JPH07128539A - Optical fiber connection method, optical fiber connection part concentrating structure, and load test method for optical fiber connection part - Google Patents

Abstract

(57) [Abstract] [Purpose] Regarding the method of connecting optical fibers, to melt and connect a large number of optical fibers at the same time with high reliability. [Structure] A tip end portion of a coating 42 of each of a plurality of optical fibers 41 is removed, and the tip end portions 43 of the coating that have been removed are on the same plane, and adjacent optical fiber intervals are set to an outer diameter of the coating 42 portion. A first optical fiber array 49 aligned and held in a parallel state that is closer than the size.
And the opposing second fiber array are fused together in a discharge arc with their respective fiber end faces aligned and facing each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for connecting optical fibers, a structure for reinforcing a line collecting structure of optical fiber connecting portions, and a method for testing a load on the optical fiber connecting portions.

In an optical communication system using an optical fiber as a transmission line, there is no need to use only one or two optical fibers.
Optical signal transmission by a large number of optical fibers has been widely used in recent years because a larger amount of communication lines can be secured.

Due to the advancement and development of technology, there is a strong demand for a higher integration and a higher density of the repeater unit main body to cope with a larger amount of communication lines, and it is possible to meet such a demand. .

In particular, a submarine repeater using a submarine optical cable is required to have long-term reliability. Therefore, a manufacturing method and a testing method, etc., with which high reliability can be obtained by a high quality technique are required. Currently, a maximum of 6 cores is used as the optical fiber cable, but in the future, the development of an optical fiber cable in which a larger number of fibers of several tens of fibers are installed will be advanced.
As described above, the present invention enables batch processing of a large number of optical fiber connecting portions, and enables highly reliable and efficient work.

[0005]

2. Description of the Related Art A conventional optical fiber connection removes a coating on an end portion of an optical cable to expose an internal optical fiber core wire,
With the coating on the ends of the optical fiber cores removed, the end faces of a pair of optical fiber wires are made to face each other, mounted on a discharge type welding device and aligned to melt the end parts of the optical fiber with the heat generated by the arc of discharge. Those that are automatically fusion-bonded can be connected reliably.

After the above-mentioned connection, a protective coating is applied to the portion exposed in the state of the optical fiber strand with a synthetic resin, and a proof test is performed to confirm the reliability. I was trying to reinforce.

Since such a connection is a pair-wise connection of the optical fiber core wires and the working time required for the pair of connections is about one hour, many connections require that much time, which is extremely inefficient. That was true.

[0008] However, there is a device in which a large number of optical fibers can be collectively melted and connected to each other. This is the tape-shaped optical fiber cable 1 shown in FIG. This tape-shaped optical fiber cable 1 is in parallel with the optical fiber core wire 2
Are housed in the jacket 3.

The coating 4 of the optical fiber core wire 2 has a circular cross section with a diameter d ₁ of 0.25 mmφ, and as shown in FIG.
Is peeled off to expose the optical fiber strands 5 of the glass portion, and the optical fiber strands 5 are held by a holder of a connecting device by a discharge arc (not shown). The diameter d ₂ of the optical fiber 5 is 0.125 mmφ, and the total lateral width B ₁ of the 12 arrays 6 is about 3 mm.

With respect to the optical fiber end surface of the first optical fiber array 6, a similar second optical fiber array (not shown) is also held by a holder, and the optical fiber end surfaces are arranged to face each other. The positions are aligned so that the respective optical axes coincide with each other.

When a discharge voltage is applied to the left and right discharge electrodes 7 and 8 in FIG. 2 (b) to cause discharge, a spindle-shaped discharge arc as indicated by a dotted line is generated. The range of the dotted line shows the temperature distribution, and it is understood that the center part has the highest temperature and the temperature becomes lower toward the outside. However, the temperature of the central portion is narrower in the lateral direction and is wider toward the outer side.

