JP2001074969A - Method and device for manufacturing optical fiber coupler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to improve the manufacturing yiel and realize miniaturization by preventing discontinuity of an optical coupling part and re-sticking of an adhesive in the mounting process of an optical fiber coupler. SOLUTION: A protective member pedestal 16 and a protective tube pedestal 18 are moved in parallel between optical fiber fixing pedestals 12, 14 by the optical fiber fixing pedestals 12, 14 which strength linearlly an optical fiber extended from both sides of a protective member in the both sides of the protective member, the protective member pedestal 16 which holds the protective member in parallel to the stretched optical fiber and also which is movable in parallel to the optical fiber, and the protective tube pedestal 18 which holds the protective tube into the internal part of which the stretched optical fiber is inserted and held in parallel to the optical fiber and also which is movable in parallel to the optical fiber. And, the protective member is inserted into the protective tube.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an optical fiber coupler having functions such as optical coupling and optical branching, and an apparatus for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, an optical fiber coupler has been used as a device incorporated in an optical communication system when coupling or splitting optical signals with each other or multiplexing or demultiplexing optical signals having different wavelengths. Such an optical fiber coupler has a structure in which a plurality of optical fibers are arranged in parallel and optically coupled to each other. Are well-known in the art, such as a polishing method of joining together along a polishing surface to form a joint, and a fusion drawing method of forming a joint by fusion-stretching a plurality of optical fibers. Is a fusion drawing method.

As shown in FIG. 7, a basic fusion drawing method is to arrange optical fibers 72 and 73, in which a protective coating 71 of an optical fiber is partially removed, in parallel, and to arrange the optical fibers back and forth at predetermined intervals. A stretching table 75 that can move in two places,
The fiber clamps 75a, 75b, 76a, 7
The parallel portion 79 of the optical fiber is heated by using a heating means 78 fixed by 6b and arranged between the stretching tables 75 and 76. Then, by moving the stretching tables 75 and 76 to the left and right, respectively, while the optical fiber is being stretched, light is incident on one of the optical fibers by the light source 80 in a measuring system as shown in FIG. And each optical fiber 72,7
While monitoring the light amount of No. 3, the extension of the optical fiber is stopped when the predetermined branching ratio is reached, and a fusion-spread portion adjusted to the predetermined branching ratio is formed.

[0004] In the fusion-spreading portion serving as an optical coupling portion, even if a small external force is applied, the coupling state is slightly changed, and as a result, the branching ratio is changed.
The fusion extension is fixed on the protection member 80. 9A is a plan view of the protection member, FIG. 9B is a side view, and FIG. 9C is a cross-sectional view taken along line BB. The protective member 80 is made of a material having the same coefficient of thermal expansion as that of an optical fiber such as a quartz glass substrate, and fixes the optical fiber with an adhesive 82. After constructing the optical fiber coupler in this manner, an adhesive is applied to the lower portion of the protective member 80 and stored and fixed in a cylindrical protective tube in order to prevent breakdown due to external force, failure due to moisture, and performance degradation. I do. Further, both ends of the protective tube are sealed with a sealing material to complete the optical fiber coupler unit.

[0005]

In such a conventional method of manufacturing an optical fiber coupler, the process of fusing and extending a plurality of optical fibers to manufacture an optical fiber coupler is automated, and a desired process is performed. Various methods for easily obtaining a branching ratio have been established. In the mounting process, the work of inserting the optical fiber coupler into the protective tube is mainly performed by hand, and the gap between the protective member 80 and the protective tube is usually designed to be minimum in order to reduce the size. For this reason,
When inserted into the protective tube, as shown in FIG. 10, there is a problem that the fusion extending portion 85 as the optical coupling portion frequently breaks upon contact with the protective tube 86.

The adhesive 88 applied to the lower portion of the protective member 80 adheres to the inner wall surface of the protective tube 86 before the protective member 80 reaches the center position of the protective tube 86, so that the adhesive 88 is melted. There is a problem that light is re-adhered to the extension portion 85, and as a result, light leaks from the fusion extension portion 85, thereby changing the branching characteristics of the coupler and causing a defective product.

