JPH04125504A - Optical fiber fusion splicing connection device - Google Patents

Abstract

PURPOSE:To generate no electric noise and realize safe connecting operation even when an optical fiber with a conductive jacket is used by using an electric conductor for the part of a fixation member for fixing an end part of the optical fiber which contacts the optical fiber, and grounding the electric conductor. CONSTITUTION:The part of the fixation member for fixing the end part of the optical fiber 3 which contacts the optical fiber 3 is formed of conductive rubbers 4a and 4b. While an electric conductor 6a connects a discharge electrode 2a to the high-voltage side of a power circuit 5, an electric conductor 6b connects the conductive rubbers 4a and 4b to the ground side of the power circuit 5 together with a discharge electrode 2b. The conductive rubbers 4a and 4b which are the fixation member for fixing the end part of the optical fiber 3 are at the ground potential. Consequently, even if discharge occurs on the optical fiber 3, a current at this time flows to the ground through the conductive rubbers 4a and 4b for fiber clamps, so no voltage is developed at the part of an external optical fiber 3.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application> The present invention (i) relates to an optical fiber fusion splicing device and is useful for fusion splicing of optical fibers and fibers having conductive coatings.

<Prior Art> Optical fiber fusion splicing devices that fuse optical fibers using heat from discharge are often used to connect optical fibers made of quartz glass or multicomponent glass.

In recent years, in order to prevent the strength of optical fibers made of silica glass from deteriorating, it has been considered to add a coating to the surface of the optical fibers to prevent moisture from passing through. Among these, a carbon-coated fiber with a carbon film is a promising optical fiber that is being put into practical use.

<Invention tries to solve! ! Title> The carbon coat M of the carbon coated fiber is electrically conductive, although it is several hundred angstroms thin. Therefore, when splicing with conventional electrical discharge fusion splicing equipment, the high voltage from the electrical discharge propagates through the optical fiber and becomes a source of noise for the electrical signals traveling through the conductors in the cable. There were layers. Additionally, there was a risk of electric shock if a worker touched the part of the optical fiber where the coating (usually an insulating polymeric material) had been removed. For example, this becomes a serious problem when connecting the other end of the optical fiber as well.

More specifically, in an optical fiber fusion splicing device, the voltage generated between the electrodes when starting a discharge is about 4000 volts, and decreases to 1000 volts or less when the discharge reaches a steady state (glow discharge state). Since the optical fiber is set at an intermediate position between the picture electrodes, if the surface of the optical fiber is conductive, a high voltage will be generated at the end of the fiber when discharge starts. When we conducted an experiment in which the fiber was discharged between the electrodes using a high-frequency trigger type discharge power source, which is the most popular type for fusion splicing, a high voltage was generated intermittently at the start of the discharge, with a maximum of about 1500 volts. Voltage confirmed.

Once a steady discharge begins, the coating evaporates or burns away, the fiber loses its conductivity, and the high voltage disappears. However, according to experiments, high voltage is generated for at least 5 milliseconds, which causes the above problem.

In view of the problems of the prior art described above, the present invention provides an optical fiber that does not generate electrical noise even if it has a conductive coating.
Moreover, it is an object of the present invention to provide an optical fiber fusion splicing device that can realize a safe splicing operation.

Means for Solving the Problems> The configuration of the present invention that achieves the above object is as follows: In an optical fiber fusion splicing device that melts and fuses both ends of opposing optical fibers with heat of electric discharge, the ends of the optical fibers are connected to each other. The part of the fixing member for fixing the optical fiber that contacts the optical fiber is formed of a conductor, and the conductor is electrically grounded.

Effect> According to the present invention having the above configuration, when carbon coated fibers having a conductive coating are fusion spliced, the conductive coating comes into contact with a conductor at ground potential. Therefore, this coating is also at ground potential.

Practical example Embodiments of the present invention will be described in detail below based on the drawings.

FIG. 1 is a perspective view showing an embodiment of the present invention with an optical fiber fixed therein. In the same figure, 1 is V clear white, 2a
, 2b is a discharge electrode, 3 is a carbon coated optical fiber,
3m is a polymer coating of the optical fiber 3, 4m and 4b are conductive rubber for fiber clamp, 5 is a power supply circuit for discharge,
6m and 6b are conducting wires. At this time, the conductor 6a connects the discharge electrode 2a to the high voltage side of the power supply circuit 5, while the conductor 6b
connects the conductive rubber 4a, 4b to the ground side of the power supply circuit 5 together with the discharge electrode 2b. Thus, the conductive rubber 4m, 4 which is the fixing member that fixes the end of the optical 7 eyeper 3
b is at ground potential.

