JPH0743554A - Optical connector and its manufacture - Google Patents

Abstract

PURPOSE:To provide an optical connector and its manufacture capable of performing PC connection even when it is a multi-fiber optical connector. CONSTITUTION:In the optical connector 1 comprised of an optical connector ferrule 4 capable of fixing an optical fiber, an optical fiber 5 fixed on the optical connector ferrule 4, and an adhesive with which the optical fiber 5 is fixed on the optical connector ferrule 4, and which optically connects the optical fiber on the fiber fixed on another optical connector by bringing the end face of the optical fiber into contact with that of the optical connector, the coupling side 6 of the optical connector 1 is formed with an end face 6a for coupling on which the end face of the optical fiber 5 is fixed by positioning and a non- contact end face 6b being inclined against the end face 6a for coupling, and at least a part of the end face 6a for coupling is brought into contact with at least a part of the end face 6b for coupling of another connector 1 when optical coupling is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical connector for connecting an optical fiber and a manufacturing method thereof.

[0002]

2. Description of the Related Art In an optical connector for connecting an optical fiber, (1) reduction of reflected return light at the connection point (reduction of reflection), and (2) back reflection or scattering due to reflection at the connection point Therefore, it is necessary to reduce the light that does not propagate to the light receiving side (reduction loss).

For this reason, physical contact (PC) coupling (direct contact coupling between end faces of optical fibers) has been studied for single-core connectors. For example, Japanese Patent Laid-Open No. 61-13.
A polishing plate for an optical connector as disclosed in Japanese Patent No. 7107 has been developed.

On the other hand, FIG. 13 shows an example of a multi-fiber optical connector of the guide pin coupling type. The multi-fiber optical connector 01 shown in FIGS. 13A and 13B has two guide pin holes 02 each penetrating in the optical fiber axial direction, and the guide pins 03 are provided in these guide pin holes 02. Optical coupling is achieved by inserting and abutting the coupling end faces 04 where the end faces of the optical fibers are positioned and arranged. It should be noted that the pair of optical connectors 01 coupled in this way
Is sandwiched by grips 07 provided with plate spring portions 06 at both ends of the plate member 05 and stably held.

In such a multi-core connector, it is difficult to connect all the cores to a PC. Therefore, conventionally, in order to achieve low reflection, an attempt has been made to obliquely polish and connect the end faces. However, since the reflection loss cannot be eliminated by this method, the optical connectors are currently coupled with each other by interposing an index matching agent having a refractive index substantially the same as that of the core of the optical fiber between the end faces of the optical fiber.

However, in such a connection in which a refractive index matching agent is interposed between the end faces of the optical fiber, the refractive index matching agent must be applied without fail, which is disadvantageous in terms of workability and handling. There is also a problem that dust easily mixes between the end faces of the fiber.

For this reason, studies have been made on a coupling method that does not use a refractive index matching agent even in a multi-core connector. Japanese Patent Laid-Open No. 4-34403 discloses a method in which a resin film having a refractive index close to that of the core is provided on the end face of the optical connector and the optical connectors are connected to each other through the resin film.

[0008]

However, in the method of providing the resin film having the refractive index close to that of the core on the end surface of the optical connector as described above, a thin resin film exists on the end surface of the optical connector. It lacks long-term reliability against repeated attachment and detachment, and is also disadvantageous in corrosion resistance. Also,
If the thickness of the resin film is increased in order to improve the reliability, there is a problem in that the loss of coupling increases.

[0009] Therefore, even in a multi-core connector, a technique capable of PC-coupling the whole core as well as the single core is desired. However, in the multi-fiber connector, it is difficult to stably project only the optical fiber by controlling the conditions for polishing the entire surface of the ferrule.

In view of such circumstances, it is an object of the present invention to provide an optical connector capable of realizing PC coupling even with multiple fibers and a manufacturing method thereof.

[0011]

SUMMARY OF THE INVENTION To achieve the above object, the present invention provides an optical connector ferrule capable of fixing an optical fiber, an optical fiber fixed to the optical connector ferrule, and the optical fiber as the optical connector ferrule. An optical connector, which comprises an adhesive for fixing, and which optically couples the optical fiber with the fiber fixed to the other optical connector by bringing the end face into contact with the end face of the other optical connector. The side end face is composed of a coupling end face on which the end face of the optical fiber is positioned and fixed, and a non-contact end face inclined to the coupling end face, and at the time of optical coupling, at least a part of the coupling end face is connected to another optical connector. An optical connector is characterized in that it is brought into contact with at least a part of a coupling end face.

