JP2970959B2 - Optical fiber ribbon - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber ribbon used for optical communication and the like, and relates to a currently used optical fiber ribbon and a thin tape ribbon having a smaller element wire than that. The present invention relates to a structure of a tape core wire preferably used to communicate

[0002]

2. Description of the Related Art Conventionally, an optical fiber ribbon used in the field of optical communication is obtained by coating a plurality of optical fiber wires in parallel and coating them collectively with a coating made of an ultraviolet curing resin or a thermosetting resin. Provided in the form of a tape. An optical fiber is a bare optical fiber such as a silica-based single mode fiber or a multi-mode fiber coated with an ultraviolet curing resin or a thermosetting resin. The outer diameter of the bare fiber of the fiber is about 125 μm, and the outer diameter of the element wire (outer diameter of the coating) is about 250 μm.

In recent years, in an optical cable using an optical fiber, an ultra-high-density, multi-core optical fiber that accommodates thousands of optical fibers has been studied so that an extremely large number of information can be transmitted. I have. In order to accommodate a very large number of optical fibers in a cable at a high density in this way, a plurality of small diameter wires whose diameters are made smaller than before are arranged in parallel, and these are almost equal to the small diameter diameter. A method of stacking a large number of thin tape core wires, which are collectively covered to the same thickness, and further storing the thin tape core wires in a cable slot and assembling a plurality of the thin tape core wires, and the like, is being studied.

[0004]

However, in the case of the above-described thin tape core, when connecting to the current tape core, the fiber spacing (hereinafter referred to as the fiber pitch) is different, so that the connection operation is not performed. There was a problem that took time. For example, when connecting a thin tape core (fiber pitch 200 μm) in which a plurality of small-diameter wires with an outer diameter of about 200 μm are collectively covered and a current tape core (fiber pitch 250 μm) are connected. Remove the covering of the end of the tape core to expose a plurality of bare wires, widen the interval between the bare wires of the thin tape core, and adjust the bare fiber of both tape cores to match the fiber pitch of the current tape core. The wire ends are fusion-spliced. At this time, in order to widen the interval between the bare wires of the thin tape, the bare wire tip of the thin tape wire gradually retreats in a fan-like manner from the center toward the tape end. Must be trimmed. In addition, if the fusion splicing is performed with the gap between the bare wires of the thin ribbon cable widened, bending force will be applied to the connection and the loss will increase. The later reinforcement operation also takes time.

The present invention has been made in view of the above circumstances, and is suitably used for connecting a currently used optical fiber ribbon to a thinner ribbon having a thinner element wire. The purpose is to provide tape cores.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method of forming a plurality of optical fiber elliptical wires each having a coating having an elliptical cross section and aligning one end of the optical fiber with the long diameter side of the elliptical wire in one line. Can be solved by an optical fiber ribbon obtained by arranging the short diameter sides of the elliptical wires in a line and covering at least both ends of the wire bundle at a time.

[0007]

In the optical fiber ribbon of the present invention, the fiber pitch is large at one end where the major diameter sides of the elliptical wires are arranged in a line, and at the other end where the minor diameter sides of the elliptical wires are arranged in a line. By making the major dimension of the elliptical strand the same as the strand diameter of the current tape core, and the minor dimension of the elliptical strand the same as the narrow strand diameter of the thin tape core. The working tape core can be connected to one end and the thin tape core can be connected to the other end without changing the spacing between the bare wires.

[0008]

FIG. 1 shows an embodiment of an optical fiber ribbon according to the present invention. The optical fiber ribbon 1 includes a plurality of optical fiber elliptical wires (hereinafter, referred to as elliptical wires) 3 having a coating 2 having an elliptical cross section.
Are arranged such that one end is aligned with the long diameter side of the elliptical wire 3 in one row, the other end is aligned with the short diameter side of the elliptical wire 3 aligned in one row, and the wire bundle 4 is collectively covered. ing.

