JP2000221367A - Optical fiber abutting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the operation efficiency without increasing the cost when end surfaces of optical fibers are made to abut against each other and optically coupled with each other with low loss. SOLUTION: A couple of optical fibers 21 and 22 are set in a V groove 11 formed on a V-groove block 10 and aligned with each other. A matching plate 12 which has excellent light transmissivity and a specific refractive index is arranged halfway along the length of the V groove 11 and the end surfaces of the optical fibers 21 and 22 are made to abut against each other across the matching plate 12. The matching plate 12 is arranged in a groove 13, which is filled with matching liquid 14, then the matching liquid 14 is present between the end surfaces of the optical fibers 21 and 22 and matching plate 12, so that no air layer is formed between them. Consequently, no Fresnel reflection is caused on the end surfaces of the optical fibers 12 and 22 and low-loss coupling is actualized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber butting apparatus for abutting end faces of a pair of optical fibers and performing optical coupling therebetween with a small loss.

[0002]

2. Description of the Related Art Heretofore, there has been a case where end faces of a pair of optical fibers are abutted with each other and optical transmission therebetween is performed with a small loss. In such a case, it is necessary to temporarily optically couple the pair of optical fibers. For example, this is the case when quality control of an optical fiber is performed or when an optical switch is configured. In other words, the optical fiber that has been extended from the measurement system is temporarily connected to the manufactured or laid optical fiber, the measurement light is incident on the former optical fiber, its characteristics are measured, and the quality is confirmed. Is often done. Also, in the case of configuring an optical switch in which the transmission route of an optical signal is switched by changing the combination of butting between optical fibers, the end faces of the optical fibers are butted and temporary coupling occurs between them. .

In the case where the end faces of the optical fibers are brought into contact with each other to cause a temporary coupling therebetween, conventionally, first, the coating of the optical fiber is peeled off at the end,
The end face treatment (end face setting) of cutting the end face so as to be a right-angled mirror surface is manually performed, and then a pair (or a plurality of pairs) of the prepared optical fibers is placed in the same V-groove in a pair. It is set every time, and the end faces are matched. A matching liquid (matching oil) having a predetermined refractive index may be applied between the butt end faces in order to prevent an increase in Fresnel reflection and loss at the end faces due to the passage of the optical signal through the air medium.

[0004] Such butting of optical fibers may all be performed manually by an operator, or may be performed by an automated device. In an automatic apparatus, a plurality of optical fibers having been subjected to an end face treatment are prepared, and these are sequentially set in a V-groove by an automatic transfer mechanism, a robot arm (automatic hand), or the like, and are then butted. The setting and butting to the V-groove (setting of an appropriate end face interval) may be performed by photographing the situation with a television camera or the like and automatically positioning the image by image processing or the like. In some cases, after setting the end face interval, matching oil is automatically applied to prevent Fresnel reflection on the end face.

[0005] In particular, an OTDR device (measured at each point of the optical fiber to be measured by backscattered light) is used to measure various characteristics of the manufactured or laid optical fiber and to confirm the quality. When the optical fibers connected to the (device) are temporarily coupled, one of the following two methods is used.

In the first method, a plurality of optical fibers to be measured whose end surfaces have been processed are prepared and arranged on a tray in advance.
Then, the optical fiber connected to the OTDR device is set on the V groove. Next, the optical fiber to be measured on the tray is picked out by an automatic hand, set in the same V-groove as the V-groove in which the above-mentioned optical fiber is set, and the end faces of these optical fibers are butted together, and the OTDR device is used. The measurement light from the optical fiber is incident on the optical fiber to be measured, and the return light is guided to the OTDR device to perform the measurement. The optical fiber to be measured after the measurement is completed is taken out by an automatic hand and transferred to a tray, and then another optical fiber to be measured on the tray is gripped and set on the V-groove. This is repeated to sequentially measure a large number of optical fibers to be measured. That is, the optical fibers to be measured are taken out one by one, set in the V-groove, and the measurement is performed.

In the second method, a large number of optical fibers to be measured whose end faces have been processed are set in advance in each of a large number of V-grooves, and an optical fiber (single core) on the OTDR device side is
Set on one side of the V groove by automatic hand,
OTDR measurement of one measured fiber is performed. When the measurement is completed, the optical fiber on the OTDR device side is set to another V-groove by an automatic hand, and the measurement is performed on another optical fiber to be measured. This is repeated to sequentially measure a large number of optical fibers to be measured. here,
The optical fiber to be measured is set in a number of V-grooves in advance, and the optical fiber on the OTDR side is sequentially changed to these V-grooves.