An optical connector ferrule capable of fixing an optical fiber, an optical fiber fixed to the optical connector ferrule, and an adhesive for fixing the optical fiber to the optical connector ferrule are provided, and the end face on the coupling side is the above-mentioned. The optical fiber has an end face for positioning in which the end face of the optical fiber is positioned and a non-contact end face that is inclined with respect to the end face for coupling, and the end face for coupling is brought into contact with the end face of another optical connector, and the optical fiber A method of manufacturing an optical connector for optically coupling an optical fiber fixed to another optical connector, wherein a coupling-side end face is inclined with the first end face serving as the coupling end face and the first end face, and Molding the optical connector ferrule having a second end surface which is a non-contact end surface, and fixing the optical fiber to the optical connector ferrule with an adhesive. , First the optical connector ferrule
And a step of polishing the end face to form the coupling end face.

[0013]

In the optical connector of the present invention, at least a part of the coupling end faces of the coupling side end faces may be brought into contact with each other.
PC coupling between optical fibers is easy.

As described above, in order to facilitate the PC coupling of the optical fiber when the optical connector is coupled, it is effective to reduce the contact area between the end faces when coupling the optical connector. As a result, (1) the amount of deformation of the end face becomes large, so that PC coupling is easy even if the end face of the optical fiber does not protrude from the optical connector ferrule. (2) Even if the end face of the optical fiber is slightly (about 1 μm), the optical connector ferrule This is because if it protrudes from the end face, it is less likely to be affected by the angle deviation.

[0015]

EXAMPLES The present invention will be described below based on examples.

FIG. 1 shows an optical connector according to a first embodiment of the present invention, (A) is a perspective view and (B) is a longitudinal sectional view thereof. As shown in FIG. 1, an optical connector 1 is an optical connector ferrule in which a plurality of (four in this embodiment) optical fiber fixing holes 2 and a pair of fitting pin holes 3 for fixing an optical fiber are formed. 4 and an optical fiber 5 fixed to the fiber fixing hole 2 of the optical connector ferrule 4 with an adhesive. The end face 6 on the coupling side of the optical connector 1
Is a coupling end face 6a that is substantially orthogonal to the optical axis of the optical fiber 5.
And a non-contact end surface 6b inclined with respect to the optical axis,
The end face of the optical fiber 5 is the non-contact end face 6 of the coupling end face 6a.
It is positioned and fixed between the pair of fitting pin holes 3 on the b side (the central portion in the thickness direction of the optical connector 1). The distance d between the boundary between the coupling end face 6a and the non-contact end face 6b and the center of the end face of the optical fiber 5 is 0.25 mm in this embodiment.

In this optical connector 1, as shown in FIG. 2, the coupling end faces 6b are made to face each other so that they are opposite to each other, and a part of the coupling end face 6a on the non-contact end face side is brought into contact with each other. The optical fibers 5 are PC-coupled to each other. A good result was obtained with an average connection loss of 0.16 dB and a PC ratio of about 90%.

An example of manufacturing the optical connector 1 will be described with reference to FIG. First, an optical connector ferrule 4 having a fitting pin hole (not shown) and a fiber fixing hole 2
Is integrally molded by transfer molding using an epoxy resin containing a glass filler as a filler (step (a)
). Next, a part of the coupling-side end face 6 in the thickness direction (the outside from a position 0.25 mm away from the center of the fiber fixing hole 2 in the thickness direction) is polished, and this inclined surface is made the non-contact surface 6b. (Step (b)). Then, the four optical fibers 5 are fixed to the fiber fixing holes 2 with an adhesive (step (c)). Finally, the end face of the optical fiber 5 perpendicular to the optical axis is polished by three steps, for example, rough polishing (diamond # 2000), medium polishing (diamond lapping film # 5000), and final polishing (polishing with cerium oxide). Is 50
The end face for bonding 6a is polished to a size of not more than μm (step (d)). In this manufacturing example, the polishing for forming the non-contact surface 6b was performed before the optical fiber 5 was coupled,
It may be performed after joining, or may be integrally formed at the time of molding.

