JPS6019483B2 - How to connect optical fiber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to reinforcement of optical transmission fibers, and particularly to a method for connecting a plurality of fibers at once.

In reality, transmission cables are connected in many places with extremely poor working conditions, such as inside manholes or overhead, and are also subject to severe time constraints, so methods that require a long time to connect each cable are not practical. A first object of the present invention is to provide a method that can connect fiber groups all at once in a short time in order to solve such problems.

On the other hand, as disclosed in Japanese Patent Application Laid-Open No. 50-68348, V-shaped grooves are cut on both sides of a thin flat plate, fibers are arranged and bonded along the grooves, and the flat plates are sequentially stacked to form a plurality of fibers. It describes how to connect fibers.

This method involves cutting a large number of grooves with a certain depth into thin plates with high precision, making it expensive to produce the flat plates.Also, the work process involves aligning the fibers along the grooves, butting them together, and repeating this process one after another to stack the thin plates. The assembly becomes complicated, and a stable work place must be secured.

A second object of the present invention is to provide a method for connecting optical fibers in which the structure of the thin plate is simple and the connection work can be easily performed in order to solve these drawbacks.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the inner surface of the stepped flat plate 1 (the side that is in contact with the fibers to be connected), and FIG. 2 is a sectional view taken along the line AA in FIG. 1. Groups of fibers to be connected 3, 3' are arranged on the horizontal surface 2 of the stepped flat plate 1 at a distance from each other in the axial direction as shown in FIG. At this time, each of the green fibers 4 of the fiber groups 3, 3' may be in close contact with each other or there may be a gap between them.

It is only necessary to connect the fibers in the correct order. Next, the other stepped flat plate 1' is attached to the fiber groups 3, 3' as shown in
Place it on top. Here, the vertical plane 5 of the stepped flat plate 1, 1',
The height of the fibers 5' is smaller than the outer diameter of the fiber tie 4, so that when they are sewn together as shown in FIG. 4, a gap 6, 6' is created. That is, the fiber wire 4 is brought into contact with the horizontal surfaces 2, 2' of the stepped flat plates 1, 1'.

Next, one of the stepped flat plates 1 and 1' is fixed and the other is moved in the direction of the arrow in FIG. 5, so that the respective front wires 4 are brought into close contact with each other.
Here, each fiber element green 4, which is made to have an external error lAm or less, has horizontal surfaces 2, 2' and vertical surfaces 5,
Since the fibers 5' are arranged in close contact with each other, the fiber groups 3 and 3' can be aligned with high accuracy.

Note that since there is a gap in the vertical direction between the fiber groups 3 and 3' at this step, one fiber group is pressed against the other fiber group in the direction of the arrow shown in FIG. 6, and both fiber groups 3,
3', butt the end surfaces of the wires 4 against each other.

The alignment of the axes of the fiber wire 4 and the butting of the end faces are thus completed.

Thereafter, while maintaining this state, a solution having refractive index matching and adhesive effects is injected from the ends 7, 7' of the stepped flat plates 1, 1'.

Then, when the adhesive has hardened and the fiber groups 3, 3' are fixed in the flat plate, they are connected using screws 8, 8' to provide mechanical reinforcement of the joint. According to the method described above, each line 4 of the fiber groups 3, 3' is finished with a high precision of less than 1 mm of external error.
.
The axial misalignment in the radial direction between the individual wires 4 can be suppressed to such an extent that it does not pose a practical problem, and connections can be made that are excellent in terms of optical coupling efficiency.

[Brief explanation of the drawing]

Figures 1 and 2 are the stepped flat plate of the present invention and its sectional view, and Figures 3-
FIG. 6 is an explanatory diagram of the connection method according to the present invention. 1, 1': Flat plate with a step, 2, 2': Horizontal surface of 1, 1',
3, 3': Fiber group, 4: Fiber wire, 5, 5':
1, 1' vertical plane, 6, 6': gap, 7, 7': 1, 1
' end face, 8, 8': screw. Gar Figures 2 Figures 3 Outside Figures 4 Figures 5 Outside Figures 6

Claims (1)

[Claims] 1. Sandwich the ends of the first fiber group 3 and the second fiber group 3' between the horizontal surfaces 2 and 2' of the two stepped flat plates 1 and 1' so that they butt each other, and then insert the strands of the fiber group. is flat plate 1,
1' vertical surfaces 5, 5' until they are tightly pressed together,
Furthermore, the fiber groups 3 and 3' are abutted until the tips of the fiber groups are joined together, and an adhesive having a refractive index matching and adhesive effect is injected into the abutted portion, thereby connecting the plurality of fibers at once. How to connect optical fiber.