SUMMARY OF THE INVENTION Accordingly, the present invention provides a method and apparatus for manufacturing an optical fiber coupler capable of preventing disconnection of an optical coupling portion and re-adhesion of an adhesive in an optical fiber coupler mounting step, thereby improving yield and realizing miniaturization. It is intended to provide.

[0008]

In order to achieve the above-mentioned object, the invention according to claim 1 of the present invention provides a fusion-stretched portion by heating and stretching a plurality of bundled optical fibers. In the method of manufacturing an optical fiber coupler in which an extending portion is fixed to a protective member, after the fusion extending portion is adhered and fixed to the protective member, the optical member extending from both ends of the protective member and the protective member is stretched on a straight line. Then, while applying an adhesive to the lower side of the protective member, the protective tube held with the optical fiber inserted therein is moved to the protective member side in parallel with the optical fiber, and the protective member is When the optical fiber is inserted into the protective tube, the optical fiber is loosened and the protective member is brought into contact with the inner wall of the protective tube and adhered.

In this method of manufacturing an optical fiber coupler, an adhesive is applied to the lower side of the protective member to which the fusion-spread portion has been adhered and fixed, while the optical fiber is inserted through the inside of the protective tube, and the protective tube is stretched. By moving toward the protection member side in parallel with the bridged optical fiber, the protection member is inserted into the protection tube in parallel. For this reason, the fused extension on the protective member does not come into contact with the protective tube and is not damaged. Also, by loosening the stretched optical fiber when the protective member is inserted into the protective tube, the protective member is brought into contact with the inner wall of the protective tube and adhered, so that the adhesive is applied to the protective tube at a position other than the protective member bonding position. Adhesion is prevented, and adhesion of the adhesive to the fusion-spreading portion can be prevented, so that safe and reliable mounting work becomes possible.

According to a second aspect of the present invention, in the method of manufacturing an optical fiber coupler, an amount of the adhesive applied is adjusted according to a gap between a lower side of the protection member and an inner surface of the protection tube.

In this method of manufacturing an optical fiber coupler, the amount of the adhesive applied is adjusted in accordance with the gap between the lower side of the protective member and the inner surface of the protective tube, so that the adhesive is applied to portions of the protective tube other than the protective member adhesive portion. The adhesive does not excessively adhere to the inner surface, and the adhesive can be prevented from adhering to the fusion-stretched portion of the optical fiber coupler.

An optical fiber coupler manufacturing apparatus according to claim 3, wherein the fused optical fiber is heated and drawn to form a fusion-stretched portion, and the fusion-stretched portion is fixed to a protective member. In the manufacturing apparatus, the optical fiber extending from both sides of the protection member is linearly stretched on both sides of the protection member, and the optical fiber fixing base is held in parallel with the stretched optical fiber. A protective member base parallel to the optical fiber and a protective tube inserted through the stretched optical fiber and held in parallel with the optical fiber; A protective tube base that can be translated with respect to the fiber,
The protection member base and the protection tube base are moved in parallel between the optical fiber fixing bases, and the protection member is inserted into the protection tube.

In this optical fiber coupler manufacturing apparatus, the optical fiber extending from both sides of the protective member is linearly stretched by the optical fiber fixing table, and the protective member held on the protective member table is attached to the protective tube table. By moving the protection member base and the protection tube base in parallel between the optical fiber fixing bases so that the held optical fiber is inserted into the protection tube inserted therein, the fusion-extending portion on the protection member is moved. Will not be damaged by contact with the protective tube. Also,
When the protection member is inserted into the protection tube, the tension of the optical fiber is released by releasing the tension of the optical fiber by one of the optical fiber fixing stands, and the protection member is brought into contact with the inner wall of the protection tube and bonded. Can be. This prevents the adhesive from adhering to the protection tube other than at the position where the protective member is adhered, and prevents the adhesive from adhering to the fusion-spreading portion, thereby enabling a safe and reliable mounting operation.

