JP2010113049A - Part and method for connecting optical fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simply achieve an optical fiber connecting part and a connecting method at a low cost, having excellent environmental resistance by bending an optical fiber to always continuously apply load to the end face of the optical fiber, thereby making physical contact (PC). <P>SOLUTION: The optical fibers 20, 30, whose end faces are tapered, are gripped and fixed while the optical fibers 20, 30 are bent at the optical fiber bending parts 12, 13 using the optical fiber connecting part 10, PC (physical contact) connection is made between the end faces 21, 31 of the optical fibers 20, 30 using stress caused by continuous bending of the optical fibers 20, 30. Further, optical fiber gripping parts 14, 15 are filled with an adhesive 40, thereby fixing the optical fibers 20, 30 and sealing an optical fiber aligning part 11 and the optical fiber bending parts 12, 13 to achieve excellent environmental resistance. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical fiber connecting component and a connecting method for permanently connecting an optical fiber.

  For permanent optical fiber connection, a refractive index matching agent is interposed between the fusion fiber connection that melts the optical fiber by the heat of discharge and the Fresnel reflection from the air to suppress the reflection. There is a mechanical splice that is connected by abutting with a V groove. Fusion splicing requires a high-voltage power supply, and mechanical splices have problems such as lack of sealing properties such as water intrusion.

Further, in the semi-permanent optical fiber connection, there is a connector connection for performing a physical contact connection (hereinafter referred to as a PC connection) in which an optical fiber and an optical fiber are directly butted and connected. In this case, PC connection is made by polishing the end face of the optical fiber fixed to the ferrule with an adhesive. [Patent Document 1]
Usually, in order to make a PC connection without polishing, it must be matched with a strong force, but a method for realizing a PC connection with a weak force has been proposed [Non-Patent Document 1]. This method is a method of realizing the PC connection between the cores by performing only the process of removing the ripple since the ripple is generated in the circumferential portion on the cleavage plane of the optical fiber.
JP 2000-310723 A Proceedings of the 2008 IEICE General Conference, “Study of on-site assembly PC connector that does not require fiber end polishing”, B-13-14

  However, the fusion splicing described above requires an expensive and large dedicated device, and is not simple and low cost. In addition, mechanical splices that can be easily connected do not have sufficient sealing properties such as water intrusion, and the refractive index matching agent is indispensable at the connection part, so it depends on the durability and environmental resistance of the refractive index matching agent. was there.

  The present invention has been made in view of the above problems, and an object of the present invention is to realize a simple optical fiber connecting component and a connecting method capable of performing PC connection and having sealing properties.

  In the present invention, the PC connection is performed only with the bending stress of the optical fiber. Moreover, long-term reliability is realized by fixing the optical fiber using an adhesive and sealing the entire connecting portion. By these means, a long-term reliable connection is possible by simply fixing the optical fiber without requiring a large force for PC connection.

  By making the structure of the optical fiber connecting component a structure in which the bending stress of the optical fiber continues to work, the return force and the bending stress generated at the end face of the optical fiber cancel each other, so that the PC connection can be maintained.

  According to the present invention, an optical fiber can be easily fixed and a permanent connection with a sealing property becomes possible. Accordingly, it is not necessary to use an expensive and large dedicated device such as fusion splicing, and since the refractive index matching agent is not present in the connection, durability and environmental resistance can be improved as compared with the mechanical splice.

  An embodiment of the present invention will be described below with reference to the drawings. In addition, this invention is not restrict | limited by this embodiment.

  FIG. 1 is a schematic external view showing an optical fiber connecting part in one embodiment of the present invention, FIG. 2 is a side sectional view showing an optical fiber connecting part in one embodiment of the present invention, and FIGS. It is a figure which shows the front-end | tip part of the optical fiber used in embodiment.

  1 and 2, reference numeral 10 denotes an optical fiber connecting part (hereinafter referred to as a connecting part), which is made of, for example, a synthetic resin and has a rectangular parallelepiped shape. In addition, an optical fiber guide path is formed in the length direction in the connection component 10, and an optical fiber aligning section 11 is formed in the center of the guide path. Further, optical fiber deflecting portions 12 and 13 are provided on both sides of the optical fiber aligning portion 11 along the guide path so as to be connected to the optical fiber aligning portion 11, respectively, and further along the guide path, the optical fiber deflecting portion 12 is provided. , 13 are provided with optical fiber gripping portions 14, 15.

  The optical fiber aligning portion 11 is composed of an optical fiber guide hole 111 formed on the guide path, and the front end surfaces (cut end surfaces) 21 and 31 of the two optical fibers 20 and 30 are abutted to each other, and the respective optical fibers 20 and 30. Are aligned within a predetermined error range.

