JPH09211250A - Optical fiber connector and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably perform manufacturing operation, make the optical fiber connector small-sized and simple in structure, and cause no breakage at a connection part even at the time of high-output transmission. SOLUTION: Two optical fibers 11 and 12 are held in holders 14 and 15 for holding them by using adhesives 13. The optical fibers 11 and 12 are held projecting from the holders 14 and 15 respectively. The projecting optical fibers 11 and 12 are fixed in the holders 14 and 15 except the abutting connection part 17 by using the adhesives 13. While the end surfaces of the two optical fibers 11 and 12 held in the two holders 14 and 15 are connected abutting against each other, the two holders 14 and 15 are fixed in common in a fixture 16 with adhesives 13. The holders 14 and 15 are not in contact with each other and the fixture 16 is provided without touching the abutting connection part 17 of the optical fibers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber connector for butt-splicing two optical fibers made of different materials at their end faces and a method for manufacturing the same, and more particularly,
The present invention relates to a device adapted to withstand transmission of high-power light.

[0002]

2. Description of the Related Art For connecting silica glass optical fibers to each other,
Usually, fusion splicing is used, but for the connection between the optical fiber made of a material other than quartz glass and the silica glass optical fiber, for example, the connection between the fluoride glass optical fiber and the silica glass optical fiber, these melting points Due to the difference, fusion splicing is not possible, but butt splicing is used. To date, as a butt connection technology, Japanese Patent Laid-Open No. 5-22409 has been proposed.
Those described in JP-A-7-84139 and JP-A-7-84139 have been proposed.

The one disclosed in Japanese Patent Laid-Open No. 224094/1993 is shown in FIG.
As shown in FIG. 2, the ends of the silica glass optical fiber 1 and the fluoride glass optical fiber 2 are held by the ferrules 4 and 5 via the adhesive 3, and the end faces of the ferrules 4 and 5 and the optical fibers 1 and 2 are held. The end faces are processed to be flush with each other, and the end faces of the optical fibers 1 and 2 are aligned so that the coupling loss of the two optical fibers is minimized, and then butt connection is made. Is fixed to the flange 6 with the adhesive 3. According to this, since the end faces of the ferrules are in close contact with each other, a small and strong butt connection can be realized, but the ferrule 4, near the butt connection portion 7,
The adhesive 3 for fixing the optical fibers 1 and 2 to the 5 and the ferrules 4 and 5 is present.

Further, in Japanese Patent Laid-Open No. 7-84139,
As shown in FIG. 5, one reinforcing member 9 having three holes 8 formed therein was prepared, and the silica glass optical fiber 1 and the fluoride glass optical fiber 2 were applied to this reinforcing member 9, and the reinforcing member was also formed. Both the optical fibers 1 and 2 are clamped from the left and right holes 8 of the optical fiber 9 and the end faces of the optical fibers are butt-connected and aligned on the central hole 8 of the reinforcing member 9, and the butt connection part 7 is bonded. The optical fibers 1 and 2 are fixed to the reinforcing member 9 with two or more point adhesives 3 after fixing with the agent 3.
According to this, although the connecting portion is not in contact with the reinforcing member and nothing is present in the vicinity of the connecting portion, the distance from the clamp portion to the butt connecting portion becomes large, and both optical fibers 1, 2 for aligning and fixing are provided. A considerable length is required at the end of the. Further, in order to protect the exposed ends of the optical fibers 1 and 2,
A sealing step will be added after the state shown in the figure.

[0005]

The conventional matching technique described above has the following problems.

(1) As in JP-A-5-224094,
The method of processing both ends of the quartz glass optical fiber and the fluoride glass optical fiber into a ferrule shape, butt-centering, and then fixing can achieve a small and strong butt connection, but the ferrule end faces are in close contact with each other. Therefore, there will be a ferrule near the optical fiber butt joint and an adhesive for fixing the fiber to the ferrule.
When attempting to transmit high-power light, these existing around the connection portion may absorb scattered light generated at the connection portion, and the heat generated by the absorption may damage the connection portion.