5. The apparatus for manufacturing an optical fiber coupler according to claim 4, wherein the protection member base and the protection tube base are arranged on a base having a concave guide groove, and the lower surfaces of the protection member base and the protection tube base. Are formed with convex sliding protrusions which engage with the guide grooves and slide.

In this apparatus for manufacturing an optical fiber coupler, the protection member base and the protection tube base are slid by engaging the concave guide groove and the convex slide projection with each other. Can be stably translated along the optical fiber.

The apparatus for manufacturing an optical fiber coupler according to claim 5, wherein the protection member base and the protection tube base are arranged on a base on which a convex slide rail is formed, and the protection member base and the protection tube base are provided. A concave sliding groove which engages with the convex sliding rail and slides, respectively.

In this optical fiber coupler manufacturing apparatus, the protective member base and the protective tube base are slid by engaging the convex slide rail and the concave slide groove. Can be stably translated along the optical fiber.

According to a sixth aspect of the present invention, in the apparatus for manufacturing an optical fiber coupler, the protective tube base has a V-shaped cross-section for a protective tube receiving groove for holding the protective tube.

In this optical fiber coupler manufacturing apparatus, when the protective tube is placed in the protective tube receiving groove formed in the protective tube table, the protective tube can be stably positioned. When fixing, the backlash of the protective tube can be prevented, and more stable positioning and fixing can be performed.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of an apparatus and method for manufacturing an optical fiber coupler according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is a perspective view showing the configuration of the optical fiber coupler manufacturing apparatus according to the first embodiment of the present invention. As shown in FIG. 1, an optical fiber coupler manufacturing apparatus 100 according to the present embodiment includes an optical fiber fixing base 1 for fixing optical fibers fixed to both ends on a base 10.
2, 14 and a protection member table 16 and a protection tube table 18 provided between the optical fiber fixing tables 12 and 14 above the base 10, and the protection member table 16 and the protection tube table 18 are The sliding protrusions 16a and 18a on the lower surface are engaged with the guide grooves 20 formed on the base 10 so as to be movable in the X direction. In addition, these protection member bases 1
6. The protection tube stand 18 is independently movable along the guide groove 20.

In the center of the upper surface of the protection member base 16, a protection member accommodation groove 26 for accommodating a protection member described later is provided with a guide groove 20.
Further, a protection tube housing groove 28 for fixing a protection tube described later is formed in the center of the upper surface of the protection tube table 18 in parallel with the guide groove 20. Further, a protection tube clamp 30 for fixing the protection tube is mounted above the protection tube storage groove 28. Here, the positional relationship between the protection member storage groove 26 and the protection tube storage groove 28 is such that the protection member storage groove 26 is concentrically linear in the optical axis direction (x direction), and the protection member storage groove 26 in the elevation direction (y direction). Shallower, protection tube storage groove 28
Is to be deeper.

Next, the configuration of the optical fiber coupler will be described. FIG. 2 shows a configuration of an optical fiber coupler 50 manufactured by the optical fiber coupler manufacturing apparatus 100 of the present invention.
FIG. 2A is a front view of the optical fiber coupler 50, and FIG. 2B is a side view. In the optical fiber coupler 50, the fusion-stretched portion 1 of the optical fiber is placed at the center in the longitudinal direction of the protective member 2, and the bare fiber portion 3 is fixed at both ends in the longitudinal direction of the protective member 2 by the adhesive 4. You. Further, the protective member 2 to which the optical fiber is adhered is housed in a protective tube 5 made of stainless steel or Invar material, is fixed to the inner surface of the protective tube 5 by an adhesive 6, and both ends are sealed by sealing materials 8.

