JP2013120364A - Optical connection component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical connection component which is easy to assemble and is low-cost and is capable of achieving low-loss connection.SOLUTION: An optical connection component 21 is configured to include a coated optical fiber 23 including an optical fiber 22, a ferrule 24 for housing and fixing the optical fiber 22, a projecting portion 25 provided at a front end part 29 of the optical fiber 22, and a housing. The optical connection component 21 is configured so that low-loss connection between the optical fibers 22 can be achieved by physical contact connection between the projecting portions 25. In the optical connection component 21, the projecting portion 25 projecting more than a front end surface 36 of the ferrule 24 is formed at the front end part 29 of the optical fiber 22 by an adhesive 44.

Description

  The present invention relates to an optical connection component including an optical fiber and a ferrule.

  Optical connection parts are used to connect optical fibers. In assembling a general optical connection component, after the optical fiber is bonded and fixed to the ferrule, the optical fiber protruding from the distal end surface of the ferrule is cut, and then polished so that the distal end surface has an arc shape. After polishing, a low-loss connection between optical fibers is realized by physical contact connection in which an arcuate tip surface is brought into contact with and pressed. By the way, since the polishing process requires a plurality of steps and requires time, there is a problem that it is difficult to simplify the assembly process and reduce the cost.

  Several proposals have been made as methods for assembling optical connection parts that do not require polishing of the tip surface by simply cutting the optical fiber (see, for example, Patent Documents 1, 2, and 3 below). Since the end face shape of the optical fiber is flat, the connection between the optical fibers has a problem that it is difficult to realize a low-loss connection due to Fresnel reflection by an air layer between the optical fibers. Although a method of removing the air layer by filling a refractive index matching agent can be considered, there is a problem that dust may be attached and end face cleaning is not easy.

  In assembling an optical connection component that does not require polishing of the tip surface, a method of inserting an optical fiber into a ferrule and then filling it with an adhesive is employed. Because it is such a method, it is difficult to fill the adhesive up to the vicinity of the tip of the optical fiber, and the optical fiber protrudes or dents from the tip surface of the ferrule due to insufficient adhesion or temperature change. I have a fear.

  Hereinafter, a conventional example will be described using Patent Document 3 as an example. In FIG. 8A, reference numeral 1 indicates a coated optical fiber. The coated optical fiber 1 is processed so that the coating 2 at the end portion is removed and the optical fiber 3 is exposed. Reference numeral 4 indicates a ferrule. An insertion hole 5 is formed in the ferrule 4. The insertion hole 5 is a fiber hole for the coated optical fiber 1 and has a small diameter portion 6 and a large diameter portion 7. Reference numeral 8 indicates an opening that opens the outer surface of the ferrule 4 and communicates with the large-diameter portion 7.

  Reference numeral 9 indicates the front end surface of the ferrule 4, and reference numeral 10 indicates an inclined surface inclined toward the ferrule body side with respect to the front end surface 9. The inclined surface 10 is formed so as to communicate with the narrow-diameter portion 6 that opens to the distal end surface 9. Reference numeral 11 indicates a sheet material in contact with the front end surface 9.

  In FIG. 8B, the coated optical fiber 1 with the optical fiber 3 exposed is inserted into the insertion hole 5 of the ferrule 4. The amount of insertion at this time is adjusted so that the distal end portion of the optical fiber 3 and the sheet material 11 have a predetermined distance S. After the adjustment, the adhesive 12 is filled into the insertion hole 5 through the opening 8 as shown in FIG. Further, as shown in FIG. 8D, the adhesive 12 is also filled from the inclined surface 10 side, and the small diameter portion 6 is filled with the adhesive 12.

  When the adhesive 12 is cured and the sheet material 11 is removed, a connection end face 13 made of the cured adhesive 12 is formed at the tip of the optical fiber 3 as shown in FIG. Such a connection end face 13 is formed with a smooth flat surface that is flush with the tip face 9 of the ferrule 4. Since the connection end surface 13 is formed with a smooth flat surface by the sheet material 11, a polishing process for making a mirror surface is unnecessary. Thus, the assembly of the optical connection component 14 is completed.