Therefore, when the optical fiber array 6 is positioned at the central portion, the temperature of each optical fiber element 5 becomes non-uniform, the fusion state varies, and good connection reliability cannot be obtained. Therefore, the same temperature condition can be obtained by performing the electric discharge fusion as a position where the substantially same temperature width of the peripheral portion as shown in FIG. A good connection state will be obtained by being added to each of the optical fiber strands 5. Then, the connected optical fiber array 6 is removed from the holder of the connecting device.

Since the coating of the connecting portion of the optical fiber is peeled off, it is necessary to take reinforcement measures to protect it from various external forces. Such a reinforcing structure is connected with reference to FIG.

The perspective view of the cross-sectional state of FIG. 1 (a) shows a state in which it is applied to the connecting portion of the pair of optical fibers 11, and the connecting portion is covered with a heating type adhesive 12 made of synthetic resin, and stainless steel is applied to this. A bar-shaped core material 13 such as steel is added. Further, the heat-shrinkable tube 14 is arranged outside these, and the heat-shrinkable tube 14 is heat-shrinked from the outside by hot air or the like.

With heating, the adhesive 12 is softened and melted to cover the periphery of the optical fiber 11, and the optical fiber 11 is added to the core material 14 and a gap exists between the core 12 and the heat-shrinkable tube 14 contracted from the periphery. It works to fill the space so that it is not done. The state shown in the drawing shows the state immediately before being contracted in this way.

FIG. 9 is a perspective view of a similar cross-sectional state of FIG.
It is shown to reinforce the connecting portion of the tape-shaped optical fiber cable 15 similar to that described in (1). Around the optical fiber cable 15, a connecting portion is covered with a heating adhesive 16 made of synthetic resin, and a rod-shaped core material 17 such as a semi-cylindrical ceramic is also added. The heat-shrinkable tube 18 is placed outside the heat-shrinkable tube 18 and the heat-shrinkable tube 18 is heat-shrinked from the outside by hot air or the like.

With heating, the adhesive 16 is softened and melted to cover the periphery of the optical fiber cable 15, and the optical fiber cable 15 is attached to the flat surface of the core material 17 and the heat shrinkable tube 18 is contracted from the surroundings. Fill the space so that there are no gaps between them. The state shown in the drawing shows the state immediately before being contracted in this way.

The optical fiber shown in FIG. 10 (a) has a single core and is accommodated in a general optical fiber cable or an optical fiber cable for submarine relay, and has an outer diameter of the optical fiber core wire. The d ₃ is about 0.4 mmφ to 0.9 mmφ, which is highly reliable. However, the coating outer diameter d ₁ shown in FIG. 9 is 0.25 m.
The mφ tape-shaped optical fiber cable is not used for such an optical fiber cable for submarine relay, but is mainly used for a land-based device.

FIG. 11 is a cross-sectional view of the optical submarine repeater 21 as shown in FIG. 11A, in which the optical fiber connecting portion accommodated in the optical fiber extra length accommodating portion in the pressure resistant casing that withstands water pressure on the seabed is attached. The fixing is performed at two places on the right and left sides in the drawing, and three pieces are attached to each. The right side of the drawing shows the state where the pressing plate is not attached, and the left side shows the state where the pressing plate 22 is attached.

The connection reinforcing portion 25 of the optical fiber 24 is accommodated in the groove of the mounting portion 23 on the right side. The connection reinforcing portion 25 has the same structure as that described with reference to FIG. 10A, and the optical fiber 24 connects the optical fiber inside the submarine repeater and the optical fiber derived from the submarine optical cable. It is the connected part.

The perspective view shown in FIG. 11 (b) is a connection reinforcing portion 29 in which one optical fiber 27 and the other optical fiber 28 are connected to the left and right of the cylindrical winding frame 26. The optical fibers 27 and 28 are wound in a symmetrical direction. Such a thing is applied and implemented in the joint box of the optical fiber cables which are not equipped with the signal amplifying device for the submarine relay.

