JPS58136008A - Method for treating end surface of optical fiber - Google Patents

Abstract

PURPOSE:To reduce the radius of curvature of a spherical end surface of a fiber wire to a half as gret as the radius of the fiber strand easily and to improve coupling efficiency remarkably by cutting the fiber strand slantingly to the fiber axis and thermally melting the external circumference of the cut end. CONSTITUTION:The optical fiber cable 10 is cut slantingly at a proper angle and its sheath 12, a secondary coating 13, and a primary coating 14 are removed to expose the fiber strand 15. The end surface 17 of the cut end part 16 of the fiber strand 15 is rugged. Therefore, the end part 17 has a lubricious surface by its surface tension to form a specular surface which is a specific spherical surface 19. The radius gamma of curvature of this spherical surface 19 is easily reduce to less than a half as gret as the radius of the fiber strand 15.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical fiber end face treatment method,
-Relates to a method for forming a spherical surface with a small radius of curvature on the end face of a fiber wire.

One of the well-known methods for connecting an optical fiber to other devices such as an optical fiber, a light emitting device, a light receiving element, etc. and for efficiently combining the optical output is to make the end surface of the fiber cable spherical. However, it is known that the radius of curvature of this spherical surface favors a small wedge coupling efficiency.

Conventionally, the end face treatment method of this auxiliary optical fiber is shown in Fig. 1(a).
) and (b). Figure 1 (a) d3,
, the secondary coating 3 and the primary coating 4 are removed to expose the fiber cable 55, and the end face 6 is polished using an IJI polishing machine (not shown).
If, this is formed into a 1LSI mirror surface along the fiber axis. Alternatively, by cutting the Rifno-Iba cable line 5 in a stress rupture manner using a cutting jig (not shown),
If the end face 6 is formed, the end face 6 is obtained. Next, Figure 1 (1
) As shown in 1, when the outer periphery of the tip of the fiber wire 5 is heated and melted, the tip of the fiber cable 5 becomes spherical due to its surface tension, and an appropriate spherical surface 7 is formed. .

However, in such an end face treatment method, it is not immediately possible to make the radius of curvature R of the spherical surface 7 smaller than the radius of the fiber strand 5, and it is necessary to improve the coupling efficiency. There was a limit. In addition, I, for end face treatment of optical fiber,
This invention was made in view of the conventional problems, and its purpose is to A simple cutting method using a cutting jig is used, and provides a method for processing the end face of an optical fiber that can obtain a spherical surface with a radius of curvature P that is less than the radius of the Noah cable. There is a particular thing.

This invention has the following advantages:
Cut the fiber cable diagonally to the fiber lllll11,
It is characterized in that the outer periphery of each cut end is heated and melted 811.

Below, these five embodiments will be explained in detail with reference to the accompanying drawings.

FIGS. 2 to 5 are diagrams showing each process in parentheses ( ) of the optical fiber end face treatment method according to the present invention.

As shown in Figure 2: J: Sea urchin, first of all, optical fiber! -1 le 10
Using a well-known cutting tool such as a wire cutter, the section to be cut is cut at an appropriate angle C diagonally with respect to the Noah axis to obtain a cut surface 11.

Next, as shown in FIG. 3(a), the outer sheath 12, the secondary sheath 13J5J, and the first sheath wi are attached to the cut portion of the optical fiber 11.
1/l is removed to expose fiber cord 155.

At this time, the end surface 17 formed on the cut end 16 of the fiber cable 15 is inclined at an arbitrary angle, and as shown in FIG.
) has an arbitrary shape with unevenness as shown in detail.

Finally, as shown in FIG. 4, the cut end 16 of the fiber cable 15 is inserted between the electrodes 18, 18 of the electric discharge heater, and is heated and melted. The results of (a) are shown in Figure 5.
-, the end portion 17 becomes a smooth surface due to its surface tension, forming a mirror surface, and a certain spherical surface 19 is also formed.

At this point, the radius of curvature r of the spherical surface 19 is equal to
It is easy to make it less than half the radius of .

Note that the heat melting method for the horn/iron wire cut end is not limited to this example, and may be performed using flame/electrical
The object of the present invention is still achieved even with the heat melting method used by Noser et al.

As explained in detail above, according to the optical fiber end processing method according to the present invention, a fiber strand is cut obliquely to the fiber axis, and the outer periphery of the cut end of the fiber strand is heated and melted. Therefore, it is possible to easily reduce the radius of curvature of the spherical surface formed on the end face of the fiber cable to more than half the radius of the fiber cable, and the coupling efficiency of the optical fiber can be dramatically reduced. 3. In addition, the cutting operation can be easily performed using a cutting tool such as a wood cutter, etc., and the work efficiency is greatly improved because there are no restrictions on lifting.
do.

[Brief explanation of the drawing]

FIGS. 1(a) and (b) are diagrams showing a conventional optical fiber end treatment method, and FIG. 1(a) is a diagram showing a conventional method for treating the end of an optical fiber. Figure 1 (1) is a schematic side view showing the process of forming a mirror surface, and Figures 2 to 5 (1) are enlarged views of important parts showing the process of forming a spherical surface of the seven-stranded cable wire. J FIG. 2 is a diagram showing an embodiment of the optical fiber end face treatment method according to the present invention divided into each step, and FIG. 2 is a schematic side view showing an optical fiber cable cut at an angle;
Figures 3(a) and 3(b) show the state in which the coating has been removed to expose the fiber cable. 1. A schematic side view and an enlarged view of the main parts; FIG. 4 is a schematic side view showing the process of forming a spherical surface at the end of the cut portion of the fiber; FIG. 5 is a schematic side view showing the formed spherical surface. . =5- 15...Fiber cable wire 16...... Cut end 17... End 19... - Spherical patent applicant Tateishi Electric Co., Ltd. 6-- Figure 1 (0) Figure 2 0 Figure 3 (0) 2 Figure 3 (b)

Claims (1)

[Claims] (1) The end a11 of the fiber cable is shaped into a spherical shape. : IIJ
In the IJI optical fiber end surface treatment method, the wood wire is cut obliquely to the fiber axis, and the outer periphery of the cut end of the wood wire is heated and melted ()I
Optical fiber end face treatment method with these features as key features.