JPH0784153A - Multiple coated optical fiber connector - Google Patents

Abstract

PURPOSE:To align the axes of individual optical fibers respectively independently to each other with high accuracy by respectively interposing fine adjusting members formed of piezoelectric elements between fine adjusting plates which come into contact with supporting substrates disposed for each of the individual optical fibers and base plates. CONSTITUTION:This multiple coated optical fiber connector is constituted by interposing the fine adjusting plates and piezoelectric fine adjusting members 14 between the V-groove substrates 10 formed with V-grooves 13a for supporting the optical fibers 1a in a Z-axis direction and the base plates 11. Members 13d having an inverter triangular shape are placed at the centers of the front ends of a pair of the piezoelectric fine adjusting members 14 so that both are not fixed and exist in sliding contrapositions. And the voltage is impressed to the piezoelectric element, by which is the respective piezoelectric element 16a, 16b are made to elongate and contract. The optical fibers 1a on the V- groove substrates 10 move vertically if both piezoelectric elements 16a, 16b are evenly expanded and contracted. The optical fibers 1a move in a diagonal direction when the one piezoelectric element is elongated and contracted more than the other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a splicing device for splicing optical fibers to each other on the basis of a multi-core V-groove method, and more particularly to a multi-core package having an axial aligning mechanism for individual core wires. The present invention relates to a connection device (multicore optical fiber core wire connection device).

[0002]

2. Description of the Related Art When connecting optical fibers, it is necessary to accurately match the cores of two optical fibers to be connected. If there is a misalignment of the core axis at the connection point, a bend between the optical fibers, or a difference in the core diameter or the relative refractive index difference between the connected fibers, a large loss occurs at the connection point.

In order to achieve a low-loss connection in optical fiber connection, it is important to obtain a good cut surface and keep the axis deviation small. With respect to the latter point, several alignment methods are known to accurately perform the alignment. Among them, the most popular one is V which enables low loss connection by using a simple jig.
This is a bonding method called the groove method. That is, in this method, two end faces of an optical fiber are abutted and set on a V-groove substrate, the optical fibers are pressed from above to perform axial alignment, and then connection by an adhesive or connection by melting is performed.

The V-groove method can also be applied to the case of a tape core wire in which a plurality of optical fibers are collectively covered and the density of the core wire is increased. A schematic configuration of a conventional multi-fiber optical fiber connecting device for performing multi-fiber collective connection based on the V-groove method will be described with reference to FIG.

In FIG. 12, reference numeral 1 is an optical fiber tape core wire in which a large number of optical fibers 1a are bundled, 2 is a fine movement table, 3 is a clamp member, 4 is a V groove table, and 5 is a melting means. . In this figure, the respective constituent elements are arranged so as to be symmetrical with respect to the melting means 5 (left-right symmetry in the drawing). A method of connecting two optical fibers by using the multi-fiber optical fiber connecting device having such a configuration will be briefly described below.

The covering member on the tip end side of the two optical fiber ribbons 1 is peeled off to expose the optical fiber 1a. The optical fiber ribbons 1 are arranged on two fine movement bases 2 arranged symmetrically and opposite to each other, and are clamped and fixed by the clamp means 3. The clamp means 3 has a hard clamp part 3a and a soft clamp part 3b. The latter clamp part 3b holds down the vicinity of the tip of the optical fiber 1a guