JP4999192B2 - Optical fiber connector and method of assembling the same - Google Patents

Description

  The present invention relates to an optical fiber connector for connecting a holey fiber, which is excellent in assembling workability in the field.

  The holey fiber (HF) is an optical fiber including a clad having a structure in which a plurality of holes (air holes) continuous in the axial direction are regularly arranged. The hole of the holey fiber is usually filled with air, and there is a problem that the performance deteriorates when a foreign substance enters. For this reason, when assembling an optical fiber connector using a holey fiber, that is, when attaching an optical fiber connector to one end to which the holey fiber is to be connected, a method of sealing the hole at the one end surface with an adhesive or melting is used. (See Non-Patent Document 1).

  In the optical fiber connector, when the light propagating through the core is emitted from the end face of the optical fiber, it is necessary to suppress reflection by air having a refractive index different from that of the core and to realize good reflection loss characteristics. As a method of suppressing reflection of air at the end face of the optical fiber, a method of suppressing by interposing an index matching agent having the same refractive index as the core between the end faces of the optical fibers to be connected, and between the cores of the optical fiber There is a method of suppressing by directly connecting (Physical Contact: PC).

  Conventionally, in order to connect the cores to each other by PC, it is necessary to polish the end face of the optical fiber fixed to the ferrule with an adhesive into a mirror shape. In order to polish the end face of the optical fiber, a dedicated polishing tool and abrasive grains are used. It was necessary to prepare a polishing sheet with embedded therein.

On the other hand, the end of the optical fiber is polished by using the pressing force generated when the optical fiber is buckled (bends) inside the connector while holding the tip of the optical fiber protruding from the ferrule. There has been proposed a method for realizing PC connection without doing this (see Non-Patent Document 2). Note that ripples are generated in the circumferential portion of the end face of the optical fiber that has not been polished, that is, the cleaved face of the optical fiber cut by a fiber cutter, etc. This is a method for realizing the PC connection.
Proceedings of the 2008 IEICE General Conference, “Examination of hole hole sealing by laser beam irradiation”, B-13-5 Proceedings of the 2008 IEICE General Conference, “Examination of on-site assembly PC connector that does not require fiber end polishing”, B-13-14

  In order to produce an end face of a holey fiber that can be connected to a PC by polishing, it is necessary to completely seal the hole of the end face so that polishing debris and abrasive do not enter into the hole of the holey fiber.

  However, sealing the hole in the end face of the holey fiber requires a large-scale machine and a dedicated tool as described in Non-Patent Document 1, a work space with little disturbance, and high expertise. Not suitable.

The present invention does not require the polishing of the end face, the optical fiber connector for assembling capable holey fiber connections in the field, and an object thereof to provide the assembled how.

In the present invention, for achieving the above object, the optical fiber aligning unit for holding the leading end portion of the holey fiber, the optical fiber holders for secure the sheathed portion of the holey fiber, the optical fiber aligning portion At least a bending space forming portion disposed between the optical fiber gripping portion and the optical fiber aligning portion, the bending space forming portion, and the optical fiber gripping portion are connected to each other and from the tip of the optical fiber aligning portion. Each has a guide hole or a guide groove through which the holey fiber is inserted to the end of the optical fiber gripping part, the bending space forming part has a bending space in which the holey fiber is bent, and the holey fiber is cleaved, while taper machined tip projecting a predetermined amount from the distal end of the optical fiber aligning portion, the light Faibakoneku the sheathed portion is fixed to the optical fiber holders In proposes an optical fiber connector which is arranged a gel material for sealing the hole in the end face of the holey fiber within the optical fiber connector.

  According to the present invention, the holey fiber whose tip is cleaved and tapered is inserted through the guide hole or guide groove from the optical fiber gripping part to the optical fiber aligning part, and the tip is the tip of the optical fiber aligning part. Just hold and fix the coated part to the optical fiber gripping part with a predetermined amount protruding, without polishing the end face of the holey fiber as in the past, that is, large machine, special tool, work with little disturbance An optical fiber connector capable of PC connection can be assembled without requiring complete sealing of the hole at the end face which requires space and high expertise.

  In this case, the length of the flexure space in the connector is made smaller than in the case of a normal single mode fiber by utilizing the characteristic of the holey fiber that loss is not easily generated even if the pressing force of the PC connection is increased. By increasing the pressing force at the time of connecting the PC, it is possible to realize an optical fiber connector that can prevent the intrusion of foreign matters without completely sealing the hole of the end face, and has little risk of performance deterioration.

