JP2007188071A - Light receptacle and optical module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive light receptacle which can highly precisely assembled, and has a high reliability. <P>SOLUTION: The light receptacle is optically coupled with an optical fiber held by a ferrule and includes: a cylindrical sleeve having an inner hole to which the ferrule is inserted; and a stopper member having a front end face to which one end face of the ferrule is abutted, a rear end face and a through-hole which penetrates from the front end face to the rear end face, and being so arranged in the inner hole of the sleeve that the front end face and the rear end face are located inside both ends of the inner hole of the sleeve, wherein the inner diameter of the contact part, with which the outer periphery of the stopper member is made in contact, is larger than the diameter of the inner hole of the non-contact part expect the contact part. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a receptacle used for an optical communication module or the like.

  In recent years, information communication has a tendency to increase in speed and capacity, and optical communication technology is used to cope with it. In general, in optical communication, an electrical signal is converted into an optical signal, the optical signal is transmitted using an optical fiber, and the received optical signal is converted into an electrical signal. The conversion between the electrical signal and the optical signal is performed by an optical element such as a semiconductor laser or a photodiode, and an optical receptacle is used to couple the optical element and the optical fiber.

  Optical receptacles include fiber stubs that hold optical fibers or those that use hollow stoppers. For relatively low-speed optical communication modules between 155 Mbps and 1 Gbps, hollow stoppers are used. Depending on the application, it is used properly. For example, Patent Document 1 discloses an optical receptacle in which a fiber stub is inserted into an inner hole of a sleeve and fixed with an adhesive. In the optical receptacle of this Patent Document 1, the ferrule on the optical connector side is inserted into the inner hole of the sleeve and is brought into contact with one end of the fiber stub.

Patent Documents 2 and 3 disclose optical receptacles for low-speed optical modules. The thing of the structure of patent document 2 is shown in FIG. In the optical receptacle of this patent document 2, the ferrule 15 of the optical connector comes into contact with the stopper surface 17. Patent Document 3 discloses a structure in which a stopper with which the tip of the ferrule contacts is made of ceramic.
JP 2005-99748 A JP 2004-287198 A Japanese Utility Model Publication No. 6-40903

  However, in the optical receptacle disclosed in Patent Document 1, since the fiber stub is inserted into the inner hole of the sleeve and fixed with an adhesive, the adhesive is uniformly applied to prevent the fiber stub from being eccentric. There was a problem that the manufacturing cost could not be reduced, such as the need for innovation.

  Further, in the optical receptacle of Patent Document 2, since the stopper surface 17 against which the ferrule 15 of the optical connector is made of metal, durability against repeated collision of the ferrule 15 or wear powder generated on the stopper surface 17 is caused by the inner diameter portion of the sleeve 1. There is a problem such as deterioration of the insertability of the ferrule 15 due to adhering to 18. In particular, the receptacle sleeve used for the single mode has a clearance between the inner diameter and the outer diameter of the ferrule of the optical connector of about 1 μm to 2 μm. Even if a small amount of abrasion powder adheres to the inner diameter, the optical connector Problems such as inability to insert or remove ferrules occur.

  Further, in the optical receptacle in which the stopper is made of ceramic as in Patent Document 3, there is a problem that the number of parts is increased or the inner diameter of the sleeve is polished and accuracy control is required after the sleeve is assembled, and the manufacturing cost cannot be reduced.

  Accordingly, an object of the present invention is to provide an optical receptacle that can be assembled with high accuracy, has high reliability, and is inexpensive.

An optical receptacle according to the present invention is an optical receptacle to which an optical fiber held by a ferrule is optically connected, and a cylindrical sleeve into which the ferrule is inserted and a distal end at which one end surface of the ferrule abuts. An inner surface of the sleeve such that the front end surface and the rear end surface are located inside both ends of the inner hole of the sleeve. A stopper member disposed in the hole, and a diameter of the inner hole of the sleeve is larger in a non-contact portion excluding the contact portion than a contact portion in contact with an outer periphery of the stopper member. And
In the present invention, the non-contact part includes taper parts on both sides of the contact part, the inner diameter of which gradually decreases as the distance from the contact part increases.
Moreover, in this invention, the length of the axial direction of the taper part located in the said front end surface side among the said taper parts is less than 0.5 mm, It is characterized by the above-mentioned.
Moreover, in this invention, the edge part by the side of the said front end surface in the through-hole of the said stopper member is chamfered, It is characterized by the above-mentioned.
Further, in the present invention, the stopper member is filled with a translucent member made of resin or glass in the through hole, and the translucent member has a uniform refractive index. . Furthermore, the refractive index of the translucent member is in the range of 1.35 to 1.45.
In the present invention, the stopper member is made of ceramics. Furthermore, in the present invention, the sleeve is made of the same material as the stopper member.
Further, in the present invention, it further comprises a holder having a sleeve press-fitting hole, and the sleeve is press-fitted into the sleeve press-fitting hole from the end face side thereof, and the end face of the sleeve is in the sleeve press-fitting hole, The insertion length of the sleeve press-fitted into the sleeve press-fitting hole is shorter than the distance between the front end surface of the stopper member and the end surface of the sleeve.
In the present invention, the diameter of the through hole of the stopper member is larger than the diameter of the through hole of the ferrule.
An optical module according to the present invention is an optical receptacle to which an optical fiber held by a ferrule is optically connected, and a tip of which a cylindrical sleeve into which the ferrule is inserted and an end surface of the ferrule are in contact with each other A through hole penetrating from the front end surface to the rear end surface. The front end surface and the rear end surface are located inside the inner holes of the sleeve so as to be located inside the inner holes of the sleeve. An optical receptacle having a diameter larger than that of the non-contact portion except for the contact portion, and the stopper. An optical element optically connected to the through-hole of the member, and a housing that is connected to the optical receptacle and accommodates the optical element.
The optical element is a light emitting element that emits light toward the through hole of the stopper member. Further, the light emitting element is a laser element selected from a Fabry-Perot laser element and a surface emitting laser element.
In the present invention, the optical element is a light receiving element that receives light transmitted through the through hole of the stopper member.
Further, in the present invention, the optical receptacle further includes a holder having a sleeve press-fitting hole, and the sleeve is press-fitted into the sleeve press-fitting hole from the end surface side thereof, and the optical element and the stopper member have a through hole. The holder and the housing are connected via a connecting member so as to be optically coupled, and the connecting member and the holder joint portion are welded in a linear shape.