The single-core optical fiber core wire 31 shown in FIG. 12A is accommodated in an optical fiber cable for submarine relay, and the outer diameter d ₄ of the coating 32 is, for example, 0.9.
The diameter d ₅ of the optical fiber wire 33 with the coating 32 removed by mmφ is 0.125 mmφ.

If a large number, for example, 12 of these optical fiber core wires 31 are aligned and arranged in an array as shown in FIG. 6B (there are six representative drawings), the width B ₂ thereof is about 10 mm. It is impossible to perform fusion connection by electric discharge because the same temperature width range suitable for fusion cannot be secured. Moreover, it takes a lot of time to connect them individually, and even more, the reinforcement structure as shown in FIG. 10 (a) cannot be accommodated in the mounting portion in the undersea repeater. It will also happen.

When a large number of optical fibers are aligned as shown in FIG. 9 (b) or FIG. 12 (b) and the opposing optical fibers are fused and connected, the optical fiber tip surface It is essential to position them accurately and to match the optical axes.

Therefore, as shown in the partial perspective view of FIG. 13A, a block 36 having a large number of V-grooves 35 formed in an accurate and parallel state at equal intervals is stripped and stripped of light. Each of the fiber strands 37 is placed (only one is shown in the figure), and the optical fiber array is pressed and fixed so as to make line contact with the V-shaped surface on average.

However, due to the difference in the diameter of the optical fiber strands 37 as shown in the front view of FIG. 2B, when the optical fiber strands 37 having a small diameter are present, the optical fiber strands are more than the apex of the V groove 35. In some cases, the surface of the line 37 becomes low, and the pressing action of the pressing member (not shown) does not affect the positioning, resulting in insufficient positioning.

Further, as shown in the partial perspective view of FIG. 7C and the front view of FIG. 3D, when a sufficient pressing action is not exerted, only one slope of the V groove 35 is provided with the optical fiber strand. Since there is a possibility that 37 will come into contact,
Inconvenience may occur that the optical axis position does not match the optical fiber strand of the other party.

In addition to this, it is invisible to directly contact the optical fiber wire 37 with the V groove 35 and press and fix it with a pressing member, and minute scratches called so-called microcracks are formed on the optical fiber wire 37. There is also an inconvenience that may occur on the surface of the optical fiber and grow over a long period of time, causing breakage of the optical fiber.

When the optical fibers are fusion-spliced, it is confirmed by a proof test method whether or not the connecting portion is in a sufficiently connected state before being reinforced by the reinforcing structure. In the case of connecting a large number of optical fibers, the time required for collective operation is improved.

FIG. 14A is a diagram showing the principle of such a proof test method. That is, in this case, the connecting portion of the four optical fibers A, B, C, D is arranged in the center,
The upper and lower sides are clamped and fixed by clamps 37 and 38 of a test device (not shown). In this state, the test apparatus is operated to move the clamps 37 and 38 so as to relatively separate them from each other in the arrow direction.

The distance, the magnitude of the force, and the time of this movement are set to predetermined values so that the optical fiber is stretched at a predetermined ratio. Such a value is set by experiments and calculations based on theory, and it does not break or adversely affect the optical fiber, and can sufficiently guarantee the reliability of the connection part. Such tests are established as the theory for optical fiber connections.

However, the four optical fibers A, B,
The clamps 37 and 38 are mounted and fixed in such a state that the test force acts on each of C and D with an equal value, but the test force is not always applied uniformly. For example, the optical fibers A and B are not always applied. , C, D are attached and fixed in such a manner that the tension force is gradually relaxed, the situation shown in FIG.

That is, the vertical axis represents the magnitude of the force, and the horizontal axis represents the passage of time. If the optical fiber is released, the tension applied to each optical fiber becomes lower in order, and as shown in FIG. (B), all the optical fibers other than the optical fiber A cannot be given a predetermined value. There is. On the contrary, if a total force is applied to all the four optical fibers evenly, the excessive acting force may concentrate on the optical fibers A.

