogonal to each other.

The second support portion 52 includes a support surface 52a and a wall surface 52b. The support surface 52 a extends along the second diameter portion 32 and supports the second diameter portion 32 . The support surface 52a extends, for example, along the XZ-axis plane. The wall surface 52 b is positioned closer to the third diameter portion 34 than the first diameter portion 31 . The wall surface 52b is connected to the support surface 52a at a position overlapping the second diameter portion 32 when viewed in a direction perpendicular to the support surface 52a. In this embodiment, the direction perpendicular to the support surface 52a corresponds to the Y-axis direction. The support surface 52a and the support surface 51a are connected by a wall surface 51b, and a step is formed between the support surface 52a and the support surface 51a. The wall surface 52b intersects with the support surface 52a and extends away from the second diameter portion 32 . In this embodiment, the wall surface 52b extends in the Y-axis direction. The wall surface 52b extends, for example, along the YZ-axis plane. The support surface 52a and the wall surface 52b are orthogonal to each other.

The third support portion 53 includes a base surface 53a and a wall surface 53b. The base surface 53 a extends along the third diameter portion 34 and supports the third diameter portion 34 . The base surface 53a extends, for example, along the XZ-axis plane. The wall surface 53 b is located closer to the third diameter portion 34 than the second diameter portion 32 . The wall surface 53b is connected to the base surface 53a at a position overlapping the third diameter portion 34 when viewed from the direction perpendicular to the base surface 53a. In this embodiment, the direction perpendicular to the base surface 53a corresponds to the Y-axis direction. The base surface 53a and the support surface 52a are connected by a wall surface 52b, and a step is formed between the base surface 53a and the support surface 52a. The wall surface 53b intersects the base surface 53a and extends away from the third diameter portion 34 . The wall surface 53b extends, for example, along the XY-axis plane. The base surface 53a and the wall surface 53b are orthogonal to each other.

The shortest distance between the support surface 51a and the core 22a is smaller than the shortest distance between the support surface 52a and the core 22a. The shortest distance between the support surface 52a and the core 22a is smaller than the shortest distance between the base surface 53a and the core 22a. When viewed from the Z-axis direction, the support surface 51a, the support surface 52a, and the base surface 53a are arranged in the order of the support surface 51a, the support surface 52a, and the base surface 53a from the side of the plurality of optical fibers 22 in the Y-axis direction. are placed.

In this embodiment, the wall surface 53b extends in the Y-axis direction. The support surface 52a corresponds to the first surface, the wall surface 52b corresponds to the second surface, the support surface 51a corresponds to the third surface, and the wall surface 51b corresponds to the fourth surface.

The lid portion 26 covers at least a portion of each groove D. As shown in FIG. The lid portion 26 covers the tip portion 22d of each optical fiber 22 arranged in each groove D when viewed from the Y-axis direction. In this specification, "cover" means to arrange so as to overlap when viewed from above. The lid portion 26 is made of the same material as the base member 24, for example.

The first diameter portion 31 of each of the plurality of optical fibers 22 is positioned between the lid portion 26 and the groove D. As shown in FIG. The lid portion 26 has, for example, a rectangular parallelepiped shape. The lid portion 26 includes a bottom surface 26a, a top surface 26b, and an end surface 26c. The bottom surface 26a and the top surface 26b are arranged at positions facing each other in the Y-axis direction. The bottom surface 26a and the top surface 26b have a rectangular shape when viewed from the Y-axis direction. The end surface 26c has a rectangular shape when viewed from the Z-axis direction.

The bottom surface 26a faces the top surface 41a. The bottom surface 26a faces the tip portion 22d of each optical fiber 22 arranged in each groove D. As shown in FIG. The end surface 26 c is formed flush with the end surface 24 b of the base member 24 . The end face 24b and the end face 26c are parallel to the Y-axis, for example.

As a modification of this embodiment, the end surface 24b and the end surface 26c may be inclined with respect to the Y-axis, for example. In this case, the tip surface 12c of the MCF 12 and the end surface 14b of the ferrule 14 may also be inclined in the Y-axis direction by the same angle. The end surface 24b and the end surface 26c may be inclined, for example, by 8 degrees with respect to the Y-axis.

A resin member 28 fixes the plurality of optical fibers 22 to the base member 24 . The resin member 28 is, for example, a thermosetting adhesive, and can be cured by heating the resin portion 25 after the resin member 28 is placed at a predetermined location. When the base member 24 and the lid portion 26 are mainly made of a ceramic material, the resin member 28 may be, for example, a thermosetting epoxy adhesive, a thermosetting acrylic adhesive, an ultraviolet curing epoxy adhesive, or , UV curable acrylic adhesive. When the base member 24 and the lid portion 26 are mainly made of a glass material, the resin member 28 may be, for example, a thermosetting epoxy adhesive, a thermosetting acrylic adhesive, an ultraviolet curing epoxy adhesive, or , UV curable acrylic adhesive. The resin member 28 is not limited to these materials, regardless of the material of the base member 24 .

