JP2001343555A - Method for producing optical fiber array and its optical fiber array - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing optical fiber array which is excellent in long-term reliability by utilizing an irradiation method of ultraviolet rays and a substrate which scatters the ultraviolet rays when optical fibers are fixed by hardening adhesive with the ultraviolet rays. SOLUTION: A light source 1 is disposed by a driving means in such a manner that an irradiating light is orthogonally crossed to the direction of a plane in which multiple optical fibers 5 are aligned and the light source 1 moves to the front and rear, and the right and left directions in parallel and, therefore, even when the existing light source which has a strongly irradiating region at the center of irradiation range is used, the ultraviolet rays are uniformly scattered toward the direction of the plane in which the multiple optical fibers 5 are aligned and, as a result, irregularities of hardening of the adhesive 2 is not generated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a support substrate and a cover substrate which hold an optical fiber, wherein a V-groove is formed in one of the substrates and an optical fiber is inserted into the V-groove. The present invention relates to a method for manufacturing an optical fiber array in which the other substrate is pressed via an ultraviolet-curable adhesive, and the adhesive is cured by irradiation with ultraviolet light to fix and align the optical fibers in V-grooves.

[0002]

2. Description of the Related Art Conventional optical fiber arrays include, for example,
The other side of the support substrate having a V-groove on one side and the coated fiber storage substrate are adhered and fixed from above the support substrate, and the coated fibers are superposed in two stages from the coating storage groove formed in the coated fiber storage substrate. The bare wires, which are inserted and whose coatings are removed at the tips of the upper and lower optical fibers, are alternately aligned in the V-groove on one side. Next, an optical fiber array is formed by installing and assembling the lid substrate from above the V-groove of the support substrate so as to press the bare wire of the optical fiber. In this case, after the optical fiber 5 is inserted between the support substrate 3 and the lid substrate 4, the ultraviolet curable adhesive 2 is injected into the gap between the support substrate 3, the lid substrate 4 and the optical fiber 5. As shown in FIG. 3, ultraviolet rays are irradiated from the light source 1 to cure and fix the ultraviolet curable adhesive 2. The curing of the adhesive utilizes the property of optical characteristics that the glass material of the substrates 3 and 4 is a commercially available glass material such as Pyrex glass or BK7 and transmits ultraviolet rays almost uniformly in the light transmitting area. Usually, the adhesive is cured by irradiating the entire optical fiber array with ultraviolet rays from the upper surface or the end surface of the optical fiber array.

[0003]

However, while the glass material of the substrate has an optically uniform property, the light source for irradiating the ultraviolet light has the intensity of the ultraviolet light within the irradiation range as shown in FIG. Even though the optical fiber array itself is small, even if the optical fiber array itself is small, the adhesive is hardened by transmitting ultraviolet light to the adhesive and hardening the adhesive because the center is strong and weakens toward the periphery. The adhesive strength of the optical fiber array may be reduced due to aging in a harsh environment in which the optical fiber array is used and may deteriorate.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to cure an adhesive with ultraviolet light to fix an optical fiber. An object of the present invention is to provide a method of manufacturing an optical fiber array having excellent long-term reliability by using an irradiation method and a substrate that scatters ultraviolet light. Therefore,
According to the first aspect of the present invention, there is provided a method of swinging a light source up and down, left and right, or front and rear with respect to an optical fiber. Thereby, the irradiation range of the light source is uniformly dispersed in the plane direction in which the optical fibers 5 are aligned, so that uneven curing of the adhesive 2 does not occur. By changing the swing direction at one end of the amplitude of the light source swinging in a single direction, the light source can be moved two-dimensionally and the range of the irradiation intensity can be dispersed.

According to the first aspect of the present invention, one light source is swung up and down, left and right, or back and forth with respect to the plane direction in which the optical fibers are aligned. The present invention attaches a plurality of multi-core optical fibers in a vertical direction, a horizontal direction, or a front-rear direction with respect to a plane direction in which the multi-core optical fibers are aligned, or swings the plurality of light sources, and simultaneously irradiates the plurality of light sources. Is the way. As described above, when a plurality of light sources are used for the adhesive to be irradiated and fixed by mounting a plurality of light sources vertically and horizontally, or before and after, or when oscillating the light sources attached to the plurality of light sources, By making the irradiation intensity uniform, ultraviolet irradiation can be simultaneously performed from multiple directions, so that irradiation of ultraviolet light and curing of the adhesive can be completed in a short time.

