JP4785663B2 - Optical receptacle and optical module using the same - Google Patents

Description

  The present invention relates to an optical receptacle and an optical module.

In optical communication, an optical module including a light emitting element and a light receiving element has an optical receptacle to which an optical connector provided at an end of an optical fiber is connected. This optical receptacle is usually composed of a sleeve into which a plug of an optical connector is inserted and a holder in which one end portion of the sleeve is fitted to hold the sleeve, but the coupling efficiency between the optical fiber and the optical fiber is increased. For this purpose, various ideas have been made.

For example, Patent Document 1 discloses a precision sleeve type optical receptacle in which a diameter of a through hole located at a portion fitted to a holder of a sleeve is made larger than other portions. With this configuration, one end of the sleeve is fitted to the holder, even if the smaller inner diameter of the through hole located at one end thereof, it is possible to insert the plug of the optical connector smoothly .

Patent Document 2 discloses an optical receptacle in which a fiber stub is bonded and fixed in a precision sleeve.
JP 2004-287198 A JP 2005-99748 A

However, since the optical receptacle disclosed in Patent Document 1 has a part with a large diameter in the through hole of the sleeve, the outer periphery of the plug of the inserted optical connector has a through hole in the part with the large diameter. The plug could not be stably held because it did not contact the inner periphery. As a result, this optical receptacle has a problem that it is difficult to hold the plug with high accuracy, and a stable connection with high coupling efficiency cannot be achieved.
In addition, the optical receptacle disclosed in Patent Document 2 may cause the shaft of the stub and the sleeve to deviate due to the expansion and contraction of the adhesive, etc., and the optical fiber on the optical connector side cannot be stably connected with high coupling efficiency. There was a problem.

  Accordingly, an object of the present invention is to provide an optical receptacle capable of stable connection with high coupling efficiency with an optical fiber on the optical connector side.

In order to achieve the above object, an optical receptacle according to the present invention has a first main surface and a second main surface which face each other, and is a groove-shaped press-fit provided on the first main surface side. A holder including a projection portion protruding from a bottom surface of the press-fitting portion, an inner hole through which light is transmitted from the tip end surface of the projection portion to the second main surface, it has holes, and a sleeve which is press-fitted into the press-fit portion, wherein the Ru same diameter der outer diameter relative to the inside diameter of the through hole, inserting the plug of the optical connector in the through hole, is retained when the tip of the plug abuts the end surface of the protrusion, the outer peripheral surface of the projecting portion outer diameter is set smaller than the inner diameter of the through hole of the protrusion protruding from the bottom surface of the press-in portion Is positioned away from the inner peripheral surface of the through hole of the sleeve, and the tip end surface of the protrusion is the slit. Characterized in that it projects from the press-fitting portion of the probe.
In the present invention, the holder includes a first member including the protrusion and a second member different from the first member.
In the present invention, the first member is made of ceramics, and the second member is made of metal.
Further, the present invention is characterized in that reflected light preventing means for preventing reflection of light traveling from the second main surface toward the tip end surface of the protrusion is provided in the inner hole.
Furthermore, the present invention is characterized in that the inner hole is filled with a translucent material.
Further, in the present invention, the first member is a fiber stub composed of a cylindrical body having the inner hole and an optical fiber inserted into the inner hole, and the second member has the press-fit portion, It has an insertion hole penetrating from the bottom surface of the press-fitting portion to the second main surface, the fiber stub is inserted into the insertion hole, and the outer peripheral surface of the protrusion is the inner periphery of the through-hole of the sleeve It is characterized by being located away from the surface via a gap.
The optical module of the present invention has the optical receptacle of the present invention and light incident on the inner hole from the second main surface side, or transmitted through the inner hole and emitted from the second main surface side. An optical element that receives light and a housing that is fixed to the optical receptacle and accommodates the optical element are provided.

In the optical receptacle according to the present invention configured as described above, the outer peripheral surface of the protrusion is positioned away from the inner peripheral surface of the through hole of the sleeve, and the tip surface of the protrusion is Since it protrudes from the press-fitted part, when one end of the sleeve is press-fitted into the press-fitted part, the inner diameter of the through hole in the part into which the plug of the optical connector is inserted is suppressed by the press-fitting, and high inner diameter accuracy is maintained. In addition, the position and shape of the protrusions do not change.
Therefore, according to the present invention, it is possible to provide an optical receptacle capable of stable connection with high coupling efficiency with an optical fiber on the optical connector side.