In the optical receptacle configured as in the present invention, the diameter of the inner hole of the sleeve is larger in the non-contact portion excluding the contact portion than the contact portion in contact with the outer periphery of the stopper member. The stopper can be held with a sufficient holding force against the force applied when inserting the ferrule of the optical connector.
In addition, the optical receptacle configured as in the present invention can hold the stopper with high accuracy by press-fitting a stopper having an outer shape larger than the inner diameter of the sleeve into the inner hole of the sleeve, so that the manufacturing process can be simplified and the manufacturing cost can be reduced. Can be made inexpensively.
Therefore, according to the present invention, all components can be fixed without using an adhesive or the like, and therefore, a highly accurate optical receptacle that can be assembled with high accuracy can be supplied at low cost. .

As shown in FIG. 1A and the like, an optical receptacle according to the present invention is a component that constitutes a part of an optical connector and an optical module including a sleeve 1, a stopper 2, and a sleeve holder 3, and is combined with a plug. Thus, the optical fiber held by the plug ferrule 15 is optically connected.
Here, in particular, the optical receptacle according to the present invention is characterized in that the diameter of the inner hole on the one end side of the sleeve 1 is smaller than the outer diameter of the stopper 2 inserted into the inner hole, and this will be described later. Have
Hereinafter, an optical receptacle according to an embodiment of the present invention and an optical module using the optical receptacle will be described with reference to the drawings.

First Embodiment FIG. 1A is a cross-sectional view showing an optical receptacle according to a first embodiment of the present invention.

The optical receptacle according to the first embodiment is arranged in a cylindrical sleeve 1 having an inner hole into which a plug ferrule 15 holding an optical fiber is inserted, and an inner hole 4 of the sleeve 1 and its distal end. A stopper 2 with which one end surface of the plug ferrule 15 is brought into contact with the surface 11 and a holder 3 having a sleeve press-fitting hole are provided, and the sleeve 1 is press-fitted into the sleeve press-fitting hole from the end face 6 side.
In the optical receptacle according to the first embodiment, the stopper 2 is formed so that not only the front end surface 11 contacting the plug ferrule 15 but also the rear end surface 5 thereof is positioned on the inner side of one end surface 6 of the sleeve 1. The diameter of the inner hole of the portion (contact portion) that is press-fitted into the inner hole and is in contact with the outer periphery of the stopper 2 is larger than the diameter of the inner hole of the non-contact portion excluding the contact portion.

  That is, in the optical receptacle according to the first embodiment, the stopper 2 is formed from the end surface 6 side (one end side) of the sleeve 1 with the stopper 2 having an outer diameter larger than the diameter of the inner hole of the sleeve 1. By press-fitting into the hole, the stopper 2 is held at a predetermined position in the inner hole. As a result, the sleeve 1 is elastically deformed so that the diameter of the inner hole of the contact portion 40 with which the outer periphery of the stopper 2 is in contact is substantially the same as the outer diameter D1 of the stopper 2. The diameter of the inner hole of the non-contact portion with the outer periphery is smaller than the inner diameter of the contact portion.

Further, in the first embodiment, the holder 3 having a sleeve press-fitting hole is further provided, and the sleeve 1 is press-fitted into the sleeve press-fitting hole from the terminal end face 6 side. The diameter of the 1 inner hole portion 41 is further reduced.
Specifically, the end surface 6 of the sleeve 1 is positioned in the sleeve press-fitting hole of the holder, and the insertion length of the sleeve 1 press-fitted into the sleeve press-fitting hole is between the front end surface 11 of the stopper 2 and the end surface 6 of the sleeve 1. It is set to be shorter than the distance. Thereby, as for the sleeve 1, the 1st inner-hole part 41 in the one end surface 6 side is compressed by the holder, and the diameter of the 1st inner-hole part 41 becomes still smaller (FIG. 1B).
As the material of the sleeve holder 3, a material having excellent weldability such as SUS metal is usually used.

