JP6904213B2 - Optical fiber holder - Google Patents

Description

The present disclosure relates to an optical fiber holder in which an optical fiber is held.

In the field of optical communication, Si-P is smaller, lower in cost, and consumes less power than conventional ones, and is expected to play an active role in the field of Datacom. This is because the optical waveguide can be miniaturized by using Si, and the optical / electronic circuits can be laminated on the same substrate, so that the optical waveguide can be further miniaturized.

One of the methods for connecting a silicon waveguide and an optical fiber is surface coupling (grating coupling). The surface coupling forms a lattice shape on the waveguide surface, guides the light rays upward by the interference of light, and allows the light to enter the optical fiber connected to the waveguide surface. Alternatively, light is introduced from the optical fiber into the waveguide.

The advantage of surface bonding is that the spot diameter is about 9 μm, so ordinary optical fibers can be used for connection.

Japanese Unexamined Patent Publication No. 2016-071025 WO2017-022026

As a demerit of surface coupling, since the optical fiber holder has a shape protruding on the silicon waveguide, a low profile is preferable in consideration of mounting. In order to reduce the height and size, it is necessary to bend the optical fiber. As a solution to this problem, the problem mentioned in the method of Patent Document 1 is that the bending radius cannot be controlled by this method. Further, Patent Document 2 requires a device for rotating a component holding an optical fiber, and there is a problem that the R-bent portion of the optical fiber is outside the optical fiber holder, resulting in a large size. ..

Therefore, an object of the present disclosure is to enable control of the bending radius without increasing the size of the component fixing the optical fiber.

The optical fiber holder of the present disclosure is
A first holding member in which an end portion of an optical fiber is arranged at one end and the optical fiber is arranged so as to extend at the other end.
A second holding member that sandwiches the optical fiber together with the first holding member,
With
The first holding member and the second holding member include an optical fiber holding portion for sandwiching an optical fiber strand at one end thereof.
The other end of the first holding member includes a curved portion that curves with a predetermined radius of curvature along the extending direction of the optical fiber.
The first plane provided in the first holding member connecting the optical fiber holding portion and the curved portion, or the second holding member provided in the second holding member facing the first plane across the optical fiber. A recess is provided in at least one of the second planes.

According to the present disclosure, it is possible to control the bending radius without increasing the size of the component fixing the optical fiber.

This is an example of connecting the optical fiber holder of the first embodiment to an optical circuit. It is a side view and the cross-sectional view which shows the 1st embodiment example of the optical fiber holder of 1st Embodiment. It is a side view and the cross-sectional view which shows the 2nd Embodiment example of the optical fiber holder of 1st Embodiment. It is a side view and the cross-sectional view which shows the 3rd Embodiment example of the optical fiber holder of 1st Embodiment. This is an example of the form of the optical fiber holder of the first embodiment in which the pressing surface is curved. This is an example of the first embodiment of the optical fiber holder of the second embodiment. This is a second embodiment of the optical fiber holder of the second embodiment. This is a third embodiment of the optical fiber holder of the second embodiment. This is an example of connecting the optical fiber holder of the third embodiment to an optical circuit. It is a side view and the cross-sectional view which shows the 1st embodiment example of the optical fiber holder of 3rd Embodiment. It is a side view and the cross-sectional view which shows the 2nd Embodiment example of the optical fiber holder of 3rd Embodiment. This is a first example of connecting the optical fiber holder of the fourth embodiment to the optical circuit. This is a second example of connecting the optical fiber holder of the fourth embodiment to the optical circuit.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The present disclosure is not limited to the embodiments shown below. Examples of these implementations are merely examples, and the present disclosure can be implemented in various modifications and improvements based on the knowledge of those skilled in the art. In addition, the components having the same reference numerals in the present specification and the drawings shall indicate the same components.

(First Embodiment)
FIG. 1 shows an example of an optical fiber holder according to the present embodiment. The optical fiber holder according to the present embodiment includes two holding members 23 and 24 for sandwiching the optical fiber 26, and a spacer 21. The holding member 23 is arranged in the extending direction D1 of the optical fiber 26 and functions as a first holding member. The holding member 24 functions as a second holding member.