The elliptical wire 3 is made of a bare optical fiber 5 such as a silica-based single mode fiber or a multimode fiber.
In addition, a coating 2 having an elliptical cross section made of a UV-curable resin or a thermosetting resin is formed thereon. The major dimension A of the elliptical strand 3 is set to the outer diameter of the current strand, for example, 250 μm, and the minor dimension B is set to the outer diameter of the small strand of the thin tape core, eg, 200 μm. Is set. In order to manufacture such an elliptical element wire 3, an ultraviolet curing resin is coated while passing an optical fiber bare wire through a coating die having a die hole that can be formed into the above-mentioned elliptical shape,
A method of irradiating ultraviolet rays to cure the resin is used.

The length of the optical fiber ribbon 1 is appropriately set according to the purpose of use. For example, the optical fiber ribbon 1 is used as a kind of adapter for connecting a thin tape ribbon to a current tape ribbon. In some cases, a short tape length of one meter or less is sufficient. The material of the covering material 6 for covering the wire bundle 4 in which the elliptical wires 3 are arranged at a time is not particularly limited, but a resin material such as an ultraviolet curable resin having a large Young's modulus is preferably used.

FIG. 2 illustrates an example of a method for connecting the working tape core 10 having a large fiber pitch and the thin tape core 11 having a small fiber pitch by the optical fiber tape core 1 configured as described above. FIG. This optical fiber tape 1 has a fiber pitch C of 250 μm at one end 12 where the major diameter sides of the elliptical wires 3 are aligned.
And the other end 13 where the minor diameter sides of the elliptical strands 3 are aligned.
Has a fiber pitch D of 200 μm. The fiber pitch C of the current tape core 10 is 250 μm, and the fiber pitch D of the thin tape core 11 is 200 μm.

Both ends of the optical fiber ribbon 1 are stripped off by a predetermined length to expose the bare wires 5. At the same time, the ends of the current tape ribbon 10 and the thin tape ribbon 11 to be connected are covered. Strip a predetermined length, each bare wire 14 ...
And the bare wires 15 are exposed. Then, the respective tape core wires are brought close to each other, the end faces of the bare wires to be connected are brought into contact, and the respective bare wires are fusion-spliced. This fusion splicing can be performed in a short time and easily in a short time because the contact portions of the bare wires are arranged in a line. Next, the connection portion after the fusion splicing is reinforced. This reinforcing operation can be performed by a conventional reinforcing method using a connecting reinforcing body used for reinforcing the connecting portion of the tape core wire.

As described above, using this optical fiber ribbon 1, the current tape ribbon 1 having a different fiber pitch is used.
In the case where the thin tape 11 is connected to the thin tape 11, the current tape core can be connected to one end and the thin tape core can be connected to the other end without changing the interval between the bare wires. Can be connected very easily and low-loss connection can be realized.

FIG. 3 shows another embodiment of the optical fiber ribbon according to the present invention. This optical fiber ribbon 20 is, like the optical fiber ribbon 1 described above,
A plurality of elliptical strands 3 are arranged such that one end is aligned with the long diameter side of the elliptical strand 3 and the other end is aligned with the short diameter side of the elliptical strand 3 in one row. The binding tape 21 is fixed to the portion, and only the both ends of the wire bundle 4 are covered collectively. The covering length of the binding tape 21 is set to a length that does not disturb the arrangement of the elliptical wires 3.

The optical fiber ribbon 20 is connected to one end of a current fiber ribbon having a large fiber pitch without changing the interval between the bare wires, similarly to the optical fiber ribbon 1 of the above embodiment. In addition, a thin tape core having a small fiber pitch can be connected to the other end side, and connection operation of each tape core having a different fiber pitch can be performed extremely easily, and low-loss connection can be realized.

