阅读说明：本技术 光纤阵列、光纤固定用基板以及光纤阵列的制造方法 (Optical fiber array, substrate for fixing optical fiber, and method for manufacturing optical fiber array ) 是由 菅野修平 于 2019-01-18 设计创作，主要内容包括：本发明涉及一种光纤阵列,在将具有熔敷部的多个光纤载置于基板时,抑制邻接的光纤的熔敷部彼此的干涉。所述光纤阵列的特征在于,具备：多个光纤,它们分别具有熔敷部,并沿宽度方向排列；以及基板,其沿上述宽度方向排列有多个沿着上述光纤的长度方向形成的光纤槽,在邻接的2根上述光纤的上述熔敷部沿上述长度方向错开位置的状态下,将多个上述光纤的上述熔敷部载置于上述基板。(The present invention relates to an optical fiber array that suppresses interference between deposited portions of adjacent optical fibers when a plurality of optical fibers having deposited portions are mounted on a substrate. The optical fiber array is characterized by comprising: a plurality of optical fibers each having a deposited portion and arranged in a width direction; and a substrate on which a plurality of optical fiber grooves formed along a longitudinal direction of the optical fibers are arranged in the width direction, wherein the deposited parts of the plurality of optical fibers are placed in the substrate in a state where the deposited parts of the adjacent 2 optical fibers are shifted in position in the longitudinal direction.)

1. An optical fiber array comprising:

a plurality of optical fibers each having a deposited portion and arranged in a width direction; and

a substrate on which a plurality of optical fiber grooves formed along a longitudinal direction of the optical fiber are arranged in the width direction,

the welding parts of the plurality of optical fibers are placed on the substrate in a state where the welding parts of the 2 adjacent optical fibers are shifted in position in the longitudinal direction.

2. The optical fiber array of claim 1,

the optical fiber module further includes a fixing member that holds the plurality of optical fibers placed in the optical fiber grooves between the optical fibers and the substrate.

3. The optical fiber array of claim 1 or 2,

the substrate has a recessed escape portion formed at a position of the welding portion.

4. The optical fiber array of claim 3,

the retreat portion is composed of a 1 st retreat portion and a 2 nd retreat portion having a position in the longitudinal direction different from the 1 st retreat portion,

a plurality of the optical fiber grooves are formed between the 1 st and 2 nd receding portions.

5. The optical fiber array according to any one of claims 1 to 4,

the optical fibers are mounted on the substrate such that positions of the welded portions in the longitudinal direction are staggered.

6. A substrate for fixing an optical fiber, characterized in that,

a plurality of optical fiber grooves formed along the length direction of the optical fiber are arranged along the width direction,

the optical fiber fixing substrate includes:

a 1 st recessed relief portion having a concave shape, the 1 st relief portion being formed at a position of a welding portion of the optical fiber arranged in the optical fiber groove; and

and a 2 nd relief portion formed at a position of the fusion-spliced portion of the optical fiber arranged in the optical fiber groove and at a position different from the 1 st relief portion in the longitudinal direction.

7. A method of manufacturing an optical fiber array,

arranging a plurality of optical fibers each having a deposited portion in a width direction of the optical fibers,

preparing a substrate in which a plurality of optical fiber grooves formed along a longitudinal direction of the optical fiber are arranged in the width direction,

the welding parts of the plurality of optical fibers are placed on the substrate in a state where the welding parts of the 2 adjacent optical fibers are shifted in position in the longitudinal direction.

8. A method for manufacturing an optical fiber array according to claim 1,

after every other one of the plurality of optical fibers having the same position in the longitudinal direction of the welding portion is placed in the optical fiber groove, the plurality of optical fibers having the same position in the longitudinal direction of the welding portion are placed in the remaining optical fiber grooves.

Technical Field

The invention relates to an optical fiber array, an optical fiber fixing substrate, and a method for manufacturing the optical fiber array.

Background

Conventionally, optical fiber arrays have been widely used in optical communications as coupling elements for coupling optical transmission lines, and have been applied to optical waveguide splitters, optical switches, and the like. The optical fiber array has a structure in which optical fibers are placed in a plurality of optical fiber grooves formed in a substrate, and the optical fibers are held from above by a fixing member and pressed and fixed. Therefore, the plurality of optical fibers mounted in the optical fiber grooves formed in the substrate can be arranged with very high density and high accuracy.

As such an optical fiber array, for example, patent document 1 discloses an optical fiber array composed of optical fibers having a welded portion formed by welding and connecting 2 optical fibers. Such fusion-spliced optical fibers are obtained by splicing optical fibers having different core diameters, such as a high NA optical fiber and a single mode optical fiber, by TEC fusion splicing, for example. In addition, when optical fibers are connected to each other by TEC welding, the outer diameter of the welded portion may be larger than the outer diameter (bulge) of each optical fiber. In the optical fiber array described in patent document 1, a portion of the optical fiber including the fusion-spliced portion is placed in an optical fiber groove formed in the substrate and fixed by a fixing member.

Patent document 1: japanese patent laid-open publication No. 2003-156662

When a plurality of optical fibers are to be placed on a substrate at high density, the interval between adjacent optical fibers is also reduced. In the optical fiber array described in patent document 1, the position of the fusion-spliced portion in the longitudinal direction of the optical fiber is the same for all the optical fibers placed in the plurality of optical fiber grooves formed in the substrate. At this time, the bulged welding portions of the adjacent optical fibers interfere with each other, and the optical fibers cannot be appropriately placed in the optical fiber grooves, and thus, there is a case where a plurality of optical fibers cannot be aligned with high accuracy.