In this embodiment, the end of the optical fiber 3 from which the polymer coating 3a has been stripped off is set in the groove stand 1 after the end face is cut at right angles.

Next, this optical fiber 3 is pressed down with conductive rubber 4m and 4b for a 7-eye clamp.

Conductive rubber 4a for this fiber clamp.

4b is held by a conductive metal part, and this metal part is connected to ground by a conducting wire 6b.

The power supply circuit 5 for discharging includes not only the most widespread high-frequency trigon type, but also a direct current discharge type and a low frequency (commercial frequency) type.
There are discharge methods, but any of them may be used.

This embodiment differs from the conventional one in that the rubber for the fiber clamp is conductive and this rubber is short-circuited to ground. Incidentally, insulating rubber has conventionally been used.

When connecting the optical fiber 3, the discharge electrode is 2 m long.

When a high voltage is applied between the discharge electrodes 2a and 2b, a discharge first occurs at the end of the optical fiber 3 from the discharge electrode 2a on the high voltage side, and as the conductive film disappears, the discharge between the discharge electrodes 2a and 2b begins and the discharge becomes steady. become. At this time, even if a discharge occurs in the optical fiber 3, the current flows to the ground through the conductive rubber 4a, 4b for the fiber clamp that is in contact with the surface of the optical fiber 3. High voltage is not generated in the outer optical fiber 3 portion.

FIG. 2 shows the results of an experiment when connecting using the device of this embodiment. In the case of the carbon coated fiber used in the experiment,
The electrical resistance per meter was 2.7 megaohms. In the experiment, both the case of the conventional connection device and the case of the connection device according to this embodiment were compared. Connected fiber 3
Both the maximum voltage developed at the other end and the maximum current flowing when the other end was shorted to ground were measured. In the case of conventional equipment, when the optical fiber length is 1 meter, the maximum voltage generated at the other end is 1500 volts, and at 100 meters, the maximum voltage generated at the other end is 7.
00 volts, and the current flowing when shorted to earth is 0.386i no ampere at 1 meter, 1
Even at a distance of 0.00 meters, the voltage was 0.024E ampere◇In contrast, the device of this example could not detect any voltage or current at all.

When the optical fibers 3 are fusion spliced, the coating may be erased during the first discharge and fusion spliced during the second discharge, instead of being spliced using the negative discharge. At this time, the optical fiber 3 becomes transparent when the film is removed by the first discharge, so the core of the optical fiber 3 is I! A connection method in which the axes are aligned using 31 can be applied. This method of observing and closely reading the core is performed using a fusion splicing device that has a structure in which the left and right v4 are independent and the positions can be adjusted, but the present invention can also be carried out with this bottle fusion splicing device. can. Alternatively, it could be implemented using a batch fusion splicing device that connects a plurality of optical fibers 3 at once.

In the above-mentioned embodiment, the fiber clamp rubber was made conductive and connected to the ground, but instead (1) the groove base 1 may be made conductive and connected to the ground. Of course, you can do both. ■When making groove base 1 conductive,■
A method of manufacturing the groove base 1 itself from conductive metal, etc., and ■
There is a method in which the groove base 1 is made of an insulating material, and the V-groove surface that contacts the optical fiber surface is thinly coated with a conductive material.

<Effects of the Invention> As specifically explained above in conjunction with the embodiments, the present invention enables the work to be performed safely without propagating electrical noise when fusion splicing carbon coated fibers etc. with excellent strength and reliability. This makes it extremely useful for constructing future optical fiber communication networks.

In addition, the present invention does not only connect optical fibers with conductive coatings (it is also possible to connect conventional optical fibers without coatings. Conventional optical fibers are originally insulating, so the present invention This is because the connection conditions are not affected by the implementation of the present invention.Therefore, the present invention can be implemented by simply modifying the conventional optical fiber fusion splicing device, and compatibility with the conventional device can be maintained. Extremely practical.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the present invention in a state where an optical fiber is fixed, and FIG. 2 is a graph showing characteristics during connection work in comparison with the conventional one. In the drawing, 1 is a V series, 2a and 2bl are discharge electrodes, 3 is an optical fiber, and 4a and 4b are conductive rubber. Patent applicant: Agent of Nippon Telegraph and Telephone Corporation

Claims (1)

[Claims] In an optical fiber fusion splicing device that melts and fuses both ends of opposing optical fibers with the heat of electric discharge, the part of the fixing member that fixes the end of the optical fiber that contacts the optical fiber is electrically conductive. 1. An optical fiber fusion splicing device characterized in that the conductor is electrically grounded.