JP4956248B2 - Unit type optical fiber ribbon - Google Patents

Description

  In the present invention, a plurality of optical fiber strands are arranged in parallel in a planar shape, and a plurality of optical fiber ribbons coated together are arranged in parallel in a planar shape, and these are connected with a connecting resin. The present invention relates to a unit type optical fiber ribbon.

Conventionally, for example, a plurality of so-called optical fiber strands in which a coating made of an ultraviolet curable resin or a thermosetting resin is applied to the outer periphery of a glass optical fiber are arranged in parallel in a planar shape, and the ultraviolet curable resin An optical fiber ribbon with a collective coating made of, etc. is known (Patent Document 1).
Furthermore, various unit-type optical fiber ribbons in which a plurality of optical fiber ribbons are arranged in parallel in a planar shape and adjacent optical fiber ribbons are connected with a connecting resin have been proposed and manufactured (patents). Reference 2).

The optical fiber ribbon described in Patent Document 1 is excellent in branching workability (hereinafter simply referred to as branching) when branching an optical fiber ribbon into individual optical fiber strands. An optical fiber ribbon capable of suppressing an increase in transmission loss of an optical fiber is proposed. At the same time, Patent Document 1 also mentions the structure of an optical fiber ribbon that can reduce the polarization mode dispersion value (hereinafter simply referred to as PMD).
Specifically, the optical fiber tape core wire in which the thickness of the collective coating is reduced and a recess having a predetermined depth corresponding to the depression between the optical fiber strands constituting the optical fiber tape core wire is formed in the collective coating. Has proposed.

Patent Document 2 proposes a unit-type optical fiber ribbon in which optical fiber ribbons are arranged in parallel in a planar shape and connected with a connecting resin.
This invention also proposes a unit-type optical fiber ribbon that is excellent in branching ability to separate the unit-type optical fiber ribbons into the respective optical fiber ribbons and that causes little increase in transmission loss. Furthermore, it is also mentioned that it is desirable to reduce the PMD even in the unit type optical fiber ribbon.

Japanese Patent No. 3664254 JP 2005-352510 A

  However, although Patent Document 1 mentioned above refers to a structure for reducing the PMD of the optical fiber ribbon, a plurality of such optical fiber ribbons are arranged in parallel in a planar shape to form a coupling resin. There is no disclosure about the reduction of PMD in the case where the unit type optical fiber ribbons are formed by connecting together.

Further, in Patent Document 2, an optical fiber cable having a small PMD and capable of high-speed long-distance transmission is desired as a unit-type optical fiber ribbon, and when the unit-type optical fiber ribbon is bundled, There is a description that if the PMDQ value is 0.2 (ps / km ^1/2 ) or less, the transmission speed is 40 Gbps and the transmission distance is 625 km, and if the transmission speed is 80 Gbps, the transmission distance is 156 km. .
However, in order to reduce the PMDQ value to 0.2 (ps / km ^1/2 ) or less, there is no specific indication as to what structure the unit-type optical fiber ribbon should have. Not.

  Accordingly, an object of the present invention is to provide a unit-type optical fiber in which a plurality of optical fiber ribbons are arranged in parallel in a planar shape, and side portions of adjacent unit-type optical fiber ribbons are connected with a connecting resin. An object of the present invention is to provide a unit-type optical fiber ribbon that is excellent in branching property in the tape core and that can further reduce the PMD value of the unit-type optical fiber ribbon.

In order to achieve the above object, the unit type optical fiber ribbon according to claim 1 of the present invention has a plurality of optical fiber strands arranged in parallel in a planar shape and corresponds to a depression between the adjacent optical fiber strands. Then, a plurality of optical fiber ribbons that are collectively covered with an ultraviolet curable resin so as to form a recess are arranged in parallel in a plane, and between adjacent optical fiber ribbons are made of an ultraviolet curable resin. In the unit type optical fiber ribbons connected with the connecting resin, a connection recess is formed in a state where the connection resin is interposed only in the range inside the recess between the adjacent optical fiber ribbons. The outer diameter of the optical fiber strand is d, the thickness of the optical fiber ribbon in the recess is g ₁ , and the thickness of the collective coating on the upper and lower surfaces of the optical fiber ribbon is a ₁ , When the thickness of the collective coating on the side surface portion of the optical fiber ribbon was _{b 1,} a _{d-g 1} ≧ 40μm, yet _a 1, _{b 1} are both set 25μm or less.