FIG. 4 shows an optical connector according to a second embodiment of the present invention, (A) is a perspective view and (B) is a longitudinal sectional view thereof. As shown in FIG. 4, the optical connector 11 is
An optical connector ferrule 14 having a plurality of (four in this embodiment) optical fiber fixing holes 12 and a pair of fitting pin holes 13 for fixing optical fibers, and for fixing the optical connector ferrule 14 to the fiber. The optical fiber 15 is fixed to the hole 12 with an adhesive. This optical connector 1
The coupling-side end face 16 of No. 1 is a coupling end face 16a that is inclined so that the inclination angle θ that is an angle formed with the optical axis of the optical fiber 15 is approximately 85 °, and the non-contact end face 1 that is orthogonal to the optical axis.
6b, and the end face of the optical fiber 15 is positioned and fixed between the pair of fitting pin holes 3 on the non-contact end face 16b side of the coupling end face 16a (the central portion in the thickness direction of the optical connector 11). In addition, the coupling end surface 16a and the non-contact end surface 16b
In the present embodiment, the distance d between the boundary between and and the center of the end face of the optical fiber 15 is 0.25 mm.

As shown in FIG. 5, the optical connector 11 is made to face each other so that the coupling end faces 16a are on opposite sides, and a part of the coupling end face 16a on the non-contact end face side is brought into contact with each other. The optical fibers 15 are PC-coupled to each other. In addition, like the optical connector 11, the coupling end surface 16a is
By inclining the optical fiber 15 so that the angle formed with the optical axis is 85 ° or less, in the first embodiment, the reflected light at the connection point that has returned to the light source side when the PC comes off can be prevented. The effect that can be obtained can be obtained.

An example of manufacturing the optical connector 11 will be described with reference to FIG. First, an optical connector ferrule 14 having a fitting pin hole (not shown) and a fiber fixing hole 12 is integrally molded by transfer molding using an epoxy resin containing a glass filler as a filler (step (a )). Next, the four-core optical fiber 15 is fixed to the fiber fixing hole 12 with an adhesive (step (b)). Finally,
Part of the coupling-side end surface 16 of the optical fiber 15 in the thickness direction (0.25 mm from the center of the fiber fixing hole 12 in the thickness direction).
The inner side from the distant side; the side on which the optical fiber 15 is fixed) is polished in the same manner as in the above-mentioned embodiment, and the inclined surface is used as the coupling end surface 16a, and the rest is used as the non-contact surface 16b (step (c)). ). Since the polishing area at this time is small, the polishing amount p can be set to 30 μm or less, for example. In this embodiment, since the polishing amount p can be reduced in this way, the connection loss can be reduced.
When 20 optical connectors 11 of this example were evaluated, the average of connection loss was 0.17 dB, and the PC ratio was 90% or more, which was good. In this manufacturing example, the coupling end face 16a is formed after the optical fiber 15 is coupled. However, the coupling end face 16a is formed by forming an inclined surface during molding or after polishing, then fixing the optical fiber 15 and then polishing. Is also good.

Another example of manufacturing the optical connector 11 will be described with reference to FIG. First, a fitting pin hole (not shown) and a fiber fixing hole 12 are provided, and the coupling side end face 1 is provided.
An optical connector ferrule 14 in which a part in the thickness direction of 6 (inward from the peripheral edge in the thickness direction of the fiber fixing hole 12; the side where the fiber fixing hole 12 exists) is an inclined surface is used as a glass filler as a filler. Are integrally molded by transfer molding using an epoxy resin containing (step (a)).

The state of molding at this time is shown in FIG. Figure 8
As shown in FIG. 2, on both sides of the resin injecting portion 21 in the upper die 22 and the lower die 23 forming the resin injecting portion 21 for molding the optical connector ferrule 14, there are respectively a fiber fixing hole and a fitting pin. A slider 24 with a molding pin for slidably holding a pin for forming a use hole and a V groove base 25 having a V groove for supporting the tip end of the molding pin of the slider with a molding pin 24 are provided. ing. In such a configuration, the slider 2 with the molding pin
The molding pin 4 is slid until its tip is supported by the V groove of the V groove base 25, resin is injected into the resin injection portion, and after the resin is hardened, the molding pin is slid in the opposite direction to remove the mold. Thereby, the optical connector ferrule 14 can be obtained. In this example, in order to facilitate the demolding, the slanted surface was formed as the slanted surface up to the fiber fixing hole which is the central portion in the demolding direction. It can also be molded to a large size.

