JP2002228859A - Angle fiber and processing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive angle fiber excellent in workability, consequently free of cracking and chipping in the front edge of the optical fiber 14 and easy to handle. SOLUTION: In an angle fiber obtained by imparting an inclined plane 12 to the front edge of an optical fiber 14 freed of its coating, the boundary part 11 between the inclined plane 12 and the circumferential surface 13 of the optical fiber is curved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an angle fiber used for optical coupling between an optical fiber used for optical communication, a light emitting source and a light receiving source.

[0002]

2. Description of the Related Art A photodiode (hereinafter referred to as PD) is used as a light receiving source for optical communication, and a laser diode (hereinafter referred to as LD) or a light emitting diode is used as a light emitting source. When these light-emitting and light-receiving elements are connected to an optical fiber, the light-emitting and light-receiving elements are damaged by the return light reflected from the end face of the optical fiber, and angle fibers having an inclined surface formed at the tip of the optical fiber are widely used. Have been.

As a method of forming an inclined surface at the tip of an optical fiber, the surface of the optical fiber from which the coating has been removed is scratched with a diamond cutter or the like in a direction perpendicular to the longitudinal direction of the fiber, and an instantaneous force is applied to the optical fiber. There is a method of breaking.

[0004] Alternatively, as shown in FIG.
4 is temporarily fixed to an optical fiber temporary fixing jig and angle-polished,
A method of forming the inclined surface 52 and then removing the temporary fixing has been widely used (see JP-A-11-295534).

Further, as a countermeasure for preventing chipping of the boundary portion 51 of the angle fiber shown in FIG. 5, as shown in FIG. 6, there is a method in which the fiber tip is immersed in hydrofluoric acid and the boundary portion 61 is chamfered. See JP-A-11-295534).

[0006]

However, in the conventional angle fiber shown in FIG. 5 described above, the boundary 51 between the optical fiber inclined surface 52 and the fiber outer periphery 53 has an acute angle as described above. The boundary 51 was very easily chipped. For this reason, as shown in FIG. 7A, there is a problem that a chip 71 is generated at the boundary portion 51 and the processing yield is very poor.
Also in the assembling process with the light emitting element, there is a problem that the boundary portion 51 is chipped or cracked, and the inclined surface 52 at the tip end portion is damaged.

Further, even after the light-receiving element and the light-emitting element are assembled, the inclined surface 52 is warmed by the light passing through the optical fiber, so that the generated microcracks proceed to the boundary 51 and the light is transmitted. There was a problem that it disappeared.

As shown in FIG. 6, in a conventional angle fiber in which only the boundary 61 between the inclined surface 52 at the tip of the optical fiber and the outer peripheral surface 53 of the optical fiber is immersed in hydrofluoric acid and the boundary 61 is chamfered. As shown in FIG. 7 (b), the chamfered boundary portion 61 is hardly chipped. However, when an external force is applied, a chip 72 may be generated around the corner 73, and the chip problem is completely solved. Could not be resolved. Moreover, in this chamfering process, hydrofluoric acid which is dangerous to the human body is used, and safety measures are required, and two steps of a polishing step and a step of immersing the polished optical fiber in hydrofluoric acid are required. Therefore, the number of working steps is increased, and it is impossible to manufacture an inexpensive angle fiber in a market where low price is required.

[0009]

According to the present invention, there is provided an angle fiber in which an end of an optical fiber from which a coating has been removed is provided with an inclined surface, wherein the boundary between the inclined surface and the outer peripheral surface of the optical fiber is curved. It is characterized by.

Further, the present invention is characterized in that the radius of curvature of the boundary between the inclined surface and the outer peripheral surface of the optical fiber is gradually increased from the outer peripheral surface of the optical fiber toward the inclined surface.

Further, the present invention is characterized in that the inclined surface is a flat surface or a curved surface.

