JP4699262B2 - Optical waveguide connector, optical connection structure using the same, and optical waveguide connector manufacturing method - Google Patents

Description

  The present invention relates to an optical waveguide connector, an optical connection structure using the same, and a method for manufacturing the optical waveguide connector.

  The spread of broadband is remarkable, and the capacity of routers that handle increasing data is increasing. In current device mounting using electrical transmission, optical mounting is indispensable for realizing a large-capacity router due to the number of connector terminals on the switch board where signals from line cards are concentrated and the limit of transmission speed in the backboard. ing. Under such circumstances, optical mounting such as optical modules that transmit and receive optical signals, optical wiring boards that transmit optical signals, optical connectors that connect optical modules and optical wiring boards, and optical wiring boards electrically and mechanically Development of parts is underway (see, for example, Patent Document 1).

  Of the optical mounting components, the optical connector generally includes an optical fiber connector having an optical fiber having a core layer and a clad layer covering the core layer, and an optical fiber having a core layer and a clad layer covering the core layer. And an optical waveguide connector having a waveguide, and the ends of the core layers of the optical fiber and the optical waveguide are connected to each other.

JP 2004-62064 A

  By the way, in order to suppress the coupling loss of light at the connection portion between the optical fiber and the optical waveguide, it is necessary to align both with high precision. As a precondition, the optical waveguide is at a desired position in the optical fiber connector. It is necessary to align with high accuracy.

  However, it is difficult to position and arrange the optical waveguide in the optical waveguide connector with high accuracy, and there is a demand for an optical waveguide connector that can easily perform such positioning.

  An object of the present invention is to provide an optical waveguide connector capable of easily and accurately aligning an optical waveguide, an optical connection structure using the optical waveguide connector, and a method for manufacturing the optical waveguide connector.

The present invention provides an optical waveguide having an optical waveguide core and an optical waveguide cladding that covers the optical waveguide core;
A ferrule body on which the optical waveguide is mounted,
The ferrule body has a convex portion in a part thereof,
The optical waveguide includes an alignment core that is in contact with a part of the ferrule body,
The alignment core is an alignment core that is different from the optical waveguide core, and is made of the same material as the optical waveguide core, and is a core that is collectively formed in the same process as the optical waveguide core. Yes,
The alignment core has its side surface directly in contact with the convex portion of the ferrule body without the optical waveguide cladding interposed therebetween,
The alignment core is disposed with a space between the optical waveguide cladding and the alignment core;
The convex portion of the ferrule body is fitted into a region between the alignment core and the optical waveguide clad arranged at a distance from the alignment core. It is.
Further, the present invention provides an optical waveguide having an optical waveguide core and an optical waveguide cladding that covers the optical waveguide core,
A ferrule body on which the optical waveguide is mounted,
The ferrule body has a convex portion in a part thereof,
The optical waveguide includes an alignment core that is in contact with a part of the ferrule body,
The alignment core is an alignment core that is different from the optical waveguide core, and is made of the same material as the optical waveguide core, and is a core that is collectively formed in the same process as the optical waveguide core. Yes,
The alignment core has its side surface directly in contact with the convex portion of the ferrule body without the optical waveguide cladding interposed therebetween,
The alignment core further abuts the upper surface directly on a part of the ferrule body without an optical waveguide cladding ,
In the optical waveguide connector, the alignment core and the optical waveguide core are substantially equal in height.

The present invention also provides the optical waveguide connector,
The optical waveguide further includes a substrate that supports the optical waveguide core, an optical waveguide cladding that covers the optical waveguide core, and the alignment core.
The substrate, the optical waveguide core, characterized in that it consists of the optical waveguide cladding and the thermal expansion coefficient than the core alignment is small materials.

The present invention also provides the optical waveguide connector,
The optical waveguide connector is characterized in that a height difference between the alignment core and the optical waveguide core is set to 15% or less of a height of the optical waveguide core.

The present invention also provides the optical waveguide connector,
The substrate is an optical waveguide connector made of a material containing copper .

The present invention also provides the optical waveguide connector,
A plurality of the alignment cores are present, and the plurality of alignment cores are arranged with a space therebetween, and the convex portion of the ferrule body is located in an area between the adjacent alignment cores. An optical waveguide connector characterized by being fitted.

The present invention also provides the optical waveguide connector,
The convex part of the ferrule body has a side surface inclined so as to become narrower toward the tip part,
The alignment core is an optical waveguide connector characterized in that a side surface of the alignment core is formed in a shape corresponding to the convex portion such that the side surface is in contact with the inclined surface of the convex portion.

The present invention also provides the optical waveguide connector;
Optical fiber,
And an optical fiber connector that accommodates the optical fiber.

Further, the present invention provides a method for manufacturing the optical waveguide connector,
An optical waveguide core, an optical waveguide clad that covers the optical waveguide core, and an alignment core that is at least partially exposed from the optical waveguide clad, and is formed in a batch in the same process as the optical waveguide core A step of preparing an optical waveguide having a core for use, and a ferrule main body on which the optical waveguide can be mounted, and a ferrule main body having a convex portion at a part thereof ,
The optical waveguide is mounted so that the side surface of the exposed portion of the alignment core is in direct contact with the convex portion of the ferrule body without the optical waveguide cladding, and the optical waveguide is mounted on the ferrule body. And a step of aligning with respect to the optical waveguide connector.

According to the present invention, in an optical waveguide connector comprising an optical waveguide and a ferrule body on which the optical waveguide is mounted, an alignment core that is in contact with a part of the ferrule body. Therefore, when the optical waveguide is mounted on the ferrule body , the mounting position of the optical waveguide on the ferrule body is defined by the alignment core , and the optical waveguide and the ferrule body are aligned with high accuracy. be able to. As a result, the optical waveguide is mounted at a desired position in the optical waveguide connector with high accuracy, and when connecting the optical waveguide connector to the optical fiber connector, the optical fiber core layer and the optical waveguide core are highly accurate. Therefore, it is possible to realize an optical connection structure with small optical coupling loss.