[0034]

DISCLOSURE OF THE INVENTION The present invention is intended to solve the above-mentioned problems of the prior art. The problem is to fuse a large number of single-core optical fibers having high reliability all together. The present invention also provides a connecting method for connecting and disconnecting, and also provides a concentrating reinforcing structure for the optical fiber connecting portion by making the single-core optical fiber after connection compact. Other aspects include providing a rational load test method for reliability testing of fiber optic connections, as well as a combination of various aspects.

[0035]

According to the first means, the coating tip portions of the plurality of optical fibers are removed and the coating is performed. A first optical fiber array which is aligned and held in a parallel state in which the removed distal ends of the optical fibers are on the same plane, and the distance between adjacent optical fibers is closer than the outer diameter dimension of the covering portion. The second optical fiber array is an optical fiber connecting method in which the respective optical fiber end faces are aligned and opposed to each other, and are collectively fused and connected in a discharge arc.

According to the second means, the coated portion of the tip is melted and removed while the coated portions of the plurality of optical fibers are aligned and held, and the coated portion including the melted and removed portion is covered with a thin synthetic resin for protection. After forming the coating, the optical fiber portion on which the protective coating is formed is aligned and held in parallel in an adjacent state in which the optical fiber portion is closer than the outer diameter of the coating portion, and the protective coating on the tip portion is melted and removed for a predetermined length. A first optical fiber array and a second optical fiber array facing each other, which are formed by a step of aligning the removed optical fiber tip end faces in a straight line, are collectively arranged with their respective optical fiber end faces aligned and facing each other. Then, the optical fibers are connected by fusion in a discharge arc.

According to the third means, after the protective synthetic resin coating is applied to the connecting portion of the optical fiber connected by the connecting method of the first means or the second means, the adhesive is applied around the core material. Of the above-mentioned reinforcing members are arranged in parallel along the longitudinal direction of the periphery of the reinforcing member, and the heat-shrinkable tube is covered on the outer periphery of the connecting section so as to shrink the heat-shrinkable tube by heating and the optical fiber around the core material. This is a concentrating structure for concentrating the optical fiber connecting portions so that the connecting portions are fixed together.

According to the fourth means, there is provided a load test method for the connecting portion of the optical fiber connected by the connecting method of the first means or the second means, wherein the connecting portion of the optical fiber is protected by After the synthetic resin coating is applied, both sides of the connection part are attached to and held by the test device, and the test device is separated to give a pulling force to the optical fiber, whereby a uniform pulling force is given to each of the plurality of optical fibers. As a condition, fix the optical fiber to the batch test device,
In this state, a load test method is applied to the optical fiber connecting portion in which a predetermined load is applied for a predetermined time.

According to the fifth means, the line concentration reinforcing structure of the optical fiber connecting portion is applied to the optical fiber after performing the load test method of the fourth means and confirming that there is no abnormality. Is.

[0040]

According to the construction means of the present invention, according to the first means, even in an optical fiber having a large coating diameter, the adjacent optical fiber strands can be sufficiently close to each other for fusion splicing. A highly reliable connection state can be obtained due to the range of the uniform temperature portion in the discharge arc.

According to the second means, even in the case of an optical fiber having a large coating diameter, the adjacent optical fiber strands can be sufficiently close to each other to be fused and spliced together. By forming a thin protective film on and holding it in alignment, the optical fiber wires do not come into direct contact with the holding part, so that inconveniences such as microcracks are prevented and protected, and a highly reliable connection part is obtained. be able to.

According to the third means, since the connecting portions of the optical fibers are arranged along the longitudinal direction around the reinforcing member having the rod-shaped core material at the center, a large number of optical fibers can be collectively gathered. It is possible and the concentrated state has a small cross section, which enables efficient attachment and accommodation in the accommodation section.

According to the fourth means, before applying a test load of a predetermined value in a state where the optical fiber is held by the supporting portion of the test apparatus, a load of a predetermined value or less is applied by the supporting portion to all optical fibers. Causes a state of causing slippage between the optical fiber and the supporting portion, and by holding the optical fiber in the supporting portion in a fixed state in that state, an equal test load is applied to all optical fibers, and a large number of optical fibers are applied. The test can be surely performed efficiently and with high reliability.