[0008]

However, when the work is performed manually as in the prior art, the setting, butting, application of matching oil, etc. of the optical fiber to the V-groove are all performed manually. In addition to the poor efficiency, there is a problem that the optical fibers come into contact with each other at the time of butting and the end face is easily damaged. Labor saving by automatic driving is desired.

Further, the conventional automatic apparatus has a problem in that development costs for automatic conveyance by a robot arm, positioning by image processing, automatic application of matching oil, and the like are increased. In order to avoid this, the end faces of the optical fibers are simply brought into contact with each other without being positioned by image processing. However, in this case, the risk of damage to the end faces becomes extremely high. Since the optical fiber on the OTDR side must be coupled to a large number of optical fibers to be measured, if this breaks, every time it breaks,
End face processing such as coating removal, cleaning, and end face cutting must be performed, which requires a great deal of labor.

In view of the above, it is an object of the present invention to provide an optical fiber butting device which can cope with various stages of automation and can improve the efficiency of a butting operation without increasing costs.

[0011]

In order to achieve the above object, in an optical fiber butting apparatus according to the present invention, at least one pair of optical fibers is placed so that the optical fibers are axially aligned. A V-groove member having a V-groove formed therein, and a V-groove located at an intermediate position between the end faces of at least one pair of optical fibers disposed in the V-groove. And a matching plate having a predetermined refractive index arranged substantially at a right angle.

A pair of optical fibers are arranged in one V-groove, and their end faces abut each other via a matching plate. The matching plate has a predetermined refractive index, which can be reduced between the end faces by being sandwiched between the end faces. In addition, by forming the matching plate with a plastic material having a relatively low surface hardness, it is possible to prevent the end face of the optical fiber from being damaged at the time of abutting. Therefore, even when the butting position is adjusted manually or automatically when the positioning is not performed by image processing of the monitor image by the TV camera, the end face of the optical fiber is prevented from being damaged, and troublesome work at the time of breakage is prevented. Can be avoided.

Further, a matching liquid storing groove is provided in the middle of the length direction of the V groove, and the matching liquid is stored in the groove.
The matching plate may be immersed, so that the matching armpit is transmitted to the surface of the matching plate, and even if a gap is formed between the end face of the optical fiber and the matching plate, the gap is filled with the matching liquid, Low loss can be achieved. That is, automatic application of the matching liquid becomes possible.

[0014]

Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view schematically showing an embodiment of the present invention, and FIG. 2 is a perspective view schematically showing the embodiment. As shown in these figures, a matching plate 12 is fixed to the center of the V-groove 11 formed in the V-groove block 10 (the center in the longitudinal direction of the V-groove 11). The matching plate 12 is provided in a matching liquid storage groove 13 provided at the center in the length direction of the V-groove 11, and the groove 13 is filled with a matching liquid 14.

The V-groove 11 is for aligning a pair of optical fibers 21 and 22 for optical coupling between the end faces. When these optical fibers 21 and 22 are set in the V-groove 11, their axes are aligned. You are in a state of mind. The matching plate 12 is made of a plastic material having a certain degree of flexibility, such as a silicon-based sheet, a polymer-based sheet, or an acrylic (PMMA or the like) -based sheet, and is a thin foil having a thickness of about 10 to 200 μm. I have. The matching plate 12 is a transparent plate having excellent light transmittance. The refractive index of the matching plate 12 has a predetermined value such that light reflection when the end faces of the optical fibers 21 and 22 come into contact with each other is small and loss is small. It is supposed to be taken.

Therefore, when a pair of optical fibers 21 and 22 whose axes are aligned on the V-groove 11 are butted, they do not directly contact each other, and their end faces face each other with the matching plate 12 interposed therebetween. become. Since the matching plate 12 is formed of a flexible material as described above,
Even if the end faces of the optical fibers 21 and 22 come into contact with each other, there is no danger of damaging these end faces. Therefore, a pair of optical fibers 2
Even if the work of pushing 1, 22 in the butting direction is performed manually, or if it is simply performed automatically by a machine without positioning by the image processing of the monitor image by the TV camera, the end face is not damaged, It is possible to avoid a situation in which the trouble is increased due to the end face damage.

Further, a pair of optical fibers 21 and 22 are pushed in the butting direction so that both end faces are matched with the matching plate 12.
In a state in which they are in close contact with each other, Fresnel reflection at their end faces is suppressed, and coupling is performed with low loss.

Further, here, since the matching plate 12 is immersed in the matching liquid 14 as described above,
Due to the viscosity of the matching liquid 14, the matching liquid 14 propagates and covers the entire surface of the matching plate 12. The matching liquid 14 is a so-called matching oil and has a refractive index that suppresses Fresnel reflection at the end faces of the optical fibers 21 and 22 to reduce the loss. Is completely eliminated, and low-loss optical coupling is possible. That is, the optical coupling can be performed with a lower loss than when the matching liquid 14 is not provided.