  As for the taper processing of the tip surface of the holey fiber, the tip of the fiber is obliquely applied to a grindstone, polishing sheet, etc., and the grindstone or polishing sheet can be moved manually or mechanically. Compared with the polishing operation that must be finished in a shape, it is a very easy operation, and at that time, there is no possibility of polishing debris and abrasives entering the holes on the end face. Further, in the PC connection using this connector, since only the cleaved surface is in contact with the connection partner fiber, the quality of the tapered surface may be ignored, and only the processing amount may be controlled by the work time. In particular, when using a machine, the work is completed by simply inserting the holey fiber into an inexpensive machine such as a pencil sharpener for a few seconds. The cleavage of the holey fiber can be processed with a commercially available optical fiber cleaver.

  Also, by providing a sealing structure that seals the gap between the guide hole or the guide groove and the holey fiber on the side of the bending space forming part of the optical fiber gripping part, the hole on the end face of the fiber in a state of being connected via an adapter or the like It is also possible to prevent foreign matter from reaching the outside.

Here, for example, an adhesive or a resin member can be used for the sealing structure in the optical fiber connector .

  Further, as a simple sealing method for the hole on the fiber end face, a structure in which a very small amount of highly viscous gel-like material enters the hole can be used. The refractive index of the gel material is set to be equal to or lower than the refractive index of the cladding material of the holey fiber. As this gel material, for example, a silicon-based resin can be used.

  Hereinafter, embodiments of the present invention will be described, but the scope of the present invention is not limited thereby.

  FIG. 1 shows an example of an embodiment of an optical fiber connector according to the present invention. In the figure, 10 is an optical fiber aligning portion, 20 is a bending space forming portion, 30 is an optical fiber gripping portion, and 40 is a holey fiber. is there.

  The optical fiber aligning portion 10 holds and aligns the distal end portion of the holey fiber 40, and has a guide hole 11 having an inner diameter substantially equal to the outer diameter (usually 125 μm) of the holey fiber from which the coating has been removed. The rear end is connected and fixed to the bending space forming portion 20.

  The bending space forming portion 20 includes a bending space 21 in which the holey fiber 40 is bent and communicates with the guide hole 11 of the optical fiber aligning portion 10, on the opposite side of the connection end with the optical fiber aligning portion 10. It is connected and fixed to the optical fiber grip 30.

  The optical fiber gripping portion 30 is for holding or fixing the coated portion of the holey fiber 40 mechanically or with an adhesive or the like, and is a portion of the covered portion of the holey fiber 40 that communicates with the bending space 21 of the bending space forming portion 20. A guide hole 31 having an inner diameter substantially equal to the outer diameter is provided. In addition, it cannot be overemphasized that this optical fiber holding part 30 can insert the holey fiber 40 freely at the time of an assembly.

  In addition, a sealing structure 32 that seals a gap between the guide hole or guide groove of the optical fiber gripper 30 and the optical fiber gripper 30 and the holey fiber 40 is provided on the side of the optical fiber gripper 30 that forms the flexure space. It has been. The optical fiber aligning portion 10 and the bending space forming portion 20 may be integrally configured.

  In order to assemble the optical fiber connector according to the above configuration, first, the coating on one end to be connected is removed, the tip is cleaved, and the corners of the cleaved end face are obliquely ground as shown in FIG. Then, a holey fiber 40 is prepared which is processed into a tapered shape and from which ripples at the circumferential portion are removed. In FIG. 2, 41 is a connection end surface, 42 is a hole, and 43 is a taper processing part.

  Next, one end of the holey fiber 40 described above is accommodated in the guide hole 31 from the optical fiber gripping portion 30. At this time, the optical fiber gripper 30 does not fix the holey fiber 40.

  Furthermore, one end of the holey fiber 40 is inserted into the guide hole 11 of the optical fiber aligning portion 10 through the bending space 21 that is also the guide hole of the bending space forming portion 20, and the tip portion thereof is inserted into the optical fiber aligning portion 10. A predetermined amount is protruded from the tip. At this time, the holey fiber 40 is aligned with sufficient accuracy for connection in the optical fiber aligning unit 10.

  In this state, the coated portion of the holey fiber 40 is held and fixed by the optical fiber holding unit 30. By doing so, the optical fiber connector can be assembled without processing the hole on the fiber end face.

