JP2002228877A - Optical connector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical connector which performs positioning by using a guide pin and a guide hole and has a reduced connection loss when connecting the optical connector. SOLUTION: The optical connector is provided with a ferrule 3A which has an optical fiber housing hole and a pair of guide holes 11 for inserting the guide pin for positioning, and an optical fiber housed in the optical fiber housing hole. The ferrule 3A is a synthetic resin molding, and has a Young's modulus of 10 to 18 GPa. The end of the optical fiber is projected from the cementation end surface of the ferrule 3A by 1 μm or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical connector used for connecting optical fibers.

[0002]

2. Description of the Related Art One of the methods for connecting the ends of optical fibers is to convert the ends of the optical fibers into connectors.
When converting the ends of the optical fiber into connectors, a component called a ferrule is used as a member for positioning and fixing the ends of the optical fibers, facilitating the positioning of the ends, and maintaining the connection state. As a connector standard using a ferrule, an MT connector, an MPO connector, and the like are generally known. As such a connector, a connector described in Japanese Patent Application Laid-Open No. 10-186175 is known.

When connecting optical fibers, it is necessary to position the cores at the center of the optical fibers with high precision. In these MT connectors and MPO connectors, a guide hole and a guide hole are required to position each other. Pins are used. A pair of guide holes are formed in the connection end face of each connector, and positioning of the pair of optical connectors is performed by inserting guide pins into these guide holes. However, the ferrule is manufactured by resin molding or the like, and the pitch between the pair of guide holes may slightly vary due to shrinkage after molding.

[0004]

In a pair of optical connectors to be connected, if there is a difference between the pitch of one of the guide holes and the pitch of the guide pins into which the guide holes are inserted, the guide holes are formed by the guide pins, especially the opening of the guide hole. In some cases, extra force is applied to the periphery. As a result, the periphery of the guide hole is lost, and the optical fiber is damaged by the debris, or the debris is caught between the connection end faces and the PC (Physical Cont.
act) There is a risk that connection will be hindered. Even if the periphery of the opening is not lost, if the periphery of the opening is deformed such as swelling toward the connection end face side, it also causes a hindrance to PC connection.

The inventors have studied to solve these problems, and have invented an optical connector which can realize more excellent performance. An object of the present invention is to provide an optical connector that performs positioning using a guide pin and a guide hole and that can further reduce connection loss at the time of connector connection.

[0006]

According to a first aspect of the present invention, there is provided a ferrule having a pair of guide holes into which an optical fiber receiving hole and a positioning guide pin are inserted, and an optical fiber received inside the optical fiber receiving hole. With fiber,
The ferrule is a resin molded product made of a synthetic resin, has a Young's modulus of 10 to 18 GPa, and is characterized in that the end of the optical fiber protrudes by 1 μm or more from the joint end surface of the ferrule.

[0007] The invention described in claim 2 is the first invention.
In the invention described in (1), the synthetic resin constituting the ferrule is a polyphenylene sulfide resin.

[0008] The invention described in claim 3 is the first invention.
In the invention described in the above, in the ferrule, the filler is 60 to 80
% By weight.

[0009] The invention described in claim 4 is the invention according to claim 3.
In the invention described in (1), each of the guide holes is formed with a chamfered portion on the joint end surface side.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical connector according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing the appearance of the optical connector of the present embodiment. FIG. 1A shows a state before the optical connectors are connected, and FIG. 1B shows a state where the optical connectors are connected.

In FIG. 1, optical connectors 1A and 1B are
This is an MPO connector, wherein the optical connector 1A is configured as a connector without guide pins, and the optical connector 1B is configured as a connector having guide pins 12. Such optical connectors 1A and 1B are detachably connected via an adapter 2.

The optical connector 1A has a ferrule 3A. The ferrule 3A has a single-core optical fiber core or a multi-core (eight in this case) optical fiber tape core 4A.
Is assembled. The optical connector 1B is a ferrule 3B
An optical fiber ribbon 4B having the same number of cores as the optical fiber ribbon 4A is attached to the ferrule 3B. These ferrules 3A, 3B
Are housed in the housings 5A and 5B, respectively.
2 to 5 show a specific configuration of the ferrule 3A.