In addition, the alignment core is an alignment core different from the optical waveguide core, and is made of the same material as the optical waveguide core, and is a core that is collectively formed in the same process as the optical waveguide core. The optical waveguide and the ferrule body can be aligned with higher accuracy.
Furthermore, since the side surface of the alignment core is in contact with a part of the ferrule body, the optical waveguide can be aligned with the ferrule body in the lateral direction with high accuracy.
Furthermore, since the part of the ferrule body that is in contact with the alignment core is a convex portion, the alignment core and the convex portion are brought into contact with each other to perform horizontal alignment with high accuracy. be able to.
Further, the alignment core is disposed with a gap between the optical waveguide clad, and the convex portion of the ferrule body is disposed with an interval between the alignment core and the alignment core. It is fitted in a region between the optical waveguide clad. As a result, the alignment of the convex portions can be performed using the alignment core, so that the alignment in the lateral direction can be performed with high accuracy.

Further, according to the present invention, in an optical waveguide connector comprising an optical waveguide and a ferrule body on which the optical waveguide is mounted, the alignment core in which the optical waveguide is in contact with a part of the ferrule body, Therefore, when the optical waveguide is mounted on the ferrule body, the mounting position of the optical waveguide on the ferrule body is defined by the positioning core, and the optical waveguide and the ferrule body are aligned with high accuracy. can do. As a result, the optical waveguide is mounted at a desired position in the optical waveguide connector with high accuracy, and when connecting the optical waveguide connector to the optical fiber connector, the optical fiber core layer and the optical waveguide core are highly accurate. Therefore, it is possible to realize an optical connection structure with small optical coupling loss.
In addition, the alignment core is an alignment core different from the optical waveguide core, and is made of the same material as the optical waveguide core, and is a core that is collectively formed in the same process as the optical waveguide core. The optical waveguide and the ferrule body can be aligned with higher accuracy.
Furthermore, since the side surface of the alignment core is in contact with a part of the ferrule body, the optical waveguide can be aligned with the ferrule body in the lateral direction with high accuracy.
Furthermore, since the part of the ferrule body that is in contact with the alignment core is a convex portion, the alignment core and the convex portion are brought into contact with each other to perform horizontal alignment with high accuracy. be able to.
Furthermore, since the upper surface of the alignment core is in contact with a part of the ferrule body, alignment of the optical waveguide with respect to the ferrule body in the height direction can be performed with high accuracy.
According to the present invention, before Kikoshirube waveguide further comprises a substrate, the substrate is made of the optical waveguide core, wherein the optical waveguide cladding and material thermal expansion coefficient than the core for the alignment is small. Therefore, even if the temperature is changed while the optical waveguide and the substrate are supported, the thermal expansion coefficient of the substrate is smaller than the thermal expansion coefficient of the optical waveguide. It is well prevented that the optical waveguide is largely displaced due to thermal expansion. Thereby, even if the temperature of the optical waveguide changes, the substrate can prevent the optical waveguide core from being undesirably displaced with respect to the ferrule body.

  Furthermore, according to the present invention, since the difference in height between the alignment core and the optical waveguide core is set to 15% or less of the height of the optical waveguide core, the alignment core was used. High-precision alignment in the height direction can be realized.

Furthermore, according to the present invention, since the substrate is made of a material containing copper, a substrate having a smaller thermal expansion coefficient than that of the optical waveguide can be realized.

Further, according to the present invention, there are a plurality of the alignment cores, the plurality of alignment cores are arranged with a space therebetween, and the ferrule is disposed in a region between the adjacent alignment cores. The convex part of the main body is fitted. As a result, the convex portions can be aligned by the two adjacent alignment cores, so that the horizontal alignment can be performed with high accuracy.

Furthermore, according to the present invention, the convex portion of the ferrule body has a side surface inclined so as to become narrower toward the tip portion, and the alignment core has a side surface that contacts the inclined surface of the convex portion. It forms in the shape corresponding to the said convex part so that it may contact | connect. Therefore, the convex portion can be easily brought into contact with the alignment core, and alignment of the optical waveguide with the ferrule body is facilitated.

  Furthermore, according to the present invention, the optical connection structure includes the above-described optical waveguide connector, an optical fiber, and an optical fiber connector that accommodates the optical fiber. Therefore, the optical fiber core layer and the optical waveguide core of the optical waveguide are provided. Can be aligned with high accuracy.

Furthermore, according to the present invention, there are an optical waveguide core, an optical waveguide clad that covers the optical waveguide core, and an alignment core that is at least partially exposed from the optical waveguide cladding, and is collectively processed in the same process as the optical waveguide core. A step of preparing an optical waveguide having an alignment core that is formed automatically, and a ferrule body that is capable of mounting the optical waveguide and has a convex portion at a part thereof, and the optical waveguide, A side surface of the exposed portion of the alignment core is mounted so as to be in direct contact with the convex portion of the ferrule body without passing through the optical waveguide cladding, and the optical waveguide is aligned with the ferrule body. because comprising the steps of, a, can be aligned with the ferrule body with high accuracy.

  Hereinafter, a plurality of embodiments for carrying out the present invention will be described with reference to the drawings. Portions corresponding to the matters described in the preceding forms in each embodiment are denoted by the same reference numerals, and overlapping description may be omitted. When only a part of the configuration is described, the other parts of the configuration are the same as those described in the preceding section. Not only the combination of the parts specifically described in each embodiment, but also the embodiments can be partially combined as long as the combination does not hinder.

(First embodiment)
<Photoelectric module structure>
FIG. 1 is a simplified perspective view showing an optoelectric module 100 according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view showing the photoelectric module 100 in a simplified manner.

  The optoelectric module 100 includes a substrate 19, an optical connector 1 on which the optical waveguide 6 is placed on the substrate 19, a mirror unit 15 connected to the optical waveguide 6 of the optical connector 1 and reflecting light, and a mirror unit 15. The light receiving element 16 that receives the light reflected by the light receiving device and converts the received light into an electric signal, and the electric signal converted by the light receiving element 16 are input, and the driver IC 22 performs processing based on the input electric signal. And a light emitting element 17 that receives an electrical signal output by the processing of the driver IC 22 and converts electricity into light based on the input electrical signal.