Thus, in the first embodiment, since the diameter of the first inner hole portion 41 is further reduced by the compression by the holder, the force for holding the stopper 2 (holding force in the direction in which the load is applied when the plug ferrule is inserted) Can be improved. When the plug ferrule 15 is brought into contact with the stopper 2, the pressing force from the plug ferrule to the stopper is about 1 kgf or less. The deformation of the sleeve in the direction in which it is difficult to come off is effective in improving the holding force.
On the other hand, since the sleeve 1 is not compressed by the holder 3 at the distal end side of the stopper 2, the deformation of the inner diameter of the second inner hole portion 42 of the sleeve 1 is suppressed, and the inner diameter accuracy during processing is maintained. Furthermore, in addition to the sleeve 1 not being compressed by the holder 3 on the distal end side of the stopper 2, a hollow cylindrical stopper is press-fitted into the inner diameter portion of the sleeve, so that a plug ferrule 15 corresponding to an optical connector is provided. Shrinkage of the inner diameter of the sleeve on the insertion side can be suppressed.

  As described above, in the first embodiment, the end surface 5 of the stopper 2 is fixed to a position recessed inward from the end surface 6 on the one end side of the sleeve 1 so that the first inner hole portion 41 is formed. Thus, the sleeve 1 is press-fitted into the sleeve press-fitting hole of the holder to deform the first inner hole portion 41 to improve the holding strength of the stopper 2. In order to effectively improve the holding strength, the rear end surface 5 of the stopper 2 is preferably recessed by 0.2 mm or more from the end surface 6 on the one end side of the sleeve. That is, the distance X between the terminal end surface 6 of the sleeve 1 and the rear end surface 5 of the stopper 2 is preferably 0.2 mm or more.

  Further, in the optical receptacle according to the first embodiment, the inner hole of the sleeve 1 is deformed by the press-fitting of the stopper 2, so that it gradually increases toward the both sides of the contact part 40 in the non-contact part as the distance from the contact part 40 increases. A tapered portion with a reduced inner diameter is formed.

  That is, the first inner hole portion 41 includes a tapered portion 41b whose inner diameter gradually decreases as the distance from the contact portion 40 increases, and a first constant diameter portion 41a whose inner diameter is substantially constant. The taper portion 42b has an inner diameter that gradually decreases with increasing distance from the contact portion 40, and a second constant diameter portion 42a having a substantially constant inner diameter. As is clear from FIG. 1B, the first constant diameter portion 41a is connected at the portion with the smallest diameter of the taper portion 41b, has the same diameter as the minimum diameter of the taper portion 41b, and the second constant diameter portion. 42a is connected at the smallest diameter portion of the tapered portion 42b, and has the same diameter as the minimum diameter of the tapered portion 42b.

As described above, in the first embodiment, since only the first inner hole portion 41 on the one end surface 6 side is compressed by the holder, the diameter of the first constant diameter portion 41a is set to the stopper 2. The diameter of the second constant diameter portion 42a is kept substantially the same as the diameter of the inner hole before the stopper 2 is press-fitted. Yes.
That is, the inner diameter of the inner hole 4 (second constant diameter portion 42a) on the side where the plug ferrule 15 of the sleeve 1 is inserted is the inner diameter D2 before the stopper 2 is press-fitted by press-fitting the sleeve 1 into the sleeve holder 3. It will never be smaller. Therefore, in the first embodiment, after the sleeve 1 is press-fitted into the sleeve holder 3, the plug ferrule 15 can be inserted into the sleeve 1 without reworking to increase the diameter of the inner hole of the sleeve 1. .

In addition, if the deformation of the second inner hole portion 42 is kept relatively small in this way, the inserted plug ferrule 15 (of the optical connector) can be held at a long distance, and the inclination of the plug ferrule can be suppressed. Thereby, connector connection loss and its dispersion | variation can be reduced.
That is, if the inner diameter deformation region (second taper portion 42b) of the sleeve 1 on the side where the plug ferrule 15 is inserted is large, the plug ferrule 15 is not held by the second taper portion 42b. There is a risk that the axis will shift when. When such an axis deviation occurs, the light emitted from the optical fiber may be reflected by the end face of the stopper 2.
Accordingly, in the present invention, the length of the second taper portion 42b is preferably short, and specifically, the length of the second taper portion 42b is preferably set within 0.5 mm from the stopper end surface.

  Thus, in the first embodiment, the first inner hole portion is formed by positioning the press-fitting portion 8 of the sleeve 1 press-fitted into the sleeve holder 3 so as to cover the portion of the sleeve 1 whose inner diameter is desired to be deformed. The stopper 2 is elastically deformed so that only the diameter of 41 becomes smaller.