Furthermore, the unit type optical fiber ribbon according to claim 1 has d-g ₂ ≧ 40 μm and d = 250 μm, where g ₂ is a thickness of the unit type optical fiber ribbon in the connection recess. It is characterized by being.
According to the unit type optical fiber ribbon of the present invention thus formed, there is a recess between the optical fiber strands, and the connection recess is formed between the connected optical fiber ribbons, Even when branching to an optical fiber ribbon or when branching for each individual optical fiber or when branching multiple optical fiber strands as a set, branching is very easy. In addition, the PMD value can be reduced. Since the PMDQ value defined by 650 can be 0.2 (ps / km ^1/2 ) or less, the transmission distance capable of high-speed transmission can be extended.

  According to the present invention as described above, a plurality of optical fiber ribbons are arranged in parallel in a planar shape, and the side portions of adjacent unit type optical fiber ribbons are connected with a connecting resin. In the unit type optical fiber ribbon, the unit type optical fiber ribbon can be provided which has excellent branching properties and can further reduce the PMD value of the unit type optical fiber ribbon.

The unit type optical fiber ribbon of the present invention will be described below in detail with reference to the drawings.
FIG. 1 is a transverse sectional view showing an embodiment of the unit type optical fiber ribbon of the present invention, and FIG. 2 is a partially enlarged transverse sectional view thereof.
As shown in FIGS. 1 and 2, in order to obtain the unit type optical fiber ribbon of the present invention, first, for example, a resin coating made of an ultraviolet curable resin or a thermosetting resin on the outer periphery of a glass optical fiber. A plurality of so-called optical fiber strands 1 having the above are prepared. These optical fiber strands 1 are arranged in parallel in, for example, four planes, and a collective coating 2 made of, for example, an ultraviolet curable resin is applied thereto to form an optical fiber ribbon 3. Note that the number of the optical fiber strands 1 is not limited to four, and may be eight, for example, and the number can be appropriately selected as needed.
When the collective coating 2 is applied, the concave portions 4 are formed in the collective coating 2 corresponding to the depressions (valleys) between the adjacent optical fiber wires 1 and 1 arranged in a plane.

In this embodiment, two optical fiber tape cores 3 obtained in this way are prepared, the two optical fiber tape cores 3 are arranged in parallel in a plane, and adjacent side portions are For example, the unit type optical fiber ribbon 6 is formed by connecting with a connecting resin 5 made of an ultraviolet curable resin.
However, in this connection, it connected so that the connection recessed part 7 might be formed corresponding to the hollow of optical fiber tape core wires 3. Incidentally, by forming the connection recess 7 in this way, the amount of the resin 5 for the connection resin 5 filled in the recess can be reduced. Therefore, the unit type optical fiber ribbon 6 is connected to the optical fiber ribbon 3, When branching to 3, it becomes easy to branch.

By the way, the present inventors have obtained the knowledge that the PMD value of the optical fiber ribbon 3 can be made smaller as the resin thickness of the batch coating 2 on the optical fiber 1 is thinner, and from that viewpoint 1 and FIG. 2, in the unit type optical fiber ribbon 6, the thickness T ₁ of the optical fiber ribbon 3, the thickness a ₁ of the collective coating 2 in the thickness direction, and the collective coating 2 of the side portion The thickness b ₁ , the thickness g _{1 of} the optical fiber ribbon in the recess 4, and the thickness of the unit type optical fiber ribbon 6 at the position of the connecting recess 7 formed in the recess between the optical fiber ribbons 3. As g ₂ , the relationship between T ₁ , a ₁ , b ₁ , g ₁ and g ₂ , and (d-g ₁ ) or (d-g ₂ ) and PMD was examined. The results are shown in Table 1.

As shown in Table 1, from the results of Experimental Examples 1 to 9, when d-g ₁ ≧ 40 μm and the collective coating 2 and the connecting resin 5 are applied so that both a ₁ and b ₁ are 25 μm or less, It has been found that the PMDQ of the unit type optical fiber ribbon 6 can be 0.2 (ps / km ^1/2 ) or less.
As a more preferable range, in order to make PMDQ 0.1 or less (ps / km ^1/2 ), d−g ₁ ≧ 40 μm, d−g ₂ ≧ 40 μm, and both a ₁ and b ₁ should be 25 μm or less. It has also been found that the collective coating 2 and the connecting resin 5 are preferably applied.
Further, as described above, in the unit type optical fiber ribbon 6, the recess 4 is provided between the optical fiber strands 1 and 1 of each optical fiber ribbon 3, and the optical fiber ribbon 3 is interposed between the optical fiber ribbons 3 and 3. Since the connecting recess 7 is formed, branching to each optical fiber strand 1 and branching to a plurality of optical fiber strands 1 are further branched to the optical fiber ribbons 3 and 3. It was also very easy to do.