  The mirror means 15 is configured by inclining the end face of the optical waveguide 6 and depositing a metal material that reflects light such as gold, aluminum, titanium, and chromium on the inclined surface. As a method of inclining the end face of the optical waveguide 6, there are a method of forming with a mold and a method of processing with a diamond tool or the like. The metal material is deposited by vapor deposition or the like.

  As the light receiving element 16, for example, a photodiode is used to receive light transmitted through the optical waveguide 6. As the light emitting element 17, a surface emitting semiconductor laser such as a VCSEL, an edge emitting laser diode, or the like is used, and emits light toward the optical waveguide 6. The light receiving element 16 and the light emitting element 17 are arranged linearly so as to correspond to the position of the optical waveguide 6.

  In the optoelectric module 100 having such a configuration, since the optical connector 1 has a configuration to be described later, the coupling loss of light in the optical connector 1 can be suppressed to be small. As a result, more accurate information than before is input by the optical connector 1, so that more accurate processing than before is performed by an electric circuit such as the driver IC 22, and the processed information is more accurately externally output by the optical connector 1 than before. It will be transmitted to. Accordingly, by incorporating the optoelectric module 100 into a device that requires high accuracy and accurate processing, for example, a computer device such as a super computer, a workstation, or a server, and a communication connection device such as a router, the performance of the device can be improved. It becomes possible to greatly improve.

<Structure of optical connector 1>
FIG. 3 is a perspective view showing the optical connector 1 and is a perspective view showing a state in which the second ferrule 3 is connected to the first ferrule 2 constituting the optical connector 1. FIG. 4A is a plan view showing a state in which the second ferrule 3 is connected to the first ferrule 2. FIG. 4B is a plan view showing a state in which the second ferrule 3 is detached from the first ferrule 2.

  The optical connector 1 according to the present embodiment is generally inserted into both the first ferrule 2 that is an optical waveguide connector, the second ferrule 3 that is an optical fiber connector, and both the first ferrule 2 and the second ferrule 3. The first and second ferrules 2 and 3 are detachably connected to each other at their end faces.

  The longitudinal direction of the guide pins 4 is defined as the x direction, the arrangement direction of the guide pins 4 is defined as the y direction, and the direction perpendicular to the x and y directions (the ferrule thickness direction) is defined as the z direction.

<< Schematic structure of first ferrule 2 >>
FIG. 5 is an end view showing the main part of the first ferrule 2 (end view taken along line VV in FIG. 4). FIG. 6 is an exploded end view of the first ferrule 2, where FIG. 6A is an end view of the fixing member 7, FIG. 6B is an end view of the optical waveguide 6, and FIG. 3 is an end view of the ferrule body 5. FIG.

  The first ferrule 2 includes a ferrule body 5 having a recess 12 and a pair of guide holes 5a and 5b, an optical waveguide 6 fitted in the recess 12 of the ferrule body 5, and the optical waveguide 6 with respect to the ferrule body 5. And a fixing member 7 for fixing.

The ferrule body 5 is made of, for example, epoxy resin, PPS (PPS: Polyphenylene
It is made of a material in which inorganic particles such as silica particles are contained in a synthetic resin such as a sulfied resin.

  Further, the ferrule body 5 (corresponding to the support) is configured to be able to support the optical waveguide 6 and is formed to be concave in the yz section as shown in FIG. At both ends, guide holes 5a and 5b into which a pair of guide pins 4 for aligning an optical waveguide 6 of the first ferrule 2 and an optical fiber 8 of the second ferrule 3 described later are inserted are formed. Yes. Each guide hole 5a, 5b is provided along the x direction. The guide holes 5a and 5b may be formed so as to penetrate the ferrule body 5. In this case, there is an effect that the processing accuracy when the ferrule body 5 is formed by the injection molding method is improved.

  A plurality (three in the present embodiment) of convex portions 30 projecting in the z direction are provided on the bottom surface 12d of the concave portion 12 of the ferrule body 5 along the y direction. The convex portion 30 abuts against the optical waveguide 6 when the optical waveguide 6 is fitted in the concave portion 12.

  As shown in FIG. 6B, the optical waveguide 6 fitted into the recess 12 of the ferrule main body 5 is a plurality of optical waveguide cores 10, an optical waveguide cladding 11 covering each optical waveguide core 10, and a later-described optical waveguide core 10. And a plurality of alignment cores 31 and 32, and a metal layer 14 which is attached to the main surface of the optical waveguide cladding 11 and functions as a reinforcing material.

  The optical waveguide core 10 is made of a material having a refractive index smaller than that of the optical waveguide clad 11 (for example, a material such as epoxy resin, acrylic resin, silicon resin, and quartz). The optical waveguide clad 11 is made of, for example, the same kind of material as that of the optical waveguide core 10 and a material in which the refractive index is changed by changing the mixing ratio of a plurality of components constituting the raw material. On the other hand, the alignment cores 31 and 32 are formed of the same material as the optical waveguide core 10.

  The optical waveguide cores 10 are connected to the core layer of the optical fiber 8, and are arranged at a substantially constant pitch δ1 (interval between centroids of adjacent optical waveguide cores 10). The optical waveguide core 10 has a function of propagating light incident from the optical fiber 8 or a function of propagating light to be incident on the optical fiber 8 (in the present embodiment, the former function). . On the other hand, the alignment cores 31 and 32 are members serving as a reference for alignment, and light incident on the inside due to a part of the alignment cores 31 and 32 being exposed from the optical waveguide cladding 11 as described later. Since it leaks to the outside from the exposed portion, it is usually not used as a light propagation medium.