Further, as a third aspect of the present invention, it is preferable to insert a scattering filter, for example, frosted glass, a filter having a different transmittance and leveling, or a lens into an optical path from the light source to the adhesive. In particular, there is provided a method of manufacturing an optical fiber array as a support substrate and a lid substrate made of crystallized glass having fine crystals precipitated on a scattering filter.
It is preferable as the invention according to the above.

According to a fifth aspect of the present invention, there is provided an optical fiber array in which the crystallized glass on which the fine crystals are precipitated is used immediately before the adhesive and used for at least one of a support substrate and a lid substrate. However, when a crystallized glass material whose coefficient of thermal expansion after crystallization is close to that of quartz is used, the separation due to the difference in thermal expansion does not occur as in the prior art, and the product reliability as an optical fiber array can be improved. Since the ultraviolet rays are uniformly transmitted through the adhesive layer due to the scattering effect and the curing occurs uniformly, the durability against thermal fatigue due to thermal expansion and contraction is improved.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic view showing an ultraviolet light source for irradiating the optical fiber array of the present invention.
The light source 1 is provided by a known driving means so that irradiation light is orthogonal to a plane direction in which the multi-core optical fibers 5 are aligned, and the light source 1 can move in parallel front, rear, left and right directions. As a result, even in the case of an existing light source having a strong irradiation area at the center of the irradiation area, the ultraviolet light is uniformly dispersed in the plane direction in which the multi-core optical fibers 5 are aligned, so that the adhesive 2 is cured. No unevenness occurs. Although the description has been made with the multi-core optical fiber here, the present invention is not limited to this, and the effects of the present invention can be obtained with a single-core optical fiber. Further, the light source 1 may be further moved in the vertical direction so that the light can be emitted also from the end faces of the substrates 3 and 4. Thereby, irradiation in the end face direction can be performed last and for a long time or with high intensity, and the adhesion strength can be increased. It is also possible to mount a plurality of fixed light sources in the moving range and irradiate these light sources simultaneously. Thus, the number of light sources attached is also increased, so that the amount of irradiation light is increased and the adhesive can be cured in a short time.

FIG. 2 is a schematic diagram showing the intensity of ultraviolet rays applied to an optical fiber array according to another embodiment. Crystallized glass in which fine crystals are precipitated is used for a substrate 4 located as a scattering filter in an optical path from a light source 1 to an adhesive 2. As a result, before reaching the substrate 4, the ultraviolet rays having a strong irradiation part at the center of the irradiation range are scattered by the fine crystals precipitated on the crystallized glass, and the transmitted ultraviolet rays do not have a strong part at the center of the irradiation range. It is a uniform light beam. Thereby, the irradiated adhesive is cured uniformly without curing unevenness, and the reliability of the optical fiber array is improved.

The crystallized glass includes, for example, the following. 60 in SiO ₂ -Al ₂ O ₃ -LiO ₂ component glass
63%, 23-25%, 4-5% as a basic composition, ZrO ₂ : 1.5-2.5%, TiO ₂ : 0.5-
It is a glass material containing 2.5% and having the following components. MgO: 0.5~1.5% ZnO: 0.5~1.2% Na 2 O: 0.5~2.0% K 2 O: 1 from 0.5 to 2.0% the following two components select. _{BaO: 0.5~1.0% B 2 O 3} : 0~1.0%

Then, by crystallizing this parent glass material by a heat treatment as shown in FIG. 3 under the following basic conditions, a glass ceramic having a thermal expansion coefficient of 5 × 10e-7 (1 / ° C.) is obtained. . By holding this material at a temperature near the deformation temperature Td for one hour, nuclei of TiO ₂ and ZrO ₂ appear uniformly. In addition, the secondary temperature is maintained at 800 ° C. to 850 ° C. when BaO is included, and 840 ° C. to 850 ° C. when B ₂ O ₃ is included, for 2 to 4 hours to uniformly precipitate the microcrystalline β-Eucryptite. I let it. At that time, the precipitation ratio with respect to the vitreous is about 30% to 50%, and the average grain size of the precipitated crystals is 0.1 μm to 0.7. When the proportion of the crystals is too large, it is difficult to transmit ultraviolet rays.

[0012]

[Examples] Samples of crystallized glass prepared above
Is a composition as shown in Table 1.

[0013]

[Table 1]

Further, Table 2 shows the properties of the parent glass material and the crystallized glass.

