JP2003270449A - Optical fiber coating layer removing apparatus and its operating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical fiber coating layer removing apparatus which prevents a bare fiber from having a microbend through gravitation. <P>SOLUTION: The optical fiber coating layer removing apparatus is equipped with a couple of grip parts 5 which grip both end parts of an optical fiber 1 perpendicularly extending, a couple of discharge electrodes 6 which are provided horizontally opposite each other across the optical fiber 11 and remove a coating layer with heat generated by discharge, a movement control part 7 which moves relatively between the optical fiber 1 and discharge electrodes 6 by moving the grip parts 6 or discharge electrodes 6 perpendicularly, and a discharge control part 8 which controls discharge conditions of the discharge electrodes 6. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber coating layer removing apparatus for removing a coating layer formed on a surface of a bare fiber, and an operating method thereof.

[0002]

Submarine cables are connected to repeaters that amplify optical signals. Since the repeater is used in a high-voltage environment, a hermetic seal is required between the case of the repeater and the optical fiber led out from the case. Welded. Therefore, as the optical fiber led out from the repeater, a fiber having heat resistance that can withstand the welding is used.

FIG. 5 is a sectional view of the optical fiber 1.
The optical fiber 1 includes a bare fiber 2 having a diameter of 0.125 mm and a thickness of a polyimide resin covering the surface of the bare fiber 2.
The coating layer 3 having a thickness of 0075 mm and the thickness of the acrylic resin which is the ultraviolet curable resin covering the coating layer 3 is 0.055 m.
and the surface layer 4 of m. The difference between this optical fiber 1 and a normal optical fiber is the presence or absence of the coating layer 3,
The optical fiber 1 has high heat resistance because the coating layer 3 made of polyimide resin is formed.

The optical fiber 1 and the submarine cable are connected by fusing the end of the bare fiber 2 of the optical fiber 1 and the end of the bare fiber of the cable. Therefore, it is necessary to remove the coating layer 3 and the surface layer 4. The polyimide resin forming the coating layer 3 has high adhesion to the bare fiber 2 and is chemically and physically stable. For removing the coating layer 3 without damaging the surface of the bare fiber 2, for example, A method of chemically removing using a chemical such as sulfuric acid is known.

As another method of removing the coating layer 3, a report was given at the Autumn Meeting of the Institute of Electronics, Information and Communication Engineers in 1994 ("Development of coating removal technology of optical fiber by discharge", Tomoki Sano et al., Sumitomo Electric Industries, Ltd. ) Has been done. FIG. 6 is a perspective view showing the optical fiber coating layer removing apparatus. This optical fiber coating layer removing device is provided with a pair of gripping portions 5 for gripping both ends of the optical fiber 1 extending on the horizontal line, and the coating layer 3 is provided by being opposed to each other with the optical fiber 1 interposed therebetween, by heat generated by discharge. A pair of discharge electrodes 6 to be removed, a movement control unit 7 for moving the optical fiber 1 with respect to the discharge electrode 6 by moving the grip portion 5 in the horizontal direction, and a discharge control unit 8 for controlling discharge conditions of the discharge electrode 6. It has and.

In this optical fiber coating layer removing apparatus, the coating layer 3 is removed according to the following procedure. (I) First, the surface layer 4 of the optical fiber 1 is previously removed with a hot jacket stripper. (II) Next, both ends of the optical fiber 1 are held by the holding portions 5. (III) In order to generate an arc discharge between the discharge electrodes 6 in an atmosphere of an inert gas, an inert gas is supplied from an inert gas supply device (not shown). (IV) Finally, an arc discharge is generated between the discharge electrodes 6 by a signal from the discharge control unit 8, and the coating layer 3 made of a polyimide resin is thermally sublimated by the heat of discharge to be removed. At the time of the discharge, a signal from the movement control unit 7 causes the holding unit 5 to move horizontally, and the optical fiber 1 also moves horizontally.

[0007]

However, when a method of chemically removing the coating layer 3 by using a chemical such as sulfuric acid is used, it is necessary to exercise extreme care in the management and handling thereof. In addition, there is a problem that it cannot be used on a ship on the ocean in consideration of shaking and the like.

