JPH0237308A - Connector type optical fiber coupler and production thereof - Google Patents

Abstract

PURPOSE:To necessitate the smaller space for housing by providing a ferrule provided with an optical fiber coupler in a connector and butting the polished surfaces to which the core of an optical fiber is exposed by a pair of the ferrule half bodies, thereby bringing the polished surfaces into contact with each other. CONSTITUTION:This coupler is constituted by butting a pair of the ferrule half bodies 8 which are fixed with the optical fiber 4 and are formed with the polished surfaces 7 exposed with the core 6 or the part near the core 6 of the optical fiber 4 on the butt surface 5 against each other to bring the respective polished surfaces into contact with each other and to constituted to ferrule 3 and disposing this ferrule into the connector. Branching and coupling of light are executed by the front end part of the ferrule 3. The integration of the connector and the optical fiber coupler 1 is possible in this way. The optical device having the optical fiber coupler 1 is thus miniaturized.

Description

Detailed Description of the Invention "Field of Industrial Application" The present invention relates to an optical fiber coupler used in optical fiber sensors, optical communication equipment, etc. to branch or combine light within an optical fiber into multiple beams. In particular, the present invention relates to a connector-type optical fiber coupler in which an optical fiber coupler is provided inside the connector.

"Conventional technology" Conventionally, optical couplers (optical couplers) branch and couple light.
As such, an optical module, an optical coupler having a substrate type waveguide structure, an optical fiber coupler, etc. are used.

Among these, optical modules have a large loss when branching or combining light, so it has been difficult to use them for the purpose of obtaining a low-loss optical coupler. Also,
The above-mentioned optical coupler having a substrate type thick wave path structure has a problem in that it is expensive due to the large number of manufacturing steps.

On the other hand, the above-mentioned optical fiber coupler has a relatively simple structure and can be lowered in price, and also has a low loss. It has been widely used as an optical coupler to branch and couple light.

An example of such an optical fiber coupler is a polished type optical fiber coupler, which has a structure in which two optical fibers, each of which has a polished surface formed by polishing a part of the optical fiber, are joined with each polished surface in contact with each other. Also known is a fusion-stretched optical fiber coupler in which a fusion-stretched portion is formed in a portion of two optical fibers.

``Problems to be Solved by the Invention'' However, when applying the above-mentioned optical fiber coupler to optical communication devices, optical fiber sensors, etc., the optical fiber coupler must be used on a substrate for embedding and fixing polished optical fibers or by long fusion splices. Because the extension part is provided, not only does the storage space for the entire optical fiber coupler become large, but when attaching a connector to the lead part of the optical fiber coupler for connection to other optical fibers,
A larger storage space is required, which poses a problem of increasing the size of the optical device equipped with the optical fiber coupler.

The present invention has been made in view of the above circumstances, and aims to provide a connector-type optical fiber coupler that can reduce storage space and a method for manufacturing the same.

"Means for Solving the Problem" As a means for achieving the above-mentioned object, the invention described in claim 1 is a connector-type optical fiber coupler in which a ferrule provided with an optical fiber coupler is provided in the connector, The ferrule is formed by a pair of ferrule halves, each of which has an optical fiber fixed thereon and a polished surface exposing the core or the vicinity of the core of the optical fiber on the abutting surface, and the polished surfaces of the two halves are brought into contact with each other. It is something.

Further, as a manufacturing method of the above-mentioned connector type optical fiber coupler, as in the invention described in claim 2, a part of the optical fiber to be fixed is formed so as to bulge toward the abutting surface side with another ferrule. An optical fiber is fixed in the groove of the base body having a groove formed by the ferrule, and then the abutting surface is polished to form a polished surface exposing the core of the optical fiber or a portion near the core, thereby forming a ferrule half. A preferred method is to then join a pair of ferrule halves by abutting their abutting surfaces and bringing their polished surfaces into contact to form a ferrule, and then placing the ferrule in the connector.

1.A pair of ferrule halves in which an optical fiber is fixed and a polished surface exposing the core or the vicinity of the core of the optical fiber are formed on the abutting surfaces, and the polished surfaces are brought into contact with each other. The ferrule has a function as an optical fiber coupler that branches and couples light at the contact area where each polished surface makes contact, and a connector-type optical fiber coupler with this ferrule installed inside the connector is It can be used as an optical fiber coupler by connecting a connector to an optical fiber.