In Table 1, ◎ indicates PMDQ is 0.1 ps / km or less, ○ indicates 0.1 ps / km to 0.2 ps / km or less, Δ indicates 0.2 ps / km to 0.4 ps / km or less, and X indicates 0.4 ps / km or more.
In Table 1, PMD is indicated as PMDQ. It is a value calculated by the Monte Carlo method defined in 650.2.
Further, the single core separation property indicates the difficulty in separating one optical fiber strand 1 from the unit type optical fiber ribbon 6 and taking it out. Incidentally, this single-core separation property is, for example, the length of time required to separate the optical fiber 1 from the unit-type optical fiber ribbon 6 using the separation tool disclosed in JP-A-2006-30684. Judged by

  Specifically, the separation tool includes a filed portion that presses the optical fiber ribbon and a concavo-convex portion that is provided adjacent to the file and includes a plurality of small protrusions that press the optical fiber ribbon. Are pivotally supported by a fulcrum provided at the base of the arm, and both arms are biased by leaf springs or coil springs in a direction in which both arms open. The pair of arms are closed against the urging force of the spring, so that the optical fiber tape core wire is pressed by the file part or the uneven part.

The optical fiber tape core wire is rubbed with the filed portion of the separation tool thus formed, and further, when the single fiber is separated into the respective optical fiber strands by rubbing with the concavo-convex portion, the single fiber separation property is determined by the length of time required. Was judged.
Incidentally, ◯ indicates that it took less than 30 seconds, Δ indicates that it took less than 1 minute, and X indicates that it took longer than 1 minute.
Moreover, although the manufacturability of whether each unit type optical fiber ribbon 6 was easy to manufacture was also examined, a significant difference was not recognized regarding the manufacturing method.

Needless to say, the single fiber separation property, that is, the branching property of branching from one optical fiber strand 1 or the optical fiber tape core wire 3 or the unit type optical fiber tape core wire 6 is between the optical fiber strands 1. The recesses 4 are formed in the recesses, and branching is easy because the resin amount of the recesses 4 is small.
In addition, since the connecting recess 7 with a small amount of resin is formed between the optical fiber ribbons 3 and 3, the branching of the optical fiber ribbon 3 from the unit type optical fiber ribbon 6 is also very easy. It is.
In the above embodiment, an ultraviolet curable resin is used as the collective coating 2 and the connecting resin 5. Specifically, an ultraviolet curable epoxy acrylate resin, polybutadiene acrylate resin, or silicone acrylate resin can be used. .

Thus, according to the present invention, a unit type in which a plurality of optical fiber ribbons are arranged in parallel in a planar shape, and the side portions of adjacent unit optical fiber ribbons are connected with a connecting resin. In the optical fiber ribbon, the branching property is excellent, and the PMD value of the unit type optical fiber ribbon can be made smaller, specifically 0.2 (ps / km ^1/2 ) or less. A unit type optical fiber ribbon that can be provided can be provided.

It is a cross-sectional view which shows one Example of the unit type optical fiber ribbon of this invention. FIG. 2 is a partially enlarged view of the unit type optical fiber ribbon of the present invention shown in FIG. 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical fiber strand 2 Collective coating 3 Optical fiber ribbon 4 Recess 5 Connection resin 6 Unit type optical fiber ribbon 7 Connection recess

Claims (1)

An optical fiber tape in which a plurality of optical fiber strands are arranged in parallel in a planar shape and collectively covered with an ultraviolet curable resin so that a recess is formed corresponding to a recess between the adjacent optical fiber strands A unit-type optical fiber ribbon in which a plurality of optical fibers are arranged in parallel in a plane, and the adjacent optical fiber ribbons are connected by a connecting resin made of an ultraviolet curable resin, the adjacent optical fibers A connecting recess is formed in a state in which the connecting resin is interposed only in a range inside the recess between the tape cores, and the outer diameter of the optical fiber is d, and the optical fiber ribbon in the recess a thickness g _1, wherein the light a ₁ the thickness of the bulk coating on the upper and lower surfaces of the fiber _ribbon, the optical fiber tape thickness of said collective coating on the side surface portion of the core wire b _1, the connecting When the thickness of the unit optical fiber ribbon was g ₂ in section,
d-g ₁ ≧ 40 μm
a ₁ and b ₁ are both 25 μm or less d−g ₂ ≧ 40 μm
d = 250 μm
A unit type optical fiber ribbon characterized by being.

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