JPH11326651A - Packaging method for grating type optical component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a packaging method for a grating type optical component which will not cause flaws to a bare optical fiber at the time of bundling and is high in yield. SOLUTION: In this packaging method for a grating type optical component, a process for removing a primary cladding 1a from a hydrogen-treated optical fiber 1, a process for manufacturing a grating 1c by irradiating the core of the bare optical fiber 1b, which is exposed by having the primary clad removed with ultraviolet rays, a process for covering the part where the grating is manufactured with a package 5, and a process for annealing the part where the grating is formed are carried out in order.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for packaging a grating type optical component.

[0002]

2. Description of the Related Art A grating-type optical component having a grating formed in the core of an optical fiber is widely used in optical communication technology such as a dispersion compensation technology for realizing high-speed and large-capacity transmission, a fiber-type filter, and the like. Attention is paid to the point.

[0003] Such a grating is formed based on a photo-induced refractive index change phenomenon in which the refractive index increases when a Ge-doped SiO ₂ glass is irradiated with strong ultraviolet light. That is,
A grating-type optical component in which a grating is formed in the core of an optical fiber is one that causes a periodic refractive index change in the core by irradiating ultraviolet light to form a diffraction grating, such as a holographic method or a phase mask. It is manufactured by the method.

Here, the holographic method is a method of producing a grating by irradiating a core with interference light generated by interfering two coherent ultraviolet lights (for example, Op
t. Lett., 14, 823, 1989), the phase mask method is a method of irradiating ultraviolet light from above the phase mask and irradiating the core with diffracted light to produce a grating (for example, Appl. Phys. Lett., 62, 1035, 1993).

The above grating type optical component is manufactured as follows.

First, as a process prior to the formation of the grating, pressurized hydrogen treatment is performed on the portion of the optical fiber where the grating is to be formed for the purpose of improving the photo-induced characteristics.

Next, the primary coating is removed from the hydrogen-treated portion, a phase mask, for example, is placed close to the exposed bare optical fiber, and ultraviolet rays are irradiated through the phase mask to apply a grating to the core. Make it.

Next, in order to prevent the strength of the optical fiber from deteriorating due to hydrogen, annealing is performed on the portion where the grating is formed, and hydrogen reacts with the optical fiber to form an OH group, thereby increasing the loss. Remove hydrogen to prevent.

Thereafter, the portion where the coating is removed is covered with a package so that the bare optical fiber exposed during handling is not damaged, and a grating type optical component is manufactured.

[0010]

By the way, in the case of the grating type optical component, the grating is manufactured in a state where the primary coating is removed and the bare optical fiber is exposed as described above. For this reason, the optical fiber for producing the grating is handled without any coating during the work involved in the grating process, so that the exposed bare optical fiber is easily damaged and the yield of the manufactured grating type optical component is reduced. There was a problem of doing.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to provide a method of packaging a grating-type optical component that has a high yield without damaging a bare optical fiber during handling. .

[0012]

According to the present invention, in order to achieve the above object, a step of removing a primary coating from a hydrogen-treated optical fiber is performed. A method for packaging a grating-type optical component, comprising: irradiating a core with ultraviolet light to form a grating; annealing the portion where the grating is formed; and covering the portion where the grating is formed with a package. , The step of producing the grating, the step of covering with the package, and the step of performing the annealing treatment.

[0013]

The optical fiber on which the grating is manufactured is subjected to a subsequent annealing process in a state of being covered with the package, so that the bare optical fiber is not damaged during handling.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a method for packaging a grating type optical component according to the present invention is shown in FIG.
A detailed description will be given based on (a) to (e).

In the method of the present invention, first, as a process prior to the formation of the grating, a desired portion of the optical fiber 1 for producing the grating for the purpose of improving the photo-induced characteristics is subjected to a pressurized hydrogen treatment (normal temperature, 15 MPa, 2 weeks). ).