According to the fifth means, a large number of optical fibers confirmed to be in a good connection state by the test by the fourth means are line-reinforced by the third means, so that reliability is improved. It is possible to compactly reinforce the optical fiber connection part with good compactness.

[0045]

EXAMPLES The method of connecting optical fibers, the concentrating structure of the optical fiber connecting portions of the present invention, and the method of testing the load on the optical fiber connecting portions according to the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, which is shown in FIG.
The perspective view of Fig. 1 shows a state in which it is possible to align adjacent ones of the optical fiber strands with a minute interval. That is, the diameter of the coating 42 portion of the optical fiber core wire 41 is 0.9 mmφ in this embodiment, and the diameter of the portion of the optical fiber strand 43 at the tip portion of the coating 42 from which peeling has been removed is 0.1.
It is 25 mmφ.

The portions of the optical fiber strands 43 are arranged in a staggered manner so as to have a vertical relationship as shown in the figure, and the tip is bent so as to be positioned in the intermediate portion as well shown in FIG. Align them so that the directions are parallel and on the same plane in plan view.

Since the coating 42 portion has a zigzag shape when viewed from the front, the coating 42 portions of the optical fiber core wires 41 adjacent to each other in the tip parallel portion of the optical fiber strand 43 have a vertical relationship, and the optical fibers adjacent to each other in the lateral direction. The core wire 41 is separated from the upper and lower optical fiber core wires 41 by one and the other optical fiber wires 43 are arranged.
Thus, the adjacent fiber pitches of the optical fiber strands 43 can be 0.45 mm or less.

In this embodiment, the upper and lower stages are two in side view,
By arranging the optical fibers 43 in stages, it is possible to set the adjacent pitch interval of the optical fiber wires 43 to 0.3 mm or less.

In principle, the tips of the optical fiber wires 43 aligned in parallel are placed on the blocks 36 having the V-grooves 35 at predetermined intervals as shown in FIG. The tips are positioned at precise predetermined pitch intervals by bringing them into contact with the V grooves 35 by pressing tools not shown. Although the optical fiber strand 43 extends in the rear direction in FIG. 6C, it is shown as a length up to the V groove in order to facilitate understanding of the shape of the V groove 35.

A large number of optical fiber core wires 41 are attached and fixed to a clamp 45 as shown in FIG. 2 (a), and the tips are put in a chemical 46 such as methylene chloride or sulfuric acid as shown in FIG. 2 (b). It is inserted and each coating is melted and removed at once. In this way, the optical fiber strands 43 are removed without being mechanically brought into contact with each other, so that the optical fiber strands 43 are not affected and the quality becomes favorable.

As shown in FIG. 3A, a thin synthetic resin film is applied to the portion of the optical fiber wire 43 from which the coating has been removed, as shown in FIG. 3A, to form a protective film 48. This protective coating 48 is achieved by applying the "optical fiber fusion splicing method" disclosed in Japanese Patent Application Laid-Open No. 62-240911 filed and filed by the present inventor. That is, a UV-curable synthetic resin, for example, a UV-curable acrylate resin is densely and uniformly coated to a thickness of about 10 μm.

The tip of the optical fiber wire 43 having the protective coating 48 formed thereon is removed to a predetermined length by using the above chemicals to remove the protective coating 48. In this way, the remaining portion of the protective film 48 is blocked by the block 36 as shown in FIG.
By placing it on the V-groove 35, there is no possibility of microcracks. In this state, a pressing tool (not shown) is pressed from above to fix and position.

Then, in order to align the tip end surface of the optical fiber strand 43 with a straight line, the tip end portion is slightly cut and removed using a known optical fiber cutter so that the end face is aligned with a straight line. Also in this figure (b), the optical fiber strand 43 extends in the rear direction, but it is shown as the length up to the V groove in order to facilitate understanding of the shape of the V groove 35.