Further, when an apparatus for removing the coating layer 3 by heat sublimation by discharge is used, a slight scratch is generated on the surface of the bare fiber 2 by the discharge heating, and the same strength as when removed by chemicals is realized. There was a problem that it could not be done. Further, although the coated coating layer can be removed more easily at higher temperatures, when high discharge heat is applied to the bare fiber 2, the bare fiber 2 that is horizontally extended is softened by the heat and the arrow in FIG. There is a problem that microbends are generated in the direction of b due to its own weight, which causes optical loss.
Further, when the bare fiber receives a high-temperature (about 1400 ° C.) discharge heat for a long time, there is a problem that the core in the fiber diffuses and the loss increases.

An object of the present invention is to solve the above problems, and to provide an optical fiber coating layer removing device which prevents generation of microbends in a bare fiber due to its own weight. With the goal. Also,
An object of the present invention is to provide an operation method of an optical fiber coating layer removing device, which can prevent the strength deterioration of a bare fiber even after the coating layer is removed by thermal sublimation by electric discharge.

[0010]

An optical fiber coating layer removing device of the present invention is an optical fiber coating layer removing device for removing a coating layer of an optical fiber having a coating layer formed on the surface of a bare fiber, A pair of gripping portions that grip both ends of the optical fiber extending on a line, a pair of discharge electrodes that are provided to face each other in the horizontal direction through the optical fiber and that remove the coating layer by heat generated by discharge, A movement control unit that moves either the gripping unit or the discharge electrode along the vertical direction to relatively move the optical fiber and the discharge electrode, and a discharge control unit that controls the discharge condition of the discharge electrode. It is equipped with.

The optical fiber coating layer removing apparatus of the present invention includes a supply unit for supplying an inert gas into the discharge atmosphere.

In the optical fiber coating layer removing apparatus of the present invention, the optical fiber is derived from a repeater that amplifies an optical signal and is fusion-spliced with a submarine cable.

In the optical fiber coating layer removing apparatus of the present invention, the coating layer of the optical fiber is made of polyimide resin.

In the method for operating the optical fiber coating layer removing apparatus of the present invention, the signal between the discharge electrodes is discharged by the first discharge heat by the signal from the discharge control section to change the coating layer into a carbide, and then the first layer. The carbide is removed by the second discharge heat whose discharge heat is lower than the discharge heat of 1.

In the optical fiber coating layer removing apparatus of the present invention, the coating layer is made of polyimide resin, the first discharge heat is about 600 to 700 ° C., and the second discharge heat is about 800 to 1000 ° C. Is.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. The same or equivalent members as the conventional ones,
The parts will be described with the same reference numerals. Embodiment 1. 1 is a configuration diagram of an optical fiber coating layer removing apparatus according to Embodiment 1 of the present invention. This optical fiber coating layer removing device is provided with a pair of gripping portions 5 for gripping both ends of an optical fiber 1 extending on a vertical line, and a coating layer that is provided so as to face each other in the horizontal direction with the optical fiber 1 interposed therebetween and is heated by electric discharge. A pair of discharge electrodes 6 for removing 3 are provided, a movement control unit 7 for moving the grip portion 5 along a vertical line, and a discharge control unit 8 for controlling discharge conditions of the discharge electrode 6.

Next, the operation procedure of this optical fiber coating layer removing apparatus will be described. (I) First, the surface layer 4 of the optical fiber 1 is previously removed by a hot jacket stripper. (II) Next, both ends of the optical fiber 1 from which the surface layer 4 has been removed are held by the holding portions 5. (III) Next, by a signal from the discharge control unit 8,
An arc discharge is generated in the discharge electrode 6 under preset discharge conditions to give discharge heat to the optical fiber 1 from which the surface layer 4 has been removed, and a signal from the movement control unit 7 is used under preset speed conditions. The grip 5 is moved upward. The discharge condition at this time is that the discharge heat is about 600 to 700 ° C.,
By applying discharge heat of about 600 to 700 ° C. to the coating layer 3, the polyimide resin of the coating layer 3 is transformed into a carbide 10 (see FIG. 2). (IV) Finally, the arc 10 is again generated between the discharge electrodes 6 to apply the discharge heat of about 800 to 1000 ° C. to the carbide 10 to remove the carbide 10 from the bare fiber 2 (see FIG. 3). The area where the second discharge is performed is
It is an inner region of the carbide 10 in order to prevent the heat of discharge from being given to the region of the coating layer 3 which should not be removed and thermally deteriorated.