In the present disclosure, the end face 26A of the optical fiber 26 is arranged so as to be sandwiched between the end face 23A which is one end of the holding member 23 and the end face 24A which is one end of the holding member 24, and light is applied to the end face 23B which is the other end of the holding member 23. The fiber 26 is curved and extends. For example, as shown in FIG. 1, when the end surface 26A of the optical fiber 26 is connected to the upper surface 3A of the optical circuit 3, the direction D1 of the optical fiber 26 is the direction along the upper surface 3A of the optical circuit 3. Here, the direction D1 can be exemplified as a direction parallel to the upper surface 3A, but the present disclosure is not limited to this, and the direction D1 can be any direction except the direction perpendicular to the upper surface 3A. Further, the optical circuit 3 is, for example, a photonic optical circuit (hereinafter referred to as an optical circuit) including an optical waveguide and an optical coupler.

The end surface 23A of the holding member 23 is joined to the upper surface 3A of the optical circuit 3. It is preferable to use a photocurable resin such as an ultraviolet curable resin for bonding. It is preferable that the end surface 23A of the holding member 23 and the end surface 24A which is one end of the holding member 24 are arranged on the same surface and joined to the upper surface 3A of the optical circuit 3. Since the bonding area of the optical circuit 3 with the upper surface 3A is large, the bonding strength can be reinforced. The holding member 24 may be end-face polished together with the optical fiber 26 and the holding member 23 fixing the optical fiber 26.

The angle α formed by the optical axis on the end surface 26A of the optical fiber 26 and the end surface 23A of the holding member 23 is preferably not 90 °, which can prevent attenuation due to reflection on the end surface 26A. Further, the angle α is preferably an angle adjusted to the light input / output direction from the optical circuit 3.

The holding members 23 and 24 are holding members using V-grooves, and V-grooves are formed in at least one of the holding members 23 and 24. For example, as shown in FIG. 2, a V-groove may be formed only in the holding member 23, or as shown in FIG. 3, a V-groove may be formed only in the holding member 24. As described above, V-grooves may be formed in both the holding members 23 and 24. The portion of the optical fiber 26 sandwiched between the holding members 23 and 24 by the V-groove is a wire 26C from which the coating 26B has been removed. When the V-groove is formed in the holding member 23, the V-groove may be formed only in the portion holding the strand 26C, but the V-groove may also be formed in the curved portion 23E.

The number of optical fibers sandwiched between the holding members 23 and 24 can be any number. For example, as shown in FIGS. 2 (a), 3 (a) and 4 (a), there may be one, or FIG. 2 (b), FIG. 3 (b) and FIG. 4 (b). There may be four as described in. When the number of optical fibers sandwiched between the holding members 23 and 24 is a plurality, the optical fiber holders of the present disclosure can form a fiber array.

The holding member 23 includes a curved portion 23E that curves with a predetermined radius of curvature along the direction D1 of the optical fiber 26. The predetermined radius of curvature is a value that can prevent the optical fiber 26 from being excessively bent and broken, and is a value that can be drawn out in a direction along the upper surface 3A of the optical circuit 3. The optical fiber 26 is preferably fixed to the curved portion 23E with an adhesive.

The spacer 21 has a function of pressing the optical fiber 26 against the curved portion 23E so that the optical fiber 26 is curved along the curved portion 23E. As a result, the optical fiber 26 can be extended in the direction D1 while the end surface 26A of the optical fiber 26 is fixed to the optical circuit 3.

The spacer 21 is a columnar or tubular structure, and the columnar or tubular cross-sectional shape is arbitrary. For example, it may have a square cross section as shown in FIGS. 1 to 4 or a circular cross section. At least a part of the pressing surface 21D in contact with the optical fiber 26 is preferably arranged along the curved portion 23E, and is curved according to the radius of curvature of the curved portion 23E, for example, as shown in FIG. Is preferable.

The materials of the holding members 23, 24 and the spacer 21 are arbitrary, but for example, in addition to glass and resin, metal can be used. When the holding members 23, 24 and the spacer 21 are made of metal, the optical fiber 26 can be fixed between the holding member 23 and the spacer 21 by using a thermosetting resin. When the holding members 23, 24 and the spacer 21 are made of glass or resin that is transparent to UV, the optical fiber 26 can be fixed between the holding member 23 and the spacer 21 by using a UV curable resin. In this way, the holding members 23, 24 and the spacer 21 transmit UV, so that they can be fixed with the UV curable resin, and the production is simplified.

