JPH07198984A - Optical fiber coupler and its production - Google Patents

Abstract

PURPOSE:To provide an optical fiber coupler which is easily connectable to a measuring system, optical parts, etc., and has an excellent housing property. CONSTITUTION:Optical fiber fixing grooves 3 and guide pin fixing grooves 4 are formed at both ends of a case body 1 and a central part is bored to form a bored part 5, as shown in a perspective view (A) and an overhead view (B). The optical fiber fixing grooves 3 are precisely positioned to the guide pin fixing grooves 4. The optical fiber part of the optical fiber coupler is placed in the optical fiber fixing grooves 3 and are adhered and fixed by the resin 7 for fixing. The optical fibers extending outside from the case body 1 are cut near the end faces of the case body 1 and the end faces are ground as shown in (C), by which the optical fiber coupler is formed. The case itself acts as a connector.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber coupler used in an optical communication line and a manufacturing method thereof.

[0002]

2. Description of the Related Art FIG. 4 is a block diagram for explaining an example of a conventional method for manufacturing an optical fiber coupler. 1 in the figure
Reference numerals 1 and 12 are coating portions of the optical fiber, 13 is a glass portion, 14 is a stretching stage, 15 is a microtorch, and 16 is a microtorch.
Is a light source, and 17 and 18 are power meters.

As shown in the figure, the coating portions 11 and 12 of the two optical fibers with the glass portion 13 exposed are fixed to a drawing stage 14, heat-fused with a micro torch 15, and then drawn with heating. The stage 14 is moved to draw the glass portion 13 to form a coupler portion. In the drawing step, the light beam from the light source 16 is made incident on one end of one optical fiber, and the outgoing light is monitored by the power meters 17 and 18 from the other side, and the drawing is stopped when a predetermined branching ratio is obtained. Then, the coupler is fixed to the protective substrate and molded.
Even after manufacturing, many inspections such as loss measurement, polarization measurement, heat screening, etc. are required.

The optical fiber used in this method requires a lot of inspections such as loss measurement, polarization measurement, and thermal screening even after manufacturing, so that it has a considerable length for connection with the measurement system. For example, an optical fiber having a length of several meters is required, and it takes time and effort to connect the optical fiber to a light source and a measurement system such as a power meter. The manufacturing equipment also becomes large. In the case of an optical fiber coupler manufactured by using a multi-fiber tape fiber, a wire number difference may occur at the time of connection, and the connection work requires a considerable time.

When the manufactured optical fiber coupler is used, the optical fiber for manufacturing the coupler needs a length of several meters because of the necessity of connecting with other optical parts. Connection work with fibers and optical components is not easy.
It is cumbersome to move around a few meters of optical fiber,
The optical fiber may be damaged.

FIG. 5 shows an optical fiber of an optical fiber coupler to which a connector is attached. In the figure, 1 is an optical fiber, 2 is a connector, 4 is a coupler section, 10 is a protective case,
7 is a fixing resin. The manufacturing process of this optical fiber coupler is performed by removing a part of the coating as described in FIG.
The optical fiber 1 of the book is fused and drawn to form the coupler portion 4,
Protective case 1 on both sides of coupler 4 with resin 7 for fixing
Adhesively fixed to 0. Then, after cutting the optical fiber to an appropriate length, the connectors 2 are attached to both ends to complete the optical fiber coupler.

Since this optical fiber coupler has connectors attached to both ends, connection after manufacturing is easy, but in consideration of the length, which is easy to attach the connector to the manufactured optical fiber coupler. The optical fiber needs to be cut.

The optical fiber coupler described in JP-B-5-44004 employs a structure in which the coupler portion is adhered and fixed to the main body of the protective case, and then the multi-fiber connectors are fixed on both sides thereof. Therefore, it is a compact optical fiber coupler, and by fixing the multi-core connector,
The connection with the optical fiber is easy and the connection work is simple. However, since the optical fiber coupler is fixed by the protective case main body and further fixed by the multi-core connector, the optical fibers are fixed at two positions on each side of the coupler unit, and the optical fiber fixing at the two positions is fixed. There is a possibility that local bending may occur in the optical fiber at a location, and there is also a problem that it is difficult to obtain characteristics.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides an optical fiber coupler which can be easily connected to a measurement system, optical parts, and the like, and is excellent in storability. And to provide a method for producing the same.