(2) As disclosed in Japanese Patent Laid-Open No. 7-83149, a method of aligning a silica glass optical fiber and a fluoride glass optical fiber, fixing both optical fiber end faces, and then fixing them to one reinforcing member is used. There is nothing that absorbs scattered light in the vicinity of the part, but even though it is applied to the reinforcing member,
Since the length of both optical fiber parts that must be clamped or manipulated at the time of centering and fixing becomes long, for optical fibers with a small diameter of 125 μm, fiber holding and centering work during centering It becomes unstable. Further, the centering and the processing after the fixing are large and complicated because a sealing work is required.

An object of the present invention is to solve the above-mentioned drawbacks of the prior art, and to provide an optical fiber connector which is small in size, simple in structure, and free from damage at the connection portion even during high-power transmission. Another object of the present invention is to provide a method for manufacturing an optical fiber connector, which enables stable operation.

[0009]

The optical fiber connector of the first invention is an optical fiber connector for butt-connecting two optical fibers made of different materials at their end faces. Are independently held by two holders, and at least one of the optical fibers is projected from the holder, and the projected one optical fiber and the other end of the other optical fiber are held in a state of being butt-connected to each other. Two holders are fixed to each other in a non-contact manner in common with a fixture, and the fixture is provided in non-contact with the butt joint of the optical fiber.

According to this, both the optical fibers to be connected are held by a holder made of a tube or the like having a hole of about the outer diameter of both optical fibers before alignment, and the holder is operated. As a result, it is possible to hold and align the optical fiber without directly touching the optical fiber during the alignment, and it is possible to improve the holding stability. The optical fiber may be held by a V groove or the like instead of being inserted and held in a tube or the like. Also,
By connecting at least one of the optical fibers in a state of protruding from the holder, the holders are not in contact with each other, and the holder is not present on the butt joint portion. There is little absorption of scattered light, which is the cause of damage to the, and the cooling effect of heat generated by absorption is also high. Further, since it is only necessary to fix the holder holding the optical fiber to the fixture, the connector can be downsized.

An optical fiber connector according to a second aspect of the present invention is the optical fiber connector according to the first aspect, wherein the two optical fibers are any one of a fluoride glass optical fiber, a chalcogenide glass optical fiber and a phosphate glass optical fiber. It is composed of an optical fiber. This is particularly effective when a fragile material such as a fluoride glass optical fiber and a strong material such as silica glass optical fiber are butted and connected.

An optical fiber connector according to a third aspect of the present invention is the optical fiber connector according to any one of the first and second aspects, wherein the holder and the fixture are made of borosilicate glass tubes.
When the holder and the fixture are made of borosilicate glass whose coefficient of thermal expansion is close to that of the optical fiber, stress is not applied to the optical fiber even when the temperature changes, so that the stability of the connection portion can be further improved.

An optical fiber connector according to a fourth invention is the optical fiber connector according to any one of the first to third inventions, wherein an adhesive is used to hold the optical fiber to the holder and to fix the holder to the fixture. is there. Since the adhesive is used for holding and fixing to the holder and the fixture, the holding and fixing are easier than in the case of laser welding.

An optical fiber connector according to a fifth invention is the optical fiber connector according to any one of the first to fourth inventions, wherein the adhesive is an epoxy resin. When an epoxy resin is used as the adhesive, stress is not applied to the optical fiber even when the temperature changes, so that the stability of the connection portion can be further improved.

A method of manufacturing an optical fiber connector according to a sixth aspect of the present invention is a method of manufacturing an optical fiber connector for butt-connecting two optical fibers made of different materials at their end faces. The optical fibers are independently held by the two holders, at least one of the optical fibers is projected from the holder, and the end faces of the one projected optical fiber and the other optical fiber are clamped by the two holders. By aligning the two optical fibers so that the coupling loss of the two optical fibers is minimized, and then butt-connecting them. After the butt-connecting, the holders are not in contact with each other and the fixtures are the optical fibers. The two holding members are commonly fixed by the fixing members so that they are not in contact with the butt connection portion.
According to this, since the butt connection and the centering can be performed by operating the clamped holder instead of directly operating the optical fiber, the connection and the centering work are stabilized.
Further, after the centering, the connection is completed by fixing the holder to the fixture, so that the connecting process is simple.