  Moreover, in this 1st Embodiment, compared with the diameter of the contact part 40 with which the outer periphery of the stopper 2 is contacting in the inner hole 4, it is a non-contact part (the 1st inner hole part 41 and the 2nd inner hole part) The diameter of the first inner hole 41 on one end side of the sleeve 1 is preferably smaller than the outer diameter of the stopper 2 by 0.5 μm or more.

  That is, the outer diameter D1 of the stopper 2 before being press-fitted into the sleeve 1 is processed to be larger than the diameter D2 of the inner hole of the sleeve 1 before the stopper 2 is press-fitted by 0.5 μm or more.

  Further, when the outer diameter D1 of the stopper 2 before press-fitting is made larger than the inner diameter D2 of the sleeve 1 before press-fitting by 0.5 μm or more, when the sleeve 1 is press-fitted into the sleeve holder 3, The shrinkage deformation of the inner diameter of the second inner hole portion 42 on the side where the plug ferrule 15 is inserted can be suppressed.

If the outer diameter D1 of the stopper 2 before press-fitting into the sleeve 1 is larger than the diameter D2 of the inner hole of the sleeve 1 before press-fitting the stopper 2 by 5.5 μm or more, the force required to press-fit the stopper 2 Becomes larger and it becomes difficult to press-fit the stopper 2.
Therefore, the outer diameter D1 of the stopper 2 before being press-fitted into the sleeve 1 is preferably set in the range of 0.5 to 5.5 μm.

  As described above, in the optical receptacle of the first embodiment, the stopper 2 is press-fitted into the inner hole 4 of the sleeve 1 to deform the inner hole 4, and the sleeve 1 is further press-fitted into the holder 3. By contracting the first inner hole portion 41 in the hole 4, the stopper 2 is fixed in the inner hole 4 of the sleeve 1 without using an adhesive. Further, after press-fitting the stopper 2 into the sleeve 1, the difference between the diameter of the inner hole of the sleeve 1 at the contact portion between the stopper 2 and the sleeve 1 and the second constant diameter portion 42a of the sleeve 1 is 0.1-2. About 0.0 μm. This is because the diameter of the inner hole of the sleeve 1 is increased by press-fitting the stopper 2, and the outer diameter of the stopper 2 is reduced by press-fitting. In addition, after press-fitting the stopper 2 into the sleeve 1, the difference between the outer diameter of the sleeve 1 corresponding to the contact portion between the stopper 2 and the sleeve 1 and the outer diameter of the sleeve 1 corresponding to the contacted portion is also present. It is about 0.1-2.0 micrometers.

In the first embodiment, the insertion length of the sleeve 1 that is press-fitted into the sleeve press-fitting hole is set to be shorter than the distance between the front end surface 11 of the stopper 2 and the end surface 6 of the sleeve 1. The front end surface 11 protrudes toward the other end surface 19 side of the sleeve 1 and the sleeve holder. Thereby, the diameter of the inner hole 4 of the sleeve 1 into which the plug ferrule 15 is inserted does not become smaller than the outer diameter D1 before the stopper 2 is press-fitted by press-fitting the sleeve 1 into the sleeve holder 3.
In assembling the optical receptacle, the stopper 2 is first press-fitted into the inner hole 4 of the sleeve 1. The pressure input at this time is desirably 100 N or more. For positioning the stopper 2 in the axial direction of the sleeve 1, for example, a dummy ferrule having a size equivalent to that of the plug ferrule 15 may be used. Specifically, first, a dummy ferrule is inserted from the insertion side of the plug ferrule 15 of the sleeve 1. Then, the stopper 2 is positioned at the position of the tip surface of the dummy ferrule. That is, the stopper 2 can be press-fitted to a predetermined position by being press-fitted from the terminal end side of the sleeve 1 until the tip end surface of the stopper 2 comes into contact with the tip end face of the dummy ferrule. Thereafter, the stopper 2 can be positioned by removing the dummy ferrule from the sleeve 1. Finally, the optical receptacle is completed by press-fitting the sleeve 1 into which the stopper 2 is press-fitted into the sleeve holder 3.

  In the optical receptacle of the first embodiment described above, the stopper 2 can be press-fitted into the sleeve 1 before the sleeve 1 is press-fitted into the sleeve holder 3. The degree of freedom can be improved.

  Here, in the optical receptacle of the first embodiment, the sleeve press-fitting hole of the sleeve holder 3 is formed into a two-stage structure having a narrow diameter portion and a thick diameter portion, and the press fit portion of the sleeve is press-fitted into the thin diameter portion. The thicker part on the upper side covers the entire part where the stopper 2 of the sleeve 1 is press-fitted. However, the present invention is not limited to this, and it is not necessary to cover the entire stopper 2 fixed in the sleeve 1.

In the present invention, the stopper 2 and the sleeve 1 are preferably made of ceramics.
If the stopper 2 and the sleeve 1 are made of ceramics, all parts where the plug ferrules of the optical connector come in contact are made of ceramic, so there is no generation of metal wear powder generated when it is made of a metal material, excellent connector insertion property, and Stable stopper position accuracy can be obtained with respect to repeated attachment / detachment of the connector.
In addition, when the sleeve is made of ceramics which is an insulating material, current can be prevented from flowing into the optical element due to static electricity.