  The optical fiber bending portions 12 and 13 are formed by bending spaces 121 and 131 for bending a part of the optical fibers 20 and 30 arranged in the guide path with a predetermined radius of curvature, and guide grooves (not shown) formed on the guide path. ) And is provided adjacent to the optical fiber aligning portion 11 along the guide path. Further, the wall surfaces of the bending spaces 121 and 131 are tapered so that the optical fibers 20 and 30 are guided to the optical fiber aligning portion 11.

  The optical fiber gripping portions 14 and 15 are provided adjacent to the optical fiber bending portions 12 and 13 along the guide path, and the optical fiber guides 141 and 151 and one ends thereof are connected to the optical fiber bending portions 12 and 13. Holes 142, 152, adhesive filling spaces 143, 153 provided along the guide paths and connected to the other ends of the optical fiber guide holes 142, 152, and adhesive entry paths 144, 154 for allowing the adhesive 40 to enter the adhesive filling spaces 143, 153 from the outside. Adhesive filling ports 145, 155 for filling the adhesive 40, and optical fiber guide holes 146, 156 formed on the guide path and connecting the adhesive filling spaces 142, 152 and the optical fiber insertion ports 141, 151. The optical fiber gripping portions 14 and 15 grip the optical fibers 20 and 30 disposed in the guide path while maintaining the state where the optical fibers 20 and 30 are bent in the optical fiber bending portions 12 and 13, and adhesives. The optical fibers 20 and 30 are bonded and fixed by the adhesive 40 filled in the filling spaces 142 and 152, and the optical fiber aligning portion 11 and the optical fiber bending portions 12 and 13 are sealed. The wall surfaces of the adhesive filling spaces 143 and 153 are tapered so that the optical fibers 20 and 30 are guided to the optical fiber flexible portions 12 and 13.

  In this embodiment, the optical fiber gripping portions 14 and 15 have a function of gripping the optical fibers 20 and 30 with an adhesive, and the optical fiber gripping portions 14 and 15 are inserted when the optical fibers 20 and 30 are inserted. 30 can pass through, and the optical fibers 20 and 30 can be bonded after the optical fibers 20 and 30 are inserted.

  When optical fiber connection using the optical fiber connection component 10 in the present embodiment is performed, the distal end portions of the two optical fibers 20 and 30 to be connected from the end portions of the optical fiber deflecting portions 12 and 13 to the distal end portion. The coating corresponding to the portion is removed, the end face is cleaved, and the optical fibers 20 and 30 that are tapered are inserted. The coating removal range is not limited as long as the coating is removed at the optical fiber aligning portion 11.

  Each of the two optical fibers 20 and 30 connected by the optical fiber connecting component 10 has the tip surfaces 21 and 31 that have been cleaved and cut to remove burrs and corners on the tip surface as described above. It is. The tip portions of the optical fibers 20 and 30 are tapered as shown in FIGS. 3 to 6, and the cross-sectional shape thereof is an n-gon (n is an integer of 3 or more) or a circle. FIG. 3 is a side view of the distal end portion of the optical fibers 20 and 30, and FIGS. 4 to 6 are plan views when viewed from the distal end side of the tapered optical fibers 20 and 30, respectively.

  When the optical fibers 20 and 30 are connected by the optical fiber connecting component 10, the tip end portion is tapered as described above, and the tip end of one optical fiber 20 is inserted from the optical fiber insertion port 141 along the guide path. And reaches the center of the optical fiber aligning portion 11. The tip of the other optical fiber 30 is inserted from the optical fiber insertion port 151 and reaches the center of the optical fiber aligning portion 11 along the guide path, and the tip surface 31 of the other optical fiber 30 is one of the optical fibers. It is abutted against the front end surface 21 of 20.

  At this time, the inserted optical fibers 20 and 30 are guided to the optical fiber aligning portion 11 along a guide path such as an optical fiber guide hole or an optical fiber guide groove, and are aligned to a sufficient axial deviation for connection. Finally, the optical fiber end faces 21 and 31 protrude from the central portion of the optical fiber aligning portion 11 by a predetermined amount. Two optical fibers are similarly inserted facing each other, and one or both of the optical fibers 20 and 30 are bent, and the tip surfaces 21 and 31 of the optical fibers 20 and 30 are PC-connected.