As described above, in the present embodiment, by pressing the optical fiber 26 against the curved portion 23E using the spacer 21, the bending of the optical fiber can be controlled by the radius of curvature of the curved portion 23E. Here, in the present embodiment, the holding member 23 has a curved portion 23E, and the spacer 21 is provided in the gap formed between the holding member 23 and the holding member 24. Therefore, in the present embodiment, the bending radius of the optical fiber 26 can be controlled without increasing the size of the component holding members 23, 24 and the spacer 21 fixing the optical fiber 26.

(Second embodiment)
FIG. 6 shows an example of the optical fiber holder according to the present embodiment. Due to the load of bending stress of the optical fiber 26, the spacer 21 is pushed up in the direction in which the optical fiber 26 is separated from the holding member 23, and the spacer 21 may be peeled off. Therefore, in the optical fiber holder according to the present embodiment, the spacer 21 and the holding member 24 are fixed by the flat surface 21C and the side surface 24C so that the spacer 21 is not pushed up.

_{In the present embodiment, the height H 24} from the upper surface 3A of the optical circuit 3 to the end surface 24E is the height from the upper surface 3A of the optical circuit 3 to the optical fiber 26 so that the spacer 21 and the holding member 24 can be bonded with an adhesive. it is preferably higher than _{H 26.} Further, although FIG. 6 shows an example in which the cross-sectional shape of the spacer 21 is a wedge shape, the cross-sectional shape of the spacer 21 can be any shape as in the first embodiment in the present embodiment.

The spacer 21 and the holding member 24 are preferably firmly fixed, and the holding member 24 and the spacer 21 are preferably in surface contact with each other. Therefore, in the present embodiment, a flat surface 21C that comes into contact with the holding member 24 is provided on the spacer 21, and the side surface 24C of the holding member 24 on the holding member 23 side is a flat surface. By joining the planes together in this way, the contact area between the holding members 23 and 24 and the spacer 21 can be increased. Thereby, in this embodiment, it is possible to prevent the spacer 21 from being peeled off due to the stress load of bending the optical fiber 26.

Here, also in the present embodiment, it is preferable that the pressing surface 21D of the spacer 21 is curved according to the radius of curvature of the curved portion 23E, as shown in FIG.

Further, as shown in FIG. 8, the surface 21E of the spacer 21 is preferably fixed to the end surface 24E of the holding member 24. As a result, the bonding area between the holding member 24 and the spacer 21 increases, so that the optical fiber 26 can be pressed against the curved portion 23E more efficiently. In addition, it is possible to simplify the positioning of the holding members 23 and 24 and the spacer 21 during manufacturing. Further, the holding member 24 and the spacer 21 may be integrally formed.

Further, the spacer 21 preferably has a sufficient length so that the optical fiber 26 extends in the direction D1. For example, as shown in FIGS. 7 and 8, the distance D ₂₁ and the distance D ₂₃ with reference to the end face 26A of the optical fiber 26 may be compared. Here, the distance D ₂₁ is the distance on the direction D1 from the position of the end surface 26A of the optical fiber 26 in the holding member 23 to the end of the spacer 21 in the direction D1. The distance D ₂₃ is the distance on the direction D1 from the position of the end surface 26A of the optical fiber 26 in the holding member 23 to the end of the holding member 23 in the direction D1. For example, the length of contact between the pressing surface 21D provided on the spacer 21 and the optical fiber 26 is longer than the length of contact between the curved portion 23E provided on the holding member 23 and the optical fiber 23.

Further, as shown in FIG. 8, when the end surface 24E of the holding member 24 is joined to the spacer 21 in a plane, the height H ₂₄ from the upper surface 3A to the end surface 24E of the optical circuit 3 is the description of the second embodiment. regardless, from the upper surface 3A of the optical circuit 3 and the optical fiber 26 and the height H ₂₆ can be comparable, be lower than the height H ₂₆ of the upper surface 3A of the optical circuit 3 and the optical fiber 26 Good.