[0015]

[Table 2]

From this evaluation, it was confirmed that when a scattering filter in which fine crystals were deposited was arranged in the optical path, even if the incident intensity had a distribution, uniform irradiation was possible to the adhesive. Further, since the deformation temperature Td of the parent glass material is 750 ° C. or less, the V-groove can be easily formed by press molding. Then, the two components BaO and B ₂ O ₃ are added to the parent glass material, respectively, and the secondary temperature during crystallization is adjusted so that the thermal expansion coefficient α is almost the same as that of quartz glass, and the transmittance of ultraviolet rays 360 nm is reduced. Can be improved. However, as shown in Tables 1 and 2, when the crystallization temperature is 900 ° C. or higher, the particle size of the precipitated crystals becomes large, the amount of UV transmission decreases, and the UV light does not pass through itself, so that curing may not be performed.

[0017]

According to the first aspect of the present invention, since the light source is swung up and down, left and right, or back and forth with respect to the optical fiber, the irradiation range of the light source can be adjusted with respect to the plane direction in which the optical fibers are aligned. Thus, since the adhesive is uniformly dispersed and does not cause uneven curing of the adhesive, it is possible to provide a highly reliable optical fiber array in which the hermeticity is maintained even with aging under a severe environment in which the adhesive is used. In particular, according to the invention according to claim 5, the optical fiber array in which the crystallized glass on which fine crystals are deposited is used immediately before the adhesive and used for at least one of the support substrate and the lid substrate is a material of the substrate. Has the same coefficient of thermal expansion as the optical fiber, so there is no peeling due to the difference in thermal expansion as in the past, which can improve the product reliability as an optical fiber array and the scattering effect of precipitated crystals causes ultraviolet rays to adhere to the adhesive layer. And the hardening occurs uniformly, so that the durability against thermal fatigue due to thermal expansion and contraction is improved.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a light source of ultraviolet light applied to an optical fiber array according to the present invention.

FIG. 2 is a schematic diagram showing a light source of ultraviolet light for irradiating an optical fiber array according to another embodiment.

FIG. 3 is a schematic diagram showing a time course of a heat treatment.

FIG. 4 is a schematic diagram showing a conventional ultraviolet light source for irradiating an optical fiber array.

FIG. 5 is a schematic diagram showing irradiation power of a light source as shown in FIG.

[Explanation of symbols]

1. Light source, 2. Adhesive, 3. Support substrate, 4. Lid substrate, 5. Optical fiber.

Claims (5)

[Claims] A V-groove is formed in one of a support substrate and a lid substrate that sandwiches an optical fiber, an optical fiber is inserted into the V-groove, and the other of the support substrate and the lid substrate is used for the V-groove. A method of manufacturing an optical fiber array in which an optical fiber is held by an ultraviolet-curable adhesive, the adhesive is cured by ultraviolet irradiation, and the optical fibers are fixed in a V-groove and aligned. A method for manufacturing an optical fiber array, characterized by swinging up and down, left and right, or back and forth directions with respect to an adhesive for fixing the adhesive to cure the adhesive. 2. A V-groove is formed in one of a support substrate and a lid substrate that sandwiches an optical fiber, an optical fiber is inserted into the V-groove, and the other substrate of the support substrate and the lid substrate is used. A method of manufacturing an optical fiber array in which an optical fiber is held by an ultraviolet-curable adhesive, the adhesive is cured by ultraviolet irradiation, and the optical fibers are fixed in a V-groove and aligned. A method for manufacturing an optical fiber array, comprising: attaching a plurality of adhesives to an adhesive for fixing the adhesive in the up, down, left, right, front and rear directions, or swinging the plurality of light sources to cure the adhesive. 3. A V-groove is formed in one of a support substrate and a lid substrate that sandwiches an optical fiber, an optical fiber is inserted into the V-groove, and the other of the support substrate and the lid substrate is used by the other substrate. A method of manufacturing an optical fiber array in which an optical fiber is held by an ultraviolet-curable adhesive, and the adhesive is cured by irradiation of ultraviolet light to fix and align the optical fibers in a V-groove. A method for manufacturing an optical fiber array, comprising: attaching a scattering filter to an optical path leading to an adhesive for fixing the adhesive; and curing the adhesive. 4. A method for manufacturing an optical fiber array, wherein the scattering filter according to claim 3 is a support substrate and a lid substrate made of crystallized glass. 5. A supporting substrate and a lid substrate which sandwich an optical fiber from both sides and form a V-groove in one substrate, and an optical fiber inserted in the V-groove, the other of the supporting substrate and the lid substrate. An optical fiber array having an adhesive held down by a substrate and cured by ultraviolet irradiation, wherein an optical fiber is fixed in a V-groove and aligned, and at least one of the support substrate and the lid substrate is made of crystallized glass. An optical fiber array characterized in that it is used.