  The metal layer 14 (substrate) is for supporting the optical waveguide core 10, the optical waveguide cladding 11, and the alignment core 31. Since the metal layer 14 is preferably formed of a material having a smaller thermal expansion coefficient than the optical waveguide core 10, the optical waveguide cladding 11, and the alignment core 31, in this embodiment, the metal layer 14 is made of copper. It is formed with the material (for example, copper foil) containing.

  On the other hand, the fixing member 7 for fixing the optical waveguide 6 to the ferrule body 5 is formed by pressing the optical waveguide 6 fitted in the recess 12 of the ferrule body 5 as shown in FIG. 6 is maintained. The fixing member 7 is made of a material in which silica particles are filled in a synthetic resin such as an epoxy resin and a PPS resin similar to the ferrule body 5. The fixing member 7 is formed in a rectangular shape in plan view, and is formed in a convex shape when viewed in the x direction.

<< Schematic structure of second ferrule 3 >>
FIG. 7 is an end view (end view taken along line VII-VII in FIG. 4) showing the main part of the second ferrule 3.

  The second ferrule 3 is formed in a rectangular parallelepiped shape from a material in which inorganic particles such as silica particles are contained in a synthetic resin such as an epoxy resin or a PPS resin. The second ferrule 3 is provided with a plurality of fiber holes 29 into which the optical fiber 8 is inserted, and guide holes 3a and 3b into which the pair of guide pins 4a and 4b are inserted.

  A plurality of fiber holes 29 are formed in parallel to the y direction. The longitudinal direction of the optical fiber 8 inserted into the fiber hole 29 is arranged parallel to the x direction. Specifically, the optical fibers 8 are arranged in the y direction by being inserted into the fiber holes 29, respectively. The optical fiber 8 has a function of propagating light transmitted to the optical waveguide 6. The optical fibers 8 are arranged at a pitch of δ1 in the y direction so as to correspond to the optical waveguide core 10 of the optical waveguide 6.

  The optical fiber 8 has a configuration in which a core layer 8a having a circular cross section is covered with a cladding layer 8b made of a material having a refractive index smaller than that of the core layer 8a, and light is leaked to the outside as much as possible by the principle of total reflection. I am trying not to. In the case of multimode, which is mainly used for short-distance communication, the optical fiber has a diameter of the cladding layer 8b of 125 μm, and the inner core layer 8a covered with the cladding layer 8b has a diameter of 50 μm or more and 62.5 μm or less. Has been standardized. In the single mode used for long-distance communication, the diameter of the clad layer 8b is standardized to 125 μm, and the diameter of the inner core layer 8a covered with the clad layer 8b is standardized to 10 μm.

<< Connection structure between optical waveguide 6 and optical fiber 8 >>
FIG. 8 is a perspective view showing the relationship between the optical waveguide 6 and the optical fiber 8.

  The optical waveguide core 10 of the optical waveguide 6 is connected to the core layer 8a of the optical fiber 8 as shown in FIG. In the connection portion between the optical fiber 8 and the optical waveguide 6, the optical waveguide core 10 is disconnected so that the outer edge of the cross section of the core layer 8 a of the optical fiber 8 is disposed inside the outer edge of the cross section of the optical waveguide core 10. The size of the area is set.

  Specifically, when the cross-sectional shape of the optical waveguide core 10 layer 10 is substantially rectangular, the length of the optical waveguide core 10 in the y direction is Lw1, the length in the z direction is Lh1, and the core layer 8a Are defined as φ, respectively. At this time, in the present embodiment, the expressions Lw1 ≧ φ1 and Lh1 ≧ φ1 are satisfied.

  As a result, most of the light propagating through the optical fiber 8 is satisfactorily transmitted to the optical waveguide core 10 at the connection portion between the optical fiber 8 and the optical waveguide 6 where light is transmitted in the order from the optical fiber 8 to the optical waveguide core 10. The Rukoto. Therefore, the coupling loss of light at the connecting portion is well prevented.

  Further, most of the light propagating through the optical waveguide core 10 is satisfactorily transmitted to the optical fiber 8 at the connecting portion between the optical fiber 8 and the optical waveguide 6 where light is transmitted in the order from the optical waveguide core 10 to the optical fiber 8. . Therefore, the coupling loss of light at the connecting portion is well prevented.

<< Detailed structure of first ferrule 2 >>
FIG. 9 is a diagram showing a support state in which the optical waveguide 6 and the ferrule body 5 are in contact with each other, and is an end view showing the y-direction center portion of the ferrule body 5 in an enlarged manner. As described above, the optical waveguide 6 includes the plurality of optical waveguide cores 10, the optical waveguide cladding 11, the plurality of alignment cores 31, and the metal layer 14.

  The optical waveguide cladding 11 has a first optical waveguide cladding 11a and a second optical waveguide cladding 11b. The first optical waveguide clad 11 a is laminated on the main surface of the metal layer 14. A plurality of optical waveguide cores 10 are stacked on the first optical waveguide cladding 11a. The alignment cores 31 and 32 are laminated on the main surface of the metal layer 14 and the first optical waveguide cladding 11a. The second optical waveguide cladding 11 b is laminated on the first optical waveguide cladding 11 a and the optical waveguide core 10 so as to expose a part of the alignment cores 31 and 32 while covering the optical waveguide core 10.

  In this embodiment, as shown in FIG. 9, in one of the two alignment cores 31 and 32, one alignment core 31 has a side surface 31b on one side in the y direction and an upper surface 31a on the other side in the z direction. In the other alignment core 32, the side surface 32b on the other side in the y direction and the upper surface 32a on the other side in the z direction are exposed outward. In other words, the side surfaces 31b and 32b facing each other of the two adjacent alignment cores 31 and 32 are exposed to the outside. In the present embodiment, the main surface of the metal layer 14 is exposed between the adjacent alignment cores 31 and 32. A fitted portion in which the convex portion 30 of the ferrule body 5 is fitted is formed in the region between the adjacent alignment cores 31 and 32. In this embodiment, the fitted portion is configured by each side surface 31 b of the adjacent alignment core 31 and the main surface of the metal layer 14.