(Third Embodiment)
FIG. 9 shows an example of the optical fiber holder according to the present embodiment. The optical fiber holder according to the present embodiment includes two holding members 23 and 24 that sandwich the optical fiber 26. In the optical fiber holder according to the present embodiment, the end surface 26A of the optical fiber 26 is connected to the upper surface 3A of the optical circuit 3 by using the holding members 23 and 24. The holding member 23 is arranged in the extending direction D1 of the optical fiber 26 and functions as a first holding member. The holding member 24 functions as a second holding member. The other end 23B of the holding member 23 includes a curved portion 23E that curves with a predetermined radius of curvature along the direction D1.

The optical fiber 26 and the holding members 23 and 24 are fixed with an adhesive. At the time of this fixing, if the adhesive flows into the curved portion 23E, the shape of the curved portion 23E changes, or the adhesive adheres to the optical fiber 26 curved by the curved portion 23E, so that the optical fiber 26 May break. Therefore, in order to prevent the adhesive from flowing into the curved portion 23E, the holding member 24 is provided with a recess 31 for allowing the adhesive used for fixing the optical fiber 26 to flow in. In the present embodiment, as an example, the recess 31 is provided only in the holding member 24, but the present disclosure is not limited to this, and the same effect can be obtained even if the recess 31 is provided in the holding member 23. It is possible and may be provided on both the holding members 23 and 24.

10 and 11 show first and second examples of the detailed structure of the optical fiber holder according to the present embodiment. The holding member 23 includes a flat surface 23C that functions as a third plane, and the holding member 24 includes a groove 33 for holding the wire 26C of the optical fiber 26. The wire 26C of the optical fiber 26 is sandwiched between the flat surface 23C and the groove 33. The portion of the optical fiber 26 in which the wire 26C is sandwiched is referred to as the optical fiber holding portion 27.

In the present embodiment, an example in which the groove 33 is provided in the holding member 24 is shown, but the groove 33 may be formed in at least one of the holding members 23 and 24 as in the first and second embodiments. .. That is, as the configuration of the optical fiber holding portion 27, any of the configurations shown in FIGS. 2, 3 and 4 shown in the first embodiment can be adopted.

The holding member 23 includes a plane 23D that functions as a first plane, and the holding member 24 includes a plane 24D that functions as a second plane. The plane 23D is a plane connected to the curved surface 23E. The plane 24D is a plane facing the plane 23D with the optical fiber 26 interposed therebetween. As described above, the flat surface 23D and the flat surface 24D are arranged on the end surface 24E side of the optical fiber holding portion 27.

The recess 31 is provided in at least one of the flat surfaces 23D and 24D. This prevents the adhesive from flowing into the curved portion 23E. Further, the plane 23D and the plane 23C are preferably parallel so that the wire 26C of the optical fiber 26 and the end portion 26E of the coating 26B of the optical fiber are kept linear, and the plane 23D and the plane 24D are parallel. Is preferable.

The recess 31 may adopt any shape capable of allowing the adhesive used for holding the optical fiber 26 to flow into the recess 31. For example, it has a groove shape as shown in FIGS. 9 and 10 (c). The width W _{31 of the} recess 31 is arbitrary, and may have a stepped shape that reaches the end surface 24E of the holding member 24, as shown in FIG. 11 (c).

In the present disclosure, the optical fiber 26 is curved at the curved portion 23E. At this time, if the wire 26C of the optical fiber 26 is curved by the curved portion 23E, the wire 26C of the optical fiber 26 may break without being able to withstand the bending stress. Therefore, it is preferable that the end portion 26E of the coating 26B of the optical fiber 26 is sandwiched between the flat surface 23D and the flat surface 24D so that the bending stress at the curved portion 23E is not applied to the wire 26C of the optical fiber 26.

The wire 26C portion of the optical fiber 26 tends to break easily. Therefore, it is preferable that the end portion 26E of the coating 26B of the optical fiber 26 is fixed to the flat surface 23D and the flat surface 24D with an adhesive. Therefore, the recess 31 is arranged closer to the end surface 24E of the holding member 24 than the end 26E of the coating 26B of the optical fiber 26, that is, the recess 31 is provided in the portion where the coating of the optical fiber is arranged. It is preferable to have. As a result, the entire wire 26C of the optical fiber 26 is fixed with an adhesive, and the coating 26B of the optical fiber 26 is also fixed with an adhesive, so that the wire 26C of the optical fiber 26 can be prevented from breaking.

