JP2000180670A - Laminated optical fiber array and its manufacturing method - Google Patents

Abstract

(57) [Problem] To provide a laminated optical fiber array having excellent position detection resolution when used for an optical position sensor or the like. SOLUTION: A plurality of substrates 11 to 15 each having a V-groove array 17 formed of a plurality of V-grooves 16 formed on the surface thereof are provided.
Are stacked so that they face each other, and the optical fibers 18 are accommodated in the gaps formed by the V-grooves 16, and the optical fiber rows
9, the position of the optical fiber row 19 is sequentially shifted for each optical fiber row, and the amount of the shift is a / n where n is the number of stages of the optical fiber row 19 and a is the outer diameter of the optical fiber 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated optical fiber array used for an optical position sensor and the like, and a method of manufacturing the same.

[0002]

2. Description of the Related Art As this type of laminated optical fiber array (hereinafter, referred to as an array), the one shown in FIG. 5 is known (JP-A-9-127375). FIG.
In the figure, reference numeral 1 denotes a first substrate made of quartz glass or the like, 2 denotes a second substrate, and 3 denotes a third substrate. On the first and third substrates 1 and 3, three V-grooves are engraved on one surface of the first and third substrates 1 and 3 in parallel with each other, and the second substrate 2 has three V-grooves on both surfaces thereof. Are engraved in parallel at a distance from each other.

Then, a second substrate 2 is placed on the first substrate 1.
The third substrate 3 is further superimposed thereon such that the V-grooves formed on the respective surfaces coincide with each other, and the optical fibers 4 and 4 are formed on the rhombic grooves formed by the opposed V-grooves. . Are accommodated, and an adhesive 5 for bonding and integrating them is injected and solidified between the substrates 1, 2, 3 and the gap of the V groove. The positions of the optical fibers overlap each other when viewed from the lamination direction of the substrates 1, 2, and 3.

When such an array is used as an optical position sensor, a light source is arranged in front of the array, and the object to be detected is moved between the array and the light source. In this case, the maximum resolution for detecting the position of the object to be detected is the center distance between the optical fibers 4, 4,.

In order to increase the resolution, each substrate 1
It is conceivable that the optical fibers 4, 4,... Have a structure in which the V-grooves formed in 2, 3 are adjacent to each other, and the optical fibers 4, 4,. However, in such an array,
Even when a bare optical fiber having an outer diameter of 125 μm was used as the optical fiber 4, the maximum resolution was 125 μm, and no higher resolution could be obtained.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an array which can be used with an optical position sensor or the like to have a sufficiently high resolution and a highly accurate position detection. .

[0007]

This object is achieved by stacking a plurality of substrates having a plurality of V-groove rows on the surface of which are engraved in parallel and adjacent to each other, such that the V-groove rows face each other. The optical fiber is accommodated in a tunnel-shaped gap having a rhombic cross section formed by facing the V-grooves to form a fiber array, and the fiber array has a structure in which two or more fiber arrays are stacked. The positions are sequentially shifted for each fiber row, and the amount of the shift can be solved by an array of a / n, where n is the number of layers in the fiber row and a is the outer diameter of the optical fiber.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
1 to 3 show an example of the array of the present invention. In the drawings, reference numeral 11 denotes a first single-sided substrate, 12 denotes a first double-sided substrate, 13 denotes a second double-sided substrate, and 14 denotes a third double-sided substrate. Double-sided board,
Reference numeral 15 denotes a second single-sided substrate. Each of the first and second single-sided substrates 11 and 15 is a plate-like material made of quartz or the like and having a rectangular planar shape, and a step is formed on one surface of a rear half portion in the longitudinal direction to be thin. . Also, on one surface thereof, a plurality of V-grooves 16 are formed along the longitudinal direction of the substrate.
16 are engraved in parallel and adjacent to each other to form a V groove row 17.

First to third double-sided substrates 12, 13, 1
Reference numeral 4 denotes a plate-like object made of quartz or the like and having a rectangular planar shape. Also, on both surfaces,
A plurality of V-grooves 16 are engraved in parallel and adjacent to each other along the longitudinal direction of the substrate to form V-groove rows 17. In addition, as shown in FIG.
V-grooves 16, 16 formed on one surface of 2, 13, 14
And the V-grooves 16, 16 formed on the other surface are slightly displaced in the lateral direction of the substrate. Furthermore, the dimensions of the first and second single-sided substrates 11, 15 and the first to third double-sided substrates 12, 13, 14 are substantially equal.

