JPS6163804A - Production of multicore optical connector and ferrule - Google Patents

Abstract

PURPOSE:To obtain a highly accurate multicore optical connector reduced at its transmission loss by using a ferrule obtained by inserting an optical fiber core into a metallic pipe to be the coupling part of the ferrule, collectively molding them with resin and then dividing a molded unit. CONSTITUTION:A 5-core tape-like core 2, e.g., is set up in a stainless metal pipe 11, set-up units are set up in a metal mold 12 and epoxy resin 13 or the like is injected to mold them collectively. The mold is cut off at a core welding 16 part on its center part and the cut surfaces are ground to obtain a pair of ferrules. The coupling parts 8 of the pair of ferrules 6 are inserted into a sleave 7 and both collar parts 9 are supported by a fixing housing member 10 so as to be pressed. Thus, highly accurate joint can be attained and an optical connector and ferrules which are reduced at the transmission loss and cost are obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an optical connector for single-mode fibers and multi-core optical fibers that require high-precision coupling.

[Problems with the prior art] Figure 7 shows the 7-work rule of a basic conventional optical connector for single-mode fibers. The ferrule 3 of the sleeve is provided with a gap part 9, and the optical fiber C:' wire 1 and the optical fiber glass part 2 whose coating is partially removed can be inserted into the central axis of the ferrule 3 in a corresponding manner. Open the hole, insert and secure the optical fiber 1, and polish the optical fiber glass part 2 protruding from the tip of the ferrule 3 to form one tX mating end face. For example, a pair of ferrules 3 to which an optical fiber core 1 is fixed are
A sleeve □ having the same inner diameter as the outer diameter of the ferrule 3 is inserted from both ends and the joining surfaces of both ferrules 3 are brought together to form an optical connector.

When such a configuration is adopted, the eccentricity of the hole needs to be made as small as possible with respect to the outer diameter of the failrail 3, for example, 2.5++ mφ, which results in an extremely high cost. .

FIG. 8 shows the basic configuration of a ferrule portion of a multi-core optical connector. 4 indicates a multi-core ferrule, and 5 indicates a pin guide hole. In accordance with the ferrule explained in FIG. 7, a thin diameter section following the large diameter section is inserted into the ferrule 4, into which the optical fiber core 1 and a plurality of optical fibers □ fiber glass sections 2 with partially removed coatings are inserted. Provided in a stepped insertion hole, the multi-core optical fiber core 1 is inserted and fixed into the stepped insertion hole, and the tip of each optical fiber glass portion 2 is made to protrude, for example, from the narrow diameter hole arranged in a straight line, The end faces of the pair of ferrules 4 to which the multi-core optical fibers are fixed are aligned by polishing the protruding end faces, and the ferrules 4 are provided in advance in the same direction as the arrangement direction of the optical fibers 1. The two opposing ferrules are positioned by passing pins through the plurality of bottle guide holes 5, and then tightened by a fixing housing to form an optical connector.

Furthermore, what is the optical fiber from which the cracks have been removed in the present invention?

Generally speaking, this refers to a lighting fiber, but in the present invention, removing the coating means removing the coating that causes instability in the positioning of the optical fiber. If the optical fiber is coated with a thin film of ~IOμm, or even a 200μm coating layer, it is in close contact with the bare optical fiber, and there is no need to remove the coating in that area if there is no problem with positioning. Needless to say.

In this case as well, the positional relationship between the hole into which the optical fiber is inserted and the guide hole is important, and the machining at a height of 11 degrees requires two steps, which poses a cost-based problem.

In addition, the area of 2 sets of optical connector ferrules for one optical fiber is approximately 51 mm per fiber.
1. Multi-core (5-core) optical connector ferrule approximately 10 am”
And for the optical fiber core area 0,6 +n'',
Both are about 10 times larger (larger), and there is also a problem in terms of miniaturization of optical connectors.

