JPH11326678A - Production of optical fiber array - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily produce a high accuracy optical fiber array. SOLUTION: A coated fiber part retaining plate 18 which is shorter than the length of many parallel V-grooves 12 is placed on a V-grooved substrate 10 formed with these V-grooves on the surface and is temporally fixed in a tight contact state thereto. A UV-curing adhesive 20 of a low viscosity is then applied near a coated fiber part retaining plate 18 on the V-grooved substrate 10 and respective coated fibers 24 of a tape-like optical fiber 22 are inserted therein, until the fibers pass through the inside of the V-grooves 12. The exposed V-grooves 12 and the front end portion of the coating part 26 of the tape-like optical fiber are coated with the optical fiber retaining member 28, and thereafter the adhesive 20 is cured through irradiation with UV rays.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an optical fiber array in which an optical fiber core is disposed on a V-groove substrate and bonded and integrated with an ultraviolet curing adhesive while being held down by a core wire pressing plate. In other words, the present invention relates to a method for manufacturing an optical fiber array in which a core wire holding plate is temporarily fixed in direct contact with a V-groove substrate in advance and then an adhesive and an optical fiber core wire are inserted into the V-groove. It is. This optical fiber array is used in, for example, a portion where an optical fiber and an optical waveguide need to be connected, such as an optical integrated circuit, an optical coupler, and an optical splitter.

[0002]

2. Description of the Related Art An optical fiber array is used at a place where an optical fiber and an optical waveguide are connected. An optical fiber array is an optical component in which a large number of optical fibers are arranged and fixed at an accurate pitch.

[0003] Conventionally, the arrangement of the optical fiber core wires is V
Groove substrates have been used. The V-groove substrate is formed by forming a large number of parallel V-grooves having a V-shaped cross section at a precise pitch on a substrate surface made of, for example, glass or silicon.
Each V-groove serves as a positioning / accommodating portion for the optical fiber core wire. In the prior art, assembly was performed by any of the following procedures. A method of arranging a core of a tape-shaped optical fiber on a V-groove substrate and applying an adhesive thereto and attaching a core wire portion holding plate thereon to bond the adhesive, or applying an adhesive to the V-groove substrate and applying each adhesive This is a method in which a core wire of a tape-shaped optical fiber is arranged in a groove, and a core wire part pressing plate is placed thereon and bonded.

[0004]

However, in the conventional method, a layer of adhesive is always formed between the V-groove substrate and the core wire pressing plate, and as a result, the adhesive layer is formed by the V groove and the core wire pressing plate. The cross-sectional area of the core wire accommodating portion is larger than the cross-sectional area of the V-groove itself. Therefore, even if a V-groove substrate formed with high precision is used, the optical fiber core wire does not fall to a certain position in the V-groove and is adhered in a dispersed state, so that high-precision light There was a drawback that a fiber array could not be manufactured.

An object of the present invention is to provide a method for easily manufacturing a high-precision optical fiber array.

[0006]

According to the present invention, a core wire pressing plate is placed on a V-groove substrate having a plurality of parallel V-grooves formed on a surface thereof, and is temporarily fixed in a close contact state. A method of manufacturing an optical fiber array, in which a low-viscosity ultraviolet-curing adhesive is applied to a substrate, a core wire of the optical fiber is inserted, and then the adhesive is cured by irradiating ultraviolet rays.

As described above, according to the present invention, an optical fiber is prepared by temporarily fixing a core wire pressing plate directly to a V-groove substrate so as to directly adhere to the V-groove substrate, and then applying a low-viscosity ultraviolet curing adhesive to the inside of the V-groove. It is characterized in that it is assembled in a different order, such as inserting As a result, there is no adhesive layer between the V-groove substrate and the core wire pressing plate. Therefore, when viewed in cross section, the optical fiber core wire has three points, the both side walls of the V groove and the core wire pressing plate. , So that the position is strictly determined and fixed in that state. Conversely, in the present invention, the V-groove formed in the V-groove substrate is set to a dimension that just fills the core wire of the optical fiber.

[0008]

For example, on a V-groove substrate having a large number of parallel V-grooves formed on its surface, a core wire pressing plate shorter than the length of the V-groove is placed and temporarily fixed in a close contact state. Next, a low-viscosity ultraviolet curing adhesive is applied along the core wire pressing plate on the V-groove substrate, and each core wire of the tape-shaped optical fiber is inserted until it penetrates into the V-groove. In this case, it is preferable to cover the exposed V-groove portion and the coated tip portion of the tape-shaped optical fiber with an optical fiber pressing member made of glass. afterwards,
The adhesive is cured by irradiating ultraviolet rays. It is also effective to make the V-groove tapered to facilitate the operation of inserting the core wire of the optical fiber.