Hereinafter, an optical receptacle and an optical module according to embodiments of the present invention will be described with reference to the drawings.
Embodiment 1 FIG.
As shown in FIG. 1, the optical receptacle according to the first embodiment of the present invention is configured by fixing one end of a sleeve 10 to a holder 20 having an inner hole 24 for transmitting light. By inserting the plug 50 on the optical connector side fixed by the ferrule 51 into the through hole 10a, the light transmitted through the inner hole 24 and the optical fiber 52 are optically coupled.

In the optical receptacle of the first embodiment, the holder 20 is, for example, a cylindrical holder having a first main surface 21 and a second main surface 22 facing each other, such as stainless steel, copper, iron, Made of metal such as nickel. Further, in the holder 20 of the first embodiment, a groove-shaped concave portion into which one end of the sleeve 10 is press-fitted is provided in a ring shape on the first main surface 21 side, thereby forming the press-fitting portion 23. A protrusion 25 protruding from the bottom surface 23 b is formed at a substantially central portion of the press-fit portion 23. Further, the holder 20 is provided with an inner hole 24 penetrating from the distal end surface 25 a of the protrusion 25 to the second main surface 22. The outer peripheries of the inner hole 24 and the press-fit portion 23 are formed so as to be coaxial, and preferably the outer periphery of the protrusion 25 (that is, the inner periphery of the press-fit portion 23) is also the outer periphery of the inner hole 24 and the press-fit portion 23. It is formed to be coaxial.
Here, particularly in the holder 20 of the first embodiment, the outer diameter of the protrusion 25 is set smaller than the inner diameter of the through hole 10 a of the sleeve 10, and the tip surface 25 a protrudes from the first main surface 21. A protrusion 25 is formed on the surface.

  In the optical receptacle according to the first embodiment, the sleeve 10 is a cylindrical body having a through hole 10a having a diameter substantially the same as the outer diameter of the plug 50 of the optical connector. That is, the plug 50 of the optical connector includes an optical fiber 52 and a ferrule 51 that holds the optical fiber 52 in its center hole, and the inner diameter of the through hole 10 a of the sleeve 10 is substantially equal to the outer diameter of the ferrule 51. Is set as follows.

  In the first embodiment, the sleeve 10 is press-fitted into the press-fit portion 23 so that the sleeve 10 contacts the bottom surface 23 b of the press-fit portion 23 and the outer peripheral surface of the one end is in contact with the outer peripheral wall 23 a of the press-fit portion 23. In the first embodiment, the sleeve 10 is press-fitted until it comes into contact with the bottom surface 23b of the press-fit portion 23. However, the sleeve 10 may not be brought into contact with the bottom surface 23b as long as the sleeve 10 can be sufficiently fixed.

Examples of the material constituting the sleeve 10 include zirconium oxide (zirconia), aluminum oxide (alumina), mullite, silicon nitride, silicon carbide, aluminum nitride, and the like, ceramics containing these as main components, and glass ceramics such as crystallized glass. , phosphor bronze, beryllium copper, brass, metal such as stainless steel, etc. plastics such as epoxy or a liquid crystal polymer and the like, preferably among them resistance to weathering and toughness excellent zirconia ceramics (ceramics mainly zirconia) is It is. Among zirconia-based ceramics, in particular, at least one selected from the group consisting of zirconium oxide (ZrO ₂ ) as a main component and Y ₂ O ₃ , CaO, MgO, CeO ₂ , Dy ₂ O _{3 and the} like is used as a stabilizer. Partially stabilized zirconia ceramics (mainly tetragonal crystals) are included as a more preferable material from the viewpoints of wear resistance and elastic deformation.

  In the optical receptacle of the first embodiment configured as described above, one end portion of the sleeve 10 is press-fitted into the press-fit portion 23, but the tip surface 25 a protrudes from the first main surface 21 in the holder 20. Thus, the tip end of the plug 50 can be brought into contact with the tip end face 25a of the projection portion 25 without inserting the plug 50 of the optical connector up to the press-fitted portion of the sleeve 10. .

That is, since one end portion of the sleeve 10 is press-fitted into the press-fit portion 23, the inner diameter of the through hole 10a at the one end portion may be smaller than that before press-fit. However, in the optical receptacle according to the first embodiment, since the insertion portion into which the plug 50 is inserted is not deformed by press-fitting, high inner diameter accuracy within ± 1 μm , for example, is maintained.

  In the optical receptacle according to the first embodiment, when the outer diameter of the protrusion 25 is set smaller than the inner diameter of the through hole 10a of the sleeve 10 in the holder 20 and one end of the sleeve 10 is press-fitted into the press-fitting part 23. In addition, since the outer periphery of the protrusion 25 is separated from the inner periphery of the through hole 10a, the position and shape of the protrusion 25 do not change even when the inner diameter of the through hole 10a changes due to press-fitting.