[Purpose of the Invention, Configuration] The present invention provides a simple and low-cost optical connector with low transmission loss and high precision when configuring an optical connector by combining ferrules with optical fiber cores as described above. The tl configuration is that in an optical connector that couples the ends of optical fibers, the ferrule that is coupled via the sleeve is provided with a plurality of coupling parts, and the ferrule is equipped with the plurality of coupling parts. As will be described later, the ferrule is characterized in that it is made by dividing a resin-molded body into which a cored optical fiber is commonly inserted into the metal pipe of the ferrule.

Fig. 1 (A) shows an exploded view of the main (M) component of the optical connector of the present invention, Fig. 1 (I') shows the top surface of the ferrule, and (
C) indicates a fixing housing, and C) indicates the overall i11 standing state. In 0 Eve, 8 indicates a +U number of ferrule joints made of a metal pipe, and the ferrule 6 includes the joint 8 of the IM h, One fiber optic cable! ! It is integrally formed with the IX9, the insertion portion 9' of the optical fiber core 1, etc. by resin molding. In this case, the resin mold allows the multi-core optical fiber 1 to be molded into a metal mold together with the ferrules that form a pair as an optical connector, as will be described later. The removed optical fiber glass portion is fixed in place.

In the figure, the optical fiber core 1 is a tape-type optical fiber, but any type of multi-core optical fiber may be used. For example, one of the ferrules may be a multi-fiber tape core, and the other may be of a single-fiber bundle type.

A metal pipe having such a plurality of coupling parts 8 is attached to an end position of the metal pipe forming the coupling parts 8 through a ferrule sleeve 7 which holds the end surfaces of a plurality of optical fiber glass parts fixedly. 8ζ, and by engaging the fixing member IO consisting of a spring 10A as shown in the figure (c) with both the flange portions 9, the optical connector is assembled as shown in the figure (b). configured.

The fixing housing member 10 is not only made of a spring material as described above, but may also be made of a plurality of parts so as to constantly apply force in the axial direction of the fiber.

The figure (1) shows a ferrule with 3 cores and 2 joints, but Figure 2 (, fl, <2), (I→, (→, ke), (to) shows a ferrule with a multi-core arrangement. An example is shown below.)
As shown in the figure, it may be a single-fiber arrangement, or as shown in (e) and (f), it can be configured as a ferrule with a multi-fiber arrangement coupling part containing three-dimensional three-dimensional optical fibers in parallel directions. You can also do it.

It has been confirmed that with such a configuration, for example, up to 20 cores can be accommodated in a 2.5+++φ ferrule.

FIG. 3 is an explanatory diagram of a method for manufacturing a ferrule including an optical fiber core according to the present invention.

In the figure, 12 is a top view of the molding die, for example 2
It is formed into two parts. This mold 12 is, for example, 1111
To manufacture the pair of ferrules shown in Figure 1,
It is provided with an enlarged surface capable of forming a ferrule including a pair of optical fibers, such as an optical fiber core, a collar portion, an optical fiber insertion portion, and a metal pipe support portion. Each Df +U of the multi-core optical fiber core wire 1 is removed by -;■ to expose the optical fiber glass portion 2, and this exposed optical fiber glass portion 2 is covered to be common to the pair of ferrules. Insert the metal pipes 11 so that The parts are taken out of the mold, the mold 12 is put together, and a mold resin 13, for example, epoxy/resin is placed inside the mold 12. Although mold gates, pipe holes, etc. are omitted here, as shown in FIG. It is also a good idea to use a metal pipe 11 with an uneven or threaded surface on its inner surface.
Bonding with the resin is in the direction of -11.

By injecting mold resin 13 into the mold, both all-metal vibes 11 are integrally combined with the two collar parts, and the metal pipe 1
The optical fiber coated wire 1 is fixed to the metal pipe 11 in a state in which the space between the optical fiber coated wire 1 and the optical fiber coated wire 1 is sufficiently filled with resin.

The batch molded body molded with the mold resin as described above is taken out from the mold, cut at the metal pipe 11 portion, and the end surface of the optical fiber glass portion is polished at the cut end surface of the metal pipe II. For example, a ferrule is formed that connects two or more optical fibers, which are then used as a pair of optical connectors.