Disclosure of Invention

The present invention is directed to suppressing interference between welding portions of adjacent optical fibers when a plurality of optical fibers having welding portions are mounted on a substrate.

Some embodiments of the present invention provide an optical fiber array including: a plurality of optical fibers each having a deposited portion and arranged in a width direction; and a substrate on which a plurality of optical fiber grooves formed along a longitudinal direction of the optical fibers are arranged in the width direction, wherein the deposited parts of the plurality of optical fibers are placed in the substrate in a state where the deposited parts of the adjacent 2 optical fibers are shifted in position in the longitudinal direction.

Other features of the present invention will become apparent from the description of the specification and the accompanying drawings.

According to some embodiments of the present invention, when a plurality of optical fibers having welded portions are mounted on a substrate, interference between the welded portions of adjacent optical fibers can be suppressed.

Drawings

Fig. 1A is a schematic diagram of an optical fiber array 10 of the present embodiment. Fig. 1B is a sectional view of the optical fiber array 10 of the present embodiment.

Fig. 2 is an overall perspective view of the optical fiber array 10 of the present embodiment.

Fig. 3 is an exploded perspective view of the optical fiber array 10 according to the present embodiment with the fixing member 30 removed.

Fig. 4 is an exploded perspective view of the optical fiber array 10 according to the present embodiment with the fixing member 30 and the deposited optical fiber 1 removed.

Fig. 5 is a six-side view of the substrate 20 in the optical fiber array 10 according to the present embodiment.

Fig. 6A is an explanatory diagram illustrating how to weld a welded part 2 of an optical fiber 1. Fig. 6B is a diagram showing how a plurality of deposited optical fibers 1 of the comparative example are mounted on a substrate 20.

Fig. 7A and 7B are views showing how the deposited optical fiber 1 according to the present embodiment is mounted on the substrate 20.

Detailed Description

At least the following matters will become apparent from the description of the specification and the drawings described later.

Disclosed is an optical fiber array, which is characterized by comprising: a plurality of optical fibers each having a deposited portion and arranged in a width direction; and a substrate on which a plurality of optical fiber grooves formed along a longitudinal direction of the optical fibers are arranged in the width direction, wherein the deposited parts of the plurality of optical fibers are placed in the substrate in a state where the deposited parts of the adjacent 2 optical fibers are shifted in position in the longitudinal direction. According to such an optical fiber array, when a plurality of optical fibers having welded portions are mounted on a substrate, interference between the welded portions of adjacent optical fibers can be suppressed.

Preferably, the optical fiber module further includes a fixing member for holding the plurality of optical fibers placed in the optical fiber grooves between the optical fibers and the substrate. This makes it possible to fix the optical fiber mounted on the substrate.

Preferably, the substrate has a recessed escape portion formed at a position of the welding portion. Thus, when a plurality of optical fibers having a welding portion that bulges more than the outer diameter of the optical fiber are placed on the substrate, the bulging portion of the welding portion can be retracted into the recessed portion.

Preferably, the escape portion includes a 1 st escape portion and a 2 nd escape portion having a different position in the longitudinal direction from the 1 st escape portion, and a plurality of the optical fiber grooves are formed between the 1 st escape portion and the 2 nd escape portion. Thus, when a plurality of optical fibers having welded portions that swell beyond the outer diameter of the optical fibers are placed on the substrate, interference between the welded portions of adjacent optical fibers can be suppressed.

Preferably, the plurality of optical fibers are placed on the substrate such that the positions of the welded portions in the longitudinal direction are staggered. Thus, when a plurality of optical fibers having welded portions that swell beyond the outer diameter of the optical fibers are placed on the substrate, interference between the welded portions of adjacent optical fibers can be suppressed.

Disclosed is an optical fiber fixing substrate, which is characterized in that a plurality of optical fiber grooves formed along the longitudinal direction of an optical fiber are arranged in the width direction, and which is provided with: a 1 st recessed relief portion having a concave shape, the 1 st relief portion being formed at a position of the optical fiber welding portion arranged in the optical fiber groove; and a 2 nd escape portion formed at a position of the fusion spliced portion of the optical fiber arranged in the optical fiber groove, the 2 nd escape portion being formed at a position different from the 1 st escape portion in the longitudinal direction. According to such an optical fiber fixing substrate, when a plurality of optical fibers having welded portions are mounted on the substrate, interference between the welded portions of adjacent optical fibers can be suppressed.

Specifically disclosed is a method for manufacturing an optical fiber array, which is characterized in that a plurality of optical fibers each having a deposited portion are arranged in the width direction of the optical fibers, a substrate in which a plurality of optical fiber grooves formed in the longitudinal direction of the optical fibers are arranged in the width direction is prepared, and the deposited portions of the plurality of optical fibers are placed on the substrate in a state in which the deposited portions of 2 adjacent optical fibers are shifted in position in the longitudinal direction. According to such a method of manufacturing an optical fiber array, when a plurality of optical fibers having welded portions are mounted on a substrate, interference between the welded portions of adjacent optical fibers can be suppressed.

Preferably, after every other one of the plurality of optical fibers having the same position in the longitudinal direction of the welded part is placed in the optical fiber groove, the plurality of optical fibers having the same position in the longitudinal direction of the welded part are placed in the remaining optical fiber grooves. This makes it possible to easily place the welded portions of 2 adjacent optical fibers on the substrate while shifting the positions in the longitudinal direction.