[0009]

1A to 1F are process explanatory views showing one embodiment of a method for manufacturing an optical fiber array according to the present invention. This is an example of connecting a tape-shaped optical fiber having four core wires.

First, as shown in FIG. 1A, a V-groove substrate 1
0 is produced. This includes, for example, etching, grinding,
Alternatively, a plurality of (four in this case) V grooves (grooves having a V-shaped cross section) 12 are formed with high precision on the surface of a substrate made of glass or silicon by a molding method or the like. High precision means that both the arrangement pitch and the cross-sectional shape of the V-groove have good manufacturing precision. V groove 1
The cross-sectional shape of 2 is set to a dimension that just fits the core wire of the optical fiber. In this embodiment, the V-groove substrate 10 includes a thick body portion 14 having four parallel V-grooves 12 on the upper surface,
This is a structure in which the thin covering portion receiving plate portion 16 is continuously integrated.

Next, as shown in FIG. 1B, the V-groove substrate 1
A glass core wire pressing plate 18 is placed on 0, and is temporarily fixed in close contact with a pressing jig (not shown) or the like. The core wire pressing plate 18 has a width (in the depth direction in FIG. 1).
Is a flat plate having the same width as the V-groove substrate 10 and a length (horizontal dimension in FIG. 1) of about half the length of the V-groove.
Such a core wire pressing plate 18 is placed on the main body portion 14 of the V-groove substrate 10 with its left ends aligned, and pressed and held.
It may be held by a clamp or the like. Alternatively, as will be described later (FIG. 3), a step may be provided by slightly lowering both sides of the upper surface of the V-groove substrate, and the step may be temporarily fixed by applying an adhesive.

Then, as shown in FIG. 1C, the V-groove substrate 1
Low-viscosity UV curable adhesive (UV adhesive) 20 on top of 0
Is applied. The ultraviolet curing adhesive 20 is supplied by a predetermined amount from a dispenser or the like along the core wire pressing plate 18 on the main body portion 14 of the V-groove substrate 10. It is assumed that this supply amount matches the difference between the cross-sectional area of the V-groove and the cross-sectional area of the core wire.

Next, as shown in FIG. 1D, the V-groove substrate 10
Then, the tape-shaped optical fiber 22 is inserted. Specifically, in FIG. 1D, each core wire 24 is inserted into the V groove 12 horizontally from the right hand direction (or obliquely downward from the upper right hand). Then, the core wire 24 enters the triangular cavity formed by the V-groove 12 and the core part pressing plate 18 while pushing the ultraviolet-curing adhesive 20 at the tip portion, and enters the inside of the V-groove by capillary action. The adhesive 20 completely fills the gap between the core wire 24 and the wall surface of the cavity.
"Low viscosity" of the low-viscosity ultraviolet curing adhesive in the present invention
The term "viscosity" means such a viscosity that flows smoothly along the gap between the core wire and the V-groove. In this manner, as shown in FIG.
0 and until it protrudes from the distal end surface of the core wire pressing plate 18 (in this case, the end surface of the coating portion 26 of the tape-shaped optical fiber 22 is in contact with the step of the V-groove substrate 10, and in this state, Until it is).

Then, as shown in FIG. 1F, the optical fiber pressing member 28 is covered. Here, the optical fiber pressing member 28 has a structure in which a thick core wire pressing portion and a thin coating pressing portion are integrated, and is made of a material that can transmit ultraviolet rays, such as glass. With the optical fiber pressing member 28 covered in this manner, ultraviolet rays are irradiated to cure the internal ultraviolet curing adhesive. It should be noted that an ultraviolet curing adhesive may be applied between the upper surface of the covering portion of the tape-shaped optical fiber 22 and the lower surface of the covering portion pressing portion of the optical fiber pressing member 28, and the adhesive may be simultaneously cured with the irradiated ultraviolet light. Good.

After the UV-curable adhesive is completely cured, the core portion protruding from the tip surface is cut, and if necessary, the tip surface of the core wire or the V-groove substrate or the core wire pressing plate is polished. Thus, an optical fiber array is obtained. Of course, it is also possible to reinforce them by covering their outer peripheral sides with another protective member. Although only a part of the tape-shaped optical fiber is illustrated in FIG. 1 as if the rear portion is cut, it is actually a long cable.

In the optical fiber array obtained in this manner, when the tip surface is viewed, as shown in FIG.
The two side walls of the groove 12 and the lower surface of the core wire pressing plate 18 are in contact with each other at three points (the gap is filled with a cured ultraviolet curing adhesive). Therefore, if the V-groove substrate 10 is precisely manufactured, the core wires 24 are automatically positioned by insertion into the V-groove 12, and are arranged with high precision.