(Experimental Example) A silica-based single mode fiber having an outer diameter of 125 μm is provided with a coating made of a urethane acrylate-based ultraviolet-curable resin and having an outer diameter of 250 μm on the long diameter side and a diameter of 200 μm on the short diameter side having an elliptical cross section. 10 elliptical strands
As shown in FIG. 1, one end is aligned with the long diameter side of each elliptic cord in one line, and the other end is aligned with the short diameter side in one line. A core wire was prepared. In addition, a current tape core wire in which 10 wires having an outer diameter of 250 μm are coated in parallel and collectively, and a thin tape core wire in which 10 thin wires having an outer diameter of 200 μm are coated in parallel and collectively were prepared. . The bare wires in the current tape core wires and the thin tape core wires are quartz-based single mode core wires having an outer diameter of 125 μm, like the bare wires in the elliptical core wires.

The coating at both ends of the optical fiber ribbon is about 3
The bare wires were exposed by stripping the ends of the active tape core wires and the ends of the thin tape core wires in the same manner. Next, the bare wire on one end side (fiber pitch 250 μm) of the optical fiber ribbon is brought into contact with the bare wire of the current tape ribbon, and the contact portion of each bare wire is fused with a fusion splicer for fusing quartz-based fiber. Was used for fusion splicing. This fusion splicing could be performed in a short time and easily in a short time because the contact portions of the bare wires were arranged in a line. Similarly, the bare wire on the other end side (fiber pitch 200 μm) of the optical fiber ribbon and the bare wire of the thin tape ribbon were fusion-spliced.

As a result of measuring the connection loss between the current tape core and the thin tape core connected via the optical fiber ribbon in this manner, the loss for each strand was 0.5 dB or less.

[0019]

As described above, the optical fiber ribbon according to the present invention comprises a plurality of optical fiber elliptical wires having a coating whose cross section is formed into an elliptical shape, and one end of which is the major axis of the elliptical wire. And the other end is arranged in a state in which the minor diameter side of the elliptical wire is aligned in a line, and at least both ends of the wire bundle are collectively covered, and the major diameter side of the elliptical wire Is the same as the wire diameter of the current tape core wire, and the minor diameter side of the elliptical wire is the same as the thin wire diameter of the thin tape core wire, so that one end side is maintained without changing the spacing between the bare wires. The current tape core can be connected to the other end, and the thin tape core can be connected to the other end, and the operation of connecting each tape core having a different fiber pitch can be performed very easily.
A low-loss connection can be realized.

[Brief description of the drawings]

FIG. 1 is an external view showing an embodiment of an optical fiber ribbon according to the present invention.

FIG. 2 is a view for explaining an example of use of the optical fiber ribbon shown in FIG. 1, wherein a current tape ribbon is provided at one end of the optical fiber ribbon and a thin tape ribbon is provided at the other end thereof. It is a top view which shows the state which connects.

FIG. 3 is an external view showing another embodiment of the optical fiber ribbon of the present invention.

[Explanation of symbols]

Reference numerals 1, 20: optical fiber ribbon, 2: coating, 3: elliptical wire, 4: elliptical wire bundle, 5, 14, 15: bare wire, 6: coating material, 10: current tape ribbon, 11: thin Tape core,
12: one end side, 13: other end side, A: long diameter side dimension, B: short diameter side dimension, C, D: fiber pitch

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shinji Araki 1440, Mukurosaki, Sakura-shi, Chiba Fujikura Electric Wire & Cable Co., Ltd. Sakura Plant (72) Inventor Shigeru Tomita 1-6-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Incorporated (58) Fields surveyed (Int.Cl. ⁶ , DB name) G02B 6/44 G02B ⁶ /04-6/08

Claims (1)

(57) [Claims] 1. A plurality of optical fiber elliptical wires each having a coating whose cross section is formed in an elliptical shape, one end of which is aligned with the longer diameter side of the elliptical wire and the other end is the shorter diameter of the elliptical wire. An optical fiber ribbon in which the sides are arranged in a line, and at least only both ends of the strand are covered collectively.