In this embodiment, the present invention is not limited to the embodiment

< overview of the optical fiber array 10 >

Fig. 1A is a schematic diagram of an optical fiber array unit 100 of the present embodiment. Fig. 1B is a sectional view of the optical fiber array 10 of the present embodiment. Fig. 2 is an overall perspective view of the optical fiber array 10 of the present embodiment.

In the following description, each direction is defined as shown in the drawing. That is, the longitudinal direction of the deposited optical fiber 1 placed on the substrate 20 is referred to as "front-rear direction", one side of the substrate end face 21 of the substrate 20 is referred to as "front", and the opposite side is referred to as "rear". The width direction of the deposited optical fiber 1 mounted on the substrate 20 is referred to as "left-right direction", the right-hand side when viewed from the front side is referred to as "right", and the opposite side (left-hand side) is referred to as "left". The direction orthogonal to the "front-rear direction" and the "left-right direction" is referred to as the "up-down direction", one side of the fixing member 30 with respect to the substrate 20 is referred to as the "up", and the opposite side is referred to as the "down".

The optical fiber array unit 100 has an optical fiber array 10 and a plurality of optical connectors 90. An optical fiber array 10 is provided at the front end of the plurality of optical fibers. Optical connectors 90 are provided at respective ends of the plurality of optical fibers on the rear side. In other words, the optical connectors 90 are provided at the rear end portions of the plurality of deposited optical fibers 1 included in the optical fiber array 10. The optical fiber array 10 is a coupling element for coupling optical transmission paths. As shown in fig. 2, the front end portions of the plurality of deposited optical fibers 1 are held so as to be positioned on the substrate end face 21 of the substrate 20 at the front portion of the optical fiber array 10. The front portion of the optical fiber array 10 is connected to, for example, a silicon chip (not shown) such as an optical transceiver. As shown in fig. 1A, an optical connector 90 is provided at the rear end of the optical fiber array unit 100, and optical connection with various devices is made detachable. The optical connector 90 is, for example, an FC connector. However, the optical connector 90 may be an optical connector other than the FC connector.

< detailed Structure of optical fiber array 10 >

Fig. 3 is an exploded perspective view of the optical fiber array 10 according to the present embodiment with the fixing member 30 removed. Fig. 4 is an exploded perspective view of the optical fiber array 10 according to the present embodiment with the fixing member 30 and the deposited optical fiber 1 removed. Fig. 5 is a six-side view of the substrate 20 in the optical fiber array 10 of the present embodiment. Fig. 6A is an explanatory diagram illustrating how to weld a welded part 2 of an optical fiber 1. The lower side view of fig. 3 indicated by an arrow is a view of the region indicated by a broken line of fig. 3 as viewed from the upper side.

The optical fiber array 10 includes a deposited optical fiber 1, a substrate 20, and a fixing member 30. The deposited optical fiber 1, the substrate 20, and the fixing member 30 are bonded together by an adhesive 5 (see fig. 1B).

The fusion-spliced optical fiber 1 is an optical fiber obtained by splicing 2 optical fibers by fusion splicing. As shown in fig. 3 and 4, the welded optical fiber 1 of the present embodiment connects the small-diameter core optical fiber 1A on the substrate end surface 21 side and the normal core optical fiber 1B on the optical connector 90 side by welding. Hereinafter, the deposited optical fiber 1 may be simply referred to as an "optical fiber". As shown in fig. 3 and 4, the optical fiber array 10 includes a plurality of (here, 24) fusion-spliced optical fibers 1. These 24 welded optical fibers 1 are arranged in the left-right direction (the width direction of the welded optical fibers 1) on the substrate 20. However, the number and arrangement direction of the deposited optical fibers 1 are not limited to these. Each of the welded optical fibers 1 is placed in an optical fiber groove 24 (described later) formed in the substrate 20, and the fixed member 30 holds the welded optical fiber 1 from above, whereby the welded optical fiber 1 is pressed and fixed.

In the optical fiber array 10 of the present embodiment, each of the plurality of welded optical fibers 1 has a welded portion 2. The welded portion 2 is a portion where the small-diameter core optical fiber 1A on the substrate end surface 21 side and the normal core optical fiber 1B on the optical connector 90 side are welded and connected. As shown in fig. 1B, in the present embodiment, the welded portion 2 is sandwiched between the substrate 20 and the fixing member 30. The welded portion 2 is accommodated in a space (described later) formed by the substrate-side receding portion 22 of the substrate 20 and the fixing-member-side receding portion 31 of the fixing member 30.

In the optical fiber array 10 of the present embodiment, a small-diameter core optical fiber such as a high NA optical fiber is used as the small-diameter core optical fiber 1A. In general, a single-mode optical fiber or the like is used as the core fiber 1B. Further, the core diameter (e.g., 6 μm) of the small-diameter core optical fiber 1A is smaller than the core diameter (e.g., 9 μm) of the normal core optical fiber 1B. Therefore, the fused fiber 1 connects the optical fibers (the small-diameter core fiber 1A and the normal core fiber 1B) having different core diameters by TEC fusion. TEC welding is a welding technique for welding and connecting optical fibers having different core diameters.

Fig. 6A is a diagram on the left side showing the state before the small-diameter core optical fiber 1A and the normal core optical fiber 1B are connected by TEC fusion bonding. The right side of fig. 6A shows a state in which the small-diameter core optical fiber 1A and the normal core optical fiber 1B are welded and connected by TEC to form a welded optical fiber 1 having a welded portion 2.