In this case, even if the pair of optical fibers 21 and 22 are completely pushed in the abutting direction and their end faces are not brought into close contact with the matching plate 12, the optical fibers 21 and 22 can be used.
Since the matching liquid 14 infiltrates between the end face of the first and the matching plate 12, no air layer is generated therebetween. Therefore, it is not necessary to bring the end faces of the optical fibers 21 and 22 into contact with the matching plate 12, and there is no possibility that the end faces may be damaged.

FIG. 3 is a schematic plan view showing an example applied to OTDR measurement. Here, one optical fiber 21 to be coupled is each core of the tape-shaped optical fiber cable 23. The tape-shaped optical fiber cable 23 is manufactured or laid, and is to be measured from now on. The optical fiber cable 23 is held by the optical fiber holder 25 so that each of the optical fibers (core wires) 2 at the distal end thereof can be measured.
1 is set in the V-groove 11 of the V-groove block 10. Here, it is assumed that eight tape-shaped optical fiber cables 23 are set and measured.

The V-groove block 10 has a number of V-grooves 11 corresponding to the number of these optical fibers 21, and the other side (the right side in the figure) of each of the V-grooves 11.
The optical fibers 22 on the OTDR side are set respectively. These optical fibers 22 are also core wires of the tape-shaped optical fiber cable 24. At the other end of the tape-like optical fiber cable 24, each optical fiber (core wire)
OTDR device 33 via optical channel selector 31
It is connected to the. The optical channel selector 31 and the OTDR device 33 include a control PC (computer) 32
The optical fiber 22 is selected one by one by the optical channel selector 31, the measurement light from the OTDR device 33 is output to the selected optical fiber 22, and the return light is output to the OTDR It is sent to the device 33. In this way, the optical channel selector 31 sequentially selects a large number of optical fibers 22, so that the measured optical fibers 21 are sequentially measured one by one.

Therefore, according to the configuration shown in FIG. 3, if many optical fibers 21 on the side to be measured and many optical fibers 22 on the OTDR side are subjected to the end face treatment and set in the V-groove block 10, Subsequent OTDR measurement and measurement core switching can be automatically performed by the control PC 32.

FIG. 4 is a schematic plan view showing a second example applied to OTDR measurement. Here, similarly to FIG. 3, a large number of optical fibers 21 on the measured side are set in the V-groove block 10 after being subjected to an end face treatment in advance, but the optical fiber 22 on the OTDR side is a single tape-shaped optical fiber. The configuration is such that only the number included in the cable 24 is set and this is sequentially set in the V groove 11.

That is, one tape-like optical fiber cable 24 on the OTDR side is mounted on a rotary stage 41 by an optical fiber holder 26 as shown in FIG. As a method of fixing the tape-shaped optical fiber cable 24 by the holder 26 and the stage 41, for example, a method using a magnetic force or the like is adopted. In that case, the holder 26
A magnet is embedded in one or both of the stage and the stage 41 and is attracted by a magnetic force, so that the tape-shaped optical fiber cable 24 is sandwiched between the holder 26 and the stage 41 and fixed. In addition, as a fixing method,
An appropriate clamp mechanism or the like may be used.

The rotary stage 41 is provided with a moving block 4
2 is mounted via a rotary shaft 45 so that it can rotate as shown by arrow A. The moving block 42 is mounted on the moving block 43. A sliding mechanism is formed between the moving block 42 and the concave and convex fitting, and the moving block 42 is moved in the direction indicated by the arrow B (the V-groove 11).
In the length direction). The moving block 43 is placed on a moving guide 44 and is positioned in a direction indicated by an arrow C (a direction perpendicular to the longitudinal direction of the V-groove 11, that is, the V-groove 1).
1 in the arrangement direction).

As shown in FIG. 4, the OTDR-side tape-like light held by the holder 26 is mounted on the other end of the V-groove 11 in which each optical fiber 21 of the first tape-like optical fiber cable 23 on the measured side is set. The optical fiber 22 at the tip of the fiber cable 24 is set, and for each of the optical fibers 21 of the first tape-shaped optical fiber cable 23,
OTDR measurement is performed sequentially. At this time, by controlling the optical channel selector 31 by the control PC 32, the plurality of optical fibers 21 included in the first tape-shaped optical fiber cable 23 are automatically and sequentially switched one by one for measurement.

