JPS63157114A - Constituting method for single mode multicore optical fiber tape core - Google Patents

Abstract

PURPOSE:To allow a variance of the outside diameter of an optical fiber at the time of manufacture, and also, to connect with a connector at a low loss by grouping a standard range of an optical fiber outside diameter dimension, in a specific range centering around a standard value, and constituting a optical fiber tape, of optical fibers of the same group. CONSTITUTION:In case single mode optical fibers of many cores are arranged, brought to batch covering and constitute a single mode multicore optical fiber tape, a standard range of an optical fiber outside diameter dimension is grouped by dividing it equally with a range of 2DELTAd successively centering around the diameter d0. For instance, the optical fibers are divided into three kinds of 122-124mum, 124-126mum, and 126-128mum by its outside diameter, and the same tape 3 is constituted of 10 pieces of optical fibers of a range of 122-124mum outside diameter. In this case, connectors consist of three kinds of hole diameters of 124.8mum, 126.8mum and 128.8mum, and the optical fiber outside diameter standard can be made strict equivalently, and a low loss connector connection is realized.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention is directed to a single mode (hereinafter abbreviated as SM) optical 7-iper used in optical fiber communication, in which multiple fibers are collectively coated.
This invention relates to a method for constructing an M multi-core optical fiber ribbon.

[Conventional technology]

An example of a tape core of a conventional SM multi-core optical fiber is shown in FIG. In FIG. 2, the reference numeral 1 means an optical fiber, 2Fi coating material, and 3 a tape core wire. This example shows a case where the number of cores N=IO. In recent years, an optical connector that connects tape fibers all at once, as shown in Figure 3, has been developed [Satake et al., X, '1. T1. E, Vol. LT-3, No. 6, p. 1339 (+985)]. In FIG. 3, the reference numeral 4 indicates a multi-core batch original connector, and 5 indicates a hole having a hole diameter slightly larger than the outer diameter of the original 7-eyeper 1. The original connector is produced by inserting the removed optical fiber 1 of the tape core wire 3 into the hole 5 and fixing it with adhesive. If the optical fiber 1 is an 8M optical fiber with a small core diameter, highly accurate axis alignment is required, and the insertion clearance between the hole 5 and the optical fiber 1 (the difference between the hole diameter and the outer diameter of the optical fiber is defined as clearance) ) affects losses. The outer diameter of the optical fiber 1 varies during manufacturing.

It is possible to realize a low-loss connector by reducing this variation and narrowing the standard range of the outer diameter, that is, by always keeping the clearance below a certain value (for example, 2 μm or less).

[Problem that the invention seeks to solve]

However, in that case, values must be set that are much stricter than the international standard of 125 μm outer diameter Jf: 3 μm stipulated by 0OITT, and this will also increase the price of multi-core optical fibers. ,
From a practical point of view, it is difficult to realize this.

The purpose of the present invention is to determine the variation in yt and fiber outer diameter during manufacturing. 8, which allows low-loss connector connection.
This paper provides a method for constructing an M multi-core optical fiber tape.

[Means for Solving the Problems] To summarize the present invention, the present invention relates to a method for constructing an SM multi-core optical fiber ribbon, and involves arranging 5M element 7 eyepers with a large number of fibers and covering them all at once. In the method of constructing an 8M multi-core optical fiber tape, the standard value of the outer diameter of the optical fiber is d. When tied, the standard range of nine optical fiber outer diameter dimensions is divided equally into a range of 2△d with do all centers, and all optical fibers in one ribbon are grouped into groups. Is it composed of optical fibers in the same group? Features.

The main feature of the present invention is that the standard range of optical fiber outer diameter dimensions is divided and grouped, and all optical fibers in one tape core are composed of optical fibers in the same group. . In the conventional technology, a tape core is constructed using optical fibers having arbitrary outer diameters, and the technical idea described in the present invention is not included.

When a tape core is constructed using the conventional method, for example, the outer diameter is 1
When using a standard optical fiber of 25±3 .mu.m, as shown in FIG. 4, there are generally optical fibers with an outer diameter Fi+ of 22 .mu.m to 128 .mu.m within the ribbon core. On the other hand, if a connector with a hole diameter of about 128.8 .mu.m is used, a multi-core connector can be manufactured at once, but the clearance will be 6.8 .mu.m instead of 0.8 .mu.m. In the case of 3M optical fiber, the mode field diameter 2ω that defines the original propagation portion is about 104 m, and when the clearance is 6.8 μm, the loss becomes large and a low-loss connector cannot be realized. Shadow of Clearance #As a result of thorough consideration, we derived that the probability density function f(L) of connector loss is expressed by the following formula (1).

Here, C is a clearance, which exists in the range of C4 to C2 with a distribution of h(c).

The amount of axial deviation of the center position of the connector hole from the design value is defined as d. In an ideal connector, d=0. Further, the angle ψ indicates the relative angle between the center positions of the two connector holes to be connected. S is represented by the following formulas (2) to (4).

