JPH0449923B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to an optical fiber connection device in which a coating is applied to a connection portion in which the end surfaces of two optical fibers are abutted against each other and fusion spliced, and the outer periphery of the connection portion is coated. The present invention relates to a film coating method and a film coating apparatus.

(Prior Art) Conventional methods for connecting two optical fibers by butting their end faces together include fusion splicing, sleeve splicing, and the like. Among these, sleeve connections are difficult to concentrically connect, so fusion splicing is currently mainly used.

Fusion splicing is a method of removing the plastic coating layer from the spliced portion of the optical fiber and then melting the optical fiber at the spliced portion using arc discharge. In this case, microcracks are generated on the surface of the optical fiber during removal of the plastic coating layer or attachment of the optical fiber to a connecting device, and these microcracks significantly reduce the strength of the connection.

To solve this problem, conventionally, the outer periphery of the fusion spliced joint is molded with plastic to make it thicker than the other parts. However, the strength of an optical fiber is controlled by the strength of the optical fiber itself connected to it, and even if it is thickly coated with plastic, the strength of the optical fiber itself will not be particularly improved.

Therefore, recently, the end surfaces of optical fibers are butted together and fusion spliced, and then this joint is immersed in hydrofluoric acid to melt the surface of the optical fiber.
Microcracks on the surface of the optical fiber are removed.

(Problems to be Solved by the Invention) The above method for removing microcracks had the following problems.

Although the strength of the optical fiber itself is somewhat stronger than when spliced using conventional splicing methods, it is considerably lower than the original strength of the optical fiber itself.

Melting the surface of an optical fiber to a thickness of microns is technically quite troublesome, so it is difficult to remove just the microcracks, and the fiber inevitably melts to a thicker layer, which also deteriorates its strength. .

(Object of the Invention) The object of the present invention is to provide a film coating method and a film coating device thereof that can obtain optical fiber splices with excellent strength, in order to eliminate the above-mentioned drawbacks of fusion splices obtained by conventional methods. It is about providing.

(Means for Solving the Problems) A method for coating an optical fiber connection part according to claim 1 of the present invention is as shown in FIG. are butted together and fusion spliced, and this connection part 4 is housed in a vacuum plating tank 7, and the optical fiber is held outside the vacuum plating tank 7, and the outside of the connection part 4 is placed in the vacuum plating tank 7. A metal coating 5 is formed by a vacuum plating method, and then the optical fiber 2 is taken out from the vacuum plating tank 7 and the outer periphery of the connecting portion 4 is coated with a synthetic resin 6.

A coating device for an optical fiber connection portion according to a second aspect of the present invention has a vacuum plating tank 7 as shown in FIG.
An optical fiber 2 from which the plastic coating layer 1 has been removed and whose connection end faces 3 are fusion-spliced is placed on both outer sides of the optical fiber 2.
The presser 8 is formed so as to be opposed to each other, and the presser 8 is formed so that it can be disassembled into two parts, and inside the presser 8 there is an elastic material which is divided into two parts in a direction orthogonal to the direction of the halving. This is achieved by disposing a sealing material 9 that has a high elasticity.

(Function) In the first invention, the fusion spliced connecting portion 4
A metal coating 5 is applied to the outer periphery by vacuum plating in a vacuum plating tank 7, and then a synthetic resin 6 is applied to the outer periphery.
Since the connection portion 4 is covered with a metal coating, the connection of the connection portion 4 is stabilized, and the synthetic resin 6 is easily coated, and furthermore, the connection portion 4 has a double coating structure, which improves mechanical strength.

In the second aspect of the invention, the presser 8 attached to face the vacuum plating tank 7 and the sealing material 9 inside thereof can be divided into two, so that the optical fiber 2 whose connecting end surfaces 3 are fusion-spliced can be separated. Presser 8
When clamping, the presser 8 and the sealing material 9 can be easily clamped by dividing them into two parts, and the connecting portion 4 of the optical fiber 2 can be easily set into the vacuum plating tank 7.

(Embodiment) In the present invention, in order to fusion splice the abutted connection end surfaces 3 of the optical fibers 2, for example, a conventional fusion splicing method using a discharge arc is used.

In the present invention, a metal coating 5 is formed on the outer periphery of the fusion-spliced connecting portion 4. The formation method is performed by various vacuum plating methods such as sputtering method, ion plating method, vacuum evaporation method, etc.

As an example, when the sputtering method is employed, the following procedure is performed. A presser 8, which is a cylinder divided into two parts, is provided on both sides of the vacuum plating tank (bell jar) 7 shown in FIG. Insert the connected optical fiber 2. In this case, an elastic sealing material 9 is used between the optical fiber 2 and the presser 8.
is interposed between the optical fiber 2 and the presser 8.
The space is sealed.