Further, in the present invention, the tip of the optical fiber from which the coating has been removed is temporarily fixed to an optical fiber fixing jig, and a resin is applied around the optical fiber protruding from the tip of the optical fiber fixing jig. Thereafter, the resin and the optical fiber are simultaneously polished to form an inclined surface and a curved boundary at the tip of the optical fiber, and then the angle fiber is processed from the step of removing the temporary fixation.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a side view of an angle fiber showing an embodiment of the present invention. Referring to FIG.
Is provided with an inclined surface 12 having an angle φ with respect to a perpendicular to the outer peripheral surface 13 of the optical fiber. Slope 1
The boundary portion 11 between the outer circumference 2 and the outer circumference 13 has a smooth curved surface.

Since the boundary portion 11 has a smooth curved surface,
Angle fiber can be manufactured with good yield,
Even during the optical fiber connection work with the light emitting element and the light receiving element, it is possible to assemble the optical fiber 14 without causing the end face of the optical fiber 14 to come into contact with a connected component, a jig, or the like, thereby causing chipping or cracking.

The boundary portion 11 of the angle fiber of the present invention
As shown in FIG. 1 (b), the shape is such that the radius of curvature is gradually increased from the outer peripheral surface of the fiber to the inclined surface. As described above, in the conventional boundary portion 65 shown in FIG. 7B, when an external force is applied, since the corner portion 73 exists,
While the chip 72 is generated in the direction from the fiber outer peripheral surface 53 to the inclined surface 52, the boundary portion 11 of the present invention has no corner and has a shape with a larger radius of curvature than the inclined surface 12. Therefore, there is no chipping in the direction from the fiber outer peripheral surface 13 to the inclined surface 12.

The angle φ of the inclined surface 12 of the optical fiber 14 is processed in the range of 0 ° to 50 °, and the inclined surface 12 has a curved surface as shown in FIG. 1 or a flat surface as shown in FIG. It may be.

The optical fiber 14 can be a single mode optical fiber or a multimode optical fiber.

The angle fiber according to the present invention can be manufactured by the following processing method. After inserting the optical fiber 14 into the optical fiber fixing jig 32 as shown in FIG.
The resin layer 31 around the optical fiber protruding from the tip of the optical fiber fixing jig 32 is formed. Next, FIG.
Is fixed to the polishing jig 41 as shown in FIG.
The resin layer 31 is polished by the polishing device 42.

The reason why the resin layer 31 is formed here is that the optical fiber 14 is fixed only by the optical fiber fixing jig 32 and, when the resin layer does not exist, the polishing sheet is formed by the polishing step. Since the tip of the fiber is caught on the tip and breaks or chipping occurs, it is necessary to surround the entire tip of the fiber with a resin layer. As the optical fiber fixing jig 32, a ferrule of a resin molded product, a ferrule of alumina, glass, or the like can be used. As a resin, the fiber can be fixed, and as a removable resin,
Examples include wax and UV-curable water-soluble resin. The number of optical fibers fixed to the fiber fixing component 32 may be one or more.

As a method of polishing, polishing is started by using a polishing sheet of diamond, alumina or the like, using a polishing sheet having a coarse particle size, sequentially reducing the particle size of the polishing sheet, and finally buffing. Finish polishing is performed. After the polishing is completed, the polished resin layer 31 is peeled off, so that the inclined surface 12 and the smooth curved boundary portion 11 continuous thereto are formed.
Is formed. The reason why the smooth curved boundary portion 11 can be formed is that the resin layer 31 is soft against the optical fiber 14, so that the resin layer 31 is polished first with a polishing sheet, and the finish polishing with a buff is performed. The boundary 11 between the inclined surfaces 12 and 21 and the outer periphery 13 of the optical fiber 14 strongly hits the buff, and a smooth curved surface is formed. By using this processing method, it is possible to form the boundary portion 11 in which the radius of curvature is gradually increased toward the inclined surface at the boundary portion 11 only by the polishing step, and the yield can be safely achieved without using hydrofluoric acid. An angle fiber can be produced well.

[0022]

Embodiments of the present invention will be described below.