In the TEC welding, heat treatment is performed to diffuse the core diameter of the optical fiber, thereby processing the optical fiber so that the core diameter of one optical fiber (the small-diameter core optical fiber 1A) and the core diameter of the other optical fiber (for example, the normal core optical fiber 1B) gradually match each other. At this time, the outer diameter of the welded portion may be larger than the outer diameter of the optical fiber before the welding connection. The welded optical fiber 1 shown in the right side of fig. 6A has a welded part 2 that is expanded from the outer diameter of the optical fiber before welding and connection. That is, the outer diameter (D2) of the welded portion 2 is increased as compared with the outer diameters (D1) of the small-diameter core optical fiber 1A and the normal-core optical fiber 1B by the connection of the small-diameter core optical fiber 1A and the normal-core optical fiber 1B by the TEC welding (D2 > D1). The outer diameter of the welded part 2 means the length of the most bulged part of the welded part 2 from the center of the welded optical fiber 1. The core diameter may be defined by a mode field diameter. In fig. 6A, the thickness of the outer diameter D2 of the welded part 2 is highlighted. For example, the outer diameter D1 of the optical fibers (the small-diameter core optical fiber 1A and the normal core optical fiber 1B) other than the fusion zone 2 is 125 μm, whereas the outer diameter D2 of the fusion zone 2 is about 127 μm to 129 μm.

As shown in the lower diagram of fig. 3, in the optical fiber array 10 of the present embodiment, the welding portions 2 of a plurality of welded optical fibers 1 are placed on the substrate 20 in a state where the welding portions 2 of the adjacent 2 welded optical fibers 1 are shifted in position in the front-rear direction (longitudinal direction of the welded optical fibers 1). In other words, a plurality of welded optical fibers 1 are placed on the substrate 20 so that the positions of the welded parts 2 in the front-rear direction (the longitudinal direction of the welded optical fibers 1) are staggered. This makes it possible to suppress interference between the welding portions 2 of adjacent welding optical fibers 1 when a plurality of welding optical fibers 1 having welding portions 2 bulging from the outer diameter of the optical fiber before welding connection are placed on the substrate 20.

In the following description, as shown in fig. 3 and 4, weld 2 located on the side of substrate end surface 21 (front side) may be referred to as "1 st weld 3". On the other hand, the welding portion 2 located on the optical connector 90 side (rear side) may be referred to as a 2 nd welding portion 4. The 1 st welded part 3 and the 2 nd welded part 4 are shifted in position in the front-rear direction (longitudinal direction of the welded optical fiber 1). As shown in fig. 3 and 4, in the optical fiber array 10 of the present embodiment, the welding portions 2 of the adjacent 2 welded optical fibers 1 are shifted in position in the front-rear direction. That is, one of the welded parts 2 of the adjacent 2 welded optical fibers 1 is the 1 st welded part 3, and the other is the 2 nd welded part 4. As shown in fig. 3 and 4, when a plurality of welded optical fibers 1 arranged on a substrate 20 are viewed in the order from the left to the right, a welded optical fiber 1 having a 1 st welded part 3, a welded optical fiber 1 having a 2 nd welded part 4, a welded optical fiber 1 having a 1 st welded part 3, and a welded optical fiber 1 having a 2 nd welded part 4 are arranged in this order. In other words, the welding portion 2 of the odd-numbered left welded optical fiber 1 is the 1 st welding portion 3 (the odd-numbered welded optical fibers 1 have the 1 st welding portion 3), while the welding portion 2 of the even-numbered even welded optical fiber 1 is the 2 nd welding portion 4 (the even-numbered even welded optical fibers 1 have the 2 nd welding portion 4).

The substrate 20 is a member that holds the fusion-spliced optical fiber 1 on the lower side. The deposited optical fiber 1 is placed on the substrate 20 and held by the substrate 20. The fusion-spliced optical fiber 1 mounted on the substrate 20 is sandwiched between the substrate 20 and the fixing member 30. The substrate 20 of the present embodiment is formed of glass. However, the substrate 20 may be formed of other materials.

The substrate 20 has: an optical fiber groove 24, a substrate end face 21, a substrate side escape portion 22, and an terrace portion 23.

The optical fiber groove 24 is a portion on which the deposited optical fiber 1 is placed. The optical fiber groove 24 is formed as a V-shaped groove along the front-rear direction (longitudinal direction of the welded optical fiber 1) on the upper surface of the substrate 20. A plurality of optical fiber grooves 24 are arranged in the left-right direction (the width direction of the welded optical fiber 1) on the upper surface of the substrate 20. As described above, the optical fiber array 10 of the present embodiment includes 24 deposited optical fibers 1. Since 1 deposited optical fiber 1 is placed in each optical fiber groove 24, 24 optical fiber grooves 24 are also arranged in the left-right direction on the upper surface of the substrate 20. When the deposited optical fiber 1 is placed in the optical fiber groove 24, the deposited optical fiber 1 abuts on 2 inclined surfaces constituting the V-shaped groove. Therefore, the deposited optical fiber 1 is positioned in the vertical direction and the horizontal direction by placing the deposited optical fiber 1 in the optical fiber groove 24. Then, the plurality of deposited optical fibers 1 are placed in the optical fiber grooves 24, respectively, thereby performing highly accurate alignment. In the present embodiment, the interval between the fiber grooves 24 is 127 μm. Therefore, the outer diameter D2 (see fig. 6A) of the welded part 2 may exceed the interval of the optical fiber grooves 24.