In these figures, the ferrule 3A is
It has eight optical fiber receiving holes 7 extending inward from a connection end face (front end face) 6 to be joined to the mating optical connector 1B. The optical fiber accommodating hole 7 communicates with a tape core wire accommodating hole 9 via an optical fiber introducing groove 8. When assembling the optical fiber ribbon 4A to such a ferrule 3A, the tape core 4A is inserted into the tape core receiving hole 9 from the rear end face side of the ferrule 3A, and is exposed from the leading end of the tape core 4A. The eight optical fibers are inserted into the optical fiber receiving holes 7.

The optical fiber is fixed to the ferrule 3A by filling the opening 10 formed on the upper surface of the ferrule 3A with an adhesive. After the tape core 4A is assembled to the ferrule 3A in this manner, the front end face 6 of the ferrule 3A is at an angle of 8 degrees with respect to a plane perpendicular to the central axis of the optical fiber receiving hole 7 (angle α in FIG. 4). (However, optical fibers are not shown in FIGS. 4 and 5). At the time of this polishing, if the tip of the optical fiber is also polished to 8 degrees in the same manner, with the connector connected,
The effect of reflected return light due to Fresnel reflection or the like is reduced.

Alternatively, the connecting end face 6 is formed so as to form the above-mentioned 8 degrees from the beginning, and the optical fiber is fixed by protruding from the end of the optical fiber receiving hole 7. In some cases, the distal end surface of the optical fiber is polished so as to be perpendicular to the central axis of the optical fiber receiving hole 7. If the tip of the optical fiber slightly projects from the connection end face 6 after polishing, so-called PC (Physical Contact) connection can be performed to reduce connection loss. At the time of polishing, a portion of the connection end face may be polished so as to be perpendicular to the central axis of the optical fiber housing hole 7.

A pair of guide holes 11 are formed on both sides of the optical fiber receiving hole 7 so as to extend inward from the front end face 6 of the ferrule 3A in parallel to the optical fiber receiving hole 7. A guide pin 12 (described later) provided on the optical connector 1B is inserted into the guide hole 11.

The ferrules 3A and 3B forming a part of the guide hole 11 are formed with a chamfered portion 13 at the opening edge on the front end face 6 side, and the opening of the guide hole 11 is formed on the front end face 6 side. It is getting wider. By forming the chamfered portion 13 in this manner, it is possible to prevent PC connection failure and damage to the end of the optical fiber due to the lack of the end of the guide hole 11, and to deform the end of the guide hole so as to rise toward the connection end surface 6. By doing so, effects such as prevention of poor PC connection and improvement of insertability can be obtained. In addition, although any method may be used to form the above-described chamfered portion 13, in the present embodiment,
After the guide hole 11 having a constant inner diameter is once formed, the end is ground by a drill and formed. If possible, the chamfered portion 13 may be formed by a mold at the time of molding the ferrule.

The ferrules 3A and 3B are resin molded products made of synthetic resin, and are formed of a material having a Young's modulus of 10 to 18 GPa. Ferrule 3A, 3B Young's modulus is 10
Therefore, even if a force is applied to the inner surface of the guide hole 11 by the guide pin 12, the guide hole 11 can be slightly elastically deformed and the guide hole 11 itself can be prevented from being damaged. If the Young's modulus is less than 10 GPa, it is too elastically deformed, so that the function of positioning the optical connectors, which is the original function of the guide pin 12 and the guide hole 11, cannot be performed with high accuracy. On the other hand, Young's modulus is 18GPa
If it exceeds, the guide hole 11 is less likely to be elastically deformed, and the guide hole 11 is easily damaged.

The synthetic resin used for the ferrules 3A and 3B includes epoxy resin and polyphenylene sulfide resin (hereinafter referred to as PPS).
Abbreviated as resin). However, as the synthetic resin used for the optical connector of the present invention, it can be seen that the PPS resin is suitable for the following reasons. PPS resin is superior in polishing property to other synthetic resins, is advantageous for protrusion polishing of fibers, has good moisture absorption resistance, and realizes stable characteristics in environmental tests.

By using these PPS resins and epoxy resins, the Young's modulus in the above range can be realized. If the chamfered portion 13 is formed around the opening of the guide hole 11 as described above, the guide hole 1
The amount of elastic deformation when absorbing the pitch difference between the pin 1 and the guide pin 12 can be reduced, and the connection loss can be further reduced.