Each of the angle fiber of the present invention, the conventional angle fiber, and 100 angle fibers subjected to chamfering were produced. The angle fiber of the present invention is obtained by first removing the coating of the optical fiber and setting the optical fiber 1 in the optical fiber fixing jig 32 having a 126 μm hole.
4 and a resin layer 31 is formed from a UV-curable water-soluble resin.
Four types of polishing sheets having a particle size of 6 μm were sequentially polished in order from the coarser one, and finally finished with a buff. The optical fiber 14 is immersed in water to dissolve the resin layer, and the optical fiber 14 is
More pulled out.

In the conventional angle fiber shown in FIG. 5, the optical fiber 14 from which the coating has been removed is inserted into an optical fiber fixing jig 32 having a 126-micron hole and temporarily fixed. Polishing was performed using a polishing apparatus together with the optical fiber fixing jig 32, and the temporary fixing was removed.

Further, in the case of the conventional angle fiber which has been chamfered as shown in FIG. 6, after the angle fiber is produced by the above-described method, the fiber tip is immersed in hydrofluoric acid to be chamfered.

While the angle fiber of the present invention has a curved surface at the boundary surface 11, the angle fiber according to the conventional temporary fixing method shown in FIG. 5 does not have a curved surface at the boundary portion 51. Further, even in the case of the chamfered angle fiber shown in FIG. Table 1 shows the results of observing the inclined surfaces 12 and 52 at the tip of each angle fiber with a metallurgical microscope × 400 to see if there are chips or flaws on the end faces.

In the conventional angle fiber shown in FIG.
In the conventional angle fiber shown in FIG. 6, the chip 13 and the end face flaw 5 were generated, whereas in the conventional angle fiber shown in FIG.
It is recognized that the chip is extremely reduced, that is, the chip is 0, the end face is flawed and the quality is 96.

[0028]

[Table 1]

[0029]

According to the present invention, in an angle fiber having an inclined surface at an end of an optical fiber from which a coating has been removed, the boundary between the inclined surface and the outer periphery of the optical fiber is formed into a curved surface, so that the optical fiber is curved. Safe without the use of acid,
It is possible to provide an inexpensive angle fiber that can prevent chipping and has a good yield.

[Brief description of the drawings]

FIG. 1A is a side view of a distal end portion of an angle fiber according to the present invention, and FIG. 1B is an enlarged view of a boundary portion.

FIG. 2 is a side view of a distal end portion of the angle fiber according to the present invention.

FIG. 3 is a side view showing a method for processing an angle fiber according to the present invention.

FIG. 4 is a side view showing a method for processing an angle fiber according to the present invention.

FIG. 5 is a side view of a tip portion of a conventional angle fiber.

FIG. 6 is a side view of a tip portion of a conventional angle fiber.

7A and 7B are enlarged views of a conventional angle fiber boundary portion.

[Explanation of symbols]

 Reference Signs List 11 boundary portion 12 inclined surface 13 outer periphery 14 optical fiber 21 inclined surface 31 resin layer 32 optical fiber fixing jig 41 polishing jig 42 polishing device 51 boundary portion 52 inclined surface 53 outer periphery 54 optical fiber 61 boundary portion 71 chip 72 chip 73 angle Department

Claims (4)

[Claims] 1. An angle fiber comprising an optical fiber from which a coating has been removed and having an inclined surface at the tip, wherein a boundary between the inclined surface and the outer peripheral surface of the optical fiber is curved. 2. The angle fiber according to claim 1, wherein the radius of curvature of the boundary between the inclined surface and the outer peripheral surface of the optical fiber is gradually increased from the outer peripheral surface of the optical fiber toward the inclined surface. 3. The angle fiber according to claim 1, wherein the inclined surface is a flat surface or a curved surface. 4. The optical fiber with the coating removed is temporarily fixed to an optical fiber fixing jig, and a resin is applied around the optical fiber protruding from the optical fiber fixing jig. A method of processing an angle fiber, comprising the steps of forming an inclined surface and a curved boundary at the tip of an optical fiber by simultaneously polishing the fiber, and then removing the temporary fixing.