As shown in FIG. 1, the first double-sided substrate 12 is superposed on the surface of the first single-sided substrate 11 on which the V-groove row 17 is formed, and the second and second substrates are placed thereon. The third double-sided substrates 13 and 14 are stacked, and the third double-sided substrate 13
The surface on which the V-groove array 17 of the second single-sided substrate 15 is formed is superimposed thereon, and each V of these substrates 11, 12, 13, 14, and 15 is overlapped.
Each substrate is overlapped so that the groove rows 17, 17... Face each other.

By superposing the substrates 11 to 15 in this manner, the V-groove rows 17, 17... Of the substrates face each other, and a large number of tunnel-shaped spaces having a diamond-shaped cross section are formed. All of these spaces have bare optical fibers 18,1
Are housed and fixed in the space by an optical adhesive, and the respective substrates are also joined and integrated with each other to form an array. Also, the distal ends of the bare optical fibers 18, 18,... Are flush with the distal end surface of the substrate. In such an array, therefore, four optical fiber rows 19, 19,... Are formed in the stacking direction of each substrate. The optical fiber row 19 is a state in which the bare optical fibers 18 are positioned substantially adjacent to each other.

The groove width of the V-groove 16 formed on each of the substrates 11 to 15 is the same as that of the bare optical fiber 1 accommodated in the V-groove 16.
8 larger than the outer diameter of No. 8 and usually 126 to 12 μm.
7 μm, and the groove depth is about 85 μm. Further, the V-grooves 16, 1 on both sides of the double-sided substrates 12, 13, 14 are provided.
6 are 1/4 of the outer diameter 125 μm of the bare optical fiber 18 to be accommodated, ie, 3
It is 1.25 μm. The shift amount w is determined by a / n, where n is the number of the optical fiber rows 19, 19,... And a is the outer diameter of the bare optical fiber, and as shown in FIG. , 19... Are 1/4 of the outer diameter of the bare optical fiber.

As shown in FIG. 3, the bare optical fiber 18 is formed by dividing a multi-core optical fiber tape core 20, 20 into optical fiber strands 21, 21 and covering the tip of the strand. It is desirable to use the bare optical fiber 18, 18 that has been removed and removed. For example, one optical fiber row 19
Is composed of 16 bare optical fiber wires 18, 18,..., Two 8-core optical fiber tape cores are used.
In this case, the optical fiber portion does not expand beyond the width of one optical fiber row 19, which is convenient. The other ends of the bare optical fibers 18, 18,... Are led out from the rear of the array as lead wires as optical fiber ribbons as shown in FIG. Connected and used as an optical position sensor. At this time, a space is formed by thinning the rear half of each substrate of the array, and the optical fiber tape is accommodated in this space, and the whole is compact.

In an array having such a configuration, 4
Since the positions of the individual bare optical fibers 18, 18, which form the optical fiber rows 19, 19,... Of the rows are shifted laterally by 31.25 μm when viewed from the stacking direction of the array, light The maximum resolution when used as a position sensor is greatly improved to 31.25 μm, and the position detection accuracy is high.

Next, an example of a method for manufacturing such a laminated optical fiber array will be described. In this example, a description will be given of a case where one optical fiber row shown in FIG. 1 is composed of 16 bare optical fiber wires and has four optical fiber rows. First, the first and second single-sided substrates 11, 15 and the first
Or a plate-like material to be the third double-sided substrates 12, 13, 14 is prepared, and the V-grooves 16, 16 are formed on one or both surfaces thereof.
Are engraved in 16 lines to form V-groove rows 17, 17,. In the double-sided substrates 12, 13, and 14, the positions of the V-grooves on each surface are 3
Needless to say, it is shifted by 1.25 μm. This V
The shift amount w of the groove array 17 is determined by a / (m-1), where m is the number of stacked substrates, and a is the outer diameter of the bare optical fiber.

Next, the first single-sided substrate 11 is fixed on a workbench, and the surface of the V-groove array 17 is cleaned with alcohol or the like.
After that, two eight-core optical fiber ribbons are prepared, and about 15 mm is divided from the tip thereof, and the eight cores are exposed to obtain eight bare optical fibers 18, 18,.
The six bare optical fibers 18 are accommodated in the V-grooves 16 of the first single-sided substrate 11, respectively. At this time, the bare optical fibers 18 from the two optical fiber ribbons are alternately arranged in the V groove row 17.