Japanese Patent Laid-Open No. 2000-258862 JP 2006-53482 A JP 2006-184794 A

  When connecting the optical fibers 3 using the optical connecting component 14 as shown in FIG. 8, the connection end faces 13 formed on the plane are not in contact with each other, so the following problems are caused. Have. That is, in the connection having a structure in which the connection end faces 13 do not contact each other, an air layer is generated between the connection end faces 13 formed at the distal end portion of the optical fiber 3, so that it is difficult to realize a low-loss connection. It has the problem of becoming.

  In addition, when the optical connection component 14 is used, the above-described polishing process is not necessary, so that the assembly is easy and the cost is low, but it is difficult to realize the low-loss connection. ing.

  In order to remove the air layer generated between the connecting end faces 13, a method of filling a refractive index matching agent can be mentioned. However, this method has the problems that dust adheres and the end face cleaning is not easy as described above. Therefore, it can be said that it is necessary to find a new method.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide an optical connection component that is easy to assemble and low in cost, and that can realize a low-loss connection.

  The optical connection component of the present invention according to claim 1, which has been made to solve the above problem, fills the insertion hole of the ferrule with a transparent adhesive when cured, and inserts an optical fiber into the insertion hole. A convex portion that protrudes from the distal end surface of the ferrule is formed at the distal end portion of the optical fiber with the adhesive.

  An optical connection component according to a second aspect of the present invention relates to the optical connection component according to the first aspect, wherein the protruding tip surface of the convex portion is formed as a physical contact portion.

  According to a third aspect of the present invention, there is provided an optical connecting component according to the second aspect, wherein the protruding tip surface of the convex portion is formed in a shape having an arcuate cross section.

  According to a fourth aspect of the present invention, there is provided an optical connecting component according to the third aspect, wherein the convex portion is formed in a deformable state when pressed.

  An optical connection component according to a fifth aspect of the present invention relates to the optical connection component according to the first, second, third, or fourth aspect, wherein the adhesive filled in the insertion hole of the ferrule is used for the optical fiber. The convex portion is formed so as to be pushed out by the tip portion.

  An optical connection component according to a sixth aspect of the present invention relates to the optical connection component according to the first, second, third, fourth, or fifth aspect, and is provided on the distal end surface of the ferrule so as to be continuous with the insertion hole. A groove for releasing the adhesive and air is formed.

  An optical connection component according to a seventh aspect of the present invention relates to the optical connection component according to the first, second, third, fourth, fifth or sixth aspect, wherein the tip surface of the ferrule is covered with a convex molding member. A concave surface for forming the convex portion is formed on the convex molding member.

  In addition, according to the characteristics of the optical connection component according to the first aspect, if a mirror part, a lens part, or an antireflection film part is added to the convex part, it becomes a more useful characteristic.

  According to the first aspect of the present invention, since the convex portion that protrudes from the distal end surface of the ferrule is formed at the distal end portion of the optical fiber with the cured adhesive, such a convex portion is used. As a result, it is possible to realize a connection with a lower loss than before. Further, according to the present invention, since the tip end surface is not required to be polished, the assembly process can be simplified and the cost can be reduced. That is, it is possible to provide an optical connection component that is easy to assemble and low in cost.

  According to the second aspect of the present invention, since the protruding front end surface of the convex portion is a physical contact portion, an air layer is not generated between the convex portions when the optical fibers are connected to each other, and thus low loss is achieved. There is an effect that the connection can be realized. In addition, according to the present invention, since an air layer is not generated, there is an effect that the refractive index matching agent is not required, the member cost can be reduced, and end face cleaning can be facilitated. That is, there is an effect that a low-cost optical connection component can be provided.

  According to the third aspect of the present invention, since the protruding front end surface of the convex portion is formed into a shape having a circular arc cross section, there is an effect that a better physical contact portion can be obtained.

  According to the present invention described in claim 4, since the convex portion is formed in a deformable state when pressed, there is an effect that a better physical contact portion can be obtained.