Further, here, the end face of the optical fiber protrudes from the connection end face 6 by 1 μm or more. Even after the optical fiber is fixed, the tip of the optical fiber can be made to protrude from the connection end face 6 by utilizing a difference in hardness between the ferrule and the optical fiber, for example, by polishing the optical fiber together with the joint end face 6. It is possible. By projecting the optical fiber from the connection end face 6, the optical fiber can be connected to the PC when the optical connector is connected. The PC connection absorbs the surface sagging of the connection end face 6 and the irregular position of the end face of the optical fiber in the case of a multi-core connector, so that the connection can be made with less loss.

Further, here, ferrules 3A and 3B
Contains 60 to 80% by weight of a filler. By using the filler in such a range, the above-described Young's modulus can be easily realized. Usually, silica or the like is used as the filler.

The ferrule 3 of the other optical connector 1B
B is the optical connector 1 as shown in FIGS.
A has the same structure as the ferrule 3A of A,
The guide pin 12 is inserted and fixed in the guide hole 11 of B. At this time, the guide pin 12 is fixed to the ferrule 3B in a state where the guide pin 12 is inserted into the guide hole 11 so as to protrude from the front end face 6 by about 2 mm. Ferrule 3B of optical connector 1B and ferrule 3 described above
The difference from A is only the presence / absence of the guide pin 12, and a detailed description of the ferrule 3B is omitted.

The present invention is not limited to the above embodiment. For example, the optical connector of the above embodiment is
Although the present invention is an MPO connector, the present invention is not particularly limited thereto, and can be applied to other types of optical connectors such as an MT connector. Further, in the above embodiment, the optical connector with the guide pin and the optical connector without the guide pin are connected, but the present invention is not particularly limited to this, and the optical connectors without the guide pin are connected to each other. The present invention can also be applied to a type in which two guide pins are used for connection.

[0026]

According to the present invention, since the ferrule has a Young's modulus of 10 to 18 GPa, the guide hole is slightly elastically deformed even if a force is applied to the inner surface of the guide hole by the guide pin. Damage to the hole itself can be avoided. As a result, it is possible to prevent an increase in connection loss due to damage to the guide hole.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an external appearance of an optical connector using an embodiment of an optical connector ferrule of the present invention.

FIG. 2 is a plan view of a ferrule of the optical connector without guide pins shown in FIG. 1;

FIG. 3 is a front view of a connection end face side of the ferrule shown in FIG. 2;

FIG. 4 is a sectional view taken along line IV-IV of FIG. 2;

FIG. 5 is a sectional view taken along line VV of FIG. 2;

FIG. 6 is a plan view of a ferrule of the optical connector with guide pins shown in FIG. 1;

FIG. 7 is a sectional view taken along line VII-VII of FIG. 6;

[Explanation of symbols]

1A, 1B: Optical connector, 3A, 3B: Ferrule, 4
A, 4B: optical fiber ribbon, 6: connection end face (front end face), 7: optical fiber accommodation hole, 11: guide hole, 11a
... 1st hole, 11b ... 2nd hole, 12 ... guide pin, 1
3 ... Chamfer part.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tomohiko Ueda 1 Tayacho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture Sumitomo Electric Industries, Ltd. Yokohama Works (72) Inventor Toshiaki Kakii 1-Tagamachi, Sakae-ku, Yokohama-shi, Kanagawa Sumitomo Electric Ki Kogyo Co., Ltd. Yokohama Works F-term (reference) 2H036 QA18 QA26 QA50

Claims (4)

[Claims] A ferrule having a pair of guide holes into which an optical fiber receiving hole and a positioning guide pin are inserted;
An optical connector comprising: an optical fiber housed inside the optical fiber housing hole; wherein the ferrule is a resin molded product made of a synthetic resin;
An optical connector having a Young's modulus of 10 to 18 GPa, wherein an end of the optical fiber protrudes by 1 μm or more from a joint end face of the ferrule. 2. The optical connector according to claim 1, wherein the ferrule is made of a polyphenylene sulfide resin as the synthetic resin. 3. The optical connector according to claim 1, wherein the ferrule contains 60 to 80% by weight of a filler. 4. The optical connector according to claim 3, wherein a chamfer is formed on each of the guide holes on the side of the joint end face.