JPH0361164B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical fiber connection, and an object thereof is to provide a connection with excellent strength.

Optical fiber connection methods include fusion splicing and sleeve connection. Among these, sleeve connections are difficult to concentrically connect, so fusion splicing is currently mainly used.

Fusion splicing is a method of splicing optical fibers by removing the plastic coating from the joints of the optical fibers and then melting the optical fibers by arc discharge. In this case, microcracks are generated on the surface of the optical fiber during removal of the plastic coating or during installation in the equipment to be connected, and these microcracks significantly reduce the strength of the connection. To solve this problem, conventionally, plastic is molded around the outer periphery of the fusion spliced joint to make it thicker than the other parts. However, the strength of the optical fiber is controlled by the strength of the optical fiber itself connected to it, and just because the fiber is thickly coated with plastic does not significantly improve the strength of the optical fiber itself.

Recently, therefore, microcracks on the surface of the optical fibers are removed by connecting the optical fibers together and then immersing the connected portion in hydrofluoric acid to melt the surface of the optical fiber. As a result, the strength of the optical fiber itself is somewhat stronger than that of the conventional splicing method, but the strength is considerably inferior compared to the strength of the original optical fiber itself, and it is technically impossible to melt the surface of the optical fiber in microns. It's quite a hassle.

The present invention eliminates the above-mentioned drawbacks of the connecting parts obtained by the conventional method, and will be described in detail below with reference to the drawings.

The optical fiber connection part of the present invention is made by connecting the end faces of optical fibers from which the plastic coating has been removed, and forming a metal coating on the outer periphery of this connection part by vacuum plating, and coating the outer periphery with a synthetic resin. It is what it is.

As for the method of manufacturing this connection part, various conceivable methods for connecting the end faces 3 of the optical fibers 2 may be employed, for example, a conventional fusion splicing method using a discharge arc.

As a method for forming the metal coating 5 on the outer periphery of the connecting portion 4, various vacuum plating methods such as a sputtering method, an ion plating method, a vacuum evaporation method, etc. may be employed.

As an example, when the sputtering method is employed, the following procedure is performed.

On both sides of the bell gear 7 shown in FIG. 2, a holding device 8, which is a cylinder divided into two parts, is provided, and within this holding device 8, an optical fiber 2 whose plastic coating layer 1 has been removed and the end faces 3 are fused and spliced is placed. insert.

In this case, an elastic sealing material 9 is interposed between the optical fiber 2 and the presser 8 to seal the optical fiber 2 and the presser 8. As the bell gear 7 and the sealing material 9, conventionally used two-split ones are used, and among these, the sealing material 9 and the presser tool 8 are arranged so that the two-splitting directions are perpendicular to each other.

In this state, a glow discharge is caused between the target 10 and the anode 11 arranged as shown in FIG. 4, and the metal atoms flying out from the target 10 are transferred to the optical fiber 2.
The evacuation time and sputtering time when using the sputtering method, the ion plating time when using the ion plating method, etc. may be appropriately selected.

Aluminum (Al) by ion plating method
When performing ion plating, Al is melted by resistance heating or the like. The distance between Al and the optical fiber is preferably 20 to 30 cm so that the optical fiber is not affected by radiant heat.

In the vacuum evaporation method in which the metal is coated by evaporating the metal, it is desirable to rotate the optical fiber 2 so that the entire outer periphery of the optical fiber 2 is coated uniformly. The optical fiber 2 is rotated by rotating the presser 8 using a known rotation mechanism (not shown). The rotation speed is selected based on the relationship with the ion plating time, etc. As an example, about 5 to 6 times in 1 to 2 minutes can be considered. In addition, 12 in FIG. 2 is a vacuum drawing tube.

As mentioned above, since the present invention provides a metal coating on the connecting portion of the optical fiber, the strength of the optical fiber itself is reinforced, and the conventional connecting portion is made by simply coating the outer periphery of the connecting portion of the optical fiber with plastic. The strength is significantly improved compared to .

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing an example of an optical fiber according to the present invention, FIG. 2 is an explanatory view showing an example of manufacturing the optical fiber according to the present invention, and FIG. , FIG. 4 is an explanatory diagram of the arrangement of the anode and the target. 1 is a plastic coating, 2 is an optical fiber, 3 is a connecting end face, 4 is a connecting portion, 5 is a metal coating, and 6 is a synthetic resin.

Claims (1)

[Claims] 1. An optical fiber connection section in which the end surfaces of optical fibers from which the plastic coating has been removed are butt-connected, a metal coating is formed on the outer periphery of this connection section by vacuum plating, and the outer periphery is coated with a synthetic resin.