Each tip portion 22 d of the plurality of optical fibers 22 is fixed in the groove D by a resin member 28 . The tip portions 22d of the plurality of optical fibers 22 are arranged in the grooves D and are adhesively fixed by the resin member 28 that fills the gaps between them. The lid portion 26 is fixed to the base member 24 with a resin member 28 . The first diameter portion 31 , the second diameter portion 32 , the tapered portion 33 and the third diameter portion 34 are fixed to the first support portion 51 , the second support portion 52 and the third support portion 53 by the resin member 28 . be done. The resin member 28 covers the entire first diameter portion 31 , the second diameter portion 32 , the tapered portion 33 and a portion of the third diameter portion 34 .

Next, with reference to FIG. 8, an optical fiber array 20A in a modified example of this embodiment will be described. FIG. 8 is a perspective view of an optical fiber array 20A in a modification of the embodiment. The optical fiber array 20</b>A differs from the optical fiber array 20 only in that the base member 24 includes a first support portion 71 instead of the first support portion 51 .

The first support portion 71 includes a support surface 71a and a wall surface 71b. The support surface 71 a extends along the first diameter portion 31 and supports the first diameter portion 31 . The wall surface 71b is positioned closer to the second diameter portion 32 than the positioning portion 41 is. The wall surface 71b is connected to the support surface 71a at a position overlapping the first diameter portion 31 when viewed from the direction perpendicular to the support surface 51a (Y-axis direction). The wall surface 71b may be connected to the support surface 71a at a position overlapping the tapered portion 33 when viewed from the direction orthogonal to the support surface 51a. The wall surface 71b intersects with the support surface 71a and extends away from the first diameter portion 31 .

The wall surface 71 b connects the support surface 71 a and the support surface 51 a and extends along the tapered portion 33 of the optical fiber 22 . The wall surface 71b may be inclined along the tapered surface 33a of the tapered portion 33 with respect to the support surface 71a and the support surface 51a. The wall surface 71b is inclined with respect to the XY-axis plane and the XZ-axis plane. As used herein, "oblique" does not include perpendicular and parallel.

Next, the effects of the optical connection structure 1 and the optical fiber arrays 20 and 20A will be described. In the optical fiber arrays 20 and 20A, the support portion 42 of the base member 24 includes a support surface 52a and a wall surface 52b. The support surface 52 a extends along the second diameter portion 32 and supports the second diameter portion 32 . The wall surface 52b is connected to the support surface 52a at a position overlapping the second diameter portion 32 when viewed from the direction perpendicular to the support surface 52a (the Y-axis direction). extending away. In this case, the amount of the resin member 28 positioned between the first diameter portion 31 and the second diameter portion 32 and the base member 24 can be reduced. Therefore, the expansion or contraction of the resin member 28 can reduce the stress applied to the optical fiber 22 . Therefore, bending loss and breakage of the optical fiber 22 can be suppressed.

The positioning portion 41 includes a plurality of grooves D in the optical fiber arrays 20 and 20A. The plurality of grooves D extends in a first direction and is arranged in a second direction intersecting the first direction. The first diameter portions 31 of the plurality of optical fibers 22 are arranged in corresponding grooves D among the plurality of grooves D, respectively. In this case, the first diameter portions 31 of the plurality of optical fibers 22 can be easily arranged by the base member 24 .

The optical fiber arrays 20 and 20A further include lids 26 that cover at least part of the grooves D. As shown in FIG. The first diameter portion 31 of each of the plurality of optical fibers 22 is positioned between the lid portion 26 and the groove D. As shown in FIG. In this case, the first diameter portions 31 of the plurality of optical fibers 22 can be easily and reliably fixed.

In the optical fiber arrays 20 and 20A, the support portion 42 includes a support surface 51a and a wall surface 51b. The support surface 51 a extends along the first diameter portion 31 and supports the first diameter portion 31 . The wall surface 51b is positioned closer to the second diameter portion 32 than the positioning portion 41 is. The wall surface 51b is connected to the support surface 51a at a position overlapping the first diameter portion 31 when viewed from the direction perpendicular to the support surface 51a. The wall surface 51b intersects with the support surface 51a and extends in a direction away from the first diameter portion 31 . In this case, the amount of resin member 28 positioned between first diameter portion 31 and base member 24 can be further reduced. Therefore, the expansion or contraction of the resin member 28 can further reduce the stress applied to the optical fiber 22 .

In the optical fiber arrays 20 and 20A, the wall surface 51b connects the support surface 51a and the support surface 52a, forming a step between the support surface 51a and the support surface 52a. In this case, the amount of the resin member 28 positioned between the first diameter portion 31 and the second diameter portion 32 and the base member 24 can be further reduced.

In the optical fiber arrays 20 and 20A, the first diameter portion 31, the second diameter portion 32, and the third diameter portion 34 each include a core 22a and a clad 22b. The shortest distance between the support surface 51a and the core 22a is smaller than the shortest distance between the support surface 52a and the core 22a. In this case, the amount of resin member 28 positioned between first diameter portion 31 and base member 24 can be further reduced.

In the optical fiber arrays 20, 20A, the third diameter portion 34 may further include a coating film that covers the clad 22b. In this case, the structure can suppress damage to the optical fiber, and bending loss and breakage of the optical fiber can be suppressed.