  According to the present invention described in claim 5, since the adhesive filled in the insertion hole of the ferrule is pushed out at the tip of the optical fiber in connection with forming the convex portion, the tip of the optical fiber The adhesive can be filled up to the portion, and the optical fiber and the ferrule can be firmly fixed. Thereby, there exists an effect that generation | occurrence | production of pistoning can be suppressed.

  According to the sixth aspect of the present invention, since the groove continuous to the ferrule insertion hole is formed on the distal end surface of the ferrule, the effect of allowing excess adhesive and air to escape through the groove. Play. As a result, it is possible to improve the formation state of the protrusions and realize a better low-loss connection.

  According to the seventh aspect of the present invention, since the tip surface of the ferrule is used as the contact surface of the convex molding member, the concave portion for molding the convex portion is formed on the convex molding member. Therefore, it becomes possible to form the convex portion with a simple structure, and thus it is possible to simplify the assembly process and reduce the cost.

It is sectional drawing which shows the coupling | bonding of the optical connection components of this invention, and the enlarged view of the convex part of an optical connection component (enlarged view before contact of convex parts). It is a figure of the member which comprises an optical connection component, (a) is sectional drawing of a coated optical fiber, (b) is sectional drawing of a ferrule, (c) is sectional drawing of a convex part shaping | molding member. It is explanatory drawing of the 1st process which concerns on manufacture of an optical connection component. It is explanatory drawing of the 2nd process which concerns on manufacture of an optical connection component. It is explanatory drawing of the 3rd process which concerns on manufacture of an optical connection component. It is explanatory drawing of the 4th process which concerns on manufacture of an optical connection component. It is sectional drawing of the optical connection component used as another example. It is a figure which concerns on the structure and manufacture of the optical connection component of a prior art example.

  The optical connecting part is filled with a transparent adhesive at the time of curing into the insertion hole of the ferrule and the optical fiber is inserted into the insertion hole, and the convex part protruding from the front end surface of the ferrule is attached to the front end of the optical fiber. Form with. The protruding front end surface of the convex part is formed in a circular arc shape in cross section and is formed as a physical contact part.

  Embodiment 1 will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing the coupling between the optical connecting parts of the present invention and an enlarged view of a convex portion of the optical connecting part. FIG. 2 is a cross-sectional view of members constituting the optical connection component, and FIGS. 3 to 6 are explanatory views of each process related to the manufacture of the optical connection component.

  In the following description, specific shapes, materials, numerical values, directions, and the like are examples for facilitating the understanding of the present invention, and can be appropriately changed according to use, purpose, specifications, and the like. To do.

  In FIG. 1, reference numeral 21 indicates an optical connection component used for realizing a low-loss connection between optical fibers 22. The optical connecting component 21 includes a coated optical fiber 23 including an optical fiber 22, a ferrule 24 that accommodates and fixes a terminal portion of the coated optical fiber 23, and a convex that protrudes outward from a distal end surface 36 described later of the ferrule 24. The unit 25 includes a housing (not shown). The optical connection component 21 is configured so as to realize a low-loss connection between the optical fibers 22 by using a convex portion 25 to perform physical contact connection. First, each component will be described.

  1 and 2, the coated optical fiber 23 includes an optical fiber 22 having a core 26 and a clad 27, and a coating 28 that covers the optical fiber 22. As the coated optical fiber 23, a known optical fiber is used, and detailed description thereof is omitted here.

  The end portion of the coated optical fiber 23 is processed so that the coating 28 is peeled off at a predetermined length and the optical fiber 22 is exposed. As for this processing, a known processing method that has been conventionally performed is adopted. The tip portion 29 (tip surface) of the optical fiber 22 exposed for a predetermined length is smoothed only by cutting. Even when the cutting cannot be performed smoothly, the adhesive 44 described later adheres to the distal end portion 29 of the optical fiber 22, so that light scattering at the end face can be suppressed. That is, there is no problem even if the cutting cannot be performed smoothly.