  As described above, in the optical receptacle according to the first embodiment of the present invention, when one end portion of the sleeve 10 is press-fitted into the press-fit portion 23, the inner diameter of the through hole 10a at least in the portion where the plug 50 is inserted is press-fitted. Therefore, the high inner diameter accuracy is maintained, and the position and shape of the protrusion 25 are not changed. Therefore, high coupling efficiency between the inner hole 24 and the optical fiber 52 can be stably obtained.

Embodiment 2. FIG.
The optical receptacle according to the second embodiment of the present invention is configured by a separate optical waveguide (first member) instead of the protrusion 25 formed integrally with the holder 20 in the optical receptacle according to the first embodiment. 2 except that a counterbore 26 is formed on the side into which the sleeve 10 is press-fitted in the press-fitting hole 23 (FIG. 2).
In the optical receptacle according to the second embodiment, the optical waveguide is inserted into a through-hole penetrating from the bottom surface 23b of the press-fit hole 23 to the second main surface 22, and the tip surface 35a of the projection 35 is a spot facing portion. 26 is fixed at a position protruding from the bottom surface 26d. This optical waveguide is fixed by press-fitting into a through-hole penetrating from the bottom surface 23 b of the press-fit hole 23 to the second main surface 22.
The optical waveguide is formed of a cylindrical body having an inner hole 24 in the center, and the material thereof is, for example, a single substance such as zirconium oxide (zirconia), aluminum oxide (alumina), mullite, silicon nitride, silicon carbide, and aluminum nitride. Alternatively, ceramics including these as main components, phosphor bronze, beryllium copper, brass, stainless steel, etc., and plastics such as epoxy and liquid crystal polymer can be used. Here, as a material of the optical waveguide, in view of the fact that the distal end surface 35a of the optical waveguide is in contact with the distal end of the plug 50, ceramics having excellent wear resistance are used from the viewpoint of suppressing deterioration of the distal end surface 35a. It is preferable to use it.
On the other hand, if ceramic is used for the optical waveguide, the portion (second member) constituting the portion other than the optical waveguide of the holder 20 is fixed to the holder 20 by press-fitting the optical waveguide. It is preferable to use a metal that can be press-fitted efficiently.

  In the optical receptacle according to the second embodiment configured as described above, the protrusion 35 is formed by providing the optical waveguide so that the front end surface 35 a protrudes from the bottom surface 26 a of the counterbore portion 26 in the holder 20. Therefore, the distal end of the plug 50 can be brought into contact with the distal end surface 35 a of the protrusion 35 without inserting the plug 50 of the optical connector up to the press-fitted portion of the sleeve 10.

  In the optical receptacle according to the second embodiment, in the holder 20, the outer diameter of the protrusion 35 is set smaller than the inner diameter of the through hole 10 a of the sleeve 10, and one end of the sleeve 10 is press-fitted into the press-fitting part 23. In addition, since the outer periphery of the protrusion 35 is separated from the inner periphery of the through hole 10a, the position and shape of the protrusion 35 do not change even when the inner diameter of the through hole 10a is changed by press fitting.

  Therefore, in the optical receptacle according to the second embodiment of the present invention, high coupling efficiency between the inner hole 24 and the optical fiber 52 can be stably obtained. Furthermore, in the optical receptacle according to the second embodiment of the present invention, the holder 20 is composed of a first member (optical waveguide) that constitutes the protrusion 35, and a portion other than the protrusion 35 is composed of another second member. Therefore, since the complicated manufacturing process which integrally manufactures the holder 20 provided with the projection part 35 can be omitted, the manufacture of the holder 20 is simplified. In Embodiment 2, if ceramic having wear resistance is used for the first member, even if the tip of the plug 50 is brought into contact with the tip surface 35a of the projection 35, the tip 35a on the tip 35a. Wear can be suppressed and reliability can be improved.

Embodiment 3 FIG.
The optical receptacle according to the third embodiment of the present invention is the same as the optical receptacle according to the first embodiment, in which the counterbore 26 is formed on the side into which the sleeve 10 is press-fitted in the press-fitting hole 23, and the tip of the protrusion 25 is formed. The structure is the same as that of the first embodiment except that a counterbore portion 24a having a diameter larger than the diameter of the inner hole 24 is formed and the antireflection means 36 including the pinhole window 36a is provided in the counterbore portion 24a. (FIG. 3).
In the optical receptacle according to the third embodiment, the protruding portion 25 is formed so that the front end surface 25 a of the protruding portion 25 protrudes from the bottom surface 26 d of the spot facing portion 26.

