JP2000081531A - Method for connecting optical parts by using tube housing type optical fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the disconnection and optical transmission loss of optical fibers by preventing tension or slack to the optical fibers induced by a change in coil diameter when a protective tube housing the optical fiber is molded to a coil form. SOLUTION: The optical fibers 30 extending from optical parts are inserted into the nearly straightened protective tube 26 and thereafter, the one ends of the optical fibers are first restrained to one end of the protective tube 26 by a rubber bushing 38. Next, the protective tube 26 is molded to the coil form and thereafter, the optical fibers are restrained to the other end of the protective tube 26 by another rubber bush 38 in the position of the same length as the length of the protective tube 26. Finally, the other ends of the optical fibers are connected to the second optical parts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical communication device such as a submarine repeater for optical communication, which connects two optical components of the optical communication device by using a tube-containing optical fiber housed in a protective tube. On how to do it.

[0002]

2. Description of the Related Art In a submarine repeater for optical communication, optical components are connected by using a tube-containing optical fiber in which an optical fiber is accommodated in a protective tube. The tube-containing optical fiber is handled in a state of being wound in a coil shape to facilitate transportation and storage. When mounting an optical component on an optical communication device such as a submarine repeater, a connection operation is performed while extending and contracting a coil connected to the optical component.

Japanese Patent Application Laid-Open No. 9-68633 describes a method for reducing the variation in the length of optical fibers housed in a protective tube when forming this kind of tube-housing optical fiber into a coil shape. I have. As shown in FIG. 1 of the present application, according to this method, an optical component 3 is connected to one end of an optical fiber 1 and these optical fibers 1 are mutually connected at a curvature that does not cause transmission loss as shown in FIG. After twisting, insert into protection tube 2. Next, in consideration of transportability and storage, the protective tube 2 is formed into a coil shape as shown in FIG. 3, and the other end of the optical fiber 1 is connected to another optical component 4 to which the optical component 3 is to be connected. .

The advantage of this method is that, by twisting the optical fibers 1 in this way, even when the protective tube 2 is wound in a coil shape, the lengths of the respective optical fibers in the protective tube 2 are substantially the same. Therefore, it is possible to prevent tension due to loosening or entanglement of the optical fiber with a single line due to a difference in inner and outer diameters of the coil in the protective tube.

[0005]

However, the problem with this method is that the length of the optical fiber accommodated in the protective tube is not always equal to the length of the protective tube. When the coil-shaped protective tube 2 is stretched to a straight state during the installation of the optical fiber, tension or slack occurs in the optical fiber in the protective tube. The reason is that, as shown in FIG. 4, if the center coil diameter of the optical fiber 1 accommodated in the protection tube 2 is equal to the center coil diameter R of the protection tube 2, no problem occurs when the protection tube 2 is straightened. When the central coil diameter R1 of the optical fiber 1 in the protective tube 2 becomes smaller than the central coil diameter R of the protective tube 2 by pulling the optical fiber 1 when connecting the optical component 4 to the optical fiber 1, or Conversely, if the center coil diameter R2 of the optical fiber 1 becomes larger than the center coil diameter R of the protection tube 2 by pushing the optical fiber 1 into the protection tube 2, the length of the protection tube 2 and the protection tube This is because a deviation occurs in the length of the optical fiber 1 in 2. If the optical fiber is tensioned or loosened when the coiled protection tube 2 is straightened in this way,
The optical fiber may be broken or optical transmission loss may occur.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art and to provide a method for preventing tension or slack in an optical fiber when a protective tube formed into a coil shape is extended. An object of the present invention is to prevent fiber breakage and deterioration of optical transmission loss, thereby contributing to improvement in reliability and productivity.

[0007]

SUMMARY OF THE INVENTION The present invention provides a method for connecting two optical components by an optical fiber.
According to the method of the present invention, after the optical fiber extending from the first optical component is inserted into the substantially straight protective tube, first of the optical fibers thus inserted into the protective tube, the optical fiber adjacent to the first optical component is inserted. The first restraining point is restrained to the first end of the protective tube by a restraining means such as a rubber bush, an adhesive, or an adhesive tape. Next, the protective tube is formed into a coil shape together with the optical fiber housed therein. And before or after the coil forming, the first of the optical fiber
A second constraint point is defined at a position of the same length as the protection tube from the constraint point, and the second constraint point of the optical fiber is constrained to a second end of the protection tube by a constraining means. Finally, the other end of the optical fiber is connected to the second optical component.