  The ferrule 24 is a resin molded product in this embodiment, and has good adhesiveness with an adhesive 44 described later. Such a ferrule 24 has an insertion hole 30 formed therethrough. The insertion hole 30 is a fiber hole for the coated optical fiber 23, and is formed with a small diameter portion 31, a large diameter portion 32, and a taper portion 33 that makes them continuous.

  Further, the ferrule 24 is formed with an opening 35 that opens the upper surface 34 and communicates with the large diameter portion 32. The insertion hole 30 is formed so that the narrow-diameter portion 31 opens at the front end surface 36 of the ferrule 24 and the large-diameter portion 32 opens at the rear end surface 37 of the ferrule 24.

  The insertion hole 30 is formed such that the small diameter portion 31 has an inner diameter slightly larger than the outer diameter of the optical fiber 22. The insertion hole 30 is formed so that the large diameter portion 32 has an inner diameter larger than the outer diameter of the coating 28 of the coated optical fiber 23. The tapered portion 33 of the insertion hole 30 is formed as a portion that guides the optical fiber 22 to the small diameter portion 31. The tapered portion 33 is arranged and formed in accordance with the position of the end portion of the coating 28 of the coated optical fiber 23. Further, the tapered portion 33 is arranged and formed in accordance with the position in the vicinity of the opening 35 in the present embodiment.

  The opening 35 is formed as an injection portion (filling start portion) of an adhesive 44 described later. The opening 35 is formed in a volume that can store a predetermined amount of the adhesive 44.

  The front end surface 36 of the ferrule 24 is formed as a plane in a direction orthogonal to the axis of the insertion hole 30. Further, the tip surface 36 is formed as a smooth surface. Furthermore, the tip surface 36 is formed as a contact surface 38 of a convex molding member 41 described later. A groove 39 is formed in the tip surface 36 (contacted surface 38).

  The groove 39 is formed as a part for releasing an adhesive 44 and air described later. The groove 39 is formed so as to extend straight from the narrow-diameter portion 31 opening in the front end surface 36 to the lower surface 40 of the ferrule 24. The depth and width of the groove 39 are not particularly limited as long as the shape allows the adhesive 44 and air to escape.

  The convex portion molding member 41 is a member for molding the convex portion 25 provided at the distal end portion 29 of the optical fiber 22, and is formed in a substantially block shape in this embodiment. The convex molding member 41 is made of a material having no adhesiveness with the adhesive 44 described later. Such a convex molding member 41 is formed with a contact surface 42 that contacts the tip surface 36 (contacted surface 38) of the ferrule 24. The contact surface 42 is formed as a smooth flat surface. A concave portion 43 is formed in such a contact surface 42.

  For example, PDMS (Polydimethylsiloxane) used in the nanoimprint technology is employed for the convex molding member 41.

  The concave portion 43 is formed as a concave portion for molding the convex portion 25 with an adhesive 44 described later. The concave portion 43 is arranged and formed in accordance with the position of the small diameter portion 31 of the ferrule 24. Further, it is formed so as to open according to the inner diameter of the narrow diameter portion 31 (or open according to the diameter of the optical fiber 22). The concave portion 43 is formed such that the thickness (projection height) of the convex portion 25 is, for example, about 0.01 mm to 1 mm. The concave portion 43 is formed in a concave shape having a circular arc shape in the present embodiment.

  The contact surface 42 in which the recess 43 is formed is formed so as to contact the tip surface 36 (contacted surface 38) of the ferrule 24 as described above. Therefore, the convex portion 25 formed by the concave portion 43 formed by denting the contact surface 42 is formed in a convex shape so as to protrude from the tip surface 36. Moreover, since the convex part 25 is the shape from which the dent of the recessed part 43 becomes a cross-sectional arc shape, it is formed in the shape from which a protrusion front end surface becomes a cross-sectional arc shape according to this.

  As the adhesive 44, a material having transparency at the time of curing is used. The adhesive 44 is hardened by heat or hardened by UV irradiation. Further, the adhesive 44 is used that can be filled in a gap generated between the optical fiber 22 and the small diameter portion 31 of the ferrule 24. Furthermore, an adhesive 44 that is slightly deformable when pressed during curing is used.

