JP2888157B2 - Optical fiber storage unit - 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 housing unit for housing an optical fiber cable.

[0002]

2. Description of the Related Art Conventionally, when an optical fiber cable is housed in an optical fiber connection box, for example, Japanese Patent Laid-Open No.
As disclosed in JP-A-215611 or JP-A-3-291609, a storage bag is formed from a resin film, and an optical fiber cable is inserted into the storage bag in a spirally rounded state, and the storage bag is inserted. In many cases, the optical fiber is connected to an optical fiber connection box. In this case, in order to store a plurality of optical fiber cables, storage bags are stacked or wound into a cylindrical shape.

In recent years, erbium (E) has been used as a core as an optical fiber amplifier for amplifying a transmitted optical signal.
A configuration has been proposed in which an optical signal is directly amplified using an optical fiber cable doped with r) (hereinafter, this optical fiber cable for optical amplification is referred to as an Er optical fiber cable). This Er-doped optical fiber cable has a mode field diameter (MF) in order to increase the optical amplification efficiency.
D) is formed so as to be smaller than a light guiding optical fiber cable (hereinafter referred to as a lead optical fiber cable), and the lead optical fiber cable is fusion-spliced at both ends so as to have low loss. Was. The Er
The outer diameter of a doped optical fiber cable is typically about 250μ.
m and the outer diameter of the lead optical fiber cable is approximately 0.9
mm.

When the Er-doped optical fiber cable is housed in a mounting panel of an optical fiber amplifier by using a resin film storage bag as disclosed in the above-mentioned publication, the resin film is rich in flexibility. Since external force and bending stress are directly applied to the Er-doped optical fiber cable, an extremely thin Er optical fiber cable is easily broken. For this reason, conventionally, an Er-doped optical fiber cable was wound around a reel as shown in FIG. 4, held and stored therein.

FIG. 4 is a perspective view showing a state in which an Er-doped optical fiber cable is mounted on a conventional mounting panel. In the figure, reference numeral 1 denotes a mounting panel. The mounting panel 1 is formed in a box shape that opens upward in the figure, and a reel 2 is fixed to one side inside. The reel 2 is formed by cutting a metal such as aluminum. Some are formed of resin. Further, on the side wall of the mounting panel 1 opposite to the reel 2,
Cable holes 4 for inserting the lead optical fiber cable 3 are opened at two places.

One end and the other end of the Er-doped optical fiber cable 5 are fusion-spliced at the ends of the two lead optical fiber cables 3 inserted into the cable holes 4. Note that the fusion spliced portion is covered with the reinforcing member 6. Since the Er-doped optical fiber cable 5 is formed with a length determined so that optical amplification is performed, the Er-doped optical fiber cable 5 is wound and held on the reel 2 and housed therein.

Reference numeral 7 denotes a surplus portion of the Er-doped optical fiber cable 5, which is housed in an open space in the mounting panel 1 in a spirally rounded state. Thus Er
The extra length of the doped optical fiber cable 5 is caused by
This is because even if this is wound around the reel 2, only a length corresponding to an integral multiple of the reel circumference can be stored.

[0008] By adopting a configuration in which the Er-doped optical fiber cable 5 is wound around the reel 2 and accommodated, it is possible to prevent the relatively thin Er-doped optical fiber cable 5 from breaking.

[0009]

However, if the reel 2 is used to hold the Er-doped optical fiber cable 5 as shown in FIG. 4, the mounting panel 1 cannot be reduced in size. there were. Therefore, high-density mounting in an optical transmission device such as an optical fiber amplifier cannot be achieved. That is, if the reel 2 is formed to have a small diameter, the thickness of the reel 2 must be increased in order to secure the cable accommodation amount, but if the reel 2 is formed to have a large diameter in order to reduce the thickness, This is because a large reel accommodation space is required. In the reel 2 formed by machining, there is a limit in reducing the thickness.

Further, since the Er-doped optical fiber cable 5 can be accommodated in the reel 2 only in a length corresponding to an integral multiple of the circumference of the reel, a space for accommodating the extra length 7 must be secured in the mounting panel 1. . This is also a problem in reducing the size of the mounting panel 1.

Further, an Er-doped optical fiber cable 5
Has an extremely small outer diameter of about 250 μm, so that the extra length portion 7 is easily broken when the extra length portion 7 is rounded in the mounting panel 1 and is difficult to handle. Since the outer diameter of the lead optical fiber cable 3 is about 0.9 mm, the lead optical fiber cable 3 is less likely to be broken than the Er-doped optical fiber cable 5.