FIG. 3 shows the optical fiber coupler 50 shown in FIG.
FIG. 2 is a cross-sectional view showing an AA cross section of FIG. According to FIG. 3, the protection member 2 has a semicircular cross section, and the optical fiber is fixed to the plane portion thereof. The protection member 2 is made of a material such as quartz, ceramic, crystallized glass, or liquid crystal polymer. As the adhesives 4 and 6, an epoxy or acrylic adhesive can be used. In particular, it is desirable to use a UV-curable adhesive from the viewpoint of workability, and in that case, it is easy to irradiate with UV light. And can be cured quickly.

Next, a procedure for manufacturing the optical fiber coupler 50 by the optical fiber coupler manufacturing apparatus 100 will be described with reference to FIG. First, after the fusion extension part 1 is fixed to the protection member 2 with an adhesive, the protection member 2 to which the fusion extension part has been fixed is stored in the protective member base 16 as shown in FIG. The optical fiber is fixed to the optical fiber fixing tables 12 and 14 using the fiber clamps 22 and 24 so as to be placed on the groove 26. The clamp is disclosed in Japanese Patent Laid-Open No. 2-1158.
A tension adjusting type as described in 07 may be used.
At this time, the optical fiber is fixed so as to be parallel to the guide groove 20 and at the center of the fiber clamps 22 and 24, and the protection member 2 is stored in the protection member storage groove 26 formed at the center of the protection member base 16. So that This allows
The optical fiber and the protection member 2 are kept substantially in a straight line when viewed from above.

After that, once the fiber clamp 24 is removed, the protection tube 5 is inserted into the optical fiber, and the protection tube 5 is placed in the protection tube storage groove 28 of the protection tube table 18 and fixed by the protection tube clamp 30. .
Also, the detached optical fiber is re-attached to the optical fiber fixing table 14.
Is fixed by a fiber clamp 24.

As shown in the sectional view of the protective tube in FIG. 3, the protective tube 5 is arranged concentrically around the bare fiber 3 bonded and fixed on the protective member 2 at this time. Are positioned such that a gap d is maintained between the protection member 2 and the protection tube 5. The gap d is set so large that an adhesive for bonding the protective tube 5 and the protective member 2 described below is not attached.

Next, as shown in FIG. 4B, the protection member base 16 is moved to the optical fiber fixing base 12 side, and
Is made to protrude from the protection member base 16, and the protection tube base 18 is moved toward the optical fiber fixing base 12 so that the protruding end of the protection member 2 is inserted into the protection tube 5. That is, the protection member table 16 and the protection tube table 18 are moved to a position where both ends of the protection member 2 overlap the protection member table 16 and the protection tube table 18. Then, in this state, the adhesive 6 is applied to the lower part of the protection member 2. The amount of the adhesive 6 to be applied is adjusted according to the gap d between the protection member 2 and the inner wall surface of the protection tube 5 so as to be within the clearance.

Thereafter, as shown in FIG. 4C, the protective tube table 18 is further moved toward the optical fiber fixing table 12 until the protective tube 5 contacts the protective member table 16. At this time, the protective member 2 and the protective tube 5 have a positional relationship shown in FIG. Therefore, the protection member 2 is reliably inserted into the protection tube 5 by the guide groove 20 and the protection member base 16 and the protection tube base 18 which operate while being restrained by the guide groove 20 without damaging the fusion-spread portion 1 of the optical fiber. can do.

Then, the protection tube table 18 is moved to the optical fiber fixing table 12 side so as to push out the protection member table 16, and when the protection member 2 reaches the center position of the protection tube 5, the protection tube table 18 is moved. Stop moving. At this time, since there is a gap d between the inner wall of the protection tube 5 and the protection member 2, the adhesive 6 does not adhere to the inner wall surface of the protection tube 5. Next, the optical fiber fixing table 1
By releasing one of the fixing members 2 and 14 and loosening the tension of the optical fiber, the restraint in the vertical direction of the protection member 2 is completely released, and the protection member 2 is self-weighted by the self-weight of the protection member 2 and the adhesive 6. The sun sinks, and the protective member 2 and the inner wall surface of the protective tube 5 come into contact with each other, and are adhered and fixed by the adhesive 6.