A method of manufacturing an optical fiber connector according to a seventh aspect of the present invention is a method of manufacturing an optical fiber connector for butt-connecting two optical fibers made of different materials at their end faces. The optical fibers are independently held by the two holders so as to protrude from the holders, the optical fibers protruding from the holders are covered with an adhesive, and the end faces of the two optical fibers covered with the adhesive are mirror-finished. Until the end of the two optical fibers protruding from the adhesive is dissolved by dipping it in a solvent until the optical fiber protrudes from the adhesive. After the holder is clamped and operated so that the coupling loss of the two optical fibers is minimized, butt connection is made, and after the butt connection, the holders are not in contact with each other, and Light fixture with two fixtures Butt so the connecting portion and the non-contact of Iba, is obtained so as to secure the two holder common to the fixture. According to this, since the optical fiber held in the holder is covered with the adhesive and a part of the adhesive is melted so that the optical fiber is projected from the holder, the optical fiber from which the adhesive is not adhered is retained. The fiber can be easily ejected.

An eighth aspect of the present invention provides a method for manufacturing an optical fiber connector, which is a method for manufacturing an optical fiber connector for butt-connecting two optical fibers made of different materials at their end faces, one of which is made of a strong material. The optical fiber of No. 2 is preliminarily broken and held in the first holder so that it protrudes from the holder, and the root of one optical fiber protruding from the holder is fixed with an adhesive, and the other optical fiber of weak material Is held by the second holder so as to protrude from the holder, and the optical fiber protruding from the holder is covered with an adhesive,
The end face of the optical fiber covered with this adhesive is polished until it becomes a mirror surface, and the end face of one optical fiber that has been subjected to fracture processing and the end face of the other optical fiber that has been mirror-finished are operated by clamping two holders. After aligning so that the coupling loss of the above two optical fibers becomes the minimum by butt connection,
After the butt connection, the two fixtures are commonly fixed by the fixtures so that the holders are not in contact with each other and the fixtures are not in contact with the butt joint of the two optical fibers. It is the one. According to this, the other optical fiber having a weak material is covered with an adhesive agent to be protected, so that it is not necessary to protect the optical fiber in an inert gas atmosphere or the like.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 shows a first embodiment of the optical fiber connector according to the present invention. The optical fiber connector is formed by butt-connecting two optical fibers 11 and 12 made of different materials at their end faces. The two optical fibers 11 and 12 are independently held by holders 14 and 15 for holding the ends 11a and 12a. The holders 14 and 15 are, for example, both optical fibers 1
It is composed of a tube with an opening having an inner diameter slightly larger than the outer diameters of 1 and 12, and the optical fibers 11 and 12 are inserted and fixed by interposing an adhesive agent 13 in the tube.

The tips 11b, 1 of the optical fibers 11, 12
2b are held by protruding substantially the same amount from the holder tips 14a and 15a. Protruding tip 11b, 12
b is covered with an adhesive 13 except near the end surface of the optical fiber and fixed to the holder tips 14a and 15a. Tip 11
Since b and 12b are fixed with the adhesive 13, the tip portion 11b,
12b can be stably held. Further, since the tip ends 11b and 12b of the optical fiber except for the vicinity of the end face of the optical fiber are covered with the adhesive 13, the optical fiber can be protected, which is particularly effective in the case of a weak optical fiber.

Two holders 14 and 15 for holding two optical fibers 11 and 12 whose end faces are butted and connected are commonly fixed to a fixture 16 by an adhesive 13. Holder 14,
Since the optical fiber tip portions 11b and 12b are projected from the holder tips 14a and 14b, the area 15 is not in contact. In addition, the fixture 16 is the butt joint 1 of the optical fiber.
7 is provided in a non-contact manner. The fixture 16 is a holder 14, 1
As with 5, they can be constructed of perforated tubes with an inside diameter slightly larger than their outside diameters to fit into the retainers 14,15.

The optical fiber connector thus constructed has the holder 1 near the optical fiber butt joint portion 17.
4, 15 and the holders 14, 15 with the optical fibers 11, 12
Since there is no adhesive 13 for fixing the optical fiber 11, even if high-power light is transmitted to the optical fibers 11 and 12, the connecting portion 17
The connection part 17 will not be damaged by the heat generated by the absorption of the scattered light generated in 1. Also, since only the holder and the fixture are basically required, the structure is small and the structure is simple.

