JP3129871B2 - Multi-core optical connector and method of manufacturing the same - Google Patents

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 method for manufacturing the same.

[0002]

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

For this reason, in a single-fiber connector, physical contact (PC) coupling (direct contact coupling between optical fiber end faces) has been studied.
A polishing machine for an optical connector as disclosed in Japanese Patent No. 7107 has been developed.

[0004] On the other hand, in a multi-core connector, it is difficult to couple the whole core to a PC. Therefore, conventionally, in order to reduce the reflection, an attempt has been made to connect the end face by polishing it obliquely. However, since this method does not eliminate the reflection loss, at present, the optical connectors are coupled to each other by interposing a refractive index matching agent having a refractive index substantially equal to that of the core of the optical fiber between the end faces of the optical fiber.

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

For this reason, a study has been made on a coupling method that does not use a refractive index matching agent even in a multicore connector. Japanese Unexamined Patent Publication No. 4-34403 discloses a method in which a resin film having a refractive index close to that of a core is provided on an end face of an optical connector, and the optical connectors are connected to each other via the resin film.

[0007]

However, in the method of providing a resin film having a refractive index close to that of the core on the end face of the optical connector as described above, a thin resin film exists on the end face of the optical connector. It lacks long-term reliability for the coupling operation of the optical connector, and is disadvantageous in corrosion resistance and coupling strength. Further, if the thickness of the resin film is increased to increase the strength of the resin film, there is a problem that the loss of the coupling increases.

Therefore, there is a demand for a technology that allows the entire core to be PC-coupled to a multi-core optical connector as well as a single core. However, multi- fiber optical connectors use optical fibers.
It is difficult to stably project only the optical fiber by controlling the conditions for polishing the entire coupling end face after fixing to the ferrule . In particular, in the material forming the ferrule
Contains filler to stabilize ferrule dimensions
The problem is that this filler tends to protrude from the polishing surface.
Therefore, it is necessary to project only the end face of the optical fiber from the polished surface.
difficult.

In view of such circumstances, an object of the present invention is to provide a multi-core optical connector capable of realizing PC connection even with multiple cores and a method of manufacturing the same.

[0010]

To achieve SUMMARY OF THE INVENTION The above objects the present invention, and the optical connector ferrule that can secure the optical fiber, an optical fiber is fixed to the optical connector ferrule, the optical connector ferrule of the optical fiber consisting of an adhesive for securing the at multifiber optical connector protrudes end faces of the plurality of <br/> optical fiber from the coupling end face of the optical connector ferrule, and the optical fiber of each of the at least projection of the coupling-side end face around have low low-hardness member hardness provided from the optical fiber, multi said low-hardness member is characterized in that it does not protrude from the optical fiber end face
It is in the optical connector.

Further, the optical connector ferrule that can secure the optical fiber, an optical fiber is fixed to the optical connector ferrule, a multi-fiber optical connector comprising a glue for fixing the optical fiber to the optical connector ferrule a method of manufacturing, the step of bonding and fixing a plurality of optical fibers to the optical connector ferrule such that the end face thereof is protruded from the coupling end face of the optical connector ferrule, the optical fiber of each of the at least projection of the coupling-side end face Around
Each As no abrasive comprising the steps of providing a low low-hardness member hardness than optical fiber, said optical connector ferrule
There of the multifiber optical connector manufacturing method characterized by comprising the step of polishing the end face of the optical fiber.

[0012]

In the multi- fiber optical connector of the present invention, only the end face of the optical fiber protrudes from the end face on the coupling side, and a low hardness member is provided at least around the optical fiber on the end face on the coupling side. Is protected by a low hardness member. In addition, filler material is included in the material that forms the ferrule.
So that the ferrule dimensions are stable,
PC connection between optical fiber end faces is ensured even with multiple cores.
You.

In the multi-core optical connector, the optical fiber is adhered and fixed so as to protrude from the end face of the optical connector ferrule, and a low-hardness member is provided at least around the protruding optical fiber on the end face. By polishing the end face of the optical connector so that the end face is not polished, the end faces of all of the plurality of optical fibers can be reliably obtained at once . That is, at the time of polishing, the tip of the optical fiber is protected by the low hardness member, and the tip is polished so that the tip protrudes from the low hardness member.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments.

FIG. 1 shows an example of an optical connector according to the present invention. As shown in FIG. 1, the optical connector 1 includes an optical connector ferrule 2 capable of fixing an optical fiber, and an optical fiber 3 fixed to the optical connector ferrule 2 with an adhesive. Protrudes from the coupling-side end surface of the optical connector ferrule 2, and a low-hardness member 4 having a lower hardness than the optical fiber 3 is provided around the distal end of the optical fiber 3 on the coupling-side end surface.