  The alignment core 31 is made of the same material as the optical waveguide core 10 and is formed at the same time as the optical waveguide core 10 is formed. Therefore, the alignment core 31 is aligned with the optical waveguide core 10 with high accuracy. The optical waveguide core 10 is formed with high accuracy at a desired position in the z direction of the optical waveguide cladding 11. Here, the height L7 shown in FIG. 9 is the distance from the upper surface of the first cladding 11a to the upper surface of the optical waveguide core 10, and the height L8 is the upper surface of the second optical waveguide cladding 11b from the upper surface of the optical waveguide core 10. It is the distance to.

  The side surface 31 b of the alignment core 31 is in contact with the side surface 30 b of the convex portion 30 of the ferrule body 5. Therefore, the position of the optical waveguide 6 in the y direction is defined by the alignment cores 31 and 32, and the lateral alignment of the optical waveguide 6 with respect to the ferrule body 5 is performed with high accuracy. Yes.

  Further, the side surfaces (side surfaces on both sides in the y direction) are inclined so that the convex portion 30 becomes narrower toward the tip portion. Therefore, the convex portion 30 of the ferrule body 5 can be easily fitted into the region between the alignment cores 31 and 32, and the alignment of the optical waveguide 6 with respect to the ferrule body 5 is facilitated. Moreover, when the hardness of the material of the alignment core 31 is low and the strength is low, the edge portion may be deformed or damaged, but by making the side surface of the convex portion 30 into the shape described above, When aligning the optical waveguide 6 and the ferrule body 5, there is a risk that a large pressing force is applied to the alignment cores 31 and 32 due to the protrusion 30 being caught by the alignment cores 31 and 32. The deformation and breakage of the alignment cores 31 and 32 can be satisfactorily prevented.

  The convex portion 30 is not limited to the shape as described above, and the side surface may be inclined in the opposite direction to the above, but when the hardness of the material of the alignment core 31 that is the waveguide material is low, and When the strength is low, there is a tendency that the edge portion tends to be deformed or damaged, which may not be preferable.

  Moreover, the end surfaces located at both ends in the x direction of the convex portion 30 may be vertical. When the end face is vertical, the dimensional accuracy of the end can be increased.

  The height L1 of the convex portion 30 may be set smaller than the total height L2 of the optical waveguide core 10 and the optical waveguide cladding 11, or may be set larger. FIG. 9 shows a case where the height L1 of the convex portion 30 is smaller than the total height L2 of the optical waveguide core 10 and the optical waveguide cladding 11. The height L1 of the convex portion 30 is a distance from the bottom surface 12d of the concave portion 12 to the upper surface 30a of the convex portion 30. When the thickness of the metal layer 14 is 100 μm or less, since the strength for supporting the optical waveguide 6 is low, the height L1 of the convex portion 30 is higher than the total height L2 of the optical waveguide core 10 and the optical waveguide cladding 11. It is preferable to set a smaller value. In this case, the positional accuracy in the height direction of the optical waveguide core 10 is controlled by the thicknesses of the optical waveguide core 10 and the optical waveguide cladding 11. When the thickness of the metal layer 14 exceeds 100 μm, the strength for supporting the optical waveguide is high, and therefore the height L1 of the convex portion 30 is set to be larger than the total height L2 of the optical waveguide core 10 and the optical waveguide cladding 11. it can.

  The height L1 of the convex part 30 is, for example, not less than 10 μm and not more than 40 μm. Further, the width dimension W1 of the convex portion 30 is set smaller than the width dimension W2 in the y direction between the adjacent alignment cores 31 and 32, for example, by the gap dimension δ2. The gap dimension δ2 is, for example, ± 3 μm, and the negative direction is a so-called interference fit, and the alignment cores 31 and 32 are fitted by being deformed. As a result, the convex portion 30 can be fitted into a fitted portion formed between the adjacent alignment cores 31 and 32.

  In FIG. 9, the convex portion 30 and the alignment core 31 are in contact with each other, but the convex portion 30 and the alignment core 32 are not in contact with each other. Although it is not without the possibility of occurrence of stagnation, as shown in FIG. 5, it is possible to more reliably prevent rattling of the optical waveguide 6 in the y direction by forming a plurality of convex portions 30 on the ferrule body 5. it can. Moreover, the convex part 30 and the alignment cores 31 and 32 may contact two or more places.

  FIG. 10 is a view showing a support state where the optical waveguide 6 and the ferrule body 5 are in contact with each other, and is an end view showing an enlarged one end portion of the ferrule body 5 in the y direction. A fitting portion into which the convex portion 30 formed at one end portion in the y direction is fitted includes one alignment core 31, an optical waveguide clad 11 provided at a distance from the alignment core 31, and The exposed main surface of the metal layer 14 is formed. The side surface 31 b of the alignment core 31 is in contact with one side surface 30 b of the convex portion 30 of the ferrule body 5. Even such a convex portion 30 is aligned with high accuracy by the alignment core 31.

  As described above, the first ferrule 2 of the present embodiment is configured such that the optical waveguide 6 includes the alignment core 31. Since the alignment core 31 is formed integrally with the optical waveguide core 10, the alignment core 31 and the optical waveguide core 10 can be aligned with high accuracy. The alignment core 31 is in contact with the side surface of the convex portion 30 of the ferrule body 5. Therefore, the optical waveguide 6 can be accurately aligned in the y direction with respect to the ferrule body 5 by the alignment core 31. Since such an alignment core 31 can be manufactured at the same time as the optical waveguide core 10, the alignment core 31 can be easily manufactured.

  By aligning with high accuracy, the light incident from the core layer of the optical fiber can be satisfactorily transmitted into the optical waveguide core 10 of the optical waveguide 6 at the connection portion between the optical fiber 8 and the optical waveguide 6. It becomes. Therefore, the coupling loss of light at the connecting portion is well prevented. In particular, when the core layer 8a of the optical fiber 8 is minute, for example, 50 μm or less, and the optical waveguide core 10 is minute, for example, has a rectangular shape with one side being 50 μm or less, the optical waveguide core 10 is displaced by 10 μm from the core layer 8a. When. Although the optical coupling loss increases, the alignment core 31 can be formed with an accuracy of 3 μm or less by using a mask. Therefore, the optical waveguide core 10 is placed at a desired position in the ferrule body 5 with an accuracy of 3 μm or less. Can be supported.

