JPH1152180A - Cylindrical body for ferrule and ferrule - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to easily obtain good workability and fixing strength to an optical fiber by constituting a cylindrical body of ceramics approximately uniformly having a hole having a specific diameter. SOLUTION: The material of the cylindrical body 11 for a ferrule is not particularly limited and is adequately the ceramics, such as, for example, partially stabilized zirconia. The holes in the ceramic forming the cylindrical body 11 for the ferrule are approximately uniformly formed and the diameter thereof is preferably 0.1 to 5 μm. The holes are formed within the ceramic in such a manner, by which the workability may be improved. The working accuracy may be improved to order of 0.1 μm and the cylindrical body 11 for the ferrule may be finished to the high accuracy in accordance with this improvement in the workability. The inner peripheral surface of the optical fiber insertion hole 12 is made unsmooth by the holes exposed on the surface and, therefore, the strength of adhesion is improved by an anchor effect.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ferrule cylindrical body and a ferrule for fixing an end of an optical fiber.

[0002]

2. Description of the Related Art At present, in an optical connector used for communication, an optical fiber is inserted and fixed in a ferrule in which an inner diameter and an outer diameter are processed with high precision, and an end face of a connection portion is formed into a convex spherical shape. Polishing is performed so that the optical fibers are physically brought into contact with each other and connected. FIG. 3 shows a cross section of a conventional ferrule on which an optical fiber is mounted.

As shown in FIG. 3, a ferrule 101 is
Ferrule cylindrical body 102 and stainless steel collar 1
03. Ferrule Tubular Body 102
Is usually manufactured by filling a mixture of a ceramic powder such as zirconia and a binder powder and a binder powder into a mold having a predetermined shape, firing the mixture, and then grinding the mixture into a predetermined size. Moreover, it may be manufactured by extrusion molding or the like.

The ferrule cylindrical body 102 thus formed has an optical fiber insertion hole 104 through which the optical fiber 201 from which the coating at the end of the optical fiber core 202 has been removed is inserted. The optical fiber insertion hole 104 generally has a diameter of 125 μm of the optical fiber 201 from which the coating has been removed.
Is a diameter having a clearance of about 1 μm, and a through hole having a length of about 10 mm. In addition, the collar 103 is a through hole 10 into which the optical fiber core 202 is inserted.
9 Such a collar 103 is connected to the ferrule cylindrical body 1.
The ferrule 101 is configured by connecting and fixing the ferrule 101 to the ferrule 101.

In order to connect and fix the ferrule 101 to the end of the optical fiber 202, the optical fiber 202 is inserted into the through hole 109 of the collar 103 of the ferrule 101, and the optical fiber 201 is inserted into the optical fiber. Hole 1
04 and is fixed by an adhesive previously filled in the optical fiber insertion hole 104 and the through hole 109. The ferrule 101 thus assembled
Is the end face of the ferrule cylindrical body 102 connected to the optical fiber 20.
After being polished together with the optical connector 1, for example, it is incorporated into an optical connector.

[0006]

However, the ferrule cylindrical body 102 used for the above-mentioned conventional ferrule 101 is extremely hard because it is formed of ceramic such as zirconia, and the optical fiber insertion hole 104 cannot be processed. There is a problem that it is very difficult. Further, in order to form the optical fiber insertion hole 104 having a predetermined size and no bending in the ferrule cylindrical body, it is necessary to polish the inner peripheral surface. As a result, the inner peripheral surface is formed smoothly. Also, there is a problem that it is difficult to obtain an adhesive strength when the optical fiber is bonded and fixed with an adhesive.

Further, in order to obtain a predetermined fixing strength, it is necessary to form the ferrule insertion hole 104 relatively long so as to increase the contact area between the optical fiber 201 and the ferrule cylindrical body 102. This further causes the polishing of the ferrule insertion hole 104 to be difficult. In view of such circumstances, an object of the present invention is to provide a ferrule cylindrical body and a ferrule which have good workability and can easily obtain a fixing strength with an optical fiber.

[0008]

According to a first aspect of the present invention, there is provided:
A ferrule cylindrical body having an optical fiber insertion hole into which an optical fiber is inserted, and having a diameter of 0.1 μm to 5 μm.
A ferrule cylindrical body comprising a ceramic having m holes substantially uniformly. A second aspect of the present invention is the ferrule tubular body according to the first aspect, wherein the ceramic is made of partially stabilized zirconia.

According to a third aspect of the present invention, there is provided a ferrule cylindrical body according to the first or second aspect, and an optical fiber insertion hole into which an optical fiber whose outer periphery is coated is inserted. And a collar member connected and fixed to one end of the ferrule cylindrical body. In such a ferrule cylindrical body or ferrule of the present invention, pores formed inside the sintered body are formed with a predetermined size and substantially uniformly during firing. As a result, the workability is relatively improved, and a hole also appears on the inner peripheral surface of the fiber insertion hole, so that the adhesive strength with the optical fiber is improved.

[0010] The material of the ferrule cylindrical body is not particularly limited, and any conventionally used material may be used. For example, ceramics such as partially stabilized zirconia are suitable. The pores inside the ceramic forming the ferrule cylindrical body are formed substantially uniformly, and have a diameter of 0.1.
It is preferable that it is from μm to 5 μm. This is because if it is smaller than this, the above-mentioned effects are hardly exhibited, while
If it is larger than this, an abrasive or the like enters the pores, which is not preferable. The number of holes is not particularly limited, but is preferably formed to be about 25 holes / mm 2.