[0010]

The present invention provides a method of manufacturing an optical fiber coupler in which a coupler portion obtained by fusion-spreading a plurality of optical fibers is fixed to a protective case to manufacture an optical fiber coupler, A protective case having a precisely positioned optical fiber fixing groove and configured to be connectable to an optical connector is used, and after fixing the coupler portion to the fixing groove, the end face is polished.

A multi-core tape fiber is used as the optical fiber, and at least a portion of the protective case for accommodating the coupler portion is bored so that the coupler portion does not come into contact with the protective case. The protective case has a guide pin mounting portion, and the optical fiber fixing groove is positioned with respect to the guide pin mounting portion.

Further, according to the present invention, in an optical fiber coupler, a coupler portion formed by fusion-spreading a plurality of optical fibers is housed in a protective case, and the protective case is connectable to an optical connector. It is characterized by that.

The protective case has at least a portion for accommodating the coupler portion bored therein so that the coupler portion is accommodated without coming into contact with the protective case, and the protective case has a guide pin mounting portion. However, the optical fiber fixing groove is also positioned with respect to the guide pin mounting portion.

[0014]

According to the method of manufacturing an optical fiber coupler of the present invention, the protective case for protecting the coupler portion formed by fusion-spreading has the optical fiber fixing groove precisely positioned and can be coupled with the optical connector. By being configured into
Since the protective case itself can be directly connected to the optical connector, it can be easily connected to the measurement system, optical parts, and the like. After fixing the coupler part in the fixing groove, by polishing the end surface,
The coupling loss can be reduced.

Further, in the protective case, at least a portion for accommodating the coupler part is bored so that the coupler part does not come into contact with the protective case, thereby realizing necessary optical characteristics and preventing a temperature change. The impact can be dampened. If the optical connector connected to the protective case is of a type that can be positioned by the guide pin, the optical fiber fixing groove of the protective case can be accurately positioned with respect to the guide pin mounting part to achieve accurate coupling. is there.

In the optical fiber coupler according to the present invention, the protective case accommodating the coupler portion is configured to be connectable to the optical connector, so that the optical fiber coupler can be connected to the measurement system after manufacturing or to the optical fiber or the optical component. Is easy to connect.

[0017]

1 is a perspective view of an embodiment of a protective case used in a method of manufacturing an optical fiber coupler according to the present invention.
In the figure, 1 is a case body, 2 is a lid, 3 is an optical fiber fixing groove, 4 is a guide pin fixing groove, and 5 is a boring portion.

The case body 1 and the lid body 2 are made of a material suitable for precision processing, such as glass, ceramics or silicon. A material having a small coefficient of thermal expansion is preferable. An optical fiber fixing groove 3 and a guide pin fixing groove 4 are formed near both ends of the case body 1. In this embodiment, the shape of each groove is the diameter of the optical fiber and the diameter of the guide pin. It is a V-groove suitable for. Further, since the 2 × 2 coupler is accommodated, the optical fiber fixing groove 3 has two ends on both sides.
One by one. The central portion of the case body 1 is scooped to form a boring portion 5. The boring portion 5 may be only a portion where the coupler portion is located, or may not necessarily be provided.

The optical fiber fixing groove 3 is formed so as to be accurately positioned with respect to the guide pin fixing groove 4.
If the optical connector does not perform positioning by the guide pin, the guide pin fixing groove 4 is not always necessary. In that case, the optical fiber fixing groove 3 is precisely positioned on the end surface of the case body.

After the optical fiber coupler is housed in the case body 1, the lid body 2 is fixed with an adhesive so as to cover it. It is preferable that the lid body 2 is provided so as to cover the coupler section at a minimum. Of course, as shown in the figure, the case body 1 may be provided so as to cover the entire body, but it is preferable to design in consideration of the shape of the optical connector.

FIG. 2 is an explanatory view of an embodiment of a method of housing the optical fiber coupler in the main body case. 2A is a perspective view, and FIGS. 2B and 2C are top views. In the figure, the same parts as those in FIG. Reference numeral 6 is a coupler portion, and 7 is a fixing resin.

As shown in FIGS. 2A and 2B, the optical fiber portion of the optical fiber coupler is placed in the optical fiber fixing groove 3, the fixing resin 7 is attached, the lid is covered, and the adhesive fixing is performed. Then, the optical fiber extending outward from the case body 1 is cut in the vicinity of the end face of the case body 1, and the end face is polished as shown in FIG. 2C, and the protective case itself is used as a connector. Is manufactured. Note that the lid is not shown in FIG. 2 (C).