FIG. 4 is a perspective view showing a state in which the block is placed on the V groove 35, aligned with the block 36, and fixed by a clamp. In this way, one of the first optical fiber arrays 4 is
9 are configured. Similarly, the second optical fiber array (not shown) to be connected is constructed symmetrically, and both are mounted on the optical fiber fusion splicing device so that they are accurately aligned with each other to realize an automated connecting device. To make a fusion splicing in a discharge arc.

The fused optical fiber is removed from the connecting device, and the exposed optical fiber strand 43 is covered with a synthetic resin such as an acrylate resin so as to protect it from contact with air.

A large number of optical fiber core wires 41 fused and connected
A structure for protecting the connection part of will be described with reference to FIG. Referring to the cross-sectional perspective view of FIG. 1A, a heating type adhesive 52 is provided on the outside of a rod-shaped core material 51 such as stainless steel at the center.
In the case of this embodiment, six fusion spliced optical fiber core wires 41 are arranged along the longitudinal direction around the reinforcing member formed by arranging.

The heat-shrinkable tube 53, in which the optical fiber core wire 41 has been inserted in advance, is moved to the connecting portion to cover the connecting portion. When the reinforcing heater is operated to heat the entire periphery of the heat shrinkable tube 53, the adhesive 52 is softened and melted to adhere the core material 51 and the heat shrinkable tube 53 while covering the periphery of the optical fiber core wire 41. . On the other hand, the heat-shrinkable tube 53 shrinks in the radial direction to discharge the internal air and reduce the size of the heat-shrinkable tube 53, so that only the interposition of the adhesive 52 is secured.

It is convenient to shrink the heat-shrinkable tube 53 from the central portion in the longitudinal direction toward both ends because no air remains. The state reinforced in this way is shown in the side view of FIG. It is preferable that the core material 51 is configured to project to both sides longer than the contracted heat-shrinkable tube, because the heat-shrinkable tube 53 does not bend the optical fiber core wire 41 at this portion. The state of FIG. (C) in which the core member 5 is further extended is shown in FIG.
It is possible to attach and fix it to a predetermined attachment portion by using 1.

Although the core material 51 has a circular cross section, it is not limited to a circular shape and various shapes such as an oval shape, an elliptical shape, a rectangular shape and a polygonal shape can be applied. Particularly, the polygonal shape is convenient for arranging and positioning the optical fiber core wire on each side, and a groove into which the optical fiber core wire is fitted can be formed in the longitudinal direction.

FIG. 6 is a sectional view of the optical submarine repeater 21 shown in FIG. The connection reinforcing portion 55 of the optical fiber 41 configured as shown in FIG. 5B is accommodated in the groove.
The connection reinforcing portion 55 is pressed and supported by a pressing plate fixed by screws.

After the optical fiber core wire 41 is fusion-spliced, a thin protective film is formed on the exposed portion of the strand near the splicing portion, and a proof test of the splicing portion is performed with reference to the principle diagram of FIG. Explain. In this embodiment, as shown in FIG. 5A, four optical fiber core wires 41 are shown as being tested. The first and second clamps 61, 62 of the test device (not shown) are arranged on both sides of the connection part as a center.
It is tightened and supported by the second clamp 62.
Is not tightened. The optical fiber core wire 41 is held by lightly tightening the third clamp 63 on the second clamp 62.

With the above configuration, when the second clamp 62 and the third clamp 63 are moved relative to the first clamp 61 so as to be separated from each other in the direction of the arrow, the optical fiber core wire 41 becomes the first clamp 61. Since it is fixed by the clamp 61, the third clamp 63 slips and a uniform pulling force acts on all of the four optical fiber core wires 41, resulting in a slight internal stress. Elongation will occur.

In this state, the second clamp 62 is tightened to fix and support the optical fiber core wire 41, and a predetermined force for separating the first clamp 61 from the second clamp and the third clamp 63 is applied, After a lapse of a predetermined time, the pulling force is released and the proof test is finished.