5lIla sin tp-cosθ)]dθ ・
−・・−・−+21S, = (erf(3−+, 5
(a/c) (I cosψ) + ts(ω/c)
-f border t cos θ) + err(5+ ts(a/
cX l -CO59'-ts(ω/c)40,000πωSθ
)]/2 ・・・・・・(3) S2= (err(3+
t5(d/c) sinψ+15(ω/c)・Schiff 7 calculation 5inl) + err(5-ts(d/c)
siaψ−15(ω/(+)()−nsinθ)
) / 2 −・・・・・・(4) erf(x) is X
represents the error function of

Using this formula, FIG. 5 shows the results of calculating the axial deviation amount O, a μm on the connector loss distribution of the lo-fiber batch original connector according to the conventional construction method.

In other words, Figure 5 is a graph showing the distribution of connector loss when fabricated using the conventional multi-core optical fiber tape construction method in terms of the relationship between connector connection loss (dB, horizontal axis) and cumulative probability density (vertical axis). It is.

A in FIG. 5 indicates a case where 10 connector holes have a diameter of 128.8 μm. The number of connector types has been increased to 3 using the conventional construction method, and the 10 hole diameters are +28.8μm1126.8
The case where μm, +24.8 and am is shown in B. It can be seen that there is little improvement. In the conventional configuration, the outer diameter standard is strictly 125 μm, 5 μm, and the connector hole diameter is 127.5 μm, as shown in t-C. In this case, the price of the tape core will increase, which is not practically advantageous.

The present invention allows for variations in the optical fiber outer diameter as shown in Fig. 4, and groups optical fibers according to the optical fiber outer diameter in order to achieve low-loss connector connection without increasing the price of the tape fiber. .

〔Example〕

EXAMPLES The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to these Examples.

Example 1 An optical fiber has an outer diameter of (122 to 124 μm) and (1
24-126μm) and (+26-728μm)
There are three types of optical fibers, each consisting of the same group of optical fibers on the same ribbon. For example, the 10-fiber tape cable 3 is composed of ten optical fibers having an outer diameter in the range of 122 to 124 μm. In this case, the connector type is hole diameter 1
24.8μm, 126.8μm, 128.8μm 3
Becomes a seed.

The loss distribution at this time is 0.8μm when the axis misalignment t of the connector is
The result is shown in D of FIG.

Here, A, B%C indicate the conventional construction method for comparison.

That is, FIG. 1 is a graph showing the distribution of connector loss in the case of the present invention and the conventional configuration method in terms of the relationship between connector connection loss (dB, horizontal axis) and cumulative probability density (vertical axis). In this example, there is a significant improvement, and at the same time,
Lower loss is possible than C, which has stricter standards.

In this configuration example, groups are grouped around the standard outer diameter value of 125 μm. Next, if optical fiber manufacturing technology improves in the future, the outer diameter values will be concentrated near 125 μm. However, it has the advantage that there is no need to change the hole diameter of the original connector. Mayu, in Figures 5 and 1, the amount of axial deviation d of the multi-core optical connector is 0.8 μm.
It is calculated as. In the future, if d becomes close to 0 μm due to improvements in the manufacturing technology of the original connector, the influence of clearance on connector loss will increase, and the construction method of the present invention will become important.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to equivalently tighten the optical fiber outer diameter standard while maintaining the standard range of the normal optical fiber outer diameter dimension.
There is an advantage that the loss of the multi-fiber-finger optical connector can be reduced without increasing the price of the 7-eye tape fiber.

[Brief explanation of the drawing]

Fig. 1 is a graph explaining the distribution of connector loss when fabricated using the present invention and the conventional construction method, Fig. 2 is a cross-sectional view of a conventional multi-fiber optical fiber tape (in the case of +0 fibers), and Fig. 3
The figure is a cross-sectional view of a conventional multi-fiber-to-finger optical connector (in the case of 10 fibers), Fig. 4 is a graph showing an example of variation in the outer diameter of conventional optical fibers, and Fig. 5 is a conventional multi-fiber optical fiber tape. It is a graph explaining the distribution of connector loss in the case of fabrication using the core wire construction method. 1: Optical fiber, 2: Covering material, 3: Tape core wire, 4: Multi-fiber-direction optical connector, 5-hole patent application filed Nippon Telegraph and Telephone Corporation Agent Hiroki Nakamoto
Upper Shodo Yoshimine Katsura Cumulative Layer # - Nendo η Diagram

Claims (1)

[Claims] 1. In a method of constructing a single-mode multi-core optical fiber ribbon by arranging and collectively covering a large number of single-mode optical fibers, the standard value of the outer diameter of the optical fiber is d_0. Then, the standard range of the optical fiber outer diameter size is divided into groups by sequentially dividing equally into a range of 2Δd around d_0, and all optical fibers in one ribbon fiber are divided into groups within the same group. A method for constructing a single mode multi-core optical fiber tape, characterized in that it is composed of optical fibers. 2. A method for constructing a single mode multi-core optical fiber tape according to claim 1, wherein d_0=125 μm and Δd=1 μm.