  In the present embodiment, the metal layer 14 is made of a material having a smaller thermal expansion coefficient than the optical waveguide core 10, the optical waveguide cladding 11, and the alignment core 31. Therefore, even if the temperature changes while the optical waveguide 6 and the metal layer 14 are supported, the thermal expansion coefficient of the metal layer 14 is smaller than the thermal expansion coefficient of the optical waveguide 6, so that the displacement of the thermal expansion due to the temperature rise of the metal layer 14. The amount can be kept small, and the optical waveguide 6 is well prevented from being greatly displaced by thermal expansion. Thereby, even if the temperature of the optical waveguide 6 changes, the metal layer 14 can prevent the optical waveguide core 10 from being undesirably displaced with respect to the ferrule body 5. Since the metal layer 14 is made of a material containing copper, the metal layer 14 having a thermal expansion coefficient smaller than that of the optical waveguide 6 made of resin can be realized.

<Method for Manufacturing Optical Connector 1>
FIG. 11 is a flowchart showing the manufacturing method of the optical connector 1 step by step. The optical connector manufacturing method of the present embodiment roughly includes a step of manufacturing the first ferrule 2 (step a1), a step of manufacturing the second ferrule 3 (step a2), the first ferrule 2 and the second ferrule 2. A step of connecting the ferrule 3 (step a3). The order of step a1 and step a2 may be switched.

  In the process of manufacturing the first ferrule 2 (step a1), first, the ferrule body 5, the optical waveguide 6, and the fixing member 7 are formed. The ferrule body 5 and the fixing member 7 are formed by a conventionally known injection molding method. Next, when the optical waveguide 6 is manufactured using a printing method, first, the first optical waveguide clad 11a is first applied to a part of the metal layer 14 made of copper foil by a well-known photolithography technique and etching technique (hereinafter, referred to as the following). Or simply using a stamping method using a mold or rubber mold, etc., and then forming the optical waveguide core 10 and the alignment cores 31 and 32 with the same mask. Use and form simultaneously by forming technology. Therefore, the optical waveguide core 10 and the alignment cores 31 and 32 are collectively formed in the same process. Next, a technique for forming the second optical waveguide cladding 11b on the first optical waveguide cladding 11a and the optical waveguide core 10 so as to cover the optical waveguide core 10 and expose a part of the alignment cores 31 and 32. Formed by. The optical waveguide 6 may be formed by a method using a conventionally known mold.

  Subsequently, the optical waveguide 6 is mounted on the recess 12 of the manufactured ferrule body 5 via an adhesive. At that time, a part of the alignment cores 31 and 32 of the optical waveguide 6, that is, the exposed portion is brought into contact with the convex portion 30. As a result, the position of the optical waveguide 6 in the y direction is defined, and the optical waveguide 6 is aligned with the ferrule body 5.

  Then, the first ferrule 2 is completed by fixing the position of the optical waveguide 6 with the fixing member 7.

  Next, in the process of manufacturing the second ferrule 3 (step a2), the second ferrule 3 is formed with a fiber hole 29 into which a plurality of optical fibers 8 can be inserted. The second ferrule 3 is formed by a conventionally known injection molding method.

  Next, in the step of connecting the first ferrule 2 and the second ferrule 3 (step a3), the first and second ferrules 2 and 3 respectively manufactured in step a1 and step a2 correspond to the connecting portions. The end surface is polished in advance using a processing machine such as a polishing machine to increase the smoothness and clean. Thereafter, the first ferrule 2 and the second ferrule 3 are pressed. If desired, the optical connector 1 is completed by connecting the connecting portions via, for example, a refractive index matching material. The refractive index matching material has substantially the same refractive index (or refractive index between the core layer 8 and the optical waveguide core 10) as the core layer 8a of the optical fiber 8 and the optical waveguide core 10 of the optical waveguide 6. The refractive index matching material is interposed between the connection end portions, so that the light reflection at the end face of the optical fiber 8 and the end face of the optical waveguide 6 can be further reduced.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. FIG. 12 is a view showing a support state in which the optical waveguide 6 and the ferrule body 5 of the present embodiment are in contact with each other, and is an end view showing the y-direction central portion of the ferrule body 5 in an enlarged manner.

  In the present embodiment, the alignment core 31 has an upper surface 31a that is in contact with the bottom surface 12d of the recess 12 of the ferrule body 5, and the height L4 of the alignment core 31 and the height L3 of the optical waveguide core 10 are substantially the same. Characterized by equal points. The difference between the height L4 of the alignment core 31 and the height L3 of the optical waveguide core 10 is the difference in the height L between the alignment core 31 and the optical waveguide core 10 (L4−L3). It is preferably 15% or less of the height L3 of the optical waveguide core 10 (in order to further reduce the loss, 10% or less is desirable, and more preferably 5% or less is used).

  In the alignment core 31 formed in the optical waveguide 6 of the present embodiment, the second optical waveguide cladding 11b is not formed on the upper surface 31a, and the upper surface 31a of the alignment core 31 is exposed. Therefore, the upper surface 31 a of the alignment core 31, that is, the exposed portion can be brought into contact with the bottom surface 12 d of the recess 12.

  The height L1 of the convex portion 30 is set to be smaller than the total height L2 of the optical waveguide core 10 and the optical waveguide cladding 11. Further, the height L1 of the convex portion 30 is set smaller than the height L4 of the alignment core 31 by, for example, the gap dimension δ3. The gap dimension δ3 is, for example, 10 μm. In this case, it is not important because there is a gap.