FIG. 4 shows the bare fiber end of the cable,
It is a figure which shows the tensile strength test result when the end part of the bare fiber 2 of the optical fiber 1 is fusion-spliced. ● in the figure
Indicated by discharging between the discharge electrodes, the coating layer 3 is transformed into the carbide 10 by the first discharge heat, and then the carbide 10 is removed by the second discharge heat whose discharge heat is lower than the first discharge heat. It is an example when the bare fiber 2 of the optical fiber 1 having a history and the optical fiber of the cable are fusion-spliced. The cross mark is an example in which the coating layer 3 is removed with a single discharge power. The mark Δ is an example in which the coating layer 3 was chemically removed using sulfuric acid. As can be seen from this figure, the example in which the discharge is performed in two times has an average tensile strength of about 1.3 times (16 .4N → 2
It can be seen that it has a strength equivalent to that of the chemically removed material in the low strength region in addition to 1.7 N).

In the test at this time, 1 is indicated by a ● mark.
The discharge heat of the second time is about 600 to 700 ° C., the heat of discharge of the second time is about 600 to 700 ° C., and the heat of discharge is about 1400 ° C. in the X mark. The adjustment of the discharge heat is performed by changing the discharge time without changing the discharge power. Of course,
The discharge heat can be adjusted by changing the discharge power while keeping the discharge time constant.

As described above, the example in which the discharge is divided into two times and the discharge power is only once,
When the tensile strength is high only once, since a high discharge heat is applied to the optical fiber 1 from which the surface layer 4 has been removed at a time, a part of the discharge heat is consumed even for the partial removal of the bare fiber 2. In contrast, when divided into two, the coating layer 3 is transformed into the carbide 10 by the first discharge,
It is considered that this is because the carbide 10 having low adhesion to the bare fiber 2 is removed by the second discharge, and the discharge heat is hardly consumed for partial removal of the bare fiber 2.

Embodiment 2. In the above embodiment, the grip portion 5 was moved up and down along the vertical direction to remove the coating layer 3, but the grip portion may be fixed and the discharge electrode may be moved up and down along the vertical direction.

Embodiment 3. Further, a supply unit (not shown) for supplying an inert gas into the discharge atmosphere may be provided. By causing an arc discharge between the discharge electrodes in an atmosphere of an inert gas, it becomes possible to obtain a predetermined discharge heat with a lower discharge power.

Fourth Embodiment In addition, in each of the above-described embodiments, as the material of the coating layer 3, a polyimide resin that has high adhesiveness to the bare fiber 2 and high heat resistance, and that is chemically and physically stable is used, of course, but is not limited to this. Instead of the polyimide resin, a material having high adhesiveness to the bare fiber and being chemically and physically stable may be used. Further, in each of the above embodiments,
The optical fiber 1 is derived from a repeater that amplifies an optical signal and is fusion-spliced to a submarine cable, but an optical fiber that is fusion-spliced to an aerial cable may be used.

[0024]

As described above, according to the optical fiber coating layer removing apparatus of the present invention, a pair of gripping portions for gripping both ends of the optical fiber extending on the vertical line and a horizontal direction via the optical fiber are provided. Between the optical fiber and the discharge electrode by moving either of the gripping part and the discharge electrode along the vertical direction, the pair of discharge electrodes being provided to face each other to remove the coating layer by heat generated by discharge. Since the movement control unit for relatively moving the discharge electrode and the discharge control unit for controlling the discharge condition of the discharge electrode are provided, the optical fiber is positioned along the vertical line in the step of removing the coating layer, and the self-weight of the optical fiber. It is possible to prevent the microbend from being generated.

Further, according to the optical fiber coating layer removing apparatus of the present invention, since the supply section for supplying the inert gas into the discharge atmosphere is provided, it is possible to obtain a predetermined discharge heat with a low discharge power.

Further, according to the optical fiber coating layer removing apparatus of the present invention, the optical fiber is derived from the repeater for amplifying the optical signal and is fusion-spliced with the submarine cable. The fiber can prevent the loss of the optical signal due to the microbend.