In the above-mentioned embodiment, the tip portions 11b and 12b of both optical fibers are the holder tip 14a,
Although the case where it projects from 15a has been described, it suffices that the amount of the holder and the adhesive in the vicinity of the connecting portion 17 be small, so that the tip of at least one of the optical fibers should protrude from the tip of the holder. Further, as long as it is only the end face of the optical fiber, it does not become a factor for absorbing scattered light, so a refractive index matching agent or a refractive index matching fixing adhesive may be applied. Furthermore, the end surface of the optical fiber may be oblique.

In order to manufacture the above-mentioned optical fiber connector, the ends 11 of the two optical fibers 11 and 12 are aligned before alignment.
a and 12a are independently held by the two holders 14 and 15 with the adhesive 13, and the tip portions 11b and 12b of the respective optical fibers are held.
Are projected from the holder tips 14a and 15a.
Then, as shown in FIG. 2, the adhesive 13 is applied so as to cover the tip portion 11b of the optical fiber protruding from the holder tip 14a.
After being fixed by ((a)), polishing is performed until the end surface becomes a mirror surface ((b)), the tip 14a of the holder 14 is immersed in a solvent or the like, and only the adhesive 13 is dissolved. The tip 11b of the optical fiber 11 is projected from the adhesive 13 ((c)). This is the other optical fiber 12
Is also common.

Then, after the two holders 14 and 15 are clamped and the end faces of the two optical fibers held by the holders 14 and 15 are butted and connected, they are aligned by an aligning jig. After aligning, make sure that the holders 14 and 15 are not in contact with each other.
Further, in order that the fixing tool 16 does not come into contact with the butt joint portion 17 of the optical fiber, the two fixing tools 14 and 1 are fixed by the fixing tool 16.
5 are commonly fixed with an adhesive 13.

As described above, the optical fiber end 11a,
11b is held by holders 14 and 15, and holders 14 and 15
Since the optical fiber is clamped to perform the centering and fixing work, the fiber holding and the centering work at the time of the centering are easier than the case where the optical fiber is directly clamped to perform the work. Further, since the tips protruding from the holders 14 and 15 can be shortened, even if the optical fiber is very thin, the fiber holding and aligning work during aligning becomes very stable. Further, the holders 14 and 15
If a pipe is used as the fixture 16, the holders 14 and 15 are inserted and fixed in the fixture 16 to form a double pipe structure, so that the sealing work is naturally completed and workability is further improved. In this case, the space 18 formed between the holder and the fixture may be filled with an inert gas.

Although not clearly shown in the figure, the portion outside the holder is a core wire with a secondary coating,
The inner part of the holder of the optical fiber is a wire with a primary coating.

(Second Embodiment) FIG. 3 shows a second embodiment of the optical fiber connector according to the present invention. This is an example of connection in which either one of the connections is made, specifically, the optical fiber having the stronger material strength is projected from the tip of the holder and the optical fiber having the weaker material strength is not substantially projected.

The end portions 11a and 12a of the optical fiber 11 having a strong material strength and the optical fiber 12 having a weak material strength are held and fixed to the holders 14 and 15 each made of a tube or the like before alignment. At this time, the tip portion 11b of the optical fiber 11 having a strong material strength projects from the holder tip 14a, but the tip portion 12b of the optical fiber 12 having a weak material strength is slightly smaller than the holder tip 15a in order to protect the optical fiber. Make it stick out or be flush with the holder tip 15a.

The tip portion 1 of the optical fiber 11 having a strong material strength
In order to make 1b protrude from the holder tip 14a, the optical fiber end face is cut beforehand to hold it by protruding from the holder tip 14a, and the root of the protruding tip 11b is held. It is fixed with an adhesive 13. On the other hand, the optical fiber 12 whose material strength is weak,
Optical fiber tip 12 protruding from the holder tip 15a
After being fixed with the adhesive 13 so as to cover b, the end face is polished while the end face is mirror-finished while being covered with the adhesive 13. Polishing the end face while covering with the adhesive 13
This is to protect the optical fiber from being damaged, and when the optical fiber 12 having a weak material strength is protected by the adhesive 13, the inert gas need not be filled.