  In the manufacturing method of the sleeve 1 and the stopper 2 made of the above ceramics, first, a resin binder and other raw materials are kneaded with powder, and a molded body having the through-holes in advance is formed by injection molding, press molding or extrusion molding. Make and sinter it at high temperature. For the stopper, the outer diameter is ground or polished after sintering, and the total length is adjusted by grinding.

FIG. 3 shows a state in which the plug ferrule 15 that holds the optical fiber on the optical connector side is inserted into the sleeve 1 in the optical receptacle of the first embodiment. Here, in particular, the diameter of the through hole of the stopper 2 is preferably larger than the diameter of the through hole of the plug ferrule, so that the reflection of light at the tip surface 11 of the stopper 2 can be reduced.
That is, when the through hole of the stopper 2 is smaller than the through hole of the plug ferrule 15, the optical fiber 14 held by the plug ferrule 15 and the through hole of the stopper 2 are emitted from the optical fiber 14 when optically coupled. The possibility that light is reflected by the tip end surface of the stopper 2 is increased. In order to prevent this, the through hole of the stopper 2 is preferably larger than the through hole of the plug ferrule 15, and the upper limit is the diameter of the through hole of the stopper 2 because the present invention has a structure in which the stopper is press-fitted. Is preferably set to 5 times or less the diameter of the through hole of the plug ferrule 15.
For example, when a normal optical communication fiber is used, the diameter of the through hole of the plug ferrule 15 is 125 μm. Therefore, the diameter of the through hole of the stopper 2 is preferably larger than 125 μm and not more than 650 μm.

Second Embodiment Hereinafter, an optical module 100 according to a second embodiment of the present invention will be described.
As shown in FIG. 4, the optical module 100 of the second embodiment holds the optical receptacle 110, the lens 121, the optical element 123, the lens 121, and the optical element 123 according to the present invention at predetermined positions. And a housing 122 connected to the optical receptacle.
In the optical module 100 of the second embodiment, the optical receptacle 110 is configured in the same manner as the optical receptacle of the first embodiment, except that the shape of the stopper 102 is different from the stopper 2 of the first embodiment. ing.

That is, in the second embodiment, the rear end surface 105 of the stopper 102 is inclined with respect to the axis of the through hole (the axis of the through hole is not orthogonal to the rear end surface 105), and the inner hole of the front end surface It differs from the stopper 2 of the first embodiment in that the outer peripheral edge of the end and the tip surface is an R surface or C surface, but the other points are the same as the stopper 2 of the first embodiment. It is configured.
As described above, when the outer peripheral end of the distal end surface is the R surface or the C surface, the stopper 102 is easier to press into the inner hole of the sleeve 1 than the stopper 2. In order to effectively prevent the stopper 102 from being pressed and scratched, and the separation of the porcelain, the chamfering of the outer periphery can be set to a range of 0.03 mm to 0.15 mm regardless of the C surface and the R surface. Preferably, it is set to about 0.05 mm.

  Further, in the second embodiment, the inner hole end of the distal end surface is the R surface or C surface, and therefore, when the plug ferrule 15 is brought into contact with the distal end surface of the stopper, Occurrence of cracks and cracks can be prevented. In order to effectively prevent the occurrence of such cracks and cracks, the chamfering of the end of the inner hole should be set in the range of 0.02 mm to 0.15 mm regardless of the C surface and R surface. More preferably, it is set to about 0.05 mm.

  For the tip surface 11 of the stopper 2 with which the plug ferrule 15 contacts, for example, the edge of the ceramic is processed into an R surface or a C surface by polishing using a diamond slurry.

  In addition, about the sleeve 1, after processing an internal diameter with high precision by grinding | polishing process, an outer diameter is ground or grind | polished. Thereafter, the overall length is adjusted by grinding, and the end face portion is ground into an R surface by grinding with a diamond slurry after grinding the insertion port of the plug ferrule 15. This is also the case with the first embodiment.

In the optical module 100 of the second embodiment, the housing 122 to which the optical element 123 and the lens 121 are attached is connected to the holder 3 of the optical receptacle, and the through-holes of the optical element 123 and the stopper 102 of the optical receptacle are connected. Are optically coupled through the lens 121.
Here, a light emitting element or a light receiving element can be used as the optical element 123. That is, when the optical element 123 is a light emitting element, the light emitted from the light emitting element is incident on the lens 121, and the light is condensed in the through hole of the stopper 2 by the condensing function of the lens 121. This is an optical module for transmission that is optically coupled to the optical fiber 14 held at 15. On the other hand, when the optical element 123 is a light receiving element, the light emitted from the optical fiber 14 is transmitted through the through hole of the stopper 2, and the emitted light is optically coupled to the light receiving element via the lens 121. It becomes an optical module.
Further, as the light emitting element, for example, a DFB laser element, a Fabry-Perot laser element, or a surface emitting laser element can be used. In particular, Fabry-Perot laser elements and surface-emitting laser elements are less affected by reflected light returning to the laser element and are less likely to generate noise due to the reflected light. That is, in the optical module of the second embodiment, if the light emitting element is a Fabry-Perot laser element or a surface emitting laser element, the influence of reflected light at the boundary with the optical fiber held by the plug ferrule 15 can be reduced. Can do. Therefore, such an optical module eliminates the need for an optical fiber or the like for matching the refractive index with the optical fiber held by the plug ferrule 15 in the through hole of the stopper 2 of the optical receptacle 110, and reduces the number of components. It can be suitably used as an optical module for distance transmission.