SUMMARY OF THE INVENTION The present invention has been made in order to solve such a problem, and an object of the present invention is to provide an optical fiber housing unit which is hard to be broken even if a thin optical fiber cable is housed, and occupies a small space. And

[0013]

According to a first aspect of the present invention, there is provided an optical fiber housing unit in which a core is doped with erbium, and a light guide optical fiber cable is joined to both ends, and the joint is covered with a cylindrical reinforcing member. The optical fiber cable for optical amplification is sandwiched between a pair of resin films in a state of being spirally rolled, and the resin films are bonded and held via an adhesive, and the reinforcing member is attached to the resin film. Along with arranging in the cable penetration part, the adhesive is adhered in the resin film to the middle of the longitudinal direction by the adhesive.
It is housed so as to be held .

The optical fiber storage unit according to the second invention is the optical fiber storage unit according to the tenth invention.
Bonding with resin that melts when heated
The composition of the agent .

[0015]

According to the first and second inventions, the resin film and, because the resin is melted by being adhesive or heat is to reinforce the fiber optic cable, optical amplification <br/> optical fiber The holding of the cable can be performed using a resin film, and a winding type cable holding member such as a reel becomes unnecessary.

Further, an optical fiber cable for optical amplification (Er
By adjusting the radius of curvature when the doped optical fiber cable) rounded, because the Er doped optical fiber cable can be accommodated without extra length portion occurs, slack storage space is required. Further, the entirety of the Er-doped optical fiber cable and the Er-doped optical fiber cable
And light guide fiber optic cable (lead fiber optic cable
To the middle of the longitudinal direction of the reinforcing member that covers the joint with
There is accommodated in the bonding area.

[0017] In addition, the resulting bending stresses on the guide Hikari Mitsumochi fiber cable when bending the optical fiber storage units with respect to guide Hikari Mitsumochi fiber cable, the optical fiber storage Uni
It can be dispersed by a reinforcing member arranged in the cable passage of the socket .

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to FIGS. 1 is a perspective view of an optical fiber storage unit according to the present invention, FIG. 2 is a cross-sectional view of the optical fiber storage unit according to the present invention, and FIG.
It is an I line sectional view. FIG. 3 is a perspective view showing a state before the Er-doped optical fiber cable is sandwiched in the base sheet.

In these figures, reference numeral 11 denotes an optical fiber housing unit according to this embodiment, and reference numeral 12 denotes an Er-doped optical fiber cable housed in the optical fiber housing unit 11 as an optical fiber cable for optical amplification. This Er-doped optical fiber cable 12 is a conventionally well-known one formed by doping the core with erbium (Er), and a lead optical fiber cable 13 as a light-guiding optical fiber cable is provided at both ends with low loss. Respectively. The Er-doped optical fiber cable 12 is housed in the optical fiber housing unit 11 in a state of being spirally rounded.

The joint between the two optical fiber cables is covered by a reinforcing member indicated by reference numeral 14 in the figure. The reinforcing member 14 is formed by providing a layer made of a resin that is melted by being heated on the inner peripheral surface of the heat-shrinkable tube. The reinforcing member 14 is heated with the joint between the two optical fiber cables inserted into the heat-shrinkable tube, and is brought into close contact with the two optical fiber cables. Further, in this embodiment, the reinforcing member 14 has a portion that is substantially half in the longitudinal direction of the optical fiber housing unit 1.
1 and is disposed in a cable penetration portion of the optical fiber storage unit 11.

Optical fiber storage unit 1 shown in this embodiment
As shown in FIG. 3, 1 includes a base sheet 15 made of a resin film and an adhesive sheet 16 superposed on the base sheet 15. The base sheet 15 is formed of a transparent resin such as polyethylene into a rectangular sheet in a plan view. Adhesive sheet 16
Is formed in a rectangular sheet shape substantially equal to the base sheet 15 by a resin that is melted by heating, for example, ethylene vinyl acetate (EVA). Note that the thickness does not necessarily have to be the same.

The optical fiber storage unit 11 has the E
In order to house the r-doped optical fiber cable 12, first, an adhesive sheet 16 is superimposed on the base sheet 15, and these are folded in two so that the adhesive sheet 16 is on the inside as shown in FIG. In addition, each of these sheet materials may be folded in advance in advance, and then these may be overlapped as shown in FIG.