The substrate end face 21 is a portion to be a connection end face of the optical fiber array 10. The end portion on the front side of the small-diameter core optical fiber 1A (the welded optical fiber 1) is located on the substrate end surface 21. The substrate end face 21 is polished so that the end portion on the front side of the small-diameter core optical fiber 1A (the deposited optical fiber 1) and the end face coincide with each other.

The substrate-side escape portion 22 is a portion that accommodates the welded portion 2 of the welded optical fiber 1. As described above, welded optical fiber 1 has 2 different outer diameters, that is, the outer diameter (D1) of the portion of small-diameter core optical fiber 1A other than welded portion 2 and normal-core optical fiber 1B and the outer diameter (D2) of welded portion 2, by the connection by TEC welding between small-diameter core optical fiber 1A and normal-core optical fiber 1B. The optical fiber groove 24 is formed based on the outer diameters (D1) of the small-diameter core fiber 1A and the normal core fiber 1B. If the fusion-spliced portion 2 (outer diameter D2) is placed in the optical fiber groove 24, the fusion-spliced optical fiber 1 is placed while being floated by the difference between the outer diameter (D2) of the fusion-spliced portion 2 and the outer diameters (D1) of the portions of the small-diameter core optical fiber 1A and the normal core optical fiber 1B. Therefore, the deposited part 2 of the deposited optical fiber 1 is placed on the optical fiber groove 24, and the arrangement accuracy of the deposited optical fiber 1 in the optical fiber array 10 may be deteriorated.

Therefore, in the optical fiber array 10 of the present embodiment, the substrate-side relief portion 22 formed in the substrate 20 allows the welding portion 2 to which the optical fiber 1 is welded to be relieved into the space formed by the substrate-side relief portion 22. The substrate-side escape portion 22 is formed in a concave shape, and the welding portion 2 for welding the optical fiber 1 is accommodated in the concave space. This can prevent the welded portion 2 of the welded optical fiber 1 from contacting the optical fiber groove 24, and thus can prevent the welded optical fiber 1 from being placed on the optical fiber groove 24 while floating. In the present embodiment, the substrate-side relief 22 is configured such that the welding portion 2 of the welded optical fiber 1 is not in contact with the substrate 20 (optical fiber groove 24). However, even if the fusion-spliced portion 2 of the fusion-spliced optical fiber 1 contacts the bottom surface of the substrate-side receding portion 22, the floating of the fusion-spliced optical fiber 1 from the optical fiber groove 24 can be reduced as compared with the case where the substrate-side receding portion 22 is not provided. The substrate 20 may not have the substrate-side escape portion 22.

The substrate-side escape portion 22 includes a substrate-side 1 st escape portion 25 and a substrate-side 2 nd escape portion 26. The substrate-side 1 st relief 25 and the substrate-side 2 nd relief 26 are formed at the positions of the 1 st fusion zone 3 and the 2 nd fusion zone 4 of the fusion-bonded optical fiber 1, respectively. That is, the substrate-side first retreating section 25 and the substrate-side second retreating section 26 are different in position in the front-rear direction (longitudinal direction of the deposited optical fiber 1). Specifically, the substrate-side 1 st escape portion 25 is located on the substrate end surface 21 side (front side), and the substrate-side 2 nd escape portion 26 is located on the optical connector 90 side (rear side).

As shown in fig. 4, the substrate-side 1 st retreating portion 25 and the substrate-side 2 nd retreating portion 26 are formed on the substrate 20 so as to extend in the left-right direction. The substrate-side 1 st retreating portion 25 and the substrate-side 2 nd retreating portion 26 are each formed by a recessed groove extending in the left-right direction. The groove depth of the substrate-side 1 st relief 25 and the substrate-side 2 nd relief 26 is larger than the outer diameter of the weld 2. In other words, the groove depth of the substrate-side 1 st relief 25 and the substrate-side 2 nd relief 26 is deeper than the depth of the optical fiber groove 24 by an amount corresponding to the height of the raised portion of the welding part 2. This makes it possible to retract the portion of the welded part 2 that bulges beyond the outer diameter of the welded optical fiber 1 into the space formed by the substrate-side first retraction 25 and the substrate-side second retraction 26 without contacting the optical fiber groove 24. Therefore, the arrangement accuracy of the deposited optical fibers 1 in the optical fiber array 10 can be improved.

In the present embodiment, a plurality of optical fiber grooves 24 are also formed between the substrate-side 1 st receding portion 25 and the substrate-side 2 nd receding portion 26. Thus, compared to the case where a large relief portion including 2 relief portions (the substrate-side 1 st relief portion 25 and the substrate-side 2 nd relief portion 26) is formed in the substrate 20, the space between the substrate 20 and the fixing member 30 can be narrowed, and the amount of adhesive between the substrate 20 and the fixing member 30 can be reduced. If the amount of adhesive between the substrate 20 and the fixing member 30 is increased, the position of the deposited optical fiber 1 may be greatly displaced due to shrinkage of the adhesive during curing. In contrast, in the present embodiment, the plurality of optical fiber grooves 24 are formed between the substrate-side first receding portion 25 and the substrate-side second receding portion 26, and thus the amount of adhesive between the substrate 20 and the fixing member 30 can be reduced, and therefore the position of the fusion-bonded optical fiber 1 can be maintained with high accuracy.