Third Embodiment FIG. 5 is a sectional view showing a part of an optical module according to a third embodiment of the present invention.
The optical module according to the third embodiment is configured in the same manner as in the second embodiment, except that the structure of the holder 103 is different from that of the holder 3 in the first embodiment.
That is, the holder 3 of the second embodiment is configured such that one end face is flattened and, for example, when the end face is brought into contact with the joining surface of the casing when the optical element is arranged on the casing. However, in the optical module of the third embodiment, the holder 103 is brought into contact (welding) with the casing in contact with a line.

Specifically, in the third embodiment, the holder 103 is formed with a concave portion 103r having a diameter larger than the diameter of the sleeve press-fitting hole on one end surface to which the housing 122 is joined. The surface between them is inclined so that only the outer peripheral edge contacts the casing. Thus, in 3rd Embodiment, since it comprises so that it may contact with a housing | casing in the end surface of the holder 103, it can prevent that an optical receptacle inclines at the time of welding with a housing | casing, and is high It becomes possible to weld the housing with accuracy.
In other words, if the holder is configured so that one end surface thereof is flat and is in contact with the housing, the receptacle may be inclined during welding if the surface accuracy of the surface to be welded is low.
Therefore, when the one end surface of the holder is brought into contact with the housing by the surface, it is necessary to increase the surface accuracy of the surface to be welded (particularly, the welding surface of the other housing). However, if the contact is made with a line as in the fourth embodiment, the influence of surface accuracy can be reduced. That is, the accuracy of fixing the receptacle is less affected by the surface accuracy of the casing on the welding partner side.

Modifications In the optical receptacle of the first embodiment and the optical receptacles of the second and third embodiments, the through hole of the stopper 2 is hollow to simplify the configuration. However, the present invention is not limited to this, and the through hole of the stopper 2 may be filled with a translucent member. The refractive index of the translucent member may be uniform or may gradually decrease from the center toward the periphery.
In this case, a translucent member having a refractive index equivalent to that of the optical fiber (refractive index in the range of 1.35 to 1.45) is filled, and the tip of the optical fiber held by the plug ferrule 15 is filled with the translucent member. When closely attached to the sex member, reflection at that portion can be reduced.
Such a translucent member is not particularly limited, and for example, an acrylic resin, an epoxy resin, or the like can be used.

  Next, examples and comparative examples of the present invention will be described.

  As Example 1, an optical receptacle according to the first embodiment of the present invention shown in FIG.

  For the sleeve 1, metal, plastic, ceramic, or the like can be used. In Example 1, the sleeve 1 was made of zirconia ceramic having excellent inner diameter accuracy and wear resistance. In general, there are optical receptacles having an inner diameter of around 1.25 mm and those of around 2.5 mm. In the first embodiment, the optical receptacle is currently mainly used for low-speed optical modules. A 25 mm type was produced.

  The sleeve 1 was produced as follows. First, a molded body having through holes is produced by extrusion molding and fired at a high temperature. After firing, the inner diameter is processed to an accuracy of 1.25 mm + 0.001 mm / −0 mm by polishing.

  Further, the inner surface was processed so that the roughness of the inner surface was Ra 0.2 μm or less in order to reduce the plug ferrule insertability and frictional force. Next, it grinds until an outer diameter becomes a predetermined dimension, and also grinds to a predetermined dimension also about a full length. Then, the cone part 16 was formed in the insertion side of the plug ferrule 15 with the diamond tool. Finally, in order to prevent ceramic chipping or the like, the edge portions of both end faces of the sleeve 1 were removed by polishing with a diamond slurry.

  Next, the stopper 2 will be described. The material was made of the same zirconia ceramic as that of the sleeve 1. By using the same material, the difference in thermal expansion due to temperature changes can be made the same, so that the holding strength, stress, and the like can be stabilized. As a manufacturing method, a molded body having a through hole is manufactured by extrusion molding in the same manner as the sleeve 1 and fired at a high temperature.

  Thereafter, grinding and polishing are performed until the outer diameter reaches a predetermined dimension. Regarding the outer diameter, since it is necessary to press fit into the inner diameter of the sleeve 1, the outer diameter is set to be 0.5 μm or more larger than the inner diameter of the sleeve 1.

  Next, the entire length was ground until it reached a predetermined dimension, and the edge on the end surface on which the plug ferrule 15 abuts was removed by polishing with a diamond slurry and processed into an R surface.