In this case, erroneous connections can be prevented by using metal pipes forming the joint portions that have different diameters for each ferrule and the corresponding joint portions having the same diameter. Further, during molding, a mark may be added to clearly indicate the bonding direction.

A pair of sleeves 7 shown in FIG. 1(A) are inserted into a pair of ferrules configured as described above, with the connecting portions 8 of both ferrules corresponding to the two sleeves 7, respectively. As already explained, if the fixed housing member 10 is supported so as to press between the two ribs S1,
An optical connector is configured.

When using the sleeve, as shown in Figure 5,
7) The storage housing 14 provided with the two sleeves 7 may be integrally manufactured by resin molding.
Alternatively, a metal sleeve with a slot or a ceramic sleeve may be used.

Also, as shown in Figure 3, there is a concave hole in a part of the metal pipe.
5 may be used. If such a shape is used, there will be no problem even if there is a metal / Practically speaking, it would be better to fusion-splice the optical fiber glass plate 92 in advance and insert the one having the front part 1B. It may be cut and divided except for the fusion P.
Dividing is performed by cutting at two places at 3 to 5 points with I (IG in between) and removing the fused d part.

As can be understood from the ferrule manufacturing method of the present invention explained above, in the present invention, the optical fiber glass portion 2 from which one skin has been removed is fixed to the metal pipe 11 with molded resin, and then cut. , When connecting as an optical connector thereafter, both cross sections obtained by the above-mentioned cutting will almost match. This is because the ferrule has at least two metal pipes formed integrally with the brim etc. using molded resin, and this metal pipe extending in the axial direction of the optical fiber conducts positioning during connection. This is because it is greatly involved.

In the previous explanation, we have described two wooden metal pipes each equipped with optical fiber cores or multi-core optical fibers, but one is not equipped with optical fiber cores and is used only for the purpose of positioning. It is also possible to use Furthermore, it is also possible to have a configuration in which the number of joints using metal pipes is increased. Furthermore, the ferrule arrangement does not necessarily need to be horizontal. In this case, the mold may be split in the axial direction.

[Example] [[11.8 An example of an optical connector with two 5-fiber tape core wires having a thickness of O and S-1 will be described.

The coating was removed by 20-■ and the stainless steel outer diameter was 2.4! +
Set in a metal pipe of 99±Q, tJQIsmφ,
Batch molding is performed using low-pressure epoxy resin in a mold, the molded body is taken out from the mold, cut at the center, and the end surfaces are polished to form an inner surface of 2.49Gth0.00 as shown in Figure 5.
The coupling loss was evaluated by passing it through a housing storage type sleeve of 1 dragon diameter.

In total fi1077) optical connector (51L, lx2x reave x 10), i.e. 100 optical fibers,
Using matching agent, average 0.23dB, maximum 0.5
A very low t-mouth loss coupling of 2dB1 maximum of 1lsO,03dB was achieved.

At this time, Director Tsuba has adopted 7 dragons.

Further, as shown in FIG. 6, since the ferrule coupling portion projects eccentrically with respect to the collar, incorrect coupling in the reverse direction can be easily confirmed.

For fixing the ferrule, a fixing song shown in FIG. 1 (c) was used. Furthermore, in the embodiment, a rubber boot for protecting the core wire is attached to the rear of the optical connector ferrule.

Similarly, when three single-mode fibers were molded into ferrules and evaluated, good results were obtained with an average of 0.20 dB for a total of 1 (1 optical connector) using a matting agent.

[Effect] According to the present invention, optical fibers (glass portions) that will later be optically connected are fixed to the metal pipes by batch resin molding in a plurality of metal pipes. It is possible to perform optical connections for each optical fiber at a position that is almost the same as in bulk resin molding, and requires special consideration in molding and placement of multiple optical fibers (glass parts). Therefore, it is possible to obtain an optical connector with extremely low transmission loss.