By carrying out the proof test of the present invention in this way, it is possible to carry out a load test that is uniform and uniform on all of the many optical fiber cores, and to ensure the long-term reliability of the optical fiber. Is something that can be done. In addition, the second clamp is used without using the third clamp 63.
The load test can also be performed by lightly tightening the clamps 62 to cause the slides to separate from each other, and tightening and fixing the second clamps 62 in a state where even stress and elongation are generated in all the optical fiber core wires 41. It is something.

Since the above description will be more clearly understood from the fact that it is shown in FIG. 7B, FIG. 7B will be described. The vertical axis shows the acting force, and the horizontal axis shows the passage of time.
In FIG. 5A, each optical fiber 41 is connected to the A.D. B. C. D
Then, the acting force first acts on A in the order of being tensioned, and then acts on B, C, and D in that order, causing slippage at all with a constant value and aligning them on the line of the prescribed acting force.

Clamp 63 at the position of time indicated by the dotted line
Alternatively, 62 is tightened and fixed, and thereafter, a force is applied to a position where a predetermined acting force set for the test is applied, and after a predetermined time has elapsed, the force is released and the process ends. By this load test, the one having an abnormality such as a microcrack in the connection portion is cut, so that the optical fiber is fusion-bonded again and tested again to obtain a good connection state.

A more specific embodiment of the load test apparatus for performing the proof test will be described with reference to the side view of FIG. In FIG. 8, columnar optical fiber supporters 65 and 66 of the load testing device are arranged vertically, and a large number of optical fibers 41 to be tested are wound on both sides with their connecting portions as central portions. Therefore, a large number of optical fibers 41 are arranged and mounted in parallel in the direction orthogonal to the paper surface.

The radii of the optical fiber supporters 65 and 66 are sufficiently large to exceed the minimum allowable bending radius of the optical fiber 41. Further, first and second clamps 67 and 68 having curved surfaces that follow the optical fiber 41 that is wound are arranged on the left side surface in the drawing, and all the optical fibers 41 are supported by a uniform predetermined pressing force. 6
It is fixed by pressing between 5, 66.

Above and below the support members 65 and 66, there are third and fourth clamps 69, which have curved surfaces along the optical fiber 41.
Although 71 is arranged, it is in a state of not being pressed against the optical fiber 41.

With the above construction, the load testing device is operated so that the two support members 65, 66 are relatively separated in the vertical direction. As a result, a tensile load smaller than the test load is applied to the optical fiber 41, elongation is generated, and the supports 65, 66 and the first and second clamps 67, 6 are generated.
As a result of slipping against 8, all optical fibers 41
A state in which even tension is generated is obtained for each.

In this state, the third and fourth clamps 69, 7
1 is fastened to fix the optical fiber 41 to the supports 65 and 66, and the supports 65 and 66 are separated from each other to apply a predetermined test load to the optical fiber 41. Optical fiber 4
Since elongation occurs within 1 within the allowable elastic stress, the test load is released after a predetermined time, and the test is terminated.

An optical fiber 41 having an abnormality in the connecting portion.
Can be easily discriminated because it is ruptured by this load test and pops out of a shape that follows the arcs of the supports 65, 66.

Although the above description of each embodiment is for one embodiment, the present invention includes combinations of embodiments of the embodiments based on the description of the claims, and each embodiment It is not limited to.

[0075]

As described in detail above, according to the optical fiber connecting method and the optical fiber connecting portion concentrating and reinforcing structure of the optical fiber connecting method, and the load testing method for the optical fiber connecting portion of the present invention, a large number of optical fibers can be used. It is possible to collectively connect all together, and according to another aspect, a large number of optical fiber connecting portions can be made compact to provide an efficient line collecting and reinforcing structure. Furthermore, the batch load test for a large number of optical fiber connection parts can be performed, and the industrial effects that can ensure high reliability of the optical fibers are extremely remarkable.