FIG. 3 is for explaining another embodiment of the optical fiber coupler of the present invention. FIG. 3 (A) is an end view of the second embodiment and FIG. 3 (B) is a third embodiment. It is an end view of an example. In the figure, the same parts as those in FIGS. 1 and 2 are designated by the same reference numerals and the description thereof will be omitted. Reference numeral 8 is an optical fiber, and 9 is a guide pin. In the second embodiment, the guide pin 9 is fixed in the circular hole. In the third embodiment, by using an eight-core tape fiber, two adjacent optical fiber core wires are fused and drawn two by two to form a coupler section. Optical fiber 8 of each coupler
Was housed in a case body having eight optical fiber fixing grooves 3 formed therein, and each optical fiber 8 was fixed in each optical fiber fixing groove 3. In this embodiment, four optical fiber couplers are housed in the case body 1. In both the second and third embodiments, the case main body is covered with the lid body 2, but the optical fiber is fixed with an adhesive and the lid body 2 is adhered at the same time.
After that, the end faces may be polished.

When the optical fiber coupler is housed and fixed in the case body, the optical fiber is clamped in the drawing stage, and when the drawing is completed, the case body is kept clamped in the drawing stage. If the clamp is removed after the adhesion is completed and the adhesion is completed, there is an advantage that it can be fixed to the protective case while maintaining the characteristics at the end of stretching.

[0025]

As is apparent from the above description, according to the present invention, it is possible to manufacture an optical fiber coupler in which the protective case also serves as a connector. Therefore, the optical fiber is excellent in storability and easily modularized. A coupler can be obtained. There is an advantage that the connection work with the measurement system can be facilitated after manufacturing and the connection is easy even during use.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of a protective case used in a method for manufacturing an optical fiber coupler according to the present invention.

FIG. 2 is an explanatory diagram of an example of a method of housing an optical fiber coupler in a main body case.

FIG. 3 is an end view for explaining another embodiment of the optical fiber coupler of the present invention.

FIG. 4 is a configuration diagram for explaining an example of a conventional method of manufacturing an optical fiber coupler.

FIG. 5 is a schematic view of an example of a conventional optical fiber coupler.

[Explanation of symbols]

 1 Case Main Body 2 Lid 3 Optical Fiber Fixing Groove 4 Guide Pin Fixing Groove 5 Bore 6 Coupler 7 Fixing Resin 8 Optical Fiber 9 Guide Pin

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Nobuhiro Yokomachi, No. 1 Taya-cho, Sakae-ku, Yokohama, Kanagawa Sumitomo Electric Industries, Ltd. Yokohama Works (72) Hidetoshi Ishida No. 1 Taya-cho, Sakae-ku, Yokohama, Kanagawa Sumitomo Electric Industry Co., Ltd. Yokohama Works

Claims (7)

[Claims] 1. An optical fiber coupler manufacturing method for manufacturing an optical fiber coupler by fixing a coupler section obtained by fusion-spreading a plurality of optical fibers to a protective case, wherein the optical fiber is precisely positioned. A method of manufacturing an optical fiber coupler, which comprises using a protective case having a fixing groove configured to be connectable to an optical connector, fixing the coupler portion in the fixing groove, and polishing the end face. 2. The method of manufacturing an optical fiber coupler according to claim 1, wherein a multi-core tape fiber is used as the optical fiber. 3. The optical fiber coupler according to claim 1, wherein the protective case has at least a portion for accommodating the coupler section, and the coupler section does not come into contact with the protective case. Manufacturing method. 4. The protective case has a guide pin mounting portion, and the optical fiber fixing groove is positioned with respect to the guide pin mounting portion. A method for manufacturing the optical fiber coupler described in. 5. An optical fiber, characterized in that a coupler portion formed by fusion-spreading a plurality of optical fibers is housed in a protective case, and the protective case is connectable to an optical connector. Coupler. 6. The optical device according to claim 5, wherein the protective case has at least a portion for accommodating the coupler portion bored therein, and the coupler portion is accommodated without coming into contact with the protective case. Fiber coupler. 7. The optical fiber according to claim 5, wherein the protective case has a guide pin mounting portion, and the optical fiber fixing groove is positioned with respect to the guide pin mounting portion. Coupler.