The exposed portion 23 is a portion having a surface located below the fiber groove 24. The coated portion of the normal core optical fiber 1B (the fusion optical fiber 1) can be arranged so as to be retracted into the space formed by the terrace portion 23. However, the substrate 20 may not have the exposed portion 23.

The fixing member 30 is a member that holds the fusion-spliced optical fiber 1 on the upper side. The fixing member 30 presses the deposited optical fiber 1 held by the substrate 20. As described above, the deposited optical fiber 1 abuts on the 2 inclined surfaces constituting the V-shaped groove. The deposited optical fiber 1 abuts against the fixing member 30, and the deposited optical fiber 1 is fixed at 3 points in total by 2 points of the optical fiber groove 24 and 1 point of the fixing member 30. However, the optical fiber array 10 may not have the fixing member 30.

The fixing member 30 has a fixing member side escape portion 31, and the fixing member side escape portion 31 includes a fixing member side 1 st escape portion 35 and a fixing member side 2 nd escape portion 36. The fixing member side 1 st relief 35 and the fixing member side 2 nd relief 36 are formed at the positions of the 1 st welding portion 3 and the 2 nd welding portion 4 of the welded optical fiber 1, respectively. That is, the position of the fixing member side 1 st receding portion 35 and the position of the fixing member side 2 nd receding portion 36 in the front-rear direction (the longitudinal direction of the welded optical fiber 1) are different. Similarly, the fixing member side 1 st receding portion 35 and the fixing member side 2 nd receding portion 36 are formed at the positions of the substrate side 1 st receding portion 25 and the substrate side 2 nd receding portion 26, respectively. As shown in fig. 3 and 4, the fixing member side 1 st relief portion 35 and the fixing member side 2 nd relief portion 36 are formed on the lower surface of the fixing member 30 so as to extend in the left-right direction. The fixing member side 1 st escape portion 35 and the fixing member side 2 nd escape portion 36 are formed by concave grooves extending in the left-right direction. However, the fixing member 30 may not have the fixing member side escape portion 31.

< comparative example >

Fig. 6B is a diagram showing how a plurality of deposited optical fibers 1 of the comparative example are mounted on a substrate 20. Fig. 6B is a view of a plurality of deposited optical fibers 1 of a comparative example mounted on a substrate 20, as viewed from above. In addition, the lower diagram of fig. 6B shows a cross-sectional view of the line a-a of the upper diagram of fig. 6B.

As described above, the plurality of deposited optical fibers 1 are arranged in the left-right direction on the substrate 20. Here, if it is desired to place a plurality of welded optical fibers 1 aligned in the left-right direction on the substrate 20 at a higher density, it is necessary to align a further plurality of welded optical fibers 1 in the left-right direction on the substrate 20. In other words, the interval between adjacent deposited optical fibers 1 is further reduced. Similarly, in the case where the optical fiber grooves 24 on which the 1 welded optical fibers 1 are placed are further densely placed on the substrate 20, the interval between the adjacent optical fiber grooves 24 becomes further small.

Even when the arrangement of the deposited optical fibers 1 in the left-right direction is densified, the interval between the deposited optical fibers 1 can be reduced to such an extent that the small-diameter core optical fibers 1A or the normal core optical fibers 1B substantially contact each other. However, as described above, the outer diameter (D2) of the fusion-spliced portion 2 may bulge more than the outer diameters (D1) of the small-diameter core optical fiber 1A and the normal core optical fiber 1B (D2 > D1). Therefore, when the interval between adjacent welded optical fibers 1 is reduced, there is a possibility that welded parts 2 of adjacent welded optical fibers 1 interfere with each other.

As shown in the upper diagram of fig. 6B, the positions of the welded parts 2 of the plurality of welded optical fibers 1 in the longitudinal direction are all the same in the comparative example. Therefore, when the interval between adjacent welded optical fibers 1 is reduced, the welded portions 2 of the adjacent welded optical fibers 1 interfere with each other, and a part of the welded optical fibers 1 float. As shown in the lower diagram of fig. 6B, the 2 nd, 4 th, and 6 th (hereinafter, sometimes referred to as "even-numbered") welded optical fibers 1 from the left are placed in the optical fiber grooves 24 of the substrate 20, but the 1 st, 3 rd, and 5 th (hereinafter, sometimes referred to as "odd-numbered") welded optical fibers 1 from the left float up, and cannot be properly placed in the optical fiber grooves 24 of the substrate 20. That is, the odd-numbered deposited optical fibers 1 cannot be positioned in the vertical direction and the horizontal direction, and cannot be aligned with high accuracy.

However, in the optical fiber array 10 of the present embodiment, the welding portions 2 of the plurality of welded optical fibers 1 are placed on the substrate 20 in a state where the welding portions 2 of the adjacent 2 welded optical fibers 1 are shifted in position in the front-rear direction (longitudinal direction of the welded optical fibers 1). In other words, a plurality of welded optical fibers 1 are placed on the substrate 20 so that the positions of the welded portions 2 in the front-rear direction are staggered. In the order of arrangement of the plurality of welded optical fibers 1 of the comparative example shown in fig. 6B, in the present embodiment, for example, the welded portions 2 (the 1 st welded portion 3 described above) of the odd-numbered welded optical fibers 1 are located on the front side, and the welded portions 2 (the 2 nd welded portion 4 described above) of the even-numbered welded optical fibers 1 are located on the rear side. This can suppress interference between the welding portions 2 of adjacent welding optical fibers 1 when a plurality of welding optical fibers 1 having the welding portions 2 are placed on the substrate 20.

