JP3118994B2 - Optical fiber fusion splice reinforcement - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for molding and reinforcing an ultraviolet curing resin at a fusion spliced portion of an optical fiber.

[0002]

2. Description of the Related Art FIG. 2 is an explanatory view of a conventional technique for reinforcing a fusion spliced portion of an optical fiber. The fusion splicing is performed at an end 12a of the optical fiber 12 from which a coating 11 is removed.
A case in which an ultraviolet-curable resin is molded 13 thereon is shown (Japanese Patent Application No. 3-120712). FIG. 3 is a sectional view showing a configuration of an apparatus for molding the above-mentioned mold. The connecting portion 12 of the optical fiber is disposed in the groove 3 having a semicircular cross section provided in the axial direction of the lower mold 1 for molding.
It is sandwiched by an upper mold 2 that transmits ultraviolet light, and is fixed with metal fittings 6a and 6b.
7b. In this state, an ultraviolet curable resin is injected from a resin injection port 4 provided in the upper mold 2 and an ultraviolet lamp 8
To cure the resin.

[0003]

Conventionally, an apparatus for molding a fusion spliced portion of an optical fiber uses quartz glass which transmits ultraviolet rays. However, there is a limit in the accuracy of the glass processing or the mechanism for holding the apparatus, and a gap is formed between the upper molding base 2 and the lower molding base 1, and the ultraviolet curable resin often oozes out there. In this state, ultraviolet rays are irradiated,
Since it is cured, so-called thin burrs 13a and 13b are formed on the mold reinforcing portion as shown in FIG. 2 (b). When such a burr is adhered to a nylon jacket or the like, poor appearance or stress concentration is liable to occur, resulting in an increase in transmission loss. Therefore, although the burrs are removed immediately after the molding, the burrs cannot always be removed, and the above-described problem has occurred. Therefore, an object of the present invention is to provide an apparatus for reinforcing an optical fiber fusion splicing part which solves such a problem.

[0004]

SUMMARY OF THE INVENTION The present invention relates to a molding made of an ultraviolet-permeable material for molding an ultraviolet-curable resin having an outer diameter substantially equal to that of an optical fiber coating on a connection portion of a fusion spliced optical fiber. A reinforcing device having an upper substrate and a molded lower substrate, wherein semi-circular grooves corresponding to the coating outer diameter of the optical fiber are provided on the surfaces of both substrates, respectively, on a plane where these substrates are joined. Is a reinforcing device for an optical fiber fusion spliced portion provided with a light shielding layer for blocking ultraviolet rays. Here, the light-shielding layer can be formed of a carbon coating layer or a metal coating layer.

[0005]

According to the above construction, since the light-shielding layer is not provided on the inner surface of the groove of the molding base according to the present invention, the ultraviolet-curable resin molded on the bare fiber can emit ultraviolet light from an ultraviolet lamp. Reaches and hardens. On the other hand, since a light-shielding layer that blocks ultraviolet light is formed on the joint plane between the upper and lower substrates of the molding, the ultraviolet light from the ultraviolet lamp is blocked even if the ultraviolet-curable resin oozes into the gap between the two substrates. ,
No so-called burrs are formed.

[0006]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a perspective view showing the configuration of the present embodiment,
The lower substrate 1 and the upper substrate 2 for forming the mold are both formed of quartz glass, and the surfaces to which they are joined are sufficiently thin so as not to affect the shape of the mold portion and to the extent that the flatness of the quartz substrate is not impaired. Sufficiently light-shielding layer 5 of carbon
a, 5b are provided. The light-shielding layers 5a and 5b are formed by lowering the molded lower substrate 1 and the molded upper substrate 2 in a hydrocarbon gas atmosphere for 100 hours.
It was formed by heating to 0 ° C. or higher and thermally decomposing hydrocarbons near the surface of the substrate. The grooves 3a and 3b on these base surfaces form a semicircle corresponding to the outer diameter of the coating of the optical fiber.
It is formed after providing a and 5b. Therefore, no light shielding layer is formed on the inner surface of the groove. Light-shielding layer 5 composed of carbon coating layer
The thickness of a and 5b was 0.05 to 0.01 μm. This thickness can be manipulated by changing the conditions of the pyrolysis reaction.

When the molding bases 1 and 2 shown in FIG. 1 are applied to the reinforcing apparatus shown in FIG. 3 to reinforce the mold of the fusion splicing part, the bases leach into the gap between the upper base and the lower base. The curing of the ultraviolet curing resin does not occur, and the burrs 13a, 1
Mold reinforcement without 3b was able to be performed. Further, when the mold base was provided with a light-shielding layer made of aluminum by vacuum evaporation and ion sputtering, the mold was reinforced, and no burrs were generated.

[0009]

As described above, the use of the apparatus for reinforcing an optical fiber fusion splicing part according to the present invention eliminates the problem of burrs occurring in the molded part, thereby improving the productivity. Also, since a mold without burrs can be obtained,
When an optical fiber core or a tape-shaped core coated with a nylon jacket or the like is formed on this, low-loss characteristics are obtained,
It is effective when applied to the connection part of a submarine optical cable.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the configuration of the present embodiment.

FIGS. 2A and 2B are views for explaining a conventional technique, in which FIG. 2A is a cross-sectional view, and FIG. 2B is a cross-sectional view along XX.

FIG. 3 is a cross-sectional view illustrating a configuration of a conventional reinforcing device.

[Explanation of symbols]

 1: Upper molding base 2: Lower molding base 3: Groove 4: Resin injection port 5: Light shielding layer 6: Metal fitting 7: Clamp 8: Ultraviolet lamp 9: Device base 11: Coating 12: Optical fiber 12a: Fusion part 13 : Mold 13a, 13b: Burr

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-61-277907 (JP, A) JP-A-2-29705 (JP, A) JP-A-3-68905 (JP, A) JP-A-2- 289311 (JP, A) Japanese Utility Model Showa 60-161305 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02B 6/24-6/42

Claims (2)

(57) [Claims] 1. A molded upper base and a lower molded base made of a material that transmits ultraviolet light for molding an ultraviolet curing resin having an outer diameter substantially equal to that of an optical fiber coating on a connection portion of the fusion spliced optical fiber. A semicircular groove corresponding to the outer diameter of the coating of the optical fiber is provided on the surface of each of the bases, and a light-shielding layer that blocks ultraviolet rays is provided on a plane where these bases are joined. An apparatus for reinforcing an optical fiber fusion spliced part, characterized in that: 2. The reinforcing device for an optical fiber fusion spliced part according to claim 1, wherein said light shielding layer is formed of a carbon coating layer or a metal coating layer.