  Next, after press-fitting the stopper 2 into the sleeve 1, the sleeve 1 was press-fitted into the sleeve holder 3. At this time, the press-fitting portion 8 of the sleeve holder 3 was adjusted so that the end surface 11 of the stopper 2 protruded from the sleeve holder 3 and the press-fitting portion 8 of the sleeve 1 by about 1 mm.

Further, the holding strength of the stopper 2 was measured by changing the length X of the indented portion from the end face 6 on the one end side of the sleeve 1 of the end face 5 of the stopper 2 in steps of 0.1 mm from 0 mm to 0.5 mm. FIG. 2 is a graph in which the abscissa indicates the recess size and the ordinate indicates the holding strength. For these samples, the press-fit portion 8 of the sleeve 1 and the sleeve holder 3 was provided so as to cover the portion of the dimension X. For this reason, the inner hole 7 in the length X portion of the hollow portion of the sleeve 1 is elastically deformed in the contraction direction.

From the result of FIG. 2, the holding strength of the stopper 2 is abruptly increased from the point where the length X of the depression exceeds 0.2 mm. This is due to the influence of the elastic deformation of the sleeve 1, and by providing this recess, the holding strength of the stopper can be stabilized, and a highly reliable optical receptacle can be supplied.

  It was also confirmed that the inner diameter after assembly of the optical receptacle was maintained at 1.25 mm + 0.001 mm / −0 mm.

Next, a conventional optical receptacle shown in FIG. 6 was fabricated, and the following measurements were performed.
The connector insertion test was performed according to the following procedure. First, an LC connector standardized in the market is prepared. Next, an optical receptacle as a test object was attached to an adapter housing in which an LC connector can be attached / detached, and an attachment / detachment test similar to a connection between an ordinary LC connector and an LC adapter was made possible. In the test method, first, the LC connector is inserted into the optical receptacle until the latch of the LC connector is completely fitted into the adapter housing. The pressing pressure at that time is determined by the spring pressure inside the LC connector, and the pressing pressure is usually about 4.9 N. Next, the LC connector attached to the adapter housing is pulled out. This operation was repeated, and the attachment / detachment test was performed 1000 times.
The inner diameter of the finished precision sleeve was measured by a gauge inspection (pass / stop inspection). On the other hand, for measuring the position of the stopper end face, the height from the sleeve holder bottom face to the stopper tip face (connector insertion side end face) was measured with a dial gauge (manufactured by Mitutoyo Corporation). The inner diameter straightness of the precision sleeve was measured by a straightness measuring instrument manufactured by Tokyo Seimitsu Co., Ltd., and the straightness was measured by running the stylus in the longitudinal direction of the inner diameter portion of the sleeve. Table 1 shows the results of performance comparison between the product of the present invention and the conventional product.

  As shown in Table 1, in the connector 1000 times attachment / detachment test, no change was observed in the insertability of the product of the present invention. On the other hand, with regard to the conventional type, 2 out of 11 tests could not be inserted into the connector. When the inner diameter of the sleeve was confirmed for the item that could not be inserted, adhesion of metal powder was observed.

  In addition, regarding the variation of the stopper position before and after the 1000 times attachment / detachment test, the variation of a maximum of 15 μm was confirmed before and after the test for the conventional type. When the stopper surface 17 was checked after the test, the wear and deformation of the metal fitting due to the contact of the plug ferrule when the connector was attached / detached were confirmed.

  On the other hand, in the product of the present invention, since the stopper 2 is ceramic, there was almost no wear even in the 1000 times attachment / detachment test, and the maximum fluctuation was about 2 μm.

  Next, the inner diameter of the sleeve 1 was confirmed in the optical receptacle finished product, and the inner diameter variation of the conventional one is about 2 μm. On the other hand, in the product of the present invention, the variation in the inner diameter dimension is about 1 μm.

  For both comparative samples, the same inner diameter dimensions of the sleeve 1 before press-fitting into the sleeve holder 3 were used, but after the press-fitting into the sleeve holder 3, a difference in variation in the inner diameter of the sleeve 1 was confirmed. In the case of the conventional embodiment, this is not a structure that suppresses deformation due to press-fitting of the inner diameter of the sleeve 1 into the sleeve holder 3, and the inner diameter of the portion of the sleeve holder 3 into which the sleeve 1 is press-fitted and the sleeve 1. This is presumed to be caused by a change in stress on the sleeve 1 due to variations in the outer diameter of the portion press-fitted into the sleeve holder 3.

  On the other hand, in the product of the present invention, when the sleeve 1 is press-fitted into the sleeve holder 3, the stopper 2 fixed to the inner hole of the sleeve 1 suppresses deformation of the inner diameter of the sleeve 1. For this reason, shrinkage of the inner diameter of the sleeve 1 does not occur, and stable dimensional accuracy can be maintained. Actually, when the straightness of the inner diameter of the sleeve 1 of each comparative sample was measured, it was about 2 μm in the conventional form and about 1 μm in the product of the present invention.