In this case, the length of the section of the optical fiber existing in the protective tube and the length of the protective tube are always the same, and the optical fiber is held by the restraining means at both ends of the protective tube in this state. Therefore, when the protective tube is formed into a coil shape, there is no deviation between the optical fiber length and the protective tube length due to the difference between the inner and outer diameters of the coil. Accordingly, even when the diameter of the coil of the protective tube is loosened or the protective tube is extended in connecting the optical components, the optical fiber is not stretched or loosened.

In a preferred embodiment of the present invention, the first restraining point of the optical fiber is restrained by the first rubber bush to the first end of the protecting tube, and then the protecting tube is formed into a coil shape. The second restriction point of the optical fiber is pulled out of the protection tube by utilizing the difference between the inner and outer diameters of the coil in the protection tube, and a second rubber bush is attached to the second restriction point of the optical fiber. The optical fiber is drawn into the protective tube by increasing the diameter, and the second rubber bush attached to the second constraint point of the optical fiber is mounted on the second end of the protective tube. With this configuration, the operation of attaching the rubber bush can be easily performed.

[0010] Preferably, the first and second constraint points of the optical fiber are marked with oil-based ink or paint, and the constraint means is positioned using these marks as a guide. With this configuration, the positioning of the restraining means is facilitated, and the section of the optical fiber existing in the protective tube and the protective tube can be easily made the same length.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The method of the present invention can be applied to, for example, submarine repeater assembly as shown in FIG.
Referring to FIG. 5, the submarine repeater 10 includes a pressure-resistant cylinder 14 closed by a pair of pressure-resistant end face covers 12, and a transmission unit 16 is accommodated in the pressure-resistant cylinder 14. An external cable 18 is passed through the pressure-resistant end face cover 12, and the external cable 18 is liquid-tightly sealed from the pressure-resistant end face cover 12 by an external cable sealing introduction portion 20. The optical fiber 22 from the external cable 18 is connected to the optical fiber connection housing 24 held by the pressure-resistant end face cover 12. The transmission unit 16 of the submarine repeater 10 and the optical fiber connection housing 24 are connected by an optical fiber housed in a coil-shaped protection tube 26 according to the method of the present invention. The end of the protection tube 26 on the transmission unit 16 side is fixed to the transmission unit 16 by a cable introduction part 28.

Next, in connection with the assembly of the submarine repeater 10,
The method of the present invention will be described. A plurality of (for example, four) optical fibers extend to both sides of the transmission unit 16 from the transmission unit 16 before being incorporated in the submarine repeater 10. First, the protective tube 26 is cut to a desired length slightly longer than the length of the optical fiber extending from the transmission unit 16. The protective tube is made of polyethylene or polytetrafluoroethylene, and has a thickness that can resist bending. Next, as shown in FIG. 6, on each side of the transmission unit 16, an optical fiber 30 extending from the transmission unit 16 is inserted into a substantially straightened protection tube. When the protection tube 26 is long, another wire is passed through the protection tube 26 in advance, the tip of this wire is bonded to the end of each optical fiber, and the wire is pulled out of the protection tube to connect the optical fiber to the protection tube. 26 can be introduced. Alternatively, pressurized gas is introduced into the protective tube from the optical fiber insertion side,
The pressure on the take-out side of the optical fiber may be reduced, and the fiber may be inserted by the action of airflow.

After inserting the optical fiber 30 in this manner,
After the protection tube 26 is straightened and the optical fiber 30 accommodated in the protection tube 26 is pulled to remove slack in the optical fiber 30, as shown in FIG. Marks 34 and 36 are made on the optical fiber 30 with oil ink or the like. Alternatively, before inserting the optical fiber 30 into the protective tube 26, the protective tube 26 and the optical fiber 30 are arranged in parallel, and marks 34 and 36 are previously formed on the optical fiber 30 at both ends of a section having the same length as the length of the protective tube 26. May be attached. The two marks 34 and 36 thus attached to the optical fiber 30 are attached to the protective tube 26.
Is defined on the optical fiber 30. These marks indicate the positions of a first restraining point 34 and a second restraining point 36 for restraining the optical fiber 30 to the protective tube 26 by attaching a rubber bush as described later.