[Brief description of drawings]

FIG. 1 is an embodiment of a method for connecting optical fibers of the present invention.

[Fig. 2] Method for removing coating from a large number of optical fibers

FIG. 3 is an alignment support method according to the present invention.

FIG. 4 is an optical fiber alignment structure according to the present invention.

FIG. 5: Concentrating line reinforcing structure of the optical fiber connecting portion of the present invention

FIG. 6 is a housing structure for an optical fiber connecting portion.

FIG. 7 is a load test method for the optical fiber connection portion of the present invention.

FIG. 8 is a specific example of FIG.

FIG. 9: How to connect tape-shaped optical fibers

FIG. 10 Reinforcement structure of optical fiber

FIG. 11: Housing structure of optical fiber connection part

FIG. 12: Connection method of single-core optical fiber

FIG. 13: Positioning of multiple optical fibers

FIG. 14: Load test of optical fiber connection part

[Explanation of symbols]

 21 Optical Submarine Repeater 35 V Groove 36 Block 41 Optical Fiber, Optical Fiber Core Wire 42 Coating 43 Optical Fiber Element Wire 45 Clamp 46 Chemicals 48 Protective Film 49 Optical Fiber Array 51 Core Material 52 Adhesive 53 Heat Shrink Tube 55 Connection Reinforcement Section 61 , 62, 63 Clamp 65, 66 Support 67, 68, 69, 71 Clamp

Claims (5)

[Claims] 1. Optical fibers which are adjacent to each other such that the coating (42) tips of the plurality of optical fibers (41) are removed and the removed tips (43) are on the same plane. A first optical fiber array (49) aligned and held in a parallel state in which the distance is closer than the outer diameter dimension of the coating (42) portion and a second optical fiber array facing each other have their respective optical fiber end faces. A method for connecting optical fibers, characterized in that the fibers are fusion-spliced together in a discharge arc in a state of being aligned and facing each other. 2. A coating (4) of a plurality of optical fibers (41).
2) In the state where the parts are aligned and held, the coated portion at the tip is melted and removed, and a thin synthetic resin film (48) for protection is formed on the coated portion including the melted and removed portion (43), and then the protective film The optical fiber portion formed with (48) is aligned and held in parallel with the adjacent state in which it is closer than the outer diameter of the coating (42) portion, and the protective film (48) at the tip portion is melted and removed for a predetermined length. The first optical fiber array (49) constituted by a step of aligning the end faces of the removed optical fiber tips (43) on a straight line, and the opposing second optical fiber array align the respective optical fiber end faces. A method of connecting optical fibers, characterized in that they are fused and connected together in a discharge arc in a state of facing each other. 3. A protective synthetic resin coating is applied to a connecting portion of an optical fiber (41) connected by the connecting method according to claim 1 or 2, and then an adhesive ( 52) along with the longitudinal direction of the reinforcing material arranged, the plurality of optical fibers (4).
The connection part of 1) is arranged in parallel, the heat shrinkable tube (53) is covered on the outer periphery thereof, and the heat shrinkable tube is shrunk by heating so that the optical fiber connection part is collectively fixed around the core material (51). Concentrated line reinforced structure for the optical fiber connection. 4. A load test method for a connecting portion of an optical fiber connected by the connecting method according to claim 1 or 2, wherein a protective synthetic resin coating is provided on the connecting portion of the optical fiber (41). After applying, the test device (61) (6
2) The optical fibers are collectively tested by setting the optical fibers in a state in which a uniform tension is applied to each of the plurality of optical fibers (41) by attaching and holding the optical fibers to (63) and separating the testing device to apply a tensile force to the optical fibers. A method for testing a load on an optical fiber connecting part, which is characterized in that the optical fiber connecting part is fixed to the optical fiber, and a predetermined load is applied for a predetermined time in that state. 5. The optical fiber (41) after the load test method according to claim 4 is performed to confirm that there is no abnormality,
The line-concentrating structure for the optical fiber connecting portion is characterized by applying the line-concentrating structure.