The optical fiber holding portion 27 sandwiches the wire 26C of the optical fiber 26, and the planes 23D and 24D sandwich the coating 26B of the optical fiber 26. Therefore, it is preferable that a step is provided between the optical fiber holding portion 27 and the flat surface 23D according to the thickness of the coating 26B of the optical fiber 26. For example, the planes 23C and 23D are parallel, and the distance between these planes is approximately equal to the thickness of the coating 26B of the optical fiber 26. As a result, the optical fiber holding portion 27 can sandwich the end portion 26E of the coating 26B of the optical fiber 26 without applying bending stress to the wire 26C of the optical fiber 26. Such a step according to the thickness of the coating 26B of the optical fiber 26 is not limited to the holding member 23, but may be provided on the holding member 24, or may be provided on both the holding members 23 and 24. ..

As described above, since the optical fiber holder according to the present embodiment includes the curved portion 23E, it is possible to control the bending radius without increasing the size of the component fixing the optical fiber 26. .. Further, since the optical fiber holder according to the present embodiment includes the recess 31, it is possible to prevent the adhesive from flowing into the curved portion 23E. Further, in the optical fiber holder according to the present embodiment, the wire 26C of the optical fiber 26 is sandwiched between the optical fiber holding portions 27, and the end portion 26E of the coating 26B of the optical fiber 26 is arranged close to the optical fiber holding portion 27. Therefore, it is possible to prevent bending stress of the optical fiber 26 on the wire 26C.

(Fourth Embodiment)
The optical fiber holder according to the present embodiment further includes the spacer 21 described in the first and second embodiments in addition to the optical fiber holder described in the third embodiment. FIG. 12 shows an example of application of the optical fiber holder shown in FIG. 10 to the third embodiment, and FIG. 13 shows an example of application of the optical fiber holder shown in FIG. 11 to the third embodiment.

In the present embodiment, the end portion 26E of the coating 26B of the optical fiber 26 is sandwiched between the flat surface 23D and the flat surface 24D, and the concave portion 31 is provided in the flat surface 24D.

The holding members 23 and 24 and the spacer 21 sandwich the optical fiber 26 and are fixed with an adhesive. In the present disclosure, since the recess 31 is provided, the adhesive of the optical fiber holding portion 27 is prevented from flowing into the curved portion 23E, whereby the spacer 21 can be bonded with the optical fiber 26 arranged at an appropriate position. ..

_{When the concave portion 31 has a stepped shape as shown in FIG. 11, the dimension H 31} from the end portion of the concave portion 31 shown in FIG. 13 on the end surface 24A side to the end surface 24E may be the same as _{the dimension H 21} of the convex portion of the spacer 21. However, a form having a size larger than that of the H _{21 can be adopted.} As a result, a gap for allowing the adhesive to flow can be provided between the end portion of the recess 31 on the end surface 24A side and the spacer 21.

This disclosure can be applied to the information and communication industry.

21: Spacer 23, 24: Holding member 26: Optical fiber 3: Optical circuit 27: Optical fiber holding portion 31: Recessed portion 33: Groove

Claims (6)

A first holding member in which an end portion of an optical fiber is arranged at one end and the optical fiber is arranged so as to extend at the other end.
A second holding member that sandwiches the optical fiber together with the first holding member,
With
The first holding member and the second holding member include an optical fiber holding portion for sandwiching an optical fiber strand at one end thereof.
The other end of the first holding member includes a curved portion that curves with a predetermined radius of curvature along the extending direction of the optical fiber.
A first plane provided in the first holding member connected to the curved portion, or a second plane provided in the second holding member facing the first plane across the optical fiber. A recess is provided in at least one of them,
Fiber optic holder. The recess is provided in a portion where the coating of the optical fiber is arranged.
The optical fiber holder according to claim 1. The optical fiber holding portion sandwiches a wire of the optical fiber by using a third plane provided in the first holding member and a groove provided in the second holding member.
The optical fiber holder according to claim 1 or 2. The third plane is substantially parallel to the first plane.
The optical fiber holder according to claim 3. The second plane is substantially parallel to the first plane.
The optical fiber holder according to any one of claims 1 to 3. A spacer for fixing the optical fiber is further provided at the other end of the first holding member.
The optical fiber is fixed between the curved portion and the spacer.
The optical fiber holder according to any one of claims 1 to 5.

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