FIG. 3 shows another example of the V-groove substrate used in the present invention. Here, only the main portion of the V-groove substrate 30 (V
Although only the portion where the groove 32 is formed is shown), a structure having a covering portion receiving plate portion may be used as in the above embodiment. In this embodiment, the V-groove substrate 30 is
Is a shape having a tapered portion that becomes gradually narrower and shallower. Here, shallow wide groove in a tapered shape in the range of the length L ₁ is also narrower (groove width of the base end side is W _1), V grooves of the same cross section in the range of the length L ₂ of the tip-sided ( The groove width is W ₂ , and therefore W ₂ <W ₁ ). Accordingly, the core wire of the inserted optical fiber is in contact with both side walls of the V-groove 32 and the lower surface of the core wire portion holding plate on the distal end side, and is provided with a larger orientation on the insertion side. As a result, workability is improved, and excessive stress is not applied to the core wire during insertion. Such a groove shape can be formed only by slightly moving the cutting grindstone vertically in the substrate length direction during groove processing. This is because, if it is slightly moved up and down, the cut amount changes. The structure in which the portion where the V-groove cross section does not change is provided as described above is advantageous because the V-groove shape does not change even when the tip surface is ground or cut in the manufacturing process of the optical fiber array. Of course, the change in the V-groove cross-sectional shape is not limited to the above example.

In FIG. 3, the upper surface of the V-groove substrate 30 has a stepped portion 34 in which both sides of the upper surface are slightly lowered.
The stepped portion 34 is an adhesive pool, and an adhesive is applied to the portion and adhered to the core portion pressing plate. An adhesive is provided between the V-groove substrate other than the stepped portion 34 and the core portion pressing plate. Avoid layers. Thereby, the V-groove substrate and the core wire portion holding plate can be temporarily fixed. Although such a configuration is not shown in FIG. 1, it is possible to provide such a step and temporarily fix it as described above.

[0019]

According to the present invention, as described above, in the state where the core wire pressing plate is directly in contact with the V-groove substrate without interposing the adhesive layer, the ultraviolet curing adhesive and the light Since it is a method of inserting and assembling the fiber core, if the V-groove substrate is manufactured with high precision, the core of the optical fiber is precisely positioned by contacting at three points when viewed in a cross section perpendicular to the V-groove. Thus, a highly accurate optical fiber array can be easily obtained.

In particular, if the V-groove is formed in a tapered shape, that is, from the wide area, the tip is processed so as to have a dimension in which the core is just buried. Also, it is difficult to apply excessive stress to the core wire after assembling, and the reliability is also improved.

[Brief description of the drawings]

FIG. 1 is a process explanatory view showing one embodiment of a method for manufacturing an optical fiber array according to the present invention.

FIG. 2 is an explanatory diagram of a state of holding a core wire at a position of a front end surface thereof.

FIG. 3 is an explanatory view showing another example of a V-groove substrate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 V-groove board 12 V-groove 18 Core wire part holding plate 20 Ultraviolet curing adhesive 22 Tape optical fiber 24 Core wire 26 Coating part

Claims (4)

[Claims] 1. A core wire pressing plate is placed on a V-groove substrate having a plurality of parallel V-grooves formed on a surface thereof, and is temporarily fixed in a close contact state. A method for manufacturing an optical fiber array, comprising applying a core wire of an optical fiber, applying an ultraviolet ray, and then irradiating ultraviolet rays to cure the adhesive. 2. A V-groove substrate having a number of parallel V-grooves formed on a surface thereof, a core wire pressing plate shorter than the length of the V-groove is placed and temporarily fixed in close contact with the V-groove substrate. Apply a low-viscosity ultraviolet curing adhesive near the upper core wire holding plate, insert each core wire of the tape-shaped optical fiber until it penetrates into the V groove, and then irradiate ultraviolet light to cure the adhesive. A method of manufacturing an optical fiber array. 3. A V-groove substrate having a number of parallel V-grooves formed on its surface, a core wire pressing plate shorter than the length of the V-groove is placed and temporarily fixed in close contact with the V-groove substrate. A low-viscosity ultraviolet curing adhesive is applied in the vicinity of the upper core wire holding plate, and each core wire of the tape-shaped optical fiber is inserted until it penetrates the inside of the V-groove. The method according to claim 1, further comprising: covering the covering end portion with an optical fiber pressing member, and thereafter irradiating ultraviolet rays to cure the adhesive. 4. The V-groove substrate has a shape in which each V-groove has a tapered portion in which each V-groove becomes gradually narrower and shallower. The light according to any one of claims 1 to 3, wherein the light is provided in contact with the side walls and the lower surface of the core wire pressing plate at three points when viewed in a cross section perpendicular to the V-groove, and on the insertion side in a direction larger than that. Fiber array manufacturing method.