< method for manufacturing optical fiber array 10 >

In the method of manufacturing the optical fiber array 10 according to the present embodiment, first, the coatings of predetermined portions of the small-diameter core optical fiber 1A and the normal core optical fiber 1B are removed. This is because the fusion-splicing between the optical fibers is generally performed in a state where the bare optical fibers are connected (in a state where the optical fibers are not provided with a coating). When the deposited optical fiber 1 is placed on the substrate 20, the entire coating of the portions of the small-diameter core optical fiber 1A and the normal core optical fiber 1B that are in contact with the optical fiber groove 24 is removed. This places the boundary between the portion where the coating is removed and the portion where the coating is present in the optical fiber groove 24, thereby suppressing a decrease in the alignment accuracy of the deposited optical fiber 1. The boundary portion and the portion where the coating is present can be arranged so as to be retracted into a space formed by the pedestal portion 23 having a surface located below the optical fiber groove 24.

Next, the small-diameter core optical fiber 1A and the normal core optical fiber 1B are fusion-spliced. The welding connection is performed by the TEC welding described above. After the fusion-splicing, the substrate end face 21-side portion (the small-diameter core optical fiber 1A portion) of the fusion-spliced optical fiber 1 is cut at a predetermined position. When the deposited optical fiber 1 is placed on the substrate 20, a predetermined position to be cut is determined so that the deposited portion 2 is accommodated in the substrate-side relief portion 22 of the substrate 20. As described above, the substrate-side escape portion 22 includes the substrate-side 1 st escape portion 25 located on the substrate end surface 21 side (front side) and the substrate-side 2 nd escape portion 26 located on the optical connector 90 side (rear side). Therefore, the cutting operation is performed by dividing the welded optical fiber 1 at a predetermined position so that the welded part 2 (1 st welded part 3) is accommodated in the substrate-side first relief part 125 and the welded optical fiber 1 at a predetermined position so that the welded part 2 (2 nd welded part 4) is accommodated in the substrate-side second relief part 2.

When the welded optical fiber 1 is placed on the substrate 20, the welded optical fiber 1 is cut so that the end portion of the welded optical fiber 1 (the portion of the small-diameter core optical fiber 1A) on the front side is slightly longer than the position of the substrate end face 21. By performing cutting with a margin in this way, the substrate end face 21 and the end face of the front end face of the deposited optical fiber 1 can be polished so as to be aligned with each other in the subsequent step.

Fig. 7A and 7B are views showing how the deposited optical fiber 1 according to the present embodiment is mounted on the substrate 20.

Fig. 7A shows how a plurality of (12) welded optical fibers 1 having the same position in the front-rear direction of the welded part 2 (longitudinal direction of the welded optical fibers 1) are placed in the optical fiber groove 24. The welding portions 2 (2 nd welding portions 4) of the even-numbered welded optical fibers 1 are located on the rear side, and thus the same is obtained. In this embodiment, a plurality of welded optical fibers 1 having 2 nd welded parts 4 are collected and placed in the optical fiber grooves 24, respectively. At this time, every other welded optical fiber 1 having 2 nd welded part 4 is placed in optical fiber groove 24.

After the state shown in fig. 7A, fig. 7B shows a state in which a plurality of (12) welded optical fibers 1 having the same position in the longitudinal direction of the welded part 2 (longitudinal direction of the welded optical fiber 1) at other positions are placed in the remaining optical fiber grooves 24, respectively. The welding portions 2 (1 st welding portion 3) of the odd-numbered welded optical fibers 1 are positioned on the front side, and thus the same is obtained. In this embodiment, a plurality of welded optical fibers 1 having the 1 st welded part 3 are collected and placed in the optical fiber grooves 24, respectively. At this time, the welded optical fibers 1 having the 1 st welded part 3 are placed in the remaining optical fiber grooves 24 where the welded optical fibers 1 are not placed, respectively.

However, when the deposited optical fiber 1 is placed in the even-numbered optical fiber grooves 24 as shown in fig. 7A, the operator collectively handles the plurality of deposited optical fibers 1 having the 2 nd deposited parts 4. As shown in fig. 7B, when placing the welded optical fibers 1 in the odd-numbered optical fiber grooves 24, the worker collectively handles the plurality of welded optical fibers 1 having the 1 st welded part 3. If the deposited optical fiber 1 is placed in order from the end of the optical fiber groove 24, the operator needs to alternately handle the deposited optical fiber 1 having the 2 nd deposited part 4 and the deposited optical fiber 1 having the 1 st deposited part 3, which makes the placing operation inconvenient. In contrast, in the present embodiment, since a plurality of welded optical fibers 1 having the same position in the longitudinal direction of the welded part 2 can be collectively processed, the work of placing the welded optical fibers 1 in the optical fiber groove 24 is simplified, and the work efficiency is improved.

In the present embodiment, as shown in fig. 7B, when the deposited optical fiber 1 is placed in the odd-numbered optical fiber grooves 24, the deposited optical fiber 1 (the even-numbered deposited optical fibers 1) is already placed in the even-numbered optical fiber grooves 24. In this state, the step difference (unevenness) between the odd-numbered fiber groove 24 on which the deposited optical fiber 1 is placed and the even-numbered deposited optical fibers 1 positioned on both sides thereof is large. Therefore, as shown in fig. 7B, when the deposited optical fibers 1 are placed in the odd-numbered optical fiber grooves 24, the operator may insert the end portions of the odd-numbered deposited optical fibers 1 between the deposited optical fibers 1 (the even-numbered deposited optical fibers 1) already placed. Therefore, in the present embodiment, the work of placing the deposited optical fiber 1 in each of the optical fiber grooves 24 (odd-numbered optical fiber grooves 24) is simplified, and the work efficiency is further improved.