  That is, when the two optical fibers 20 and 30 are pushed in, one of the optical fibers 20 is bent in the bending space 121 in the optical fiber bent portion 12 by the pushing force, and the other optical fiber 30 is bent in the optical fiber bent portion. 13, the bending space 131 is bent. In addition, it is preferable that the curvature radius of the bending of the optical fibers 20 and 30 is 2.5 mm or more. This is because if the optical fibers 20 and 30 are bent to a small diameter, the loss increases and the life is shortened. Assuming that the service period is 20 years, the minimum fracture probability is obtained when a quartz fiber having a cladding diameter of 125 mmφ is used. This is because the bending radius is said to be 2.5 mm or more in order to maintain the above.

  Thus, in the state where the two optical fibers 20 and 30 are bent in the optical fiber bending portions 12 and 13, the two optical fibers 20 and 30 are held by the optical fiber holding portions 14 and 15, respectively. 30 bent states are maintained.

  Since each of the optical fibers 20 and 30 is gripped by the optical fiber gripping portions 14 and 15, the distal end surface 21 of the optical fiber 20 and the distal end surface of the optical fiber 30 are caused by the stress generated by the bending formed in the optical fibers 20 and 30. 31 is strongly pressed in the optical fiber aligning part 11, and the front end surfaces 21 and 31 are abutted and PC-connected. Further, the optical fiber aligning portion 11 and the optical fiber deflecting portions 12 and 13 are sealed by the adhesive 40 filled in the adhesive filling spaces 143 and 153 of the optical fiber gripping portions 14 and 15.

  Thus, the adhesive 40 is filled in the adhesive filling spaces 143 and 153 of the optical fiber gripping portions 14 and 15 in a state where the end faces 21 and 31 of the two optical fibers 20 and 30 are abutted with each other. The optical fibers 20 and 30 are bonded and fixed to the optical fiber gripping portions 14 and 15 by being cured. Thereby, the front end surfaces 21 and 31 of the optical fibers 20 and 30 are connected to two.

  As described above, since the optical fiber connecting component 10 of the present embodiment has a structure in which the bending stress of the optical fiber continues to work, the return force and the bending stress generated at the end face of the optical fiber cancel each other at the optical fiber bonding portions 12 and 13. Therefore, even when the fixing force in the shearing direction of the adhesive 40 is less than the pressing force necessary for PC connection, the PC connection can be maintained. Further, long-term reliability can be realized by fixing the optical fibers 20 and 30 using the adhesive 40 and sealing the optical fiber aligning portion 11 and the optical fiber bending portions 12 and 13. As a result, by using the optical fiber connection component 10 of the present embodiment, the optical fibers 20 and 30 can be simply fixed and a long-term reliable connection is possible without requiring a large force for PC connection. It can be.

  Therefore, by using the optical fiber connection component 10 of the present embodiment, it is possible to easily fix the optical fiber and enable a permanent connection with a sealing property, as in the conventional fusion connection. It is not necessary to use an expensive and large dedicated device, and since no refractive index matching agent is interposed in the connection, durability and environmental resistance can be improved as compared with the mechanical splice.

  The optical fiber aligning portion 11 and the optical fiber bonding portions 12 and 13 may be configured by individual members, or may be integrally formed.

  Further, as shown in FIG. 7, the optical fiber aligning portion 11 is provided with a filling space 112 of the adhesive 40 and an adhesive intrusion passage 113 and an adhesive filling port 114 leading from the adhesive filling space 112 to the external space. The portions where the tip surfaces 21 and 31 of the two optical fibers 20 and 30 are connected to each other may be bonded and fixed by the adhesive 40.

  In the above embodiment, the bending spaces 121 and 131 and the adhesive filling spaces 143 and 153 are formed so that the periphery of the optical fibers 20 and 30 is a space in the optical fiber bending portions 112 and 13 and the optical fiber gripping portions 14 and 15. The bending spaces 121 and 131 and the adhesive filling spaces 143 and 153 in which guide grooves along the optical fibers 20 and 30 are formed may be formed. In this case, a bending space for the optical fiber is provided on the guide groove in the optical fiber bending portions 12 and 13. Moreover, you may provide the optical fiber bending parts 12 and 13 in which the bending spaces 121 and 131 are formed in a part of guide hole provided along the guide path.

  Further, in order to realize the sealing property that is a feature of the present invention, the entire connection component 10 may be sealed using a shrink member such as a heat shrink sleeve after the both optical fibers 20 and 30 are held and fixed. .

  Further, in order to fix the optical fibers 20 and 30 to the connecting member 10, the gripping force may be assisted by using a mechanical gripping mechanism or an adhesive other than the adhesive.