Then, as shown in FIG. 7, the four-core optical fiber 15 is fixed to the fiber fixing hole 12 with an adhesive (step (b)). Finally, the inclined surface is ground as in the above-described embodiment to form the coupling end surface 16a, and the rest is the non-contact surface 16
b (step (c)). In this embodiment, since the polishing amount can be further reduced, the connection loss can be reduced and the polishing time can be shortened significantly. When 20 optical connectors 11 of this example were evaluated, the average connection loss was 0.18 dB, and the PC ratio was 90% or more, which was good.

FIG. 9 shows an optical connector according to a third embodiment of the present invention, (A) is a perspective view and (B) is a longitudinal sectional view thereof. As shown in FIG. 9, the optical connector 31 is
An optical connector ferrule 34 having a plurality of (four in this embodiment) optical fiber fixing holes 32 and a pair of fitting pin holes 33 capable of fixing optical fibers, and for fixing the optical connector ferrule 34 to the fiber. An optical fiber 35 fixed to the hole 32 with an adhesive. This optical connector 3
The coupling-side end face 36 of No. 1 is a coupling end face 36a that is inclined so that the inclination angle θ that is an angle formed by the optical axis of the optical fiber 35 is approximately 85 °, and a non-contact end face 36b that is inclined in the opposite direction.
And the end face of the optical fiber 35 is the end face 36 for coupling.
It is positioned and fixed between the pair of fitting pin holes 33 on the non-contact end face 36b side of a (the central portion in the thickness direction of the optical connector 31). The distance d between the boundary between the coupling end face 36a and the non-contact end face 36b and the center of the end face of the optical fiber 35 is 0.25 mm or less in this embodiment.

As shown in FIG. 10, the optical connector 31 is made to face each other so that the coupling end faces 36a are opposite to each other, and a part of the coupling end face 36a on the non-contact end face side is brought into contact with each other. The optical fibers 35 are PC-coupled.

The optical connector 31 can be manufactured according to the above-described manufacturing examples, but especially the end face 3 for coupling.
This is useful when the 6a and the non-contact end surface 36b are formed by molding. This is because the shape of this ferrule is close to a symmetric shape, so that it is unlikely to be affected by molding shrinkage or warpage of the resin.

In each of the optical connectors described above, since at least a part of the coupling end faces of the coupling side end faces may be brought into contact with each other, it is easy to couple the optical fibers to each other by PC.
Further, since the polishing amount after molding is smaller than that of the conventional one, the connection loss due to polishing is less reduced. This point will be further described. In the optical connector ferrule manufactured by ordinary molding, the fiber fixing hole is bent due to the influence of tree pressure and resin contraction. This state is shown in FIG. In the optical connector ferrule 42 having the thus bent fiber fixing hole 41, the position 42a before polishing and the position 42b after polishing are different. That is, when the bonding end surface 43 is polished, as shown in FIG.
As shown in (B), the post-polishing position 42b is displaced from the pre-polishing position 42a, which leads to an increase in connection loss. Therefore, as shown in FIG. 12, an optical connector ferrule 52 having a fiber fixing hole 51 is molded (step (a)), and then the coupling-side end face 53 is obliquely polished (step (b)). When 54 is fixed (step (c)) and then the coupling-side end surface 53 is further polished, the total polishing amount p is about 100 μm, and the connection loss increases.

[0029]

As described above, in the optical connector of the present invention, at least a part of the coupling end faces of the coupling side end faces may be brought into contact with each other, so that the optical fiber can be easily PC-coupled. Further, since the polishing amount after molding is smaller than that of the conventional one, the connection loss due to polishing is less reduced.

[Brief description of drawings]

FIG. 1 shows an optical connector according to a first embodiment of the present invention, (A) is a perspective view and (B) is a sectional view thereof.