  Since the height L1 of the convex portion 30 is set to be smaller than the total height L2 of the optical waveguide core 10 and the optical waveguide cladding 11, the bottom surface 12d that is one end surface in the y direction of the concave portion 12 is not desired in the supported state. A recess 12 a is formed so as not to contact the optical waveguide 6. The recess 12 a is provided at a position corresponding to the optical waveguide core 10, and prevents the optical waveguide cladding 11 b covering the optical waveguide core 10 from contacting the ferrule body 5.

  The convex part 30 is fitted to the aforementioned fitted part. The side surfaces 31 b of the alignment cores 31 and 32 abut on the side surface 30 b of the convex portion 30 of the ferrule body 5. Further, the upper surface 30 a of the convex portion 30 is separated from the main surface of the metal layer 14 by the gap dimension δ3, and the upper surface 31 a of the alignment core 31 is in contact with the bottom surface 12 d of the concave portion 12.

  Thus, in the present embodiment, the positional relationship between the optical waveguide 6 and the ferrule body 5 is defined by the alignment cores 31 and 32 with respect to the y direction and the z direction, and the optical waveguide 6 is aligned with high accuracy in both directions. be able to.

  Further, the difference in height L (L4−L3) between the alignment core 31 and the optical waveguide core 10 is set to 15% or less of the height of the optical waveguide core 10. By setting the heights of the alignment core 31 and the optical waveguide core 10 in this way, it is possible to achieve highly accurate alignment in the y direction with the ferrule body 5.

(Third embodiment)
Next , the third embodiment will be described. FIG. 13 is a view showing a support state in which the optical waveguide 6 and the ferrule body 5 of the present embodiment are in contact with each other, and is an end view showing an enlarged central part in the y direction of the ferrule body 5. In the present embodiment, the ferrule body 5 is characterized in that the convex portion 30 is not formed and the alignment pin 40 (reference member) is further provided.

  The alignment pin 40 is formed in a substantially cylindrical shape. A pin receiving portion 41 is formed in the recess 12. The pin accommodating portion 41 is formed so as to abut on the outer peripheral surface 40a of the alignment pin 40 and restrict the displacement of the alignment pin 40 in the y direction. In this embodiment, the pin accommodating portion 41 is bent in an L shape in the other direction in the y direction. Formed by two inclined surfaces 12b and 12c. In a state where the alignment pin 40 is accommodated in the pin accommodating portion 41, the outer peripheral surface 40a of the alignment pin 40 protrudes from the recess 12 in one direction in the y direction. In other words, a convex portion is formed that protrudes from the concave portion 12 in one direction in the y direction with an arc shape in cross section.

  The alignment pin 40 has a diameter D1 such as a distance W3 between adjacent alignment cores 31, a total height L2 of the optical waveguide core 10 and the optical waveguide clad 11, and a pin accommodating portion formed in the recess 12. It is set based on the depth dimension L5 of 41. The diameter D1 of the alignment pin 40 is set larger than the distance W3 between the alignment cores 31. The diameter D1 of the alignment pin 40 is set larger than the depth dimension L5 of the pin housing portion 41.

  The alignment pin 40 is accommodated in the pin accommodating portion 41 while being fitted to the above-described fitted portion. The side 31b of the alignment core 31 abuts on the outer peripheral surface 40a of the alignment pin 40. Further, the outer peripheral surface 40 a of the alignment pin 40 is separated from the main surface of the metal layer 14.

  As described above, in the present embodiment, the alignment pin 40 is used to align with the alignment core 31. Thereby, both the y direction and the z direction can be aligned with high accuracy. Further, in the present embodiment, the columnar alignment pin 40 is used as the reference member, but it is not limited to the columnar shape, and may be a prismatic shape.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described. FIG. 14 is a view showing a support state in which the optical waveguide 6 and the ferrule body 5 of the present embodiment are in contact with each other, and is an end view showing an enlarged central part in the y direction of the ferrule body 5.

  In the present embodiment, the ferrule body 5 is characterized in that the convex portion 30 is not formed and the plated portion 50 (positioning member) is further provided on the optical waveguide 6.

  The plated portion 50 is formed by, for example, electrolytic plating from the main surface between the adjacent alignment cores 31 where the metal layer 14 is exposed to the outside. The plated portion 50 is formed such that its height L6 is larger than the total height L2 of the optical waveguide core 10 and the optical waveguide cladding 11. The plating part 50 is formed with a convex part protruding in the other direction in the y direction with an arc-shaped cross section.

  A plating contact portion 51 is formed in the recess 12. The plating contact part 51 is formed so as to contact the outer peripheral surface of the plating part 50 and restrict the displacement of the plating part 50 in the y direction. In the present embodiment, the plating contact part 51 bends in an L shape in the other y direction. The two inclined surfaces 12b and 12c are formed.

  The plating part 50 is fitted to the plating contact part 51. The outer peripheral surface 50 a of the plating part 50 comes into contact with the two inclined surfaces 12 b and 12 c of the plating contact part 51.

  As described above, in the present embodiment, since the plating portion 50 is formed with the alignment core 31 as a reference, alignment with the optical waveguide core 10 can be performed with high accuracy. By using such a plating part 50, it is possible to align the ferrule body 5 with both the y direction and the z direction with high accuracy.

  Each embodiment of the present invention as described above is merely an example of the invention, and the configuration can be changed within the scope of the invention. In each of the above-described embodiments, the fitted portion is realized by the adjacent alignment core 31 or the like, but is not limited thereto, and the fitted portion is the alignment core 31 and the optical waveguide core. 10 may be formed.

  In the first embodiment described above, the alignment core 31 is formed according to the three convex portions 30, but is not limited to this, and the adjacent cores 31 are adjacent to each other according to the number of the optical waveguide cores 10. It is preferable to provide each between the optical waveguide cores 10. By forming the convex portion 30 in accordance with such an alignment core 31, each optical waveguide core 10 of the optical waveguide 6 can be aligned with the ferrule body 5 with high accuracy.

  In addition, unlike the optical waveguide core 10, the alignment core 31 does not need to guide light, so that the dimension in the x direction only needs to be formed for alignment. Therefore, by forming the alignment core 31, it is possible to prevent the degree of freedom in designing the optical waveguide core 10 from being lowered.