Finally, after the adhesive 6 is cured, both ends of the protective tube 5 are filled with a sealing material 7 as shown in FIG. Then, after the sealing material 7 is cured, the protective tube clamp 3
0, the fiber clamps 22 and 24 are removed, and the completed optical fiber package is placed in the optical fiber coupler manufacturing apparatus 10.
Remove from 0.

As described above, in the optical fiber coupler manufacturing apparatus according to the present embodiment, the protective member 2 and the protective tube 5 are moved in an appropriate positional relationship while being kept parallel to each other while the protective member 2 is moved in an appropriate positional relationship. Since it is inserted and mounted in the inside 5, the fusion extension 1 is prevented from being damaged. In addition, since the protection member 2 and the protection tube 5 are moved to the bonding position while maintaining the gap, the adhesive does not re-adhere to the fusion extension 1. As a result, the occurrence of defective products at the time of mounting the optical fiber coupler is greatly reduced, and the effect of improving the yield is produced. Further, since mounting can be performed even with an extremely small clearance, a small-diameter tube can be used, and the size of the optical fiber coupler can be easily reduced.

Next, an optical fiber coupler manufacturing apparatus according to a second embodiment of the present invention will be described with reference to the drawings. FIG. 5 shows an optical fiber coupler manufacturing apparatus 20 according to this embodiment.
FIG. 2 is a perspective view showing a configuration of a No. 0. As shown in FIG. 5, in the present embodiment, a slide rail 21 that slidably supports the protection member base 16 and the protection tube base 18 is provided instead of the guide groove of the first embodiment. . In addition, sliding concave portions 16b and 18b are formed on the lower surfaces of the protective member table 16 and the protective tube table 18 so as to engage with the sliding rail 21. ,

In the case of the guide groove 17 shown in FIG. 1, a certain depth is required for stable sliding, and the length and width of the sliding projections 16a and 18a to be fitted with the guide groove 17 are also required. Will be. In this regard, in the present embodiment, the height of the sliding rail 21 may be low, and stable sliding is possible even when the sliding recesses 16b and 18b of the protective member table 16 and the protective tube table 18 are shallow. In addition, the manufacturing of the optical fiber coupler manufacturing apparatus becomes easy, and the manufacturing cost can be reduced.

Next, a third embodiment of the present invention will be described with reference to the drawings. FIG. 5 is a perspective view showing a third embodiment of the optical fiber coupler manufacturing apparatus according to the present invention. In the optical fiber coupler manufacturing apparatus 300 of the present embodiment, a V-shaped protective tube housing groove 29 is used instead of the protective tube housing groove 28 of the optical fiber coupler manufacturing apparatus of the first embodiment. By adopting the V-shaped storage groove shape, the cylindrical protection tube 5 shown in FIG. 3 can be positioned stably, and when the protection tube 5 is fixed by the protection tube clamp 30, the position of the protection tube 5 is reduced. The occurrence of rattling can be prevented, and more stable positioning and fixing can be performed.

In the above-described method and apparatus for manufacturing an optical fiber coupler according to the present invention, the procedure for accommodating the protection member 2 in the protection tube 5 is performed manually at low cost and with good yield. However, this process can be easily automated using a drive mechanism such as a motor, a cylinder, and a feed screw, a position detection mechanism using a sensor, a control device, and the like. In this case, it is possible to configure an optical fiber coupler manufacturing apparatus capable of easily supplying a large quantity of stable quality optical fiber couplers.

[0036]

According to the present invention, an adhesive is applied to the lower side of the protective member to which the fusion-spread portion is adhered and fixed, and at the same time, the optical fiber is inserted through the inside of the protective tube. The protective member is inserted in parallel into the protective tube by moving to the protective member side in parallel with the optical fiber, so that the fused extension on the protective member is prevented from coming into contact with the protective tube and being damaged. it can. In addition, when the protective member is inserted into the protective tube, the protective member is brought into contact with the inner wall of the protective tube and adhered, so that the adhesive is prevented from adhering to a position other than the position where the protective member is adhered to the protective tube. Adhesives can be prevented from being attached to the parts, and a safe and reliable mounting operation can be performed. Thus, the yield of the optical fiber coupler can be improved, and the size of the manufacturing apparatus can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of an optical fiber coupler manufacturing apparatus according to the present invention.