Embodiment FIGS. 1 to 3 are diagrams showing an embodiment of the invention set forth in claim 1, and reference numeral 1 indicates a connector type optical fiber coupler.

This connector type optical fiber coupler 1 has a connector body 2
A cylindrical ferrule 3 having the function of an optical fiber coupler is provided inside.

The ferrule 3 is a pair of semi-cylindrical ferrules that fix an optical fiber 4 and have a polished surface 7 on the tip of the abutting surface 5 that has been polished to the center of the optical fiber 4 to expose the core 6. The ferrule halves 8 are butted together and joined with their respective polished surfaces 7, 7 in contact.

Each of the optical fibers 4 extending from the rear end of the ferrule half 8.8 extends a predetermined length from the rear end of the connector body 2, and each forms a lead portion 9.9.

On the other hand, at the tip end surface of the ferrule 3, as shown in FIG. The thick end face 11 is exposed.

The optical fiber 4 may be quartz-based, doped quartz-based,
Single-mode optical fibers, multi-mode optical fibers, graded multi-mode optical fibers, polarization-maintaining optical fibers, etc. made of multi-component or plastic materials are used.

The ferrule half 8 has a semi-cylindrical shape, and an optical fiber 4 is inserted into the groove 13 of the base body 12, which has an arc-shaped groove 13 formed on the abutting surface 5 so that the tip is shallow and the rear end is deep.
is embedded and fixed, and the abutting surface 5 side of the tip of the base body 12 is polished to expose the core 6 of the optical fiber 4.

Connector type optical fiber coupler configured as above
By connecting the ends of the connector body 2 and the two lead parts 9 to other optical fibers to be connected, for example, when light is input from the optical fiber connected to the connector body 2, the incident light is can be branched and taken out from each lead part 9, and when light is incident from each lead part 9, these incident lights can be combined, and the combined light can be taken out from the tip of the ferrule 3. can.

The connector-type optical fiber coupler 1 according to this example can branch and couple light at the tip of the ferrule 3, so the optical fibers to be connected are connected to each of the connector main body 2 and the lead portion 9, and the optical fibers to be connected are It can be used as a fiber coupler, and it is possible to downsize an optical device equipped with an optical fiber coupler.

In the above embodiment, the tip of the optical fiber 4 fixed to the base body +2 was polished to form the polished surface 7. However, the position where the polished surface 7 is formed is not limited to this, and is located at the center of the base body 12. It may be on the rear end side or on the rear end side.

Further, in the above embodiment, the tip of the optical fiber 4 fixed to the base 12 is polished and removed to the center of the optical fiber 4 to form the polished surface 7, but the amount of polishing of the optical fiber 4 is limited to this. It is also possible to expose the vicinity of the core 6 without exposing the core 6.

Next, an example of a method for manufacturing the connector-type optical fiber coupler according to the second aspect of the present invention will be described.

In order to create the connector-type optical fiber coupler 1 shown in FIG. 1 using this example, first, form a semi-cylindrical shape as shown in FIGS. A base body 12 is prepared in which an arcuate groove 13 is formed to become deeper.

Next, an optical fiber 4 is inserted into 1ll13 of this base 12, and an adhesive 14 is further laminated on the abutting surface 5.
As shown in FIGS. 6 and 7, the tip fiber 4 is attached to the base 1.
Fixed at 2.

Next, the abutting surface 5 side of the base 12 to which the optical fiber 4 is fixed is polished. This amount of polishing is calculated from A-A' in Fig. 6.
As shown by the line, the tip fiber 4 at the tip of the base 12 is polished to the center and removed. This polishing operation produces a ferrule half 8 in which a polished surface 7 is formed on the optical fiber 4 at the tip of the base 12.

Next, the pair of ferrule halves 8 produced in the above manner are butted together with a butt that has their respective polished surfaces 7, 7 in contact with each other.
Join with adhesive. By this joining operation, the cylindrical ferrule 3 shown in FIGS. 2 and 3 is produced.

Then, the ferrule 3 produced as described above is placed inside the connector main body 2, and the connector-type optical fiber coupler l shown in FIG. 1 is produced.