As shown in fig. 7A and 7B, in the present embodiment, each of a plurality of deposited optical fibers 1 having the same position in the front-rear direction of the deposited part 2 (longitudinal direction of the deposited optical fiber 1) is placed in the optical fiber groove 24. This makes it easy to manage the positional relationship between the welded part 2 and the substrate-side relief part 22 when the optical fiber is placed in each optical fiber groove 24. Therefore, in the method of manufacturing the optical fiber array 10 according to the present embodiment, the welded parts 2 of the adjacent 2 welded optical fibers 1 can be easily placed on the substrate 20 while being shifted in position in the longitudinal direction of the welded optical fibers 1.

The arrangement is such that the welded part 2 is housed in the space formed by the substrate-side retracted part 22 by placing the welded optical fiber 1 in the optical fiber groove 24 so that the welded part 2 corresponds to the positional relationship between the substrate-side retracted part 22. Thus, the portion of the welded part 2 that bulges beyond the outer diameter of the welded optical fiber 1 does not contact the optical fiber groove 24, and the arrangement accuracy of the welded optical fibers 1 in the optical fiber array 10 can be improved.

After the deposited optical fiber 1 is disposed in the optical fiber groove 24, the fixing member 30 is attached, and the deposited optical fiber 1, the substrate 20, and the fixing member 30 are fixed by adhesion. The fusion-spliced optical fiber 1 mounted on the substrate 20 is pressed and fixed by the fixing member 30. The adhesive is injected from the substrate end face 21 and is transmitted through capillary action in the space between the deposited optical fiber 1, the substrate 20, and the fixing member 30. Finally, the substrate end face 21 and the end face of the deposited optical fiber 1 are polished so as to match each other.

The term "other" means

In the optical fiber array 10 of the present embodiment described above, as shown in fig. 1B, the substrate-side escape portion 22 and the fixing member-side escape portion 31 are formed in a concave shape having a wall surface and a bottom surface. However, the substrate-side escape portion 22 and the fixing-member-side escape portion 31 may have a U-groove shape or a V-groove shape. As shown in fig. 3 and 4, the substrate-side escape portion 22 and the fixing-member-side escape portion 31 have shapes extending in the left and right directions of the substrate 20. However, the substrate-side relief 22 and the fixing-member-side relief 31 may be formed only in the vicinity of the weld 2.

In the optical fiber array 10 of the above embodiment, an example is shown in which the small-diameter core optical fiber 1A (D1) having the same outer diameter and the normal-core optical fiber 1B (D1) are fusion-spliced. However, optical fibers having different outer diameters may be deposited. For example, the small-diameter core optical fiber 1A having the outer diameter D3 and the normal core optical fiber 1B having the outer diameter D4(≠ D3) may be fusion-spliced. In this case, the fiber groove 24 is formed based on the outer diameters of the loaded small-diameter core fiber 1A and normal core fiber 1B. In other words, the optical fiber groove 24 of the portion in which the small-diameter core optical fiber 1A (D3) is placed is formed based on D3, and the optical fiber groove 24 of the portion in which the normal core optical fiber 1B (D4) is placed is formed based on D4. Thus, when the fusion optical fiber 1 is disposed in the optical fiber groove 24, the positions of the central axes of the small-diameter core optical fiber 1A and the normal core optical fiber 1B are located on the same straight line.

The optical fiber array 10 of the above embodiment has 2 escape portions, i.e., the substrate-side 1 st escape portion 25 and the substrate-side 2 nd escape portion 26. However, a larger one of these 2 escape portions may be included. However, in the case of forming a large one of the relief portions, since more adhesive is used, the displacement of the deposited optical fiber 1 placed in the optical fiber groove 24 may increase due to contraction of the adhesive.

In the optical fiber array 10 of the above-described embodiment, a plurality of welded optical fibers 1 are placed on the substrate 20 so that positions of the welded portions 2 in the front-rear direction are staggered by 2 steps (the 1 st welded portion 3 and the 2 nd welded portion 4). However, a plurality of welded optical fibers 1 may be placed on the substrate 20 so that 3 or more stages of the positions of the welded portions 2 in the front-rear direction are staggered.

The above-described embodiments are intended to facilitate understanding of the present invention, and are not intended to be restrictive. It is obvious that the present invention can be modified and improved without departing from the gist thereof, and the present invention includes equivalents thereof.

Description of reference numerals

1 … (fusion-spliced) optical fiber; 1a … (fine core) fiber; 1B … (typically core) optical fiber; 2 … deposit; 3 … No. 1 deposit; 4 … # 2 weld; 5 … an adhesive; 10 … optical fiber array; 11 … optical fiber fixing substrate box; 20 … a substrate; 21 … end face of substrate; 22 … substrate-side receding section; 23 … exposing the platform part; 24 … fiber grooves; 25 … substrate side 1 st receding part; 26 … substrate side 2 nd escape part; 30 … securing element; 31 … fixing member side escape part; 35 … fixing member side 1 st escape part; 36 … fixing member side 2 nd escape part; 90 … optical connectors; 100 … optical fiber array unit.