Taking the example of 2.5@IIφ as an example, in an optical connector that includes a 1G optical fiber in two ferrule diameters of 2.5m-φ, the area per fiber core is l.
-■8 and the conventional 115°~1/1G density.゛Also, the single mode fiber has three cores inside the ferrule, and similarly the conventional 3G'j j:
'+1 The density has increased to 11. The average coupling loss of conventional single-type optical connectors was only 0.6 dB, which could only be achieved even with the use of matching agents.
In the present invention, 0.20 dB could be easily achieved. These points are as stated at the beginning of this section. For example, as in the conventional system shown in FIG. 8, in the present invention, a metal pipe having a plurality of multi-core fibers fixedly performs positioning without using a guide pin for positioning.
Therefore, the size of the brim itself can be reduced, and the shape can be reduced.

Regarding the connection, all that is needed is a sleeve and a fixing housing, and the cost can be reduced by two times with a single +i configuration.

In addition, the sleeves are made easier to work with by integrating multiple sleeves using a housing.

4. Drawing) ITiT! 11 Explanation Figure 1 shows an embodiment of the present invention, (A) Figure 1 shows the framework of the main optical connector 5il (Figure J1 is a hemostatic diagram of the ferrule, (C) Figure shows the fixing housing, ( Figure 1 shows an assembled diagram.

Figure 2 (A), (I:I), (C), Zeng, (E)
, (f) shows a ferrule equipped with the multi-core optical fiber of the present invention, and (b) shows the same C11-core ferrule.

FIG. 3 is an explanatory diagram of the manufacturing method of the present invention.

FIG. 4 shows a metal pipe that serves as a ferrule joint.

FIG. 5 shows a storage housing with a molded sleeve.

FIG. 6 shows an example of a ferrule with which the bonding direction can be identified.

FIG. 7 shows a ferrule configuration of a conventional optical connector for a single-mode fiber.

FIG. 8 shows a seven-erule configuration of a conventional optical connector for multi-core optical fibers.

DESCRIPTION OF SYMBOLS 1... Optical fiber core wire, 2... Optical fiber glass part, 3... Single-core ferrule, 4... Multi-core ferrule, 5/0 pin guide hole, 6...° ferrule, 7... Sleeve , 8... Ferrule coupling part, 9... Brim part, 1G
... Fixed housing, 11 ... Metal pipe, 12
...Metal pipe, 13...Mold resin, 14...
・Mold storage housing.

Figure 11 (d) 2 large fertilizers 7?3 figure

Claims (9)

[Claims] (1) In an optical connector that couples the ends of optical fibers, a pair of ferrules that are coupled via a sleeve are each provided with a plurality of corresponding coupling parts, and the pair of ferrules equipped with the plurality of coupling parts include: A multi-fiber optical connector characterized by using a ferrule that is made by dividing an integral molded body in which optical fiber core wires are inserted into a metal pipe that serves as a joining part of the ferrule and then molded with a resin all at once. (2) The multi-core optical connector according to claim 1, characterized in that metal pipes of different diameters are used. (3) The multi-core optical connector according to claim 1, wherein the pair of ferrules is provided with a mark indicating the coupling direction or has a shape indicating the coupling. (4) The multi-core optical connector according to claim 1, characterized in that the metal pipe has a recessed portion at a portion of its outer diameter, and is divided by the recessed portion. (5) A multi-core optical connector according to any one of claims 1 to 4, characterized in that a plurality of sleeves are housed in one housing as the sleeve. (6) In manufacturing ferrules for optical connectors that connect the ends of optical fibers, multiple metal pipes are placed in a mold, and optical fibers with a portion of the coating removed are inserted into the pipes and placed in a predetermined position. After molding the optical fiber and metal pipe together with resin, the middle of the metal pipe is cut,
A method for manufacturing a ferrule for a multi-core optical connector, characterized by simultaneously manufacturing a pair of ferrules for an optical connector. (7) The method for manufacturing a ferrule for a multi-core optical connector according to claim 6, wherein the metal pipe through which the optical fiber is inserted has a groove or a hole. (8) The method for manufacturing a ferrule for a multi-core optical connector according to claim 6, wherein the optical fiber from which a portion of the coating has been removed is fusion-spliced in advance. (9) A method for manufacturing a ferrule for a multi-fiber optical connector according to any of claims 6 to 8, wherein the ferrule is divided and cut by removing the fused portion.