In the manufacturing method according to this example, by performing the process of manufacturing an optical fiber coupler and the process of manufacturing a connector at the same time, a connector-type optical fiber coupler l that has both the functions of a connector and an optical fiber coupler can be manufactured with a small number of man-hours. can do.

(Manufacturing example).

Core diameter 8μm1 Clad diameter 125μm1 Covering diameter 400
The coating at one end of a μm silica-based single mode optical fiber was removed, and the removed portion was replaced with a metal base having the same shape as that shown in Fig. 4 (length 8mm+, width of abutting surface 2, 5+mm). The optical fiber was inserted into the groove of the substrate, and an epoxy adhesive was applied to the abutting surface side of the substrate to fix the optical fiber to the substrate.

Next, the abutting surfaces of the substrate were polished to form a polished surface so that the optical fiber at the tip of the substrate was polished down to the center. Next, the two ferrule halves produced by the polishing operation were butted together so that their polished surfaces were in contact with each other, and bonded using an epoxy adhesive. Through the above operations, a ferrule having a configuration equivalent to that shown in FIG. 2 was obtained.

Next, place the obtained ferrule inside the connector body,
A connector-type optical fiber coupler with a configuration equivalent to that shown in FIG. 1 was obtained.

The connector-type optical fiber coupler obtained in the above manner is connected to a light source at the end of the connector as shown in FIG. 8, and at the same time a conventional connector 15.
5 and their ends were connected to a photodetector. Then, light was incident on the connector-type optical fiber coupler from the light source and the optical branching characteristics were measured. As a result, it was confirmed that the incident light was branched into l:l ratio.

"Effects of the Invention" Since the present invention is configured as described above, it produces the following effects.

In the connector type optical fiber coupler according to claim 1,
A connector is a ferrule formed by a pair of ferrule halves in which an optical fiber is fixed and a polished surface exposing the core or the vicinity of the core of the optical fiber is formed on the abutting surface, and the polished surfaces of each half are brought into contact with each other. Since the ferrule has a configuration in which the optical fiber coupler is placed inside the ferrule, and the light can be branched and coupled at the tip of the ferrule, the connector and the optical fiber coupler can be integrated, allowing for the miniaturization of optical devices equipped with the optical fiber coupler. be able to.

In addition, in the invention described in claim 2, by performing the process of manufacturing the optical fiber coupler and the process of manufacturing the connector at the same time, the connector-type optical fiber coupler has the functions of both a connector and an optical fiber coupler with a small number of steps. can be created.

[Brief explanation of the drawing]

1 to 3 are views showing an embodiment of the invention as claimed in claim 1, in which FIG. 1 is a perspective view of a connector-type optical fiber coupler, FIG. 2 is a side sectional view of a ferrule, and FIG. 3 is a front view of the same, FIGS. 4 to 7 are diagrams for explaining the invention in detail in claim 2, FIG. 4 is a side view of the base body, FIG. 5 is a front view of the same, FIG. 6 is a side sectional view showing a state in which the optical fiber is fixed to the base, FIG. 7 is a front view thereof, and FIG. 8 is a configuration diagram for explaining a method for measuring branching characteristics of a connector type optical fiber coupler. l... Connector type optical fiber coupler, 3... Ferrule, 4... Optical fiber, 5-... Butt surface, 6
... Core, 7 ... Polished surface, 8 ... Ferrule half, 12 ... Base, 13 ... Groove.

Claims (2)

[Claims] (1) A connector-type optical fiber coupler in which a ferrule with an optical fiber coupler is provided in the connector, and the ferrule fixes the optical fiber and has the core or the vicinity of the core of the optical fiber on the abutting surface. 1. A connector-type optical fiber coupler, characterized in that it is formed by a pair of ferrule halves formed with exposed polished surfaces and brought together so that the respective polished surfaces are in contact with each other. (2) A part of the optical fiber to be fixed is fixed in a groove of a base body having a groove formed so that it bulges out to the side of the abutment surface with another ferrule, and then the above abutment is made. A ferrule half is formed by polishing the surface to form a polished surface exposing the core of the optical fiber or a portion near the core, and then the pair of ferrule halves are brought into contact with each other by abutting their abutting surfaces. 1. A method of manufacturing a connector-type optical fiber, the method comprising: joining the fibers to form a ferrule; and arranging the ferrule in a connector.