  Next, an example relating to the assembly of the optical connection component 21 will be described. Here, it is assumed that a manufacturing method is adopted in which the assembly of the optical connection component 21 is completed by sequentially performing the following first to fourth steps.

  In FIG. 3, in the first step, an operation of contacting the contact surface 42 of the convex molding member 41 with the tip surface 36 (contacted surface 38) of the ferrule 24 is performed. In addition, an operation for preparing a state in which the adhesive 44 from which bubbles are sufficiently removed can be injected into the opening 35 of the ferrule 24 is performed. Furthermore, the end portion of the coated optical fiber 23 is processed so that the end portion of the coated optical fiber 23 can be inserted into the insertion hole 30 through the rear end surface 37 of the ferrule 24.

  In FIG. 4, in the second step, the adhesive 44 is injected through the opening 35 of the ferrule 24, and the work of filling the adhesive 44 into the insertion hole 30 of the ferrule 24 located in the vicinity of the opening 35 is performed.

  In FIG. 5, in the third step, an operation of inserting the end portion of the coated optical fiber 23 into the insertion hole 30 through the rear end surface 37 of the ferrule 24 is performed. In the third step, when the end portion of the coated optical fiber 23 is inserted into the insertion hole 30 (in this embodiment, until the distal end portion 29 of the optical fiber 22 comes to the position of the distal end surface 36 of the ferrule 24), With this insertion, the distal end portion 29 of the optical fiber 22 pushes out the adhesive 44, whereby the concave portion 43 of the convex portion molding member 41 is also filled with the adhesive 44.

  The adhesive 44 is filled in the small diameter portion 31 of the insertion hole 30 so as to fill the periphery of the optical fiber 22, and when there is excess adhesive 44 or air, it is released into the groove 39. .

  In the third step, the adhesive 44 that has been filled is cured. The end portion of the coated optical fiber 23 is firmly fixed to the ferrule 24 by the curing of the adhesive 44.

  In FIG. 6, in the fourth step, an operation of removing the convex molding member 41 from the tip surface 36 of the ferrule 24 is performed. When the convex molding member 41 is removed, a convex portion 25 is formed on the distal end portion 29 of the optical fiber 22 so as to project outward from the distal end surface 36 of the ferrule 24 and the projected distal end surface has an arcuate cross section. The convex portion 25 is formed as a physical contact portion 45.

  In FIG. 1, the convex portions 25 come into contact with each other by the interconnection of the optical connection components 21, and these are deformed and flattened by pressing. For this reason, there is no air layer between the optical fibers 22 (between the convex portions 25), and a low-loss connection can be realized in the connection between the optical fibers 22.

  As described above with reference to FIGS. 1 to 6, according to the optical connection component 21, the convex portion 25 protruding from the distal end surface 36 of the ferrule 24 is formed on the distal end portion 29 of the optical fiber 22 with the adhesive 44. Therefore, it is possible to realize a connection with a lower loss than in the prior art by using such a convex portion 25. Moreover, according to the optical connection component 21, since the grinding | polishing process of a front end surface is unnecessary, there exists an effect that an assembly process can be simplified and cost reduction can be achieved. That is, it is possible to provide the optical connection component 21 that can be easily assembled and is low-cost.

  Further, according to the optical connecting component 21, since the protruding tip surface of the convex portion 25 is the physical contact portion 45, an air layer is not generated between the convex portions 25 when the optical fibers 22 are connected to each other. There is an effect that a lossy connection can be realized. Moreover, according to the optical connection component 21, since an air layer is not produced as described above, there is an effect that the refractive index matching agent is not required, the member cost can be reduced, and end face cleaning can be facilitated. That is, there is an effect that the low-cost optical connection component 21 can be provided.

  Further, according to the optical connection component 21, the tip surface 36 of the ferrule 24 is used as the contact surface 42 of the convex molding member 41, and the concave portion 43 for molding the convex portion 25 on the convex molding member 41. Therefore, it is possible to form the convex portion 25 with a simple structure, thereby achieving an effect that the assembly process can be simplified and the cost can be reduced.