Next, the lead optical fiber cable 13
Is connected, and the Er-doped optical fiber cable 12 in which the reinforcing member 14 is provided at the joining portion is superposed on the above-mentioned sheet material while being positioned inside the two-folded portion. At this time,
The Er-doped optical fiber cable 12 is spirally rounded, and the reinforcing member 14 is arranged on the side edge of the base sheet 15 such that about half of the length in the longitudinal direction is located on the base sheet 15 side. By adjusting the radius of curvature when the Er-doped optical fiber cable 12 is rounded, the entirety thereof can be accommodated in the upper surface of the sheet material, and the extra length can be prevented.

After the Er-doped optical fiber cable 12 is temporarily placed on the sheet material as described above, the Er-doped optical fiber cable 12 and the reinforcing member 14 are bonded to the base sheet 15 and the adhesive sheet so that the folded sheet material is folded. Sheet 16 for use. Thereafter, hot air is blown on the upper surface of the base sheet 15, and the bonding sheet 16 is heated to the melting temperature. This hot air is stopped after the bonding sheet 16 is melted.

In this way, the bonding sheet 16 is once melted and then hardened again, and as shown in FIG. Sheet 15 and E
The r-doped optical fiber cable 12 and the reinforcing member 14
It is bonded via the bonding sheet 16. This gives E
The r-doped optical fiber cable 12 and the reinforcing member 14 are fixed and held on the base sheet 15, and the optical fiber storage unit shown in FIG. 1 is obtained.

Therefore, according to the optical fiber housing unit configured as described above, since the base sheet 15 and the bonding sheet 16 reinforce the Er-doped optical fiber cable 12, the extremely thin Er-doped optical fiber cable 12 can be used. The Er-doped optical fiber cable 12 is housed in a resin film case.
Is difficult to break. At the same time, the Er-doped optical fiber cable 12 can be held by using a resin film (base sheet 15) to hold the Er-doped optical fiber cable 12, and a wound cable holding member such as a reel is not required, so that the occupied space can be reduced. This occupied space is the base sheet 1
5. A relatively thin space corresponding to the volume of the bonding sheet 16 and the rounded Er-doped optical fiber cable 12.

Moreover, the Er-doped optical fiber cable 1
By adjusting the radius of curvature when rounding 2, it can be stored in the optical fiber storage unit 11 without any extra length, so that it is not necessary to secure an extra length storage space. For this reason, in addition to the fact that the winding type cable holding member is unnecessary as described above, further space saving can be achieved.

In addition, by positioning the reinforcing member 14 within the bonding range of the optical fiber storage unit 11, the E
Since the entirety of the r-doped optical fiber cable 12 is housed in the optical fiber housing unit 11, the Er-doped optical fiber cable 12 is not exposed outside the optical fiber housing unit 11. For this reason, even if the optical fiber storage unit 11 is held or gripped, the finger does not touch the Er-doped optical fiber cable 12 and the handling is easy. Further , as shown in this embodiment, the reinforcing member 14
Is installed in the cable penetration part of the optical fiber storage unit 11.
The resin film (base sheet) halfway in the longitudinal direction.
15), the bending stress applied to the lead optical fiber cable 13 is dispersed by the reinforcing member 14 even when the optical fiber storage unit 11 is bent with respect to the lead optical fiber cable 13, so that the handling is improved. It becomes even easier .

In this embodiment, the base sheet 15 has E
In bonding the r-doped optical fiber cable 12, the bonding sheet 16 made of a resin that is melted by being heated is used, but an adhesive may be used instead of the resin-made bonding sheet 16. In this case, the adhesive is used in the form of a sheet, or applied to the base sheet 15 in a liquid state.

Further, in this embodiment, an example is shown in which a resin that is melted by heating is formed in a sheet shape and is superposed on the base sheet 15 as an adhesive sheet 16, but this resin is not formed in a sheet shape. Base sheet 15 in a liquid state
May be applied. In this case, a resin layer that is melted by heating is formed on the base sheet 15.