Next, the primary coating 1a is removed from the portion subjected to the hydrogen treatment (FIG. 1 (a)), and a phase mask 3 is arranged close to the exposed bare optical fiber 1b. Irradiation with UV (FIG. 1 (b)) produces a grating 1c (see FIG. 1 (c)) on a core (not shown).

Here, in FIGS. 1 (c) to 1 (e),
Since the bare optical fiber 1b is thin, the grating 1c is exaggerated. Further, the grating 1c may be manufactured by a holographic method in addition to the phase mask method using the phase mask 3.

At this time, the ultraviolet light UV is emitted from a light source composed of a KrF excimer laser pulse light source having an oscillation wavelength of 248 nm and an output of 30 W, for example. Alternatively, an Ar 2nd harmonic laser or a YAG 4th harmonic laser can be used as the other ultraviolet light UV. Further, the reflection wavelength of the grating produced by ultraviolet rays depends on the pitch of the grating, and the wavelength width of whether the reflected light has a narrow band or a wide band depends on the length of the formed grating.

Next, as shown in FIG. 1C, the portion of the bare optical fiber 1b on which the grating 1c has been formed is covered with a package 5 composed of two half bodies 5a and 5b.

Here, the package 5 is divided into half-pieces 5a, 5
In addition to b, for example, a metal pipe such as stainless steel may be used. Alternatively, a package rod 5c having a U-shaped groove as shown in FIG. 2 may be used as the package.

Thereafter, as shown in FIG. 1 (d), the portion where the grating 1c is formed is accommodated in an annealing tank 7, and an annealing process (120 ° C., 1 day) is performed. Thereby, in the optical fiber 1, hydrogen accompanying the hydrogen treatment is removed, and strength deterioration due to hydrogen is prevented.

When the above annealing process is completed, the bare optical fiber 1b where the grating 1c is formed is taken out of the annealing bath 7 and the portion of the bare optical fiber 1b is covered with the package 5 as shown in FIG.
Optical fiber 1 (grating type optical component) shown in (e)
Is obtained.

At this time, in the method of the present invention, after the grating 1c is manufactured, the portion of the bare optical fiber 1b is covered with the package 5, so that the bare optical fiber 1b is hardly damaged at the time of handling, and the manufactured grating mold is manufactured. The yield of optical components is improved.

Here, 1,000 optical fibers 1 having the above structure were manufactured by the method of the present invention and the conventional method of covering with a package after the annealing treatment. As a result, while the defect occurrence rate was 1% in the method of the present invention, the defect occurrence rate was as high as 20% in the conventional method, and the grating type optical component manufactured by adopting the method of the present invention. It was confirmed that the yield was improved.

In the above embodiment, the single-core optical fiber 1
However, the method of the present invention can be applied to a plurality of optical fibers, and can also be applied to a tape fiber in which a plurality of optical fibers are arranged in parallel.

[0026]

According to the first aspect of the present invention, it is possible to provide a method of packaging a grating type optical component having a high yield without damaging the bare optical fiber during handling.

[Brief description of the drawings]

FIGS. 1A to 1E are process diagrams illustrating a packaging method for a grating type optical component of the present invention.

FIG. 2 is a perspective view showing one embodiment of a package of the grating type optical component of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical fiber (grating type optical component) 1a Primary coating 1b Bare optical fiber 1c Grating 3 Phase mask 5 Package 5a, 5b Half body 5c Package rod 7 Annealing tank UV Ultraviolet ray

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Shigeto Yodo 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Inside Furukawa Electric Co., Ltd.

Claims (1)

[Claims] 1. A step of removing a primary coating from a hydrogen-treated optical fiber, a step of removing the primary coating and irradiating an exposed core of the bare optical fiber with ultraviolet rays to form a grating, and the grating. A method of packaging a grating-type optical component, comprising: a step of performing an annealing treatment on a portion where the grating is formed and a step of covering the portion where the grating is formed with a package, wherein the step of forming the grating, the step of covering with the package, and A method for packaging a grating-type optical component, wherein the steps are performed in the order of annealing.