FIG. 2 is a diagram illustrating a configuration of an optical fiber coupler covered with a protective tube.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is an explanatory diagram illustrating a procedure of a method of manufacturing an optical fiber coupler according to the present invention.

FIG. 5 is a perspective view showing a second embodiment of the optical fiber coupler manufacturing apparatus according to the present invention.

FIG. 6 is a perspective view showing a third embodiment of the optical fiber coupler manufacturing apparatus according to the present invention.

FIG. 7 is a plan view of a conventional fusion stretching apparatus.

FIG. 8 is a diagram showing a measurement system of an optical branching ratio at the time of manufacturing an optical fiber coupler.

FIG. 9 is a diagram illustrating a configuration of an optical fiber coupler adhered and fixed on a protection member.

FIG. 10 is a view showing a state in which a protection member is mounted in a conventional protection tube.

[Description of Signs] 1 Fused and stretched portion 2 Protective member 3 Bare fiber portion 4 Adhesive 5 Protective tube 10 Base 12, 14 Optical fiber fixing base 16 Protective member base 16a Sliding protrusion 16b Sliding concave portion 18 Protective tube base 18a Sliding protrusion 18b Sliding recess 20 Guide groove 21 Sliding rail 29 V-shaped protective tube housing groove 50 Optical fiber coupler 100, 200, 300 Optical fiber coupler manufacturing apparatus

Claims (6)

[Claims] 1. A method for manufacturing an optical fiber coupler, comprising: forming a fused extension by heating and stretching a plurality of bundled optical fibers; and fixing the fused extension to a protective member. After adhesively fixing to the protection member, the protection member and the optical fiber extending from both ends of the protection member are stretched linearly, and an adhesive is applied to the lower side of the protection member, while the optical fiber is placed inside. The protective tube held in the inserted state is moved to the protective member side in parallel with the optical fiber, and when the protective member is inserted into the protective tube, the optical fiber is loosened to bring the protective member into contact with the inner wall of the protective tube. A method for producing an optical fiber coupler, comprising: 2. The method of manufacturing an optical fiber coupler according to claim 1, wherein an application amount of the adhesive is adjusted according to a gap between a lower side of the protection member and an inner surface of the protection tube. 3. An optical fiber coupler manufacturing apparatus in which a plurality of bundled optical fibers are heated and drawn to form a fusion-stretched portion, and the fusion-stretched portion is fixed to a protective member. An optical fiber fixing base that stretches the output optical fiber linearly on both sides of the protective member, and holds the protective member in parallel with the stretched optical fiber, and translates the optical fiber in parallel with the optical fiber. A possible protection member base, and a protection tube base capable of holding a protection tube inserted through the stretched optical fiber therein and held in parallel with the optical fiber, and being movable in parallel with respect to the optical fiber. Wherein the protective member base and the protective tube base are moved in parallel between the optical fiber fixing bases, and the protective member is inserted into the protective tube. . 4. The protection member base and the protection tube base,
It is arranged on a base on which a concave guide groove is formed, and a convex slide protrusion that engages with the guide groove and slides is formed on the lower surface of the protection member base and the protection tube base, respectively. 4. An apparatus for manufacturing an optical fiber coupler according to claim 3, wherein: 5. The protection member base and the protection tube base,
A concave slide groove is provided on the base on which the convex slide rail is formed, and the lower surface of the protection member base and the protection tube base is engaged with the convex slide rail to slide. The apparatus for manufacturing an optical fiber coupler according to claim 3, wherein: 6. The light according to claim 2, wherein the protection tube receiving groove for holding the protection tube has a V-shaped cross section. Fiber coupler manufacturing equipment.