In this structure, the tip of the optical fiber 3 is made to protrude from the end face on the coupling side of the optical connector ferrule 2 and a low hardness member 4 is provided around the tip, and then the tip of the optical fiber 3 is connected to the low hardness member. 4, the optical connector ferrule 2 can be obtained by polishing so as not to be polished. That is, at the time of this polishing, the optical fiber 3
Since the low-hardness member 4 is more easily shaved than the tip of the optical fiber 3, the low-hardness member 4 does not protrude beyond the end face of the optical fiber 3. If the low-hardness member 4 contains a filler (filler) having a hardness equal to or higher than that of the optical fiber 3, as shown in FIGS. May protrude from the polished end face of the optical fiber 3 by protruding from the low-hardness member 4 and, as shown in FIG. It is desirable that the hardness member 4 does not include a filler having a hardness equal to or higher than that of the optical fiber 3.

Next, a manufacturing example of the present invention will be described with reference to a multi-core optical connector of a guide pin coupling type shown in FIG. The multi-fiber optical connector 11 shown in FIGS. 3A and 3B has two guide pin holes 12 penetrating in the axial direction of the optical fiber.
The optical fibers are optically coupled by inserting the guide pins 13 into the guide pin holes 12 and abutting the coupling end surfaces 14 at which the end surfaces of the optical fibers are positioned and arranged. The pair of optical connectors 11 coupled in this manner is stably held by being sandwiched by clips 17 having plate spring portions 16 provided at both ends of a plate-like member 15.

FIG. 4 shows an example of manufacturing such a multi-core optical connector 11. An epoxy resin containing a filler was used as an optical connector ferrule, a four-core tape fiber was used as an optical fiber, and an epoxy adhesive to which no filler was added was used as an adhesive for fixing an optical fiber. In order to simplify the process, an adhesive for fixing the optical fiber was used as a low hardness member provided around the optical fiber.

As shown in FIG. 4, first, a four-core tape fiber 22 is inserted into an optical fiber insertion hole (not shown) formed in the optical connector ferrule 21, and its tip protrudes from the coupling end face of the optical connector ferrule 21. ((A), (b)). Next, an epoxy-based adhesive 23 is applied from the distal end side of the optical fiber 22, and the optical fiber 22 is bonded and fixed, and is fixed as a low hardness member around the distal end portion ((c)). Thereafter, the tip of the coupling-side end face of the optical fiber 22 is roughly polished (diamond # 2).
000), medium polishing (diamond wrapping film #)
5000) and finish polishing (polishing with cerium oxide) to the point where the coupling-side end face of the optical connector ferrule 21 is not polished, thereby obtaining the optical connector 24 of the present invention ((d)).

The optical connector 24 thus obtained is
As a result of the evaluation, the connection loss was 0.29 dB on average and the reflection was 40.8 dB. In addition, when a test was conducted on the variation in attachment and detachment, a good result of about 0.1 dB was obtained.

FIG. 5 shows another manufacturing example. This manufacturing example is basically the same as the above-described manufacturing example, except that the end face of the optical connector is inclined by 8 ° with respect to a plane orthogonal to the optical axis in order to prevent reflection at the connection point. FIG. 5 shows a side view of the optical connector.

As shown in FIG. 5, first, the coupling end face of the optical connector ferrule 31 is polished so as to be inclined by 8 ° with respect to the optical axes of all the optical fibers ((a), (b)). Next, after cleaning, a four-core tape fiber 32 is inserted into an optical fiber insertion hole (not shown) of the optical connector ferrule 31, and its tip is projected ((c)). Next, an epoxy-based adhesive 33 is applied from the front end side of the optical fiber 32, and the optical fiber 32 is bonded and fixed as a low hardness member around the front end portion ((d)). Then, the tip of the optical fiber 32 may be polished in the same manner as in the above-described example. In this example, a spacer 34 as shown in FIG. This spacer 34 has a thickness corresponding to the amount of protrusion of the optical fiber, in this example, a spacer body 34 having a thickness of 20 μm.
and 8 ° from a vertical state on one surface of the spacer body 34a.
It is composed of a pin 34b that is erected and is used in a state where the pin 34b is inserted into the guide pin hole 31a of the optical connector ferrule 31 and fixed. The optical connector 35 of the present invention was obtained by using this spacer 34 and polishing it under the same conditions as in the above-described example until the spacer 34 abuts on the spacer body 34a.

The optical connector 35 obtained in this way is
When evaluated individually, good results were obtained with an average connection loss of 0.30 dB and an average reflection of 60 dB or more.

In order to obtain the effect of obliquely polishing the coupling end face of the optical connector to prevent reflection at the connection point as in the present embodiment, it is necessary that the angle is 5 ° or more with respect to the plane perpendicular to the optical axis. You only have to lean.