Further, according to the optical fiber coating layer removing apparatus of the present invention, since the coating layer is made of the polyimide resin, the adhesion to the bare fiber and the heat resistance are high, and it is chemically and physically stable. The coating layer of the optical fiber can be removed without causing microbending due to the weight of the optical fiber in the step of removing the coating layer.

Further, according to the operating method of the optical fiber coating layer removing apparatus of the present invention, the signal between the discharge electrodes is discharged by the first discharge heat by the signal from the discharge control unit to transform the coating layer into carbide, In addition, since the carbide is removed by the second discharge heat whose discharge heat is lower than the first discharge heat, it is possible to reduce the partial deletion of the bare fiber due to the discharge heat, and the physical properties of the bare fiber after the covering layer is removed. It is possible to prevent the reduction of the physical strength.

According to the method of operating the optical fiber coating layer removing apparatus of the present invention, the coating layer is made of polyimide resin, the first heat of discharge is about 600 to 700 ° C., and the second discharge is Since the heat is about 800-1000 ° C,
Carbides with low adhesion to bare fibers are easily removed by the second discharge heat, which has a lower discharge heat than the first discharge heat,
It is possible to reduce the partial removal of the bare fiber due to the heat of discharge, and prevent the physical strength of the bare fiber after the coating layer is removed from decreasing.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an optical fiber coating layer removing device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of the optical fiber coating layer removing apparatus of FIG. 1 during operation.

FIG. 3 is a configuration diagram of the optical fiber coating layer removing apparatus of FIG. 1 during operation.

FIG. 4 is a diagram showing a tensile strength test result of an optical fiber.

FIG. 5 is a cross-sectional view of an optical fiber.

FIG. 6 is a perspective view showing the configuration of a conventional optical fiber coating layer removing apparatus.

FIG. 7 is a diagram showing a state in which a microbend is generated in an optical fiber.

[Explanation of symbols]

1 optical fiber, 2 bare fiber, 3 coating layer, 5
Gripping part, 6 discharge electrode, 7 movement control part, 8 discharge control part, 10 carbide.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hisayasa Sasakura             2-3 2-3 Marunouchi, Chiyoda-ku, Tokyo             Inside Ryo Electric Co., Ltd. (72) Inventor Kenji Takahashi             Fuji Co., Ltd. 1440 Rokuzaki, Sakura City, Chiba Prefecture             Inside the club (72) Inventor Manabu Tabata             Fuji Co., Ltd. 1440 Rokuzaki, Sakura City, Chiba Prefecture             Inside the club (72) Inventor Shigeru Saito             Fuji Co., Ltd. 1440 Rokuzaki, Sakura City, Chiba Prefecture             Inside the club F-term (reference) 2H038 AA21 CA04 CA67

Claims (6)

[Claims] 1. An optical fiber coating layer removing device for removing a coating layer of an optical fiber having a coating layer formed on the surface of a bare fiber, wherein a pair of end portions of the optical fiber extending vertically are grasped. A gripping portion, a pair of discharge electrodes provided to face each other in the horizontal direction via the optical fiber to remove the coating layer by heat generated by discharge, and one of the gripping portion and the discharge electrode in the vertical direction. An optical fiber coating layer removing device comprising: a movement control unit that moves the optical fiber and the discharge electrode relative to each other, and a discharge control unit that controls discharge conditions of the discharge electrode. 2. The optical fiber coating layer removing apparatus according to claim 1, further comprising a supply unit for supplying an inert gas into the discharge atmosphere. 3. The optical fiber coating layer removing apparatus according to claim 1, wherein the optical fiber is derived from a repeater that amplifies an optical signal and is fusion-spliced with a submarine cable. 4. The optical fiber coating layer removing device according to claim 1, wherein the coating layer is made of a polyimide resin. 5. A method of operating the optical fiber coating layer removing device according to claim 1, wherein a signal from a discharge control unit discharges between the discharge electrodes with a first discharge heat. To convert the coating layer to carbide and then remove the carbide with the second discharge heat whose discharge heat is lower than the first discharge heat. 6. The light according to claim 5, wherein the coating layer is composed of a polyimide resin, the first heat of discharge is about 600 to 700 ° C., and the second heat of discharge is about 800 to 1000 ° C. A method of operating a fiber coating layer removing device.