1 is a schematic external view showing an optical fiber connecting component according to an embodiment of the present invention. Side surface sectional drawing which shows the optical fiber connection component in one Embodiment of this invention The figure which shows the front-end | tip part of the optical fiber used in one Embodiment of this invention The figure which shows the front-end | tip part of the optical fiber used in one Embodiment of this invention The figure which shows the front-end | tip part of the optical fiber used in one Embodiment of this invention The figure which shows the front-end | tip part of the optical fiber used in one Embodiment of this invention Side surface sectional drawing which shows the other example of the optical fiber connection component in one Embodiment of this invention

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Optical fiber connection part, 11 ... Optical fiber aligning part, 12, 13 ... Optical fiber bending part, 14, 15 ... Optical fiber holding part, 20, 30 ... Optical fiber, 21, 31 ... End face, 40 ... Adhesion 111: optical fiber guide hole, 112 ... adhesive filling space, 113 ... adhesive intrusion path, 114 ... adhesive filling port, 121, 131 ... bending space, 141, 151 ... optical fiber insertion port, 142, 152 ... optical fiber guide hole, 143, 153 ... Adhesive filling space, 144,154 ... Adhesive entry path, 145,155 ... Adhesive filling port, 146,156 ... Optical fiber guide hole.

Claims (6)

An optical fiber connecting part for connecting the cut end faces of two optical fibers together,
A guide path comprising at least one of a guide hole or a guide groove for guiding two optical fibers;
An optical fiber aligning portion that is provided at the center in the length direction of the guide path and that matches the cut end faces of the two optical fibers so that the axial positions of the optical fibers coincide with each other within a predetermined error range. When,
Deflection for bending a portion of the optical fiber disposed along the guide path adjacent to at least one of the optical fiber alignment portions and disposed in the guide path with a predetermined radius of curvature. An optical fiber bending portion having a space;
Along the guide path and adjacent to the optical fiber aligning part or the optical fiber bending part, an optical fiber insertion port, an intrusion path for allowing an adhesive to enter from the outside, and filling the adhesive with light. An adhesive-filled space along the guide path for bonding and fixing a fiber, and grips the optical fiber disposed in the guide path while maintaining a state where the optical fiber is bent in the optical fiber bending portion. An optical fiber connecting component comprising: two optical fiber gripping portions for performing The wall surface of the bending space is formed in a tapered shape so that the optical fiber bending portion guides the optical fiber from the bending space to a guide path that leads to the optical fiber alignment portion. The optical fiber connection part described. The adhesive filling space of the optical fiber gripping portion is a wall surface of the adhesive filling space so as to guide the optical fiber to a guide path leading to the optical fiber bending portion or the optical fiber aligning portion adjacent to the adhesive filling space. The optical fiber connection component according to claim 1, wherein the optical fiber connection component is formed in a tapered shape. The adhesive filling space and the adhesive intrusion path leading from the filling space to the external space are arranged so that the portion where the two optical fibers are abutted and connected in the optical fiber aligning portion can be fixed with an adhesive. The optical fiber connecting part according to any one of claims 1 to 3, wherein the optical fiber connecting part is formed in an optical fiber aligning portion. An optical fiber connection method using the optical fiber connection component according to any one of claims 1 to 3,
Insert each of the two optical fibers that have been cleaved and cut to remove the burrs and corners of the tip surface from different optical fiber insertion ports of the optical fiber connection parts,
In a state where the front end surfaces of the two optical fibers are in contact with each other in the optical fiber alignment part, the optical fiber is further pushed so that the optical fiber is bent in the bending space of the optical fiber bending part,
In a state where the optical fiber is gripped by the optical fiber gripping portion, the adhesive filling space of the optical fiber gripping portion is filled with an adhesive to bond and fix the optical fiber, and the optical fiber aligning portion and the light An optical fiber connection method comprising sealing a fiber bending portion. An optical fiber connection method using the optical fiber connection component according to claim 4,
Insert each of the two optical fibers that have been cleaved and cut to remove the burrs and corners of the tip surface from different optical fiber insertion ports of the optical fiber connection parts,
In a state where the front end surfaces of the two optical fibers are in contact with each other in the optical fiber alignment part, the optical fiber is further pushed so that the optical fiber is bent in the bending space of the optical fiber bending part,
In a state where the optical fiber is gripped by the optical fiber gripping portion, the adhesive filling space of the optical fiber gripping portion is filled with an adhesive and the optical fiber is bonded and fixed.
An optical fiber connecting method, wherein an adhesive is filled in a filling space of an optical fiber aligning portion, and a portion where two optical fibers are abutted and connected is fixed with an adhesive.

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