Further, in this embodiment, when the Er-doped optical fiber cable 12 is sandwiched between a pair of resin films on the front and back sides of the optical fiber housing unit, the Er-doped optical fiber cable 12 is positioned inside and the sheet material is separated. Although folded, the present invention is not limited to such a limitation. For example, the base sheet may be formed in a bag shape in advance, and the Er-doped optical fiber cable 12 may be inserted into the bag-shaped base sheet in a state of being spirally rolled. With this configuration, the work of housing the optical fiber cable can be performed extremely easily.
In this case, the bonding sheet is inserted into the bag-shaped base sheet before the cable is inserted, or a resin that is melted by being heated is applied to the inner surface of the bag-shaped base sheet. .

Further, the heating of the bonding sheet 16 is not limited to the method using hot air as described in the present embodiment, but may be performed by placing the base sheet 15 on a hot plate. When the bonding sheet 16 is heated, the reinforcing member 14 can be fixed at the same time. That is, in the present embodiment, the Er-doped optical fiber cable 12 is temporarily placed on the sheet material after the reinforcing member 14 is brought into close contact with the cable joint, but the joint is inserted into the reinforcing member 14 without employing such a method. In this state, the Er-doped optical fiber cable 12 is temporarily placed on a sheet material, and then the reinforcing member 14 is heated together with the bonding sheet 16. In this case, only one heating step is required.

[0033]

As described above, the optical fiber storage unit according to the first aspect of the present invention has a core-doped erbium-bonded optical fiber cable at both ends and a cylindrical reinforcing member. The covered optical fiber cable for optical amplification is sandwiched between a pair of resin films in a state of being spirally rolled, and is adhered and held to these resin films via an adhesive. Arranged in the cable penetration part of the film, and glued to the middle of the longitudinal direction with the adhesive in the resin film
The optical fiber accommodating unit according to the second aspect of the present invention is the optical fiber accommodating unit according to the first aspect, wherein the optical fiber accommodating unit comprises an adhesive made of a resin that is melted by being heated. Therefore, the resin film, the adhesive, and the resin that is melted by being heated reinforce the optical fiber cable.

Therefore, even if the optical fiber cable is stored in the resin film case, the optical fiber cable is hardly broken. Moreover, it is possible to hold the optical fiber cable by using a resin film,
Since a winding type cable holding member such as a reel becomes unnecessary,
The occupied space is small.

Therefore, even if a thin optical fiber cable is stored, an optical fiber storage unit can be obtained which is hard to be broken and occupies a small space.

Further, by adjusting the radius of curvature when the Er-doped optical fiber cable is rounded, the Er-doped optical fiber cable can be stored without any extra length, so that an extra-long storage space becomes unnecessary.

For this reason, as described above, in addition to the necessity of the winding type cable holding member, further space saving can be achieved. Further, since the entire Er-doped optical fiber cable is accommodated within the bonding range, Er
The doped optical fiber cable is not exposed outside the optical fiber housing unit. For this reason, even if the optical fiber storage unit is held or gripped, the finger does not touch the Er-doped optical fiber cable, so that the handling is easy.

[0038] In addition, the resulting bending stresses on the guide Hikari Mitsumochi fiber cable when bending the optical fiber storage units with respect to guide Hikari Mitsumochi fiber cable, the optical fiber storage Uni
It can be dispersed by a reinforcing member arranged in the cable passage of the socket .

[Brief description of the drawings]

FIG. 1 is a perspective view of an optical fiber storage unit according to the present invention.

FIG. 2 is a sectional view of an optical fiber storage unit according to the present invention.

FIG. 3 is a perspective view showing a state before an Er-doped optical fiber cable is sandwiched in a base sheet.

FIG. 4 is a perspective view showing a state where an Er-doped optical fiber cable is mounted on a conventional mounting panel.

[Explanation of symbols]

11 optical fiber storage unit, 12 Er doped optical fiber cable, 13 lead optical fiber cable, 1
4 ... reinforcement member, 15 ... base sheet, 16 ... adhesive sheet.

Claims (2)

(57) [Claims] 1. An optical fiber cable for optical amplification in which erbium is doped into a core and a light guide optical fiber cable is joined to both ends and a joint portion is covered with a cylindrical reinforcing member in a state of being spirally rounded. It is sandwiched between a pair of resin films, and is adhered and held to these resin films via an adhesive. The reinforcing member is disposed at the cable penetrating portion of the resin film, and the reinforcing member is disposed halfway in the longitudinal direction. An optical fiber housing unit, which is housed in the resin film so as to be adhered and held by the adhesive . 2. The optical fiber storage unit according to claim 1, wherein the adhesive is made of a resin that is melted by being heated.