[0031]

【Example】

(Embodiment 1) A first embodiment will be described with reference to FIG.
One optical fiber 11 is made of a quartz optical fiber having high material strength, its core diameter is 3 μm, and numerical aperture is 0.37.
The outer diameter is 0.125 mm. The other optical fiber 12 is made of a fluoride glass optical fiber having low material strength and high brittleness, and has a core diameter of 1 μm, a numerical aperture of 0.6, and an outer diameter of 0.125 mm. The end faces of both optical fibers were processed by the steps shown in FIG.

First, in the first step (a), the holder 14 is made of a borosilicate glass tube having an outer diameter of 2 mm, an inner diameter of 0.127 mm, and a length of 15 mm, and the tip portion 11b of the optical fiber 11 is attached to this by about 1 mm. The end 11a of the optical fiber 11 was inserted so as to protrude, and fixed with an epoxy resin serving as an adhesive 13. Further, the tip portion 11 of the optical fiber 11
Epoxy resin was applied so as to cover b and cured. As the second step (b), polishing was performed until the end face of the optical fiber 11 appeared and became a mirror surface. As the third step (c), the holder tip 14a is dipped in a solvent to form the optical fiber 11
Until the tip 11b of the
The epoxy resin was dissolved.

The fixture 16 has an inner diameter of 2.1 mm and an outer diameter of 3 m.
A borosilicate glass tube having a length of m and a length of 7 mm was used. After the resin is melted, the holder 14 for the one optical fiber 11
The fixture 16 was passed through the holder and the holders 14 and 15 for both optical fibers 11 and 12 were attached to the centering jig. Fixing device 3 after alignment
Was moved to the connecting portion 17 as shown in FIG. 1 and fixed with an epoxy resin as the adhesive 13.

When a high-power laser with an output of 200 mW, which is about twice as much as that in actual use, was transmitted to the optical fiber connector thus manufactured by continuous light having a wavelength of 1 μm, the conventional structure as shown in FIG. Although the connection portion was damaged to some extent and the laser light was no longer propagated, in the structure of this example, the laser light was stably propagated for 2 hours or more.

(Embodiment 2) Explaining the second embodiment with reference to FIG. 3, the optical fibers 11, 12 used for connection, the holders 14, 15 and the fixture 16 are the same as those in the first embodiment.

The end face of the one optical fiber 11 having a strong material strength was formed by breaking the end face of the optical fiber in advance, and the protruding root was fixed with an epoxy resin in a state of protruding from the holder tip 14a.

The end face of the other optical fiber 12 having a weak strength was processed only up to the first step (a) and the second step (b) as shown in FIG. That is, first, the outer diameter is 2 m.
m, an inner diameter of 0.127 mm, and a length of 15 mm, the end 12a of the optical fiber 12 is inserted into a borosilicate glass tube,
The epoxy resin was fixed so that the tip 11b of the optical fiber 11 protruded from the glass tube by about 1 mm. further,
Polishing was performed until the end surface of the optical fiber 11 appeared and became a mirror surface.

Since the other optical fiber 12 is fragile, in order to protect it, the end face of the optical fiber is originally ground together with the holder 15 so as to be flush with the tip 15a of the holder. Better. However, if the polishing is performed together, only the optical fiber 12 having a weak strength is polished, so that the polishing cannot be performed together. Therefore, as described above, the optical fiber tip portion 12b is projected from the holder tip 15a, protected by an epoxy resin, and then polished.

The subsequent steps were the same as in Example 1, and when continuous light with a wavelength of 1 μm and a high-power laser with an output of 200 mW were transmitted to the obtained optical fiber connector, it took 30 minutes with the structure shown in FIG. Although the connection portion was damaged to some extent and the laser light was no longer propagated, in the structure of this example, the laser light was stably propagated for 2 hours or more.

[0040]

According to the optical fiber connector of the present invention, 2
It is compact and simple in structure because it only requires one holder and fixture. Also, since the holder and fixture are not in contact with the butt joint, heat dissipation is high, and scattering when high-power laser is incident It is possible to effectively prevent damage to the connection portion due to heat due to light absorption.

