JP3130091B2 - Reinforcing method of optical fiber connection point - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel method for reinforcing an optical fiber connection point, and more particularly to a method for forming a bubble-free reinforcement by a very simple method.

[0002]

2. Description of the Related Art Optical fibers are generally fusion-spliced,
It is formed to have the same performance as other parts,
The connection points are reinforced because they can be mechanically weak for minutes. A typical method is to provide a hot melt adhesive layer having a uniform thickness on one surface of each of a flat Invar alloy and a flat glass ceramic,
The former is mounted on an induction heating head, the latter is mounted on a normal table, and the induction heating head with the flat Invar alloy attached is heated under pressure from above and below the optical fiber connection point. Then, the hot melt adhesive layer is brought into pressure contact with the connection point of the optical fiber to be fused and integrated to reinforce. .

[0003]

In such a conventional technique, in the process of melting a hot melt adhesive,
In some cases, bubbles may be generated inside or stress may be applied to the fusion splicing point of the optical fiber, thereby increasing the transmission loss of the optical fiber at the splicing point. The cause is that the thickness of the hot-melt adhesive varies randomly and the angle at which the flat-plate invar alloy or glass ceramic is pressed varies, so that the molten hot-melt adhesive cannot be pressed uniformly. When the hot melt adhesive is pressed to the fusion spliced part of the optical fiber, a stress acts in the pressing direction, and the transmission loss of the optical fiber spliced part may increase. understood.

[0004]

The present invention has been made as a result of intensive studies to solve the problems in the prior art as described above. As a result, a hot-melt adhesive provided on one side of a flat Invar alloy is used as in the prior art. Instead of being applied to a uniform thickness, the central portion is made to have the maximum thickness and the thickness is gradually reduced on both sides, so that the hot melt adhesive and the reinforcing member that does not generate bubbles in the vicinity thereof are formed. Is formed.

[0005]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the structure of the reinforcing material used in the present invention,
The central part has the maximum thickness on one side of the flat Invar alloy 1, and the hot melt adhesive layer 3-1 of reduced thickness is provided on both sides, and the flat thickness of the flat glass ceramic 2 is uniform on one side. A hot melt adhesive layer 3-2 is provided to form a reinforcing material.

FIGS. 2 and 3 are schematic explanatory views showing steps of the method of the present invention. First, a reinforcing member 4 described in FIG. 1 is placed above and below an optical fiber 12 having a connection point 11 in FIG.
Are mounted on the induction heating head 4 and the table 5 with the hot melt adhesive layers 3-1 and 3-2 inside, respectively,
The optical fiber 12 is brought closer to above and below the connection point 11. At this time, as shown in FIG. 3, while the induction heating head 4 to which the flat Invar alloy 1 is attached is induction-heated, the adhesive layers 3-1 and 3-2 are sandwiched between the connection points of the optical fibers from above and below. Apply pressure to make contact. In this manner, the hot melt adhesive is first melted by the induction heating of the Invar alloy, and the upper and lower hot melt adhesive layers 3-1 and 3-2 are integrated by covering the vicinity of the connection point 11 of the optical fiber 12. To form the hot melt adhesive layer 3,
Since the center portion of the -1 is thick, air easily escapes to the side, that is, the thinner portion of the adhesive, and does not remain in the adhesive layer and in the vicinity thereof.

[0007]

According to the present invention, the thickness of the adhesive layer between the conventional Invar alloy and the glass ceramic varies,
Due to the uneven angle between the Invar alloy and the glass ceramic, the melted adhesive could not be pressed evenly, so the air inside the reinforcement was difficult to escape. Around the connecting portion, it can be easily wrapped around and can be reinforced without applying stress thereto. As a result, no air bubbles remain inside the reinforcing member, and the connection portion can be completely mechanically protected, and an increase in transmission loss at the connection point can be reduced. In the present invention, the inside can be observed due to the transparency by using one of the glass ceramics as in the conventional case.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of a reinforcing material used in the present invention.

FIG. 2 is a schematic illustration of the method of the present invention.

FIG. 3 is a schematic illustration of the method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Invar alloy 2 Glass ceramic 3 Hot melt adhesive layer 3-1 Hot melt adhesive layer 2-2 Hot melt adhesive layer 4 Induction heating head 5 units 11 Connection point 12 Optical fiber

Continuation of the front page (56) References JP-A-61-124905 (JP, A) JP-A-5-19132 (JP, A) JP-B 1-59563 (JP, B2) (58) Fields investigated (Int) .Cl. ⁷ , DB name) G02B 6/24-6/40

Claims (1)

(57) [Claims] After the optical fibers are fusion-spliced, a hot-melt adhesive layer is formed on one surface of a flat invar alloy so that the center portion is thicker and gradually thinner toward both ends when reinforcing the connection portion. The former is attached to the induction heating head, the latter is attached to the base, and the latter is attached to the base by using the hot melt adhesive layer with a uniform thickness on one side of a flat glass ceramic as a reinforcement. It is arranged above and below the connection point of the optical fiber so that the agent layer is on the inside, and then the two are brought close to each other while induction heating the induction heating head to which the flat Invar alloy is attached, and the upper and lower hot melt adhesives A method for reinforcing an optical fiber connection point, which comprises bringing a layer into pressure contact with a connection point of an optical fiber and fusing and integrating the layer.