In the optical fiber array 20A, each of the multiple optical fibers 22 includes a tapered portion 33. As shown in FIG. The tapered portion 33 includes a tapered surface 33a and connects the first diameter portion 31 and the second diameter portion 32 by the tapered surface 33a. The wall surface 51b connects the support surface 51a and the support surface 52a, and is inclined with respect to the support surface 51a and the support surface 52a along the taper portion 33 (taper surface 33a). In this case, concentration of stress between the first diameter portion 31 and the second diameter portion 32 in the optical fiber 22 is suppressed, and the resin member 28 positioned between the tapered portion 33 and the base member 24 is prevented from being stressed. amount can be reduced.

In the optical fiber arrays 20 and 20A, the support portion 42 includes a base surface 53a extending along the third diameter portion 34. As shown in FIG. In this case, the amount of the resin member 28 located between the third diameter portion 34 and the base member 24 can be reduced while the plurality of optical fibers 22 are more firmly supported by the base member 24 .

Although the embodiments of the present disclosure have been described in detail above, the present invention is not limited to the above embodiments, and can be applied to various embodiments.

For example, the shape of the base member 24 is not limited to that illustrated. For example, the wall surfaces 51b, 52b, 53b are not limited to shapes orthogonal to the support surfaces 51a, 52a and the base surface 53a, respectively. For example, the wall surface 52b may be inclined with respect to the XY-axis plane and the XZ-axis plane like the wall surface 71b.

Reference Signs List 1 Optical connection structure 10 Optical fiber holder 12 MCF
Reference Signs List 12a Core 12b Clad 12c End face 14 Ferrule 14a Inner hole 14b End face 20 Optical fiber array 20A Optical fiber array 22 Optical fiber 22a Core 22b Clad 22c End face 22d End portion 24 Base member 24b End surface 25 Resin portion 26 Lid portion 26a Bottom surface 26c Top surface 26c End surface 28 Resin member 31 First diameter portion 32 Second diameter portion 33 Tapered portion 33a Tapered surface 34 Third Three-diameter portion 41 Positioning portion 41a Top surface 41b Wall surface 42 Support portion 51 First support portion 51a Support surface 51b Wall surface 52 Second support portion 52a Support surface 52b Wall surface 53 Third support portion 53a... Base surface 53b... Wall surface 71... First support part 71a... Support surface 71b... Wall surface D... Groove

Claims (10)

a first diameter portion, a second diameter portion having a diameter greater than the diameter of the first diameter portion, and a third diameter having a diameter greater than the diameter of the second diameter portion, each a plurality of optical fibers comprising a portion, wherein the first diameter, the second diameter, and the third diameter are positioned in sequence;
a base member supporting the plurality of optical fibers;
a resin member fixing the plurality of optical fibers to the base member,
The base member includes a positioning portion that positions the first diameter portions of the plurality of optical fibers, and a support portion that is connected to the positioning portion and supports the plurality of optical fibers. and
The support includes a first surface and a second surface,
The first surface extends along the second diameter and supports the second diameter,
The second surface is positioned closer to the third diameter portion than the first diameter portion, and the first surface overlaps the second diameter portion when viewed in a direction orthogonal to the first surface. and extending across said first surface and away from said second diameter. The positioning portion includes a plurality of grooves extending in a first direction and arranged in a second direction intersecting the first direction,
2. The optical fiber array according to claim 1, wherein said first diameter portions of said plurality of optical fibers are respectively arranged in corresponding said grooves among said plurality of grooves. further comprising a lid covering at least part of the groove,
3. The optical fiber array of claim 2, wherein the first diameter of each of the plurality of optical fibers is located between the lid and the groove. The support includes a third surface and a fourth surface,
the third surface extends along the first diameter and supports the first diameter;
The fourth surface is positioned closer to the second diameter portion than the positioning portion, and is connected to the third surface at a position overlapping the first diameter portion when viewed in a direction perpendicular to the third surface. and extends in a direction that intersects the third surface and away from the first diameter. 5. The optical fiber array according to claim 4, wherein said fourth surface connects said third surface and said first surface, and forms a step between said first surface and said three surfaces. the first diameter, the second diameter, and the third diameter include a core and a clad;
6. The optical fiber array according to claim 4, wherein the shortest distance between said third surface and said core is smaller than the shortest distance between said first surface and said core. 7. The optical fiber array according to claim 6, wherein said third diameter portion further includes a coating film covering said clad. each of the plurality of optical fibers further includes a tapered portion including a tapered surface and connecting the first diameter portion and the second diameter portion by the tapered surface;
The fourth surface connects the first surface and the third surface, and is inclined with respect to the first surface and the third surface along the tapered portion. Item 8. The optical fiber array according to any one of Item 7. 9. The optical fiber array of any one of claims 1-8, wherein the support further includes a base surface extending along the third diameter. An optical fiber array according to any one of claims 1 to 9;
a multicore fiber including a plurality of cores and a cladding covering the plurality of cores;
An optical connection structure in which at least one of the plurality of cores included in the multi-core fiber and at least one core of the plurality of optical fibers are optically coupled.

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