According to the method for manufacturing an optical fiber connector of the present invention, since the butt connection and the alignment of the optical fibers can be performed by using the holder, the work can be stably performed.

[Brief description of drawings]

FIG. 1 is a sectional view of an optical fiber connector showing a first embodiment of the present invention.

FIG. 2 is a process diagram of an optical fiber end face processing according to the first embodiment.

FIG. 3 is a sectional view of an optical fiber connector showing a second embodiment of the present invention.

FIG. 4 is a cross-sectional view of an optical fiber connector showing a conventional example.

FIG. 5 is a cross-sectional view of an optical fiber connector showing another conventional example.

[Explanation of symbols]

 11 one optical fiber 12 the other optical fiber 13 adhesive 14 holding tool 15 holding tool 16 fixing tool 17 butt joint

Claims (8)

[Claims] 1. An optical fiber connector for butt-splicing two optical fibers made of different materials at their end faces, wherein the two optical fibers are independently held by two holders, respectively. At least one optical fiber protrudes from the holder, and the two holders that hold one of the protruding optical fibers and the other optical fiber in a state where the end faces of the other optical fibers are butted and connected to each other are common to the fixture without contacting each other. An optical fiber connector, wherein the optical fiber connector is fixed, and a fixture is provided in a non-contact manner with the butt connection portion of the optical fiber. 2. The optical fiber connector according to claim 1, wherein the two optical fibers are a fluoride glass optical fiber, a chalcogenide glass optical fiber, a phosphate glass optical fiber, and a silica glass optical fiber. . 3. The optical fiber connector according to claim 1, wherein the holder and the fixture are made of a borosilicate glass tube. 4. The optical fiber connector according to claim 1, wherein an adhesive is used to hold the optical fiber to the holder and to fix the holder to the fixture. 5. The adhesive is an epoxy resin.
5. The optical fiber connector according to any one of 4 to 4. 6. A method of manufacturing an optical fiber connector for butt-splicing two optical fibers made of different materials at their end faces, wherein the two optical fibers are independently provided in two holders. Hold at least one optical fiber protruding from the holder, and the end faces of the protruding one optical fiber and the other optical fiber are clamped by two holders to minimize the coupling loss of the two optical fibers. Butt connection, and then, after the butt connection, make sure that the holders are not in contact with each other and that the fixtures are not in contact with the butt joint of the optical fiber. A method of manufacturing an optical fiber connector, characterized in that two holders are commonly fixed. 7. A method of manufacturing an optical fiber connector for butt-splicing two optical fibers made of different materials at their end faces, wherein the two optical fibers are provided so as to protrude from a holder. The optical fiber protruding from the holder is covered with an adhesive, and the end faces of the two optical fibers covered with the adhesive are ground to a mirror surface. By immersing it in the adhesive until the optical fiber is in a state of sticking out from the adhesive, and clamping the two end faces of the two optical fibers sticking out of the adhesive with two holders to operate it. After aligning so that the coupling loss of two optical fibers is minimized, butt connection is made. After butt connection, the holders are not in contact with each other and the fixtures are butt connection of two optical fibers. I will not be in contact with the department A method of manufacturing an optical fiber connector which is characterized in that so as to secure the two holder common to the fixture. 8. A method of manufacturing an optical fiber connector for butt-splicing two optical fibers made of different materials at their end faces, wherein one optical fiber having a strong material is preliminarily fracture-processed and then a holding tool is used. While holding the first holder so that it sticks out,
The root of one of the optical fibers protruding from the holder is fixed with an adhesive, the other optical fiber of weak material is held by the second holder so as to protrude from the holder, and the optical fiber protruding from the holder is also held. Is covered with an adhesive, and the end face of the optical fiber covered with this adhesive is polished until it becomes a mirror surface, and two holders are attached to the end face of one optical fiber that has been ruptured and the other end of the optical fiber that has been mirror-finished. After clamping and operating so that the coupling loss of the above two optical fibers is minimized, butt connection is made. After butt connection, the holders are not in contact with each other and the fixtures are A method of manufacturing an optical fiber connector, characterized in that two holders are commonly fixed by a fixture so as not to come into contact with the butt splicing portion of the two optical fibers.