It is a perspective view which simplifies and shows the optoelectric module 100 of the 1st Embodiment of this invention. 2 is a cross-sectional view showing a simplified photoelectric module 100. FIG. FIG. 2 is a perspective view showing the optical connector 1, and is a perspective view showing a state in which a second ferrule 3 is connected to a first ferrule 2 constituting the optical connector 1. 3 is a plan view showing a connection state between the first ferrule 2 and the second ferrule 3. FIG. FIG. 5 is an end view showing the main part of the first ferrule 2 (end view taken along line VV in FIG. 4). FIG. 3 is an end view showing the first ferrule 2 in an exploded manner. FIG. 5 is an end view showing the main part of the second ferrule 3 (end view taken along line VII-VII in FIG. 4). 3 is a perspective view showing a relationship between an optical waveguide 6 and an optical fiber 8. FIG. It is a figure which shows the support state which the optical waveguide 6 and the ferrule main body 5 contact | abutted, Comprising: It is an end elevation which expands and shows the y direction center part of the ferrule main body 5. FIG. It is a figure which shows the support state which the optical waveguide 6 and the ferrule main body 5 are contact | abutting, Comprising: It is an end elevation which shows the y direction one end part of the ferrule main body 5 in an enlarged manner. 4 is a flowchart showing a manufacturing method of the optical connector 1 in stages. It is a figure which shows the support state which the optical waveguide 6 and the ferrule main body 5 contact | abutted, Comprising: It is an end elevation which expands and shows the y direction center part of the ferrule main body 5. FIG. It is a figure which shows the support state which the optical waveguide 6 and the ferrule main body 5 contact | abutted, Comprising: It is an end elevation which expands and shows the y direction center part of the ferrule main body 5. FIG. It is a figure which shows the support state which the optical waveguide 6 and the ferrule main body 5 contact | abutted, Comprising: It is an end elevation which expands and shows the y direction center part of the ferrule main body 5. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical connector 2 1st ferrule 3 2nd ferrule 5 Ferrule main body 6 Optical waveguide 7 Fixing member 8 Optical fiber 10 Optical waveguide core 11 Optical waveguide clad 12 Concave part 30 Convex part 31, 32 Alignment core 40 Alignment pin 50 Plating part 100 Photoelectric module

Claims (9)

An optical waveguide having an optical waveguide core, and an optical waveguide cladding that covers the optical waveguide core;
A ferrule body on which the optical waveguide is mounted,
The ferrule body has a convex portion in a part thereof,
The optical waveguide includes an alignment core that is in contact with a part of the ferrule body,
The alignment core is an alignment core that is different from the optical waveguide core, and is made of the same material as the optical waveguide core, and is a core that is collectively formed in the same process as the optical waveguide core. Yes,
The alignment core has its side surface directly in contact with the convex portion of the ferrule body without the optical waveguide cladding interposed therebetween,
The alignment core is disposed with a space between the optical waveguide cladding and the alignment core;
The convex portion of the ferrule body is fitted into a region between the alignment core and the optical waveguide clad arranged at a distance from the alignment core. . An optical waveguide having an optical waveguide core, and an optical waveguide cladding that covers the optical waveguide core;
A ferrule body on which the optical waveguide is mounted,
The ferrule body has a convex portion in a part thereof,
The optical waveguide includes an alignment core that is in contact with a part of the ferrule body,
The alignment core is an alignment core that is different from the optical waveguide core, and is made of the same material as the optical waveguide core, and is a core that is collectively formed in the same process as the optical waveguide core. Yes,
The alignment core has its side surface directly in contact with the convex portion of the ferrule body without the optical waveguide cladding interposed therebetween,
The alignment core further abuts the upper surface directly on a part of the ferrule body without an optical waveguide cladding ,
An optical waveguide connector, wherein the alignment core and the optical waveguide core are substantially equal in height. The optical waveguide connector according to claim 1 or 2,
The optical waveguide further includes a substrate that supports the optical waveguide core, an optical waveguide cladding that covers the optical waveguide core, and the alignment core.
The optical waveguide connector, wherein the substrate is made of a material having a smaller thermal expansion coefficient than the optical waveguide core, the optical waveguide cladding, and the alignment core. The optical waveguide connector according to claim 2, wherein
An optical waveguide connector, wherein a difference in height between the alignment core and the optical waveguide core is set to 15% or less of a height of the optical waveguide core. The optical waveguide connector according to claim 3, wherein
The optical waveguide connector, wherein the substrate is made of a material containing copper. The optical waveguide connector according to any one of claims 2 to 5,
A plurality of the alignment cores are present, and the plurality of alignment cores are arranged with a space therebetween, and the convex portion of the ferrule body is located in an area between the adjacent alignment cores. An optical waveguide connector characterized by being fitted. In the optical waveguide connector according to any one of claims 1 to 6,
The convex part of the ferrule body has a side surface inclined so as to become narrower toward the tip part,
The optical waveguide connector, wherein the alignment core is formed in a shape corresponding to the convex portion such that a side surface thereof is in contact with an inclined surface of the convex portion. An optical waveguide connector according to any one of claims 1 to 7,
Optical fiber,
And an optical fiber connector for housing the optical fiber. In the manufacturing method of the optical waveguide connector according to any one of claims 1 to 7,
An optical waveguide core, an optical waveguide clad that covers the optical waveguide core, and an alignment core that is at least partially exposed from the optical waveguide clad, and is formed in a batch in the same process as the optical waveguide core A step of preparing an optical waveguide having a core for use, and a ferrule main body on which the optical waveguide can be mounted, and a ferrule main body having a convex portion at a part thereof,
The optical waveguide is mounted so that the side surface of the exposed portion of the alignment core is in direct contact with the convex portion of the ferrule body without the optical waveguide cladding, and the optical waveguide is mounted on the ferrule body. And a step of aligning with respect to the optical waveguide connector.

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