As described above, by forming holes in the ceramics, the workability can be improved, and with the improvement of the workability, the processing accuracy can be improved to the order of 0.1 μm. The ferrule cylindrical body can be finished with high precision. Also, since the inner peripheral surface of the optical fiber insertion hole is not smooth due to the hole that has emerged on the surface,
The bonding strength is improved by the anchor effect.

In order to produce such a ceramic having pores having a predetermined diameter uniformly, the particle size of the ceramic as a raw material, the particle size of the binder, the mixing ratio, and the temperature, time, etc., of the preliminary firing and firing are required. What is necessary is just to adjust suitably. For example, zirconia is used as a raw material in an amount of 12 to 14 wt%.
And a firing temperature of 1300 to 140
The firing may be performed at 0.5 ° C. within 0.5 to 3 hours. Note that the firing temperature is preferably about 100 ° C. lower than the firing temperature that does not cause voids. When 100% alumina (Al2O3) is used as a raw material, the firing may be performed at a lower firing temperature of about 100 to 200C.

[0013] The ferrule cylindrical body of the present invention is not limited to a simple cylindrical body in outer shape, but has a chamfered portion formed at least at one end, and has a predetermined shape such as a chamfered shape. It refers to one processed into a conical shape or a convex spherical shape. The same applies to a ferrule using this. This ferrule is used for an optical connector or the like after the optical fiber is bonded and fixed and then polished into a convex spherical shape.

[0014]

FIG. 1 is a sectional view of a ferrule to which an optical fiber according to an embodiment of the present invention is attached, and FIG. 2 is a perspective view showing a state in which the optical fiber is adhered and fixed to the ferrule of the present embodiment. FIG. Ferrule 1 of the present embodiment
Numeral 1 has a substantially cylindrical shape and has an optical fiber insertion hole 12 in the longitudinal direction.

The ferrule cylindrical body 11 of the present embodiment comprises:
Fill zirconia powder as a raw material into a mold of a predetermined shape,
It is formed by heating at 150 ° C., then firing at a high temperature of 1400 ° C., and finally grinding to a predetermined size. The sintered body thus obtained is
Voids having a diameter of about 1 μm were uniformly contained. Therefore, the outer peripheral surface processing and the ferrule insertion hole processing in the final stage could be performed relatively easily. This processing time was about 85% of that of a conventional zirconia sintered body having substantially no pores.

The ferrule cylindrical body 11 thus formed is made of stainless steel and has a fitting hole 22 as shown in FIG.
The ferrule 10 is combined with a flange 21 formed with a through hole 23 into which an optical fiber core wire is inserted. At this time, the tip portion is ground into a predetermined shape, for example, a shape in which a circumferential portion is chamfered, or a convex spherical surface, a conical shape, or the like. It was about 80% of that of the zirconia sintered body having no holes.

Thereafter, the optical fiber core wire 32 is inserted through the through hole 23 of the collar 21, and the optical fiber 31 is inserted through the optical fiber insertion hole 12, and the adhesive previously filled in the optical fiber insertion hole 12 and the through hole 23 is used. Optical fiber 3 by 41
1 and the optical fiber core 32 are bonded and fixed, and the tip is polished to a convex spherical surface. In addition,
Needless to say, the collar 21 can be applied not only to stainless steel but also to a ferrule in which the collar 21 is integrally molded with the cylindrical body 11 with plastic.

The adhesive strength of the optical fiber 31 bonded and fixed to the optical fiber insertion hole 12 is such that the adhesive enters the hole exposed on the inner peripheral surface of the optical fiber insertion hole 12 and the anchor effect works. Notably improved. This adhesive strength was improved by about 30% as compared with the case of the conventional zirconia sintered body having no pores. As a result, even when the length of the optical fiber insertion hole 12 was reduced from 9.5 mm to 6 mm, sufficient adhesive strength could be secured.

[0019]

As described above, according to the present invention,
By forming the ferrule cylindrical body using ceramics having holes substantially uniformly, it is possible to achieve excellent workability and improve the fixing strength. Further, since the fixing strength can be easily obtained, the length of the optical fiber insertion hole can be shortened, and the processing is further facilitated. Therefore, the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a ferrule cylindrical body of the present invention.

FIG. 2 is a perspective view showing a use state of the ferrule of the present invention.

FIG. 3 is a sectional view of a conventional ferrule.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Ferrule 11 Ferrule cylindrical body 12 Optical fiber insertion hole

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shigeru Watanabe 6-4-6 Kameido, Koto-ku, Tokyo

Claims (3)

[Claims] 1. A ferrule cylindrical body having an optical fiber insertion hole into which an optical fiber is inserted, wherein the ferrule cylindrical body is made of ceramics having a hole having a diameter of 0.1 μm to 5 μm substantially uniformly. Ferrule cylindrical body. 2. The ferrule cylindrical body according to claim 1, wherein the ceramic is made of partially stabilized zirconia. 3. The ferrule cylinder according to claim 1 or 2, wherein an optical fiber core insertion hole for inserting a coated optical fiber core on the outer periphery of the optical fiber is formed, and the ferrule cylinder. A ferrule comprising a brim member connected and fixed to one end of the body.