Next, as shown in FIG. 6, a rubber bush 38 is attached to the first constraint point 34 of the optical fiber 30 on the transmission unit 16 side. At this time, in order to easily attach the rubber bush 38 to the optical fiber, it is preferable to shift the protective tube 26 from the first mark 34 to the second mark 36 of the optical fiber. As shown in FIG. 8, the rubber bush 38 is provided with a plurality of holes 40 having a diameter slightly smaller than the diameter of the optical fiber 30, and each hole 40 has a bush 38.
A radial slit 42 is cut out from the outer peripheral surface of the rim.
On the insertion side of the bush 38, an annular convex portion 44 having an outer diameter slightly larger than the inner diameter of the protective tube 26 is provided on the circumferential surface.
A flange 46 having an outer diameter substantially equal to the outer diameter is provided.
The rubber bush 38 can be formed of silicone rubber.

By fitting each optical fiber 30 into the hole 40 through the slit 42 of the rubber bush 38, the rubber bush 38 is mounted on the optical fiber 30 at the position of the first mark 34 as shown in FIG. Next, the protective tube 26 shifted to the side of the second mark 36 is attached to the rubber bush 3.
8, and the end of the protective tube 26 on the transmission unit 16 side is fitted into the rubber bush 38 as shown in FIG. Thereby, the first constraint point 3 of the optical fiber
4 is restrained by the end of the protection tube 26 on the transmission unit 16 side. Next, the end of the protection tube 26 on the transmission unit 16 side is fixed to the cable introduction portion 28 of the transmission unit 16 by bonding or the like.

Next, the protection tube 26 is formed into a coil shape together with the optical fiber 30 accommodated therein. continue,
A rubber bush 38 is attached to the end of the optical fiber 30 opposite to the transmission unit 16. At this time, in order to improve the workability of mounting the rubber bush, the optical fiber 30 is pulled against the protective tube 26 so that the protective tube 26
Of the optical fiber using the difference between the inner and outer diameters of the coil
The mark 36 is pulled out of the protective tube 26. At this time, the coil diameter is maintained to such an extent that stress is not applied to the optical fiber. After the other end of the optical fiber is pulled out of the protective tube 26 in this manner, the rubber bush 38 is moved to the position of the second mark (second constraint point) 36 in the same manner as the above-described procedure of mounting the rubber bush on the transmission unit 16 side. Attach to fiber. After attaching the rubber bush 38, the rubber bush 38 is fitted to the end of the protective tube 26. At this time, if it is difficult to fit the rubber bush 38 into the protective tube 26 due to the resistance of the optical fiber, the optical fiber 30 is pulled into the protective tube 26 by gradually increasing the coil diameter of the protective tube 26, When sufficiently close to the end of the protection tube 26, the rubber bush 38 is inserted into the end of the protection tube 26. At this time, it is confirmed that the positions of the mark 36 and the rubber bush 38 on the optical fiber are not shifted.

The transmission unit 1 thus prepared
6 and an assembly of the coil-shaped protection tube 26 and the optical fiber 30 housed in the protection tube 26 are combined with the submarine repeater 1
In the assembly of No. 0, it is inserted into the pressure-resistant cylinder 14. Next, the pressure-resistant end face cover 12 is disposed at a position where the coiled protection tube 26 can reach, and the outer end of the optical fiber 30 housed in the protection tube 26 is connected to the optical fiber connection housing 1.
Connect to 3. Finally, the pressure-resistant end face cover 12 is attached to the pressure-resistant cylinder 1
Attach to 4.

FIGS. 10 to 12 show modifications of the rubber bush 38 described above. Referring to FIG. 10, in this embodiment, a U-shaped slit 54 having a width capable of receiving the optical fiber 30 is formed in the flange 52 at the head of the rubber bush 50 in the radial direction. The rubber bush 50 includes a tapered portion 56 having a conical surface, and a portion of the tapered portion 56 below the neck of the flange 52 has an outer diameter that is obtained by subtracting the outer diameter of the optical fiber 1 from the inner diameter of the protective tube 26. FIG.
After arranging the optical fibers 30 in the slits 54 of the rubber bush 50 as shown in FIG. 1 and fitting the rubber bush 50 to the end of the protective tube 26 as shown in FIG. The optical fiber 30 is held and restrained by the close contact of the tapered portion 56 of the rubber bush. As a material of the rubber bush 50, a material such as neoprene or chloroprene can be used.

Alternatively, instead of using a rubber bush, as shown in FIG.
May be constrained to the constraining point of the optical fiber 30 with respect to the protective tube 26. Alternatively, it is also possible to restrain the optical fiber 30 and the protective tube 26 by taping with an adhesive tape (not shown).