The optical receptacle of the third embodiment configured as described above has the same function and effect as the optical receptacle of the first embodiment.
That is, in the holder 20, the protrusion 25 is formed by providing the optical waveguide so that the front end surface 25 a protrudes from the bottom surface 26 a of the counterbore portion 26, so that the plug 50 of the optical connector is pressed into the sleeve 10. The distal end of the plug 50 can be brought into contact with the distal end surface 25a of the protrusion 25 without inserting the portion.

  In the optical receptacle of the third embodiment, when the outer diameter of the protrusion 25 is set smaller than the inner diameter of the through hole 10a of the sleeve 10 in the holder 20 and one end of the sleeve 10 is press-fitted into the press-fitting part 23. In addition, since the outer periphery of the protrusion 25 is separated from the inner periphery of the through hole 10a, the position and shape of the protrusion 25 do not change even when the inner diameter of the through hole 10a is changed by press fitting.

  Therefore, in the optical receptacle according to the third embodiment of the present invention, high coupling efficiency between the inner hole 24 and the optical fiber 52 can be stably obtained.

Furthermore, since the optical receptacle of the third embodiment is provided with the antireflection means 36 having the pinhole window 36a at the tip portion of the projection 25, for example, a laser diode is provided behind the second main surface. When the laser light is used to be input to the optical fiber 52 of the optical connector, it is possible to prevent the laser light reflected by the tip surface of the plug 50 from returning to the laser diode as the light source.
The antireflection means 36 is formed of, for example, a flat plate and is made of a metal such as stainless steel, plastics, ceramics, or the like, and has a pinhole window 36a formed of a small hole through which the laser beam transmitted through the inner hole 24 can pass. Has been. Furthermore, if the antireflection film 36 is coated with an antireflection film made of black chrome plating or the like for reducing the reflected light on the main surface on the protrusion 35 side, the antireflection effect of light is further enhanced. Can do.

Embodiment 4 FIG.
The optical receptacle according to the fourth embodiment of the present invention is configured in the same manner as in the first embodiment except that a light-transmissive member 37 is provided in the inner hole 24 in the optical receptacle according to the first embodiment (see FIG. 4).
Here, in the optical receptacle according to the fourth embodiment, if a translucent member having a refractive index close to that of the optical fiber of the plug, that is, an optical fiber made of quartz is used, a high temperature such as fused silica is used. It is preferable to use pure quartz or a glass material that requires a refractive index equivalent to that of quartz, which can reduce the Fresnel reflection at the contact portion of the plug with the optical fiber, thereby further improving the coupling efficiency. be able to.

  The optical receptacle of the fourth embodiment configured as described above has the same function and effect as the optical receptacle of the first embodiment, and can further increase the coupling efficiency between the inner hole 24 and the optical fiber 52.

Embodiment 5 FIG.
The optical receptacle according to the fifth embodiment of the present invention is configured such that, in the optical receptacle according to the second embodiment, a fiber stub 40 including an optical fiber 42 and a ferrule 41 is used instead of a separate optical waveguide. Except for this, the configuration is the same as in the second embodiment (FIG. 5).

Ferrule 41 is made of a material such as zirconium oxide (zirconia), aluminum oxide (alumina), mullite, silicon nitride, silicon carbide, aluminum nitride, or the like, ceramics containing these as main components, or glass ceramics such as crystallized glass. , phosphor bronze, beryllium copper, brass, metal such as stainless steel, etc. plastics such as epoxy or a liquid crystal polymer and the like, preferably among them resistance to weathering and toughness excellent zirconia ceramics (ceramics mainly zirconia) is It is. Among zirconia-based ceramics, in particular, at least one selected from the group consisting of zirconium oxide (ZrO ₂ ) as a main component and Y ₂ O ₃ , CaO, MgO, CeO ₂ , Dy ₂ O _{3 and the} like is used as a stabilizer. Partially stabilized zirconia ceramics (mainly tetragonal crystals) are included as a more preferable material from the viewpoints of wear resistance and elastic deformation.

  In the optical receptacle of the fifth embodiment configured as described above, the same effect as that of the optical receptacle of the second embodiment can be obtained, and the optical fiber 42 of the same material as the optical fiber 52 of the plug 50 is used as the fiber. Since it can also be applied to the stub 40, reflection at the contact portion between the optical fiber 52 and the optical fiber 40 can be made extremely small. Further, the back end surface 40b of the fiber stub 40 is an inclined surface that is inclined 5 degrees to 10 degrees with respect to the axial direction of the optical fiber 40, so that the reflection return to the laser disposed on the rear end side of the fiber stub 40 is achieved. It becomes possible to prevent light.