  Further, since the positional accuracy of the stopper of the optical receptacle of the conventional form depends on the processing accuracy of the sleeve holder, the limit is about ± 15 μm. In the present invention product, the position of the stopper 2 is assembled with high accuracy. It was confirmed that it was possible to manage up to about ± 5 μm with a jig.

  From the above comparison results, it can be seen that the structure of the present invention can provide an optical receptacle with excellent mechanical stability and high accuracy.

Sectional drawing which shows the optical receptacle which concerns on the 1st Embodiment of this invention. Sectional drawing which expands and shows a part of optical receptacle which concerns on 1st Embodiment. The graph which shows the relationship between a hollow part length and stopper holding strength. Sectional drawing which shows a mode when the ferrule is inserted in the optical receptacle which concerns on the 1st Embodiment of this invention. Sectional drawing which shows the optical module which concerns on the 2nd Embodiment of this invention. Sectional drawing which shows the optical receptacle which concerns on the 3rd Embodiment of this invention. The fragmentary sectional view which expands and shows a part of sectional drawing of FIG. 5A. Sectional drawing showing the conventional optical receptacle.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Sleeve, 2 Stopper, 3 Sleeve holder, 4 Inner hole, 5 End surface, 6 End surface of one end side, 7 Inner hole, 8 Press-fit part, 14 Optical fiber, 15 Plug ferrule, 40 Contact part, 41 1st inner hole part 41a first constant diameter part, 41b first taper part, 42 second inner hole part, 42a second constant diameter part, 42b second taper part, 100 optical module, 102 stopper, 103 holder, 103r concave part, 110 optical receptacle , 121 lens, 123 optical element, 122 housing, D1 stopper outer diameter, D2 sleeve inner diameter, X length of the recess.

Claims (15)

An optical receptacle to which an optical fiber held by a ferrule is optically connected,
A cylindrical sleeve into which the ferrule is inserted;
A front end surface with which one end surface of the ferrule abuts, a rear end surface, and a through-hole penetrating from the front end surface to the rear end surface, and the front end surface and the rear end surface are both ends of the inner hole of the sleeve. A stopper member disposed in the inner hole of the sleeve so as to be located on the inner side,
The diameter of the inner hole of the sleeve is larger in the non-contact portion excluding the contact portion than in the contact portion where the outer periphery of the stopper member is in contact.   2. The optical receptacle according to claim 1, wherein the non-contact portion includes a tapered portion whose inner diameter gradually decreases as the distance from the contact portion increases on both sides of the contact portion.   3. The optical receptacle according to claim 2, wherein a length of the taper portion in the taper portion located on the tip surface side in the axial direction is within 0.5 mm.   The optical receptacle according to claim 1, wherein an end of the through hole of the stopper member on the tip surface side is chamfered.   The said stopper member is filled with the translucent member which consists of resin or glass in the said through-hole, and this translucent member has a uniform refractive index. The optical receptacle according to any one of the above.   The optical receptacle according to claim 5, wherein a refractive index of the translucent member is in a range of 1.35 to 1.45.   The optical receptacle according to claim 1, wherein the stopper member is made of ceramics.   The optical receptacle according to claim 7, wherein the sleeve is made of the same material as the stopper member. A sleeve press-fitting hole, further comprising a holder into which the sleeve is press-fitted into the sleeve press-fitting hole from the end surface side;
The terminal end surface of the sleeve is in the sleeve press-fitting hole, and the insertion length of the sleeve press-fitted into the sleeve press-fitting hole is shorter than the distance between the front end surface of the stopper member and the terminal end surface of the sleeve. The optical receptacle in any one of -8.   The optical receptacle according to claim 1, wherein a diameter of the through hole of the stopper member is larger than a diameter of the through hole of the ferrule. An optical receptacle to which an optical fiber held by a ferrule is optically connected, a cylindrical sleeve into which the ferrule is inserted, a front end surface, a rear end surface, and a front end with which one end surface of the ferrule abuts A stopper member disposed in the inner hole of the sleeve so that the front end surface and the rear end surface are located inside both ends of the inner hole of the sleeve. An optical receptacle in which the diameter of the inner hole of the contact portion that is in contact with the outer periphery of the stopper member is larger than the diameter of the inner hole of the non-contact portion excluding the contact portion;
An optical element optically connected to the through hole of the stopper member;
An optical module comprising: a housing connected to the optical receptacle and accommodating the optical element.   The optical module according to claim 11, wherein the optical element is a light emitting element that emits light toward the through hole of the stopper member.   The optical module according to claim 12, wherein the light emitting element is a laser element selected from a Fabry-Perot laser element and a surface emitting laser element.   The optical module according to claim 11, wherein the optical element is a light receiving element that receives light transmitted through the through hole of the stopper member. The optical receptacle further includes a holder having a sleeve press-fitting hole, and the sleeve is press-fitted into the sleeve press-fitting hole from the end face side,
The holder and the housing are connected via a connecting member so that the through-holes of the optical element and the stopper member are optically coupled, and the connecting member and the holder joint portion are welded linearly. The optical module according to claim 11.

Images