The holding tool 8 and the sealing material 9 are split into two pieces, and the directions of the splitting of the sealing material 9 and the holding tool 8 are shifted by 90 degrees from each other and are arranged so as to be perpendicular to each other.

Next, a glow discharge is caused between the target 10 and the anode 11 arranged in the vacuum plating tank 7 as shown in FIG. 4 to form a metal coating 5 on the outer periphery of the connection portion 4.

Vacuuming time when using the sputtering method,
The sputtering time, the ion plating time when using the ion plating method, etc. may be appropriately selected.

When aluminum (A) is ion plated on the outer periphery of the connecting portion 4 by the ion plating method, the A is melted by resistance heating or the like. In this case, it is preferable that the distance between A and the optical fiber 2 be 20 to 30 cm so that the optical fiber 2 is not affected by axial heat.

In the vacuum evaporation method in which the metal coating 5 is formed by evaporating the metal, it is desirable to rotate the optical fiber 2 so that the entire outer periphery of the connecting portion 4 of the optical fiber 2 is coated with the coating 5 uniformly. The optical fiber 2 is rotated by a presser 8 using a known rotation mechanism (not shown).
Do this by rotating. The rotation speed in this case is selected based on the relationship with the ion plating time and the like.
As an example, about 5 to 6 times in 1 to 2 minutes can be considered. Note that 12 in FIG. 2 is a vacuum drawing tube.

(Effects of the Invention) A According to the first aspect of the present invention, the metal coating 5 is applied to the outer periphery of the fusion-spliced connecting portion 4 of the optical fiber 2, so that the strength of the optical fiber 2 itself is reinforced. Therefore, the strength is significantly improved compared to the conventional connection part in which the outer periphery of the connection part 4 is directly coated with synthetic resin.

Further, since the metal coating 5 is applied to the outer periphery of the connection part 4 while holding the optical fiber 2 outside the vacuum plating tank 7, the connection part 4 is coated when the metal coating 5 is formed.
becomes stable.

B The invention of claim 2 of the present invention has the following effects.

Since the presser 8 is formed on the outside of the vacuum plating tank 7, it is easy to sandwich the optical fibers whose end faces 3 are abutted against each other and are fusion spliced in a straight line.

Since the presser 8 is divided into two parts, the optical fiber 2 can be easily clamped by opening the presser 8.

Since the elastic sealing material 9 is arranged inside the presser 8, the optical fiber 2 can be securely clamped and the optical fiber 2 will not be damaged.

Since the splitting directions of the presser 8 and the sealing material 9 are orthogonal, even if they are split into two, the space between the optical fiber 2 and the presser 8 is sealed and no gap is created, and the presser There is no chance that the powder will leak out to the outside of the 8.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view showing an example of a connecting portion of an optical fiber obtained by the film coating method of the present invention, and FIG.
The figure is an explanatory diagram showing an example of the optical fiber coating device of the present invention, FIG. 3 is a sectional view taken along the line X-X of FIG. 2, and FIG. 4 is an explanatory diagram of the arrangement of an anode and a target in a vacuum plating tank. . 1 is a plastic coating layer, 2 is an optical fiber, 3
4 is a connecting end surface, 4 is a connecting portion, 5 is a metal coating, 6 is a synthetic resin, and 7 is a vacuum plating tank.

Claims (1)

[Scope of Claims] 1. The connecting end surfaces 3 of the optical fibers 2 from which the plastic coating layer 1 has been removed are brought together and fusion-spliced, and this connecting portion 4 is housed in a vacuum plating tank 7, and the optical fiber is vacuum-bonded. The optical fiber 2 is held outside the plating tank 7, and a metal coating 5 is formed on the outside of the connection part 4 in the same vacuum plating tank 7 by a vacuum plating method, and then the optical fiber 2 is taken out from the vacuum plating tank 7 and the connection part 4 is connected. A method for coating an optical fiber connection part, characterized in that the outer periphery of the part 4 is coated with a synthetic resin 6. 2 Opposing pressers 8 are formed on both outer sides of the vacuum plating tank 7 to hold the optical fiber 2 from which the plastic coating layer 1 has been removed and whose connection end surfaces 3 are abutted against each other and are fusion-spliced. The tool 8 is formed so that it can be disassembled into two parts, and an elastic sealing material 9, which is divided into two parts, is placed inside the holding tool 8 in a direction perpendicular to the direction of the two parts. Coating equipment for optical fiber connections.