In the embodiment described above, the same material as the adhesive for fixing the optical fiber was used as the low hardness member.
If the hardness is lower than that of the optical fiber, a material different from the adhesive may be used. As the low-hardness member, it is preferable to use the same material as the optical connector ferrule except for the filler, as in the above-described embodiment, from the viewpoint of long-term reliability, but of course, it is not limited to this. Instead, other reaction-curable resins, heat-curable resins, and ultraviolet-curable resins can be used. Furthermore, the low-hardness member may be provided not only around the optical fiber at the coupling-side end face of the optical connector ferrule but also on the entire end face.

[0026]

As described above, the multi-core optical core of the present invention
Connectors protrude the end face of the optical fiber from the coupling end face of the optical connector ferrule, and a low low-hardness member hardness than optical fiber around each of the optical fibers at least the projection of the coupling-side end face is provided Structure, the tip of the optical fiber is protected by a low-hardness material.
And a filler in the material forming the ferrule.
Can be included and the ferrule dimensions are stable,
Even in the heart, the PC connection between the optical fiber end faces is ensured.
You. The tip of the optical fiber is protected by a low-hardness member.
Therefore, do not grind the end face of the optical connector ferrule.
By polishing the end face of the optical connector, multiple
The end faces of all the optical fibers can be reliably obtained.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an optical connector according to one embodiment of the present invention.

FIG. 2 is a schematic view showing a problem of the optical connector according to one embodiment of the present invention.

FIG. 3 is a schematic view illustrating an optical connector manufactured by the method of the present invention.

FIG. 4 is a process diagram illustrating one production example according to the present invention.

FIG. 5 is a process chart for explaining another manufacturing example according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical connector 2 Optical connector ferrule 3 Optical fiber 4 Low-hardness member 21 and 31 Optical connector ferrule 22 and 32 Four-core tape fiber 23 and 33 Adhesive 24 and 35 Optical connector 34 Spacer

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Makoto Honjo 1-chome Taya-cho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture Sumitomo Electric Industries, Ltd. Yokohama Works (72) Inventor Toshiaki Kakii 1-chome Taya-cho, Sakae-ku, Yokohama-shi, Kanagawa Sumitomo Electric (72) Inventor Toru Yamanishi 1 in Tayacho, Sakae-ku, Yokohama, Kanagawa Prefecture Sumitomo Electric Industries, Ltd. Yokohama Works (72) Inventor Shinji Nagasawa 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Japan (56) References JP-A-63-85606 (JP, A) JP-A-2-226205 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02B 6 / 36-6/42

Claims (9)

(57) [Claims] And 1. A optical fiber can be fixed optical connector ferrule, an optical fiber is fixed to the optical connector ferrule, the multi-fiber optical connector comprising a glue for fixing the optical fiber to the optical connector ferrule ,
The end face protrudes from the coupling end face of the optical connector ferrule of the plurality of optical fibers, and have low low-hardness member hardness than the optical fiber around the optical fiber of each of the at least projection of the coupling-side end face is provided , multi-fiber optical connector the low-hardness member, characterized in that does not protrude from the optical fiber end face. 2. The multi- fiber optical connector according to claim 1, wherein the low-hardness member does not include a filler having a hardness equal to or higher than a material of the optical fiber. 3. The multi- piece member according to claim 1, wherein the low-hardness member is made of a material obtained by removing a filler having a hardness equal to or higher than the material of the optical fiber from the material of the optical connector ferrule. Heart optical connector. 4. The multi- fiber optical connector according to claim 1, wherein the low-hardness member is a reaction-curable resin. 5. The multi-core optical connector according to claim 4, wherein the adhesive for fixing the optical fiber to the optical connector ferrule is the same reaction-curable resin as the low-hardness member. 6. An end face of an optical connector ferrule and an end face of an optical fiber according to any one of claims 1 to 5,
A multi- fiber optical connector, wherein the optical fiber is inclined by 5 ° or more with respect to a plane orthogonal to an optical axis of the optical fiber. 7. A optical connector ferrule that can secure the optical fiber, an optical fiber is fixed to the optical connector ferrule, a multi-fiber optical connector comprising a glue for fixing the optical fiber to the optical connector ferrule a method of manufacturing, the step of bonding and fixing a plurality of optical fibers to the optical connector ferrule such that the end face thereof is protruded from the coupling end face of the optical connector ferrule, the optical fiber of each of the at least projection of the coupling-side end face a step of providing a low low-hardness member hardness than the optical fiber is surrounded,
Method for producing a multi-fiber optical connector, characterized by comprising a step of polishing the end face of each optical fiber so as not to polish the optical connector ferrule. 8. The method according to claim 7, further comprising a step of polishing the end face of the optical connector ferrule so as to be inclined at a predetermined angle with respect to a plane orthogonal to the optical axis of the optical fiber before bonding and fixing the optical fiber. A method for manufacturing a multi-core optical connector, comprising: 9. The method of claim 7 or 8, when polishing the end face of the optical fiber, and wherein interposing the spacer of a predetermined thickness between the polishing plate and the end face of the optical connector ferrule multifiber Manufacturing method of optical connector.