Embodiment 6 FIG.
Embodiment 6 according to the present invention is an optical module including the optical receptacle of Embodiment 5 and an optical element module 70 (FIG. 6).
In the optical module according to the sixth embodiment, the optical element module 70 includes an optical element 73 that is a light emitting element or a light receiving element mounted on a stem 72 and sealed by a cap 71, and a window portion 75 of the cap 71. Light is input / output through a lens 74 provided in the.
In addition, a jack 61 into which the cap portion of the optical element module 70 is fitted is attached to the second main surface of the optical receptacle by laser welding, resistance welding, an adhesive, or the like.
As described above, the cap portion of the optical element module 70 is inserted into the jack 61 attached to the optical receptacle, and the lens 74 of the window portion 75 is positioned so as to be connected to the input / output end of the optical fiber of the fiber stub. Adjust to fix.

  The optical module according to the sixth embodiment configured as described above is configured using the optical receptacle according to the fifth embodiment of the present invention in which high coupling efficiency can be stably obtained with the optical fiber 52 of the optical connector. Therefore, high coupling efficiency can be stably obtained between the optical element module 70 and the optical fiber 52 of the optical connector.

  In the above sixth embodiment, the optical receptacle according to the fifth embodiment of the present invention is used. However, the present invention is not limited to this, and the optical receptacle according to another embodiment of the present invention is used. You may comprise.

It is sectional drawing which shows the structure of the optical receptacle of Embodiment 1 which concerns on this invention. It is sectional drawing which shows the structure of the optical receptacle of Embodiment 2 which concerns on this invention. It is sectional drawing which shows the structure of the optical receptacle of Embodiment 3 which concerns on this invention. It is sectional drawing which shows the structure of the optical receptacle of Embodiment 4 which concerns on this invention. It is sectional drawing which shows the structure of the optical receptacle of Embodiment 5 which concerns on this invention. It is sectional drawing which shows the structure of the optical receptacle of Embodiment 6 which concerns on this invention.

Explanation of symbols

10 Sleeve, 10a Through-hole, 20 Holder, 21 First main surface, 22 Second main surface, 23 Press-fit portion, 23a Outer peripheral wall, 23b Bottom surface, 24 Inner hole, 25, 35 Projection portion, 25a, 35a Tip surface , 26 counterbore, 26a bottom surface,
36a Pinhole window, 36 cover, 37 translucent member, 40 fiber stub, 41 ferrule, 42 optical fiber, 50 plug, 52 optical fiber,
70 optical element module, 71 cap, 72 stem, 73 optical element, 74 lens, 75 window part.

Claims (7)

A groove-shaped press-fit portion provided on the first main surface side, having a first main surface and a second main surface facing each other, a protrusion projecting from the bottom surface of the press-fit portion, and the protrusion A holder that includes an inner hole that penetrates the second main surface from the distal end surface of the portion and transmits light therein;
A sleeve having a through hole and press-fitted into the press-fitting portion,
The outer diameter relative to the inner diameter of the through hole is Ru same diameter der plug of the optical connector is inserted into the through hole, when held, the tip of the plug abuts the end surface of the protrusion,
The outer diameter of the protrusion protruding from the bottom surface of the press-fit portion is set smaller than the inner diameter of the through-hole, the outer peripheral surface of the protrusion is located away from the inner peripheral surface of the through-hole of the sleeve, and An optical receptacle characterized in that a tip end surface of a protruding portion protrudes from a press-fitted portion of the sleeve.   The optical receptacle according to claim 1, wherein the holder includes a first member including the protrusion and a second member different from the first member.   The optical receptacle according to claim 2, wherein the first member is made of ceramics, and the second member is made of metal.   4. The reflected light preventing means for preventing reflection of light traveling from the second main surface toward the tip end surface of the protrusion is provided in the inner hole. Optical receptacle according to crab.   The optical receptacle according to claim 1, wherein the inner hole is filled with a translucent material. The first member is a fiber stub composed of a cylindrical body having the inner hole and an optical fiber inserted into the inner hole,
The second member includes the press-fit portion and an insertion hole penetrating from the bottom surface of the press-fit portion to the second main surface,
3. The optical receptacle according to claim 2, wherein the fiber stub is inserted into the insertion hole, and an outer peripheral surface of the protrusion is positioned away from an inner peripheral surface of the through hole of the sleeve via a gap. An optical receptacle according to any one of claims 1 to 6;
An optical element that receives light from the second main surface side into the inner hole, or receives light emitted from the second main surface side through the inner hole;
An optical module comprising: a housing fixed to the optical receptacle and accommodating the optical element.

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