  FIG. 3 shows a state when the optical fiber connector is connected, that is, a state when another optical fiber connector is abutted against the end face of the optical fiber aligning portion. The distal end portion of the holey fiber 40 protruding from the distal end of the optical fiber aligning portion 10 is pushed in, and a bend 44 is generated in the bend space 21. The holey fiber 40 is pressed against the opposite end face of the optical fiber connector by the restoring force of the bending 44. By this pressing force, the end face of the holey fiber 40 is brought into close contact with the end face of the fiber on the optical fiber connector side and can be connected to the PC. With this structure, it is possible to apply a pressing force generated by bending between the end faces of the fiber regardless of the abutting force between the connectors. The bend radius of the bend 44 of the holey fiber 40 in the bend space 21 is always set to be 5 mm or more so as not to cause a large bend loss.

FIG. 4 shows an example of an embodiment of the adapter of the present invention (however, it is not included in the scope of the claims). In the figure, 51 is a centering part, 52 is a centering part cover, 53 is It is the main body.

  The aligning portion 51 is for aligning and abutting the optical fiber aligning portions of the optical fiber connector, and includes a split sleeve having an inner diameter substantially equal to the outer diameter of the optical fiber aligning portion.

  The aligning part cover 52 is for accommodating and holding the aligning part 51 therein, and the both ends of the aligning part cover 52 are in close contact with the outer periphery of the optical fiber aligning part of the optical fiber connector and sealed. A sealing structure 54 is provided.

  The main body 53 holds the aligning portion cover 52 fixedly therein. The main body 53 also has a function of fitting a portion other than the optical fiber alignment portion of the optical fiber connector, for example, a bending space forming portion to maintain the connection state, and this is usually a hook mechanism using a resin component. (Not shown) or the like is used.

  In this adapter, the optical fiber connectors to be connected are respectively inserted from both sides of the main body 53 so that the optical fiber aligning portions are aligned and abutted in the aligning portion 51 to be connected. .

  FIG. 5 shows a state where the optical fiber connector of the present invention shown in FIG. 1 is connected to another optical fiber connector (however, only the optical fiber aligning portion is shown) using the adapter of the present invention shown in FIG. It is shown.

  With the optical fiber connector sealing structure 32 and the adapter sealing structure 54 of the present invention, when the other optical fiber connector is a factory-assembled connector, the fiber end face is the optical fiber alignment portion of the other optical fiber connector. The adapter aligning portion cover 52, the optical fiber aligning portion 10 of the optical fiber connector of the present invention, and the space surrounded by the bending space 21 are sealed. Even if the other optical fiber connector is the optical fiber connector of the present invention, the fiber end face is a space surrounded by the aligning portion cover 52 of the adapter, the optical fiber aligning portion 10 of the optical fiber connector of the present invention, and the bending space 21. It will be sealed inside. Thereby, it can prevent that a foreign material penetrate | invades from a fiber end surface.

  Since the sealing structure of the optical fiber connector does not relate to the attachment / detachment of the optical fiber connector and the adapter, it may be a structure that is permanently adhered or a structure that is temporarily adhered. That is, the intended function may be achieved using an adhesive, or a resin material may be used. This function and the fiber gripping function may be achieved simultaneously with the same member.

  On the other hand, the sealing structure of the adapter is desired to be a structure in which the optical fiber connector and the adapter are attached in order to allow the adapter to be attached and detached. In order to achieve the aimed function, for example, a resin material can be used. However, a permanent adhesion method using an adhesive or the like may be used according to the usage form. In this case, this sealing structure may be substituted for the fitting function of the main body with the optical fiber connector.

  FIG. 6 shows the hole on the end face of the holey fiber sealed with a gel material. The gel material 60 is applied to the connection end surface 41 of the holey fiber 40, and then wiped to allow a minute amount to enter the hole 42, thereby sealing the end surface.

  The gel-like material 60 may be applied after assembling the connector. Alternatively, the gel-like material may be arranged in advance in the guide hole or guide groove of the optical fiber aligning portion or the bending space forming portion of the optical fiber connector. During assembly, the tip of the holey fiber inserted in the guide hole or guide groove may be applied by hitting the gel material. In this case, it is necessary to wipe away the gel-like material extruded from the tip of the optical fiber aligning portion together with the excessive gel-like material on the end face of the tip of the holey fiber.

  In addition, the sealing structure of an optical fiber connector and an adapter may be employ | adopted simultaneously, and only either one may be employ | adopted as needed. In addition, by utilizing the characteristics of holey fiber, which is less likely to cause loss even when the PC connection pressure is increased, the length of the bending space in the connector is reduced compared to the case of a normal single mode fiber, etc. By increasing the connection pressing force, it is possible to prevent the entry of foreign objects without completely sealing the hole on the end face. You can also.