At this time, when viewed from the side, FIG.
As shown in (2), the optical fiber holder 26 is inclined and the OTDR-side optical fiber 22 is pressed into the V-groove 11 and advances to the other optical fiber 21 side. That is, as the moving block 42 moves in the direction of arrow B with respect to the moving block 43, the moving block 42, the rotary stage 41, and the optical fiber holder 26 advance, whereby the end face of the tip of the optical fiber 22 is moved to the matching plate 12. Pressed.

In this state, when the measurement for each optical fiber 21 of the first tape-shaped optical fiber cable 23 on the measured side is completed, first, as shown in FIG. The fiber holder 26 (moving block 4
(With 2 and rotating stage 41).
Next, as shown in FIG. 6C, the optical fiber holder 26 is rotated in the direction of arrow A. That is, the rotating stage 41 is rotated with respect to the moving block 42.
Then, the optical fiber 22 on the OTDR side becomes (c) in FIG.
As shown in the figure, the groove comes off the V-groove 11 and is located above it.

At this time, the moving block 43 is moved in the direction of arrow C (see FIG. 5) on the moving guide 44, and the V on which each optical fiber 21 of the second tape-shaped optical fiber cable 23 on the measured side is set. The OTDR-side optical fiber 22 is positioned on the groove 11. Then, measurement is performed for each optical fiber 21 of the second tape-shaped optical fiber cable 23 on the measurement side in the same manner as the state shown in FIG.

By repeating this, a number of tape-shaped optical fiber cables 23 on the measured side are sequentially turned on.
TDR measurements can be made. The above-described forward / backward and rotational movement are performed by the rotation stage 41 and the moving blocks 42 and 43.
It can also be performed automatically by controlling a driving device (motor) incorporated in the like (the moving amount in the C direction is easy because the interval between the V-grooves 11 is known in advance), but it is manual. Operation is also possible. Further, without using these mechanisms, it is also possible to perform each of the above steps using a general robot arm.

In this case, by holding one tape-like optical fiber cable 24 on the OTDR side with an optical fiber holder 26, a large number of optical fibers
2 is moved, but one optical fiber 22 is held by one optical fiber holder (not shown), and sequentially moved to each of the V-grooves 11 to be reset. It can also be configured as follows. In this case, the optical channel selector 31 becomes unnecessary.

Furthermore, various shapes and the like of the matching liquid storing groove can be considered. For example, as shown in FIG. 7, a matching liquid storage groove 15 having a circular cross section is provided, and the matching liquid 14 is filled therein.
2 may be fixed.

In addition, the specific structure and the like can be variously changed without departing from the spirit of the present invention. The present invention can of course be applied not only to the case where the optical fiber to be measured is a tape-shaped optical fiber cable, but also to the case where a single-core optical fiber cable is used.

[0034]

As described above, according to the optical fiber butting apparatus of the present invention, it is possible to improve the working efficiency in the case where the end faces of the optical fibers are butted and optically coupled with low loss without increasing the cost. it can. Also, it can cope with various stages of automation of the matching operation.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an embodiment of the present invention.

FIG. 2 is a schematic perspective view of the embodiment.

FIG. 3 is a schematic plan view showing a first example in which the embodiment is applied to OTDR measurement.

FIG. 4 is a schematic plan view showing a second example in which the embodiment is applied to OTDR measurement.

FIG. 5 is a schematic perspective view of the second example.

FIG. 6 is a schematic side view for explaining the operation of the second example.

FIG. 7 is a schematic cross-sectional view showing another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 V-groove block 11 V-groove 12 Matching plate 13, 15 Matching liquid storing groove 14 Matching liquid 21, 22 Optical fiber 23, 24 Tape optical fiber cable 25, 26 Optical fiber holder 31 Optical channel selector 32 Control PC 33 OTDR Apparatus 41 Rotary stage 42, 43 Moving block 44 Moving guide 45 Rotating axis

Claims (2)

[Claims] 1. A V-groove member having at least one pair of optical fibers mounted thereon and formed with a V-groove for axially aligning the optical fibers, and at least one pair of V-groove members arranged in the V-groove. The V is located between the end faces of the optical fiber.
An optical fiber butting device comprising a matching plate having a predetermined refractive index and disposed at a middle of a length direction of the groove and substantially at right angles to the length direction. 2. A V-groove for centering these optical fibers by mounting at least one pair of optical fibers, and a matching liquid storage groove located at an intermediate position in the longitudinal direction of the V-groove. The length of the V-groove so that the V-groove member is located between the end faces of at least one pair of optical fibers disposed in the V-groove and is immersed in the matching liquid in the matching-liquid storage groove. An optical fiber butting device comprising a matching plate having a predetermined refractive index disposed substantially at right angles to the direction.