Although a specific embodiment of the present invention has been described above, the present invention is not limited to this, and various modifications and changes can be made. For example, in the embodiment, the case where the number of the optical fibers 30 is four is illustrated, but the number of the optical fibers can be appropriately increased or decreased as needed by changing the optical fiber holding portion of the rubber bush.

[0021]

According to the present invention, the optical fiber is held and constrained at the same length as the protective tube at both ends of the protective tube for accommodating the optical fiber. There is no deviation between the optical fiber length and the protective tube length. Therefore, even if the diameter of the coil of the protective tube is loosened or the protective tube is extended when connecting the optical components, the optical fiber does not become stretched or loosened, preventing breakage of the optical fiber and preventing deterioration of transmission loss. And contribute to improvement of reliability. Another advantage of the present invention is that the optical fibers do not need to be twisted together as in the prior art when the optical fibers are inserted into the protective tube, thus improving the productivity. The reason is that, since the optical fibers are constrained at both ends of the housing protection tube, the lengths of the respective optical fibers do not shift even if the protection tube is formed into a coil shape.

[Brief description of the drawings]

FIG. 1 is a diagram showing a conventional connection method between an optical component and an optical fiber.

FIG. 2 is a diagram showing a conventional connection method between an optical component and an optical fiber.

FIG. 3 is a diagram showing a conventional connection method between an optical component and an optical fiber.

FIG. 4 is a conceptual diagram showing occurrence of length deviation in a conventional connection method.

FIG. 5 is a sectional view of a submarine repeater assembled by applying the method of the present invention.

FIG. 6 is a perspective view showing the steps of the method of the present invention.

FIG. 7 is a perspective view showing the steps of the method of the present invention.

FIG. 8 is a perspective view of a rubber bush used in the method of the present invention.

FIG. 9 is a perspective view showing the steps of the method of the present invention.

FIG. 10 is a perspective view showing a variation of a rubber bush.

FIG. 11 is a perspective view showing a connection method using the rubber bush shown in FIG.

FIG. 12 is a perspective view showing a connection method using the rubber bush shown in FIG.

FIG. 13 is a perspective view showing a variation of the restraining means.

[Explanation of symbols]

 16, 24: Optical component 26: Protective tube 30: Optical fiber 34: First constraint point of optical fiber 36: Second constraint point of optical fiber 38, 50: Rubber bush (restraining means) 58: Adhesive (restraining means)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroyuki Takahashi 3--18-21 Shibaura, Minato-ku, Tokyo Inside NEC Engineering Co., Ltd. (72) Koichi Kawada 3-18-21 Shibaura, Minato-ku, Tokyo Japan Electric Engineering Co., Ltd. F-term (reference) 2H036 EA01 FA02 GA21 HA02 HA11 HA24 2H038 AA21 CA38 CA67

Claims (6)

[Claims] 1. A method of connecting two optical components by an optical fiber, wherein an optical fiber extending from the first optical component is inserted into a substantially straightened protection tube, and the first optical component of the optical fibers is connected to the first optical component. An adjacent first restraining point is restrained by a restraining means against a first end of the protective tube, and the protective tube is formed into a coil shape together with an optical fiber housed therein, before or after the coil forming. A second constraint point is defined at a position of the same length as the protective tube from the first constraint point of the fiber, and before or after the coil forming, the second constraint point of the optical fiber is set to a second position of the protective tube by a constraint means. Binding to the end and connecting the other end of the optical fiber to the second optical component. 2. The method according to claim 1, wherein said restraining means comprises a rubber bush attached to an end of the protective tube. 3. A protection tube is formed into a coil shape after restraining a first restraining point of the optical fiber to a first end of the protection tube by a first rubber bush, and then the inside and outside of the coil in the protection tube are formed. By using the diameter difference, the second constraint point of the optical fiber is pulled out from the protective tube, a second rubber bush is attached to the second constraint point of the optical fiber, and then the coil diameter of the protective tube is increased. The second optical component-side portion of the optical fiber is drawn into the protective tube, and the second rubber bush attached to the second constraint point of the optical fiber is attached to the second end of the protective tube. 2 based method. 4. The method according to claim 1, wherein said restraining means comprises an adhesive adhered to an end of the protective tube. 5. The method according to claim 1, wherein said restraining means comprises an adhesive tape applied to an end of the protective tube. 6. The optical fiber according to claim 1, wherein said first constraint point and said second
6. A method according to claim 1, further comprising the steps of: marking a constraint point; and positioning the constraint means at a first constraint point and a second constraint point of the optical fiber based on the mark.