Next, the cleaned first double-sided substrate 12 is
The V-grooves 16, 16 are overlapped with the V-groove of the first single-sided substrate 11 so as to be renewed, and the bare optical fibers 18, 18. At this time, as shown in FIG. 4, the distal ends of the bare optical fibers 18, 18... Are projected outward from the distal end surface of the substrate by about 5 mm. In this state, both substrates 11, 1
An ultraviolet-curable liquid adhesive is injected between the substrates 11 and 12 from the space on the rear side with a dispenser 22 and irradiated with ultraviolet light to solidify the adhesive, and bare optical fibers 18, 18.
Is fixed to the V-groove, and both substrates 11 and 12 are joined.

The above operation is performed by the second and third double-sided substrates 13,
This is sequentially repeated for 14 and the second single-sided substrate 15.
When a series of work is completed, about 1 mm from the tip of the substrate
The entire substrate is cut at the portion where the substrate has entered, the cut surface is polished, and the obtained array is inserted into a stainless steel cylindrical die for protection, filled with an epoxy resin or the like, and solidified.

According to such an array manufacturing method, an array having the structure shown in FIG. 1 can be easily and efficiently manufactured. In particular, since the bare optical fiber 18 is separated from the core of the optical tape and the lead is used, the lead portion of the bare optical fiber 18, 18,... Can be reduced, and the entire array can be made compact. Further, by using a low-viscosity ultraviolet-curing adhesive as the adhesive, the V-grooves 1 can be formed without disturbing the arrangement of the bare optical fibers 18.
6, 16 ... can be securely fixed.

[0020]

As described above, according to the laminated optical fiber array of the present invention, the resolution can be improved in accordance with the number of stages by forming the array of optical fibers in multiple stages. it can. Therefore, when this array is used for an optical position sensor, the position detection accuracy of the detected object can be greatly improved. Further, according to the method for producing a laminated optical fiber array of the present invention, a laminated optical fiber array can be produced efficiently and easily.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a laminated optical fiber array according to the present invention.

FIG. 2 is a perspective view showing an example of a double-sided board according to the present invention.

FIG. 3 is a perspective view showing an embodiment of a bare optical fiber according to the present invention.

FIG. 4 is a drawing showing a part of a method for manufacturing a laminated optical fiber array of the present invention.

FIG. 5 is a front view showing an example of a conventional laminated optical fiber array.

[Explanation of symbols]

11: first single-sided substrate, 12: first double-sided substrate, 13 ...
Second double-sided substrate, 14: Third double-sided substrate, 15: Second single-sided substrate, 16: V-groove, 17: V-groove row, 18: bare optical fiber, 19: optical fiber row

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Takashi Tsumanuma 1440 Mutsuzaki, Sakura City, Chiba Prefecture Fujikura Sakura Plant F-term (reference) 2H036 JA02 LA03 LA05 LA08 QA12 QA17 QA22 2H038 AA03 2H050 AD06

Claims (3)

[Claims] 1. A plurality of substrates each having a plurality of V-groove rows in which a plurality of V-grooves are engraved in parallel and adjacent to each other on a surface, and stacked such that the V-groove rows face each other, and formed such that the V-grooves face each other. The optical fiber is accommodated in the tunnel-shaped gap having a diamond-shaped cross section, and a fiber row is formed. This fiber row is laminated in two or more stages, and the position of each optical fiber row is sequentially shifted for each fiber row. Wherein the amount of deviation is a / n, where n is the number of layers in the fiber row and a is the outer diameter of the optical fiber. 2. A first single-sided substrate having a plurality of V-groove rows engraved in parallel and adjacently on one surface of the substrate is prepared, and the V-groove row of the first single-sided board is prepared. Then, a plurality of V grooves are formed on both surfaces of the substrate in parallel with and adjacent to each other, and a V groove array is formed by shifting the positions of the V grooves on both surfaces. The substrates are superimposed so that the optical fiber inserted in the V-groove row of the first single-sided board enters the V-groove row on one side thereof, and then the V-groove row on the other side of the first double-sided board. After inserting the optical fiber, the second double-sided substrate is overlapped with the V-groove array on one surface thereof so that the optical fiber inserted into the V-groove array on the other surface of the first double-sided substrate is inserted. Similarly, the N-th (N is an integer greater than or equal to the first)
And then superimposing the second single-sided substrate on its V-groove array so that the optical fibers put in the V-groove array on the other surface of the N-th double-sided substrate enter. Manufacturing method of laminated optical fiber array. 3. The manufacturing method according to claim 2, wherein the amount of deviation of the position of the V-grooves in the V-groove row on both surfaces of the double-sided substrate is as follows: where m is the number of stacked substrates and a is the outer diameter of the optical fiber. / (M-
1) A method for producing a laminated optical fiber array, which is characterized in that 1) above.