Sectional structure diagram showing an example of an embodiment of an optical fiber connector of the present invention Cross-sectional structure diagram showing an example of holey fiber after processing FIG. 1 is a cross-sectional structure diagram showing a state when the optical fiber connector of FIG. 1 is connected. Sectional structural diagram showing an example of an embodiment of an adapter of the present invention FIG. 4 is a cross-sectional structural diagram illustrating a state in which the optical fiber connector of FIG. 1 is connected to another optical fiber connector using the adapter of FIG. Explanatory drawing showing how the hole on the end face of the holey fiber is sealed with a gel material

Explanation of symbols

  10: Optical fiber alignment part, 11: Guide hole, 20: Deflection space forming part, 21: Deflection space, 30: Optical fiber gripping part, 31: Guide hole, 32: Sealing structure, 40: Holey fiber, 41: Connection end face, 42: hole, 43: taper processed part, 44: deflection, 51: aligning part, 52: aligning part cover, 53: main body, 54: sealing structure, 60: gel-like material.

Claims (4)

An optical fiber connector for connecting a holey fiber,
An optical fiber aligning part for holding the leading end of the holey fiber, deformation space disposed between the optical fiber holders for secure the sheathed portion of the holey fiber, the optical fiber aligning unit and the optical fiber gripper And at least a forming part,
The optical fiber aligning portion, the bending space forming portion, and the optical fiber gripping portion are connected to each other, and guide holes or guide grooves are inserted through the holey fiber from the tip of the optical fiber aligning portion to the end of the optical fiber gripping portion, respectively. Have
The bending space forming portion has a bending space in which the holey fiber is bent,
The holey fiber is cleaved, the tip portion which is tapered in a state projecting a predetermined amount from the distal end of the optical fiber aligning unit, an optical fiber connector sheathed portion is fixed to the optical fiber holders,
An optical fiber connector characterized in that a gel-like material for sealing a hole on an end face of a holey fiber is disposed inside the optical fiber connector. 2. One end of a holey fiber that is cleaved at one end to be connected and is tapered by chamfering the corners of the cleaved end face into a guide hole or a guide groove of the optical fiber connector according to claim 1. Receiving from the fiber gripping part;
Insert one end of the holey fiber up to the tip of the optical fiber aligning portion of the optical fiber connector, and apply the tip of the holey fiber to the gel-like material arranged inside the optical fiber connector to make a hole in the end face A step of allowing a very small amount of gel material to enter ,
Fixing the covered portion of the holey fiber with the optical fiber gripping portion in a state in which the tip portion of the holey fiber protrudes from the tip of the optical fiber aligning portion by a predetermined amount ;
A method of assembling an optical fiber connector, comprising at least a step of wiping off a gel-like material extruded from the tip of the optical fiber aligning portion and an excessive gel-like material on the end face of the tip of the holey fiber . An optical fiber connector for connecting a holey fiber,
An optical fiber aligning portion that holds the tip of the holey fiber, an optical fiber gripping portion that fixes the sheathed portion of the holey fiber, and a bending space formed between the optical fiber aligning portion and the optical fiber gripping portion And at least
The optical fiber aligning portion, the bending space forming portion, and the optical fiber gripping portion are connected to each other, and guide holes or guide grooves are inserted through the holey fiber from the tip of the optical fiber aligning portion to the end of the optical fiber gripping portion, respectively. Have
The bending space forming portion has a bending space in which the holey fiber is bent,
In the optical fiber connector in which the holey fiber is cleaved and the tapered tip protrudes a predetermined amount from the tip of the optical fiber aligning portion, the coated portion is fixed to the optical fiber gripping portion.
Guide hole or guide groove fiber optic connector you characterized in that inside was placed gel material for sealing the hole in the end face of the holey fiber. 4. One end of the holey fiber, which is cleaved at one end to be connected and is ground into a tapered shape by obliquely grinding the corners of the cleaved end face, is inserted into the guide hole or guide groove of the optical fiber connector according to claim 3. Receiving from the fiber gripping part;
Insert one end of the holey fiber up to the tip of the optical fiber aligning portion of the optical fiber connector, and apply the tip of the holey fiber to the gel-like material arranged inside the guide hole or guide groove. A step of allowing a small amount of gel material to enter the pores;
Fixing the covered portion of the holey fiber with the optical fiber gripping portion in a state in which the tip portion of the holey fiber protrudes from the tip of the optical fiber aligning portion by a predetermined amount;
A method of assembling an optical fiber connector, comprising at least a step of wiping off a gel-like material extruded from the tip of the optical fiber aligning portion and an excessive gel-like material on the end face of the tip of the holey fiber.

Images