  In addition, according to the optical connection component 21, since the operation procedure of inserting the end portion of the coated optical fiber 23 into the insertion hole 30 after filling the adhesive 44 is adopted, the bonding is performed up to the tip portion 29 of the optical fiber 22. The agent 44 can be filled, so that the end of the coated optical fiber 23 can be firmly fixed to the ferrule 24. Thereby, there exists an effect that generation | occurrence | production of pistoning can be suppressed.

  Embodiment 2 will be described below with reference to the drawings. FIG. 7 is a cross-sectional view of another example of an optical connection component. In addition, the same code | symbol is attached | subjected to the same component as the said Example 1, and detailed description is abbreviate | omitted.

  In FIG. 7, a convex portion 52 that protrudes outward from the distal end surface 36 of the ferrule 24 is formed by an adhesive 44 at the distal end portion 29 of the optical fiber 22 in the optical connecting component 51. The convex portion 52 is formed by forming a concave portion having a right-angled triangular section in a convex molding member (not shown) and curing the adhesive 44 filled in the concave portion. The convex part 52 has a 45-degree mirror 53 in this embodiment.

  Since the convex part 52 having the 45-degree mirror 53 can bend the optical path by 90 degrees, the coated optical fiber 23 (optical fiber 22) arranged in the horizontal direction and a light receiving / emitting element (surface-mounted on a substrate not shown) This is a useful part when optically connecting an optical element).

  Although not particularly illustrated, a condensing lens or a collimating lens may be formed on the convex portion. The condensing lens is effective for optical connection with the light emitting / receiving element, and the collimating lens is effective for optical connection with the light receiving / emitting element surface-mounted in combination with the 45 degree mirror 53. Of course, the optical fiber 22 and the light emitting and receiving element can be connected with low loss by the lens as described above.

  In addition, when the nanoimprint technique described in the first embodiment is used, it is possible to form an antireflection film with a nanostructure on the convex portion formed at the tip portion 29 of the optical fiber 22. If an antireflection film is formed, the end face loss can be reduced.

  It goes without saying that the present invention can be variously modified without departing from the spirit of the present invention.

  DESCRIPTION OF SYMBOLS 21 ... Optical connection component, 22 ... Optical fiber, 23 ... Optical fiber with coating, 24 ... Ferrule, 25 ... Convex part, 26 ... Core, 27 ... Cladding, 28 ... Coating, 29 ... Tip part, 30 ... Insertion hole, 31 ... small diameter part, 32 ... large diameter part, 33 ... taper part, 34 ... upper surface, 35 ... opening, 36 ... front end surface, 37 ... rear end surface, 38 ... contacted surface, 39 ... groove, 40 ... lower surface, 41 ... convex molding member, 42 ... abutment surface, 43 ... concave, 44 ... adhesive, 45 ... physical contact part, 51 ... optical connecting part, 52 ... convex part, 53 ... 45 degree mirror

Claims (7)

Filling the insertion hole of the ferrule with a transparent adhesive when cured, and inserting an optical fiber into the insertion hole, and forming a convex portion protruding from the tip surface of the ferrule at the tip of the optical fiber to the adhesive An optical connecting part characterized by being formed by The optical connecting component according to claim 1,
An optical connection component, wherein the protruding tip surface of the convex portion is formed as a physical contact portion. The optical connection component according to claim 2,
The protruding end surface of the convex portion is formed into a shape having a circular arc cross section. The optical connection component according to claim 3,
The convex part is formed in a deformable state when pressed. An optical connection component. In the optical connection component according to claim 1, 2, 3, or 4,
The optical connection component, wherein the convex portion is formed by extruding the adhesive filled in the insertion hole of the ferrule at the tip end portion of the optical fiber. In the optical connection component according to claim 1, 2, 3, 4 or 5,
An optical connection component, wherein a groove for allowing excess adhesive and air to escape from the insertion hole is formed in the distal end surface of the ferrule. In the optical connection component according to claim 1, 2, 3, 4, 5 or 6,
An optical connection component, wherein the tip surface of the ferrule is a contacted surface of a convex molding member, and a concave portion for molding the convex portion is formed on the convex molding member.

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