JPH0153761B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for stripping a metal coated optical fiber.

Conventionally, when removing the coating from a metal-coated optical fiber, there has been no specific equipment, which has been a major hindrance in connecting the fibers. One way to connect metal-coated optical fibers is to connect them without removing the metal coating, as (1) the discharge becomes unstable during discharge welding, and (2) the fibers tend to vibrate and become misaligned. , (3) the metal coating is partially peeled off,
The surface of the fiber becomes dirty, resulting in adverse effects such as a decrease in strength and the introduction of metal scum during reinforcement. Therefore, a good connection cannot be made unless some method is used to remove the metal coating.

Possible methods for removing the coating include mechanically peeling the coating from the fiber surface and removing the coating by melting the metal with chemicals or heat. Since the metal coating and the fiber have a high degree of adhesion, it is necessary to rub the fiber surface with a certain degree of force to remove the coating, which has the disadvantage that the glass fiber surface is easily damaged. ₂ It can be removed with strong acidic chemicals such as SO ₄ , but it is dangerous, and when the metal coating is melted with heat, metal clumps occur during removal due to the surface tension effect of the molten metal coating. Therefore, in either case, there is a drawback that a connection with good characteristics cannot be expected.

The present invention has been made in view of the above circumstances, and is a method for removing a metal coating from an optical fiber, which can remove the metal coating in a relatively safe manner and in a short time without damaging the surface of the optical fiber. The object of the present invention is to provide a method in which the coating is electrically removed.

The present invention will be described in detail below with reference to the drawings.

The drawing shows an example of an apparatus for implementing the present invention, and in the drawing, reference numeral 1 indicates a base. Base 1
A container 2 is formed on the upper surface of the container 2, and a support wall portion 3 is provided upright along the side wall of the container 2. A movable table 4 is attached to the support wall portion 3 so as to be movable in the vertical direction, and a fiber holding portion 6 for holding a metal-coated fiber 5 is formed at the tip of the movable table 4. Further, protrusions 7 and 8 are formed on the support wall portion 3, and a screw rod 9 is supported by these protrusions. The screw rod 9 is screwed into a female screw hole (not shown) formed in the moving table 4. Further, a drive motor 10 is fixed to the support wall 3, and a rotating shaft of the drive motor 10 is connected to an end of a threaded rod 9 that projects downward from the projection 8. When the drive motor 10 is rotated based on this configuration, the screw rod 9 rotates and the movable table 9 moves in the vertical direction, and the lower part of the fiber 5 held by the holding part 6 moves into the container 2. It is gradually inserted into the container 2, and conversely, it is pulled out from inside the container 2.

On the other hand, an electrolytic solution 11 is placed in the container 2, and a cathode-side electrode 13 whose intermediate portion is covered with an insulating material 12 is disposed.

To explain the method for removing the metal coating of the fiber 5 using the above-mentioned apparatus, first, the metal coated fiber 5 is set in the fiber holder 6. At this time, the fiber 5 is not placed in the electrolyte 11.
Note that the fiber holding portion 6 also serves to electrically connect the anode side power source and the metal coating of the fiber 5. After the fiber 5 is set, a voltage is applied between the cathode electrode 13 and the fiber 5, which is the anode electrode. Since the electrolytic reaction occurs from the fiber tip, only the portion of the cathode side electrode 13 located at the bottom of the electrolyte is exposed. Thereafter, the drive motor 10 is started, and the movable table 4 to which the fiber 5 is fixed is gradually moved downward. When the fiber 5 enters the electrolyte, an electrolytic reaction begins,
The metallization is removed. Once the required fiber length has been removed, the applied voltage is turned off and the removal operation is completed.

In the above operating procedure, if the fiber is inserted in advance into the electrolytic solution by a required length and then a voltage is applied, the metal coating will not be removed cleanly for the following reasons. On the anode side, the metal coating of the fiber is used as an electrode and also as a conductor. When a fiber is inserted into an electrolytic solution in advance and a voltage is applied, an electrolytic reaction proceeds on the entire surface of the fiber immersed in the electrolytic solution. At this time, if the metal coating is removed at the base of the fiber, it will no longer function as a conductor, and the electrolytic reaction at the tip of the fiber will no longer proceed, and the coating will be removed from various parts of the fiber even after a certain period of time has passed. There will be some parts left that will not be processed. Therefore, the procedure of gradually inserting the fiber into the electrolyte in the present invention is essential for cleaning and removing the coating.

The selection of electrolyte needs to be changed depending on the type of fiber coating material, and it is particularly effective to use an electrolyte containing metal ions whose ionization tendency is the same or slightly lower than that of the fiber coating material. For example, using aluminum as a coating material
When nickel chloride (NiCl ₂ ) is used as the electrolyte for a fiber coated to a thickness of 10 μm, it is possible to remove the coating from a fiber with a length of 30 mm in about 2 to 3 minutes at an applied voltage of 20 V. The speed at which the fiber is inserted into the electrolyte is approximately 100 μm/Sec.
The following are desirable.

The present invention utilizes the reverse reaction of electroplating, and by the method described above, it is possible to remove the metal coating without leaving contact scratches or the like on the fiber surface.

As explained above, since the present invention is a method for electrically removing the coating of a metal-coated fiber, it has the advantage that the coating can be safely removed in a short time without damaging the fiber surface. By splicing fibers whose coating has been removed according to the present invention, they can be spliced with the same handling as fibers coated with ordinary plastic materials, and fiber splicing with good characteristics can be achieved.

[Brief explanation of drawings]

The drawing is a schematic diagram of an apparatus for carrying out the present invention. DESCRIPTION OF SYMBOLS 1... Base, 2... Container, 3... Support wall part, 4... Moving table, 5... Metal coated fiber, 6... Fiber holding part, 7, 8... Projection part, 9... Threaded rod, 10... Drive motor, 11... Electrolyte, 12... Insulating material, 13...
Cathode side electrode.

Claims (1)

[Claims] 1 In a method for removing the coating of an optical fiber coated with metal, a metal electrode is inserted into an electrolytic solution, the metal electrode is used as a cathode, the metal coated part of the fiber is used as an anode, and a voltage is applied between both electrodes. 1. A method for removing a coating from an optical fiber, which comprises gradually inserting the metal-coated fiber into an electrolytic solution to remove the metal coating by electrolysis.