FIG. 2 is a cross-sectional view showing a coupled state of optical connectors according to the first embodiment of the present invention.

FIG. 3 is a schematic view showing one manufacturing example of the optical connector according to the first embodiment of the present invention.

FIG. 4 shows an optical connector according to a second embodiment of the present invention, (A) is a perspective view, and (B) is a sectional view thereof.

FIG. 5 is a cross-sectional view showing a coupled state of optical connectors according to a second embodiment of the present invention.

FIG. 6 is a schematic view showing one manufacturing example of the optical connector according to the second embodiment of the present invention.

FIG. 7 is a schematic view showing another manufacturing example of the optical connector according to the second embodiment of the invention.

FIG. 8 is a schematic diagram showing a state of molding an optical connector ferrule of an optical connector according to a second embodiment of the present invention.

9 (A) is a perspective view and FIG. 9 (B) is a sectional view showing an optical connector according to a third embodiment of the present invention.

FIG. 10 is a cross-sectional view showing a coupled state of optical connectors according to a third embodiment of the present invention.

FIG. 11 is a schematic diagram illustrating a bent state of a fiber fixing hole of an optical connector ferrule.

FIG. 12 is a schematic view showing an example of a manufacturing process of a conventional optical connector.

FIG. 13 is a schematic diagram showing a coupled state of a multi-fiber optical connector.

[Explanation of symbols]

 1, 11, 31 Optical connector 2, 12, 32 Fiber fixing hole 3, 13, 33 Fitting pin hole 4, 14, 34 Optical connector ferrule 5, 15, 35 Optical fiber 6, 16, 36 Coupling side end surface 6a , 16a, 36a End face for coupling 6b, 16b, 36b Non-contact end face

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Toru Yamanishi Toru Yamanishi 1 Taya-cho, Sakae-ku, Yokohama-shi, Kanagawa Sumitomo Electric Industries, Ltd. Yokohama Works (72) Ichiro Tsuchiya 1 Taya-cho, Sakae-ku, Yokohama-shi, Kanagawa Sumitomo Electric Ki Industry Co., Ltd. Yokohama Works (72) Inventor Toshiaki Kakii 1 Taya-cho, Sakae-ku, Yokohama-shi, Kanagawa Sumitomo Electric Industries Co., Ltd. Yokohama Works (72) Inventor Shinji Nagasawa 1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo No. Japan Telegraph and Telephone Corporation

Claims (4)

[Claims] 1. An optical connector ferrule capable of fixing an optical fiber, an optical fiber fixed to the optical connector ferrule, and an adhesive for fixing the optical fiber to the optical connector ferrule, the end face of which is made of other material. In an optical connector that optically couples the optical fiber and a fiber fixed to the other optical connector by contacting with the end face of the optical connector, the coupling-side end face of the optical connector is positioned and fixed to the end face of the optical fiber. Consisting of a connecting end face and a non-contacting end face inclined with this connecting end face,
An optical connector, wherein at least a part of the coupling end face is brought into contact with at least a part of the coupling end face of another optical connector during optical coupling. 2. The connecting end surface according to claim 1,
An optical connector characterized in that an angle formed by the optical axis of the optical fiber is 85 ° or less. 3. An optical connector ferrule capable of fixing an optical fiber, an optical fiber fixed to the optical connector ferrule, and an adhesive for fixing the optical fiber to the optical connector ferrule. The optical fiber has an end face for positioning in which the end face of the optical fiber is positioned and a non-contact end face that is inclined with respect to the end face for coupling, and the end face for coupling is brought into contact with the end face of another optical connector, and the optical fiber A method for manufacturing an optical connector for optically coupling an optical fiber fixed to the other optical connector,
A first end face having a coupling side end face as the coupling end face and the first end face;
Mold-molding the optical connector ferrule having an end face of the second connector and a second end face that is inclined and becomes the non-contact end face.
An optical connector comprising: a step of fixing the optical fiber to the optical connector ferrule with an adhesive; and a step of polishing a first end surface of the optical connector ferrule to form the coupling end surface. Production method. 4. The connecting end surface according to claim 3,
An optical connector manufacturing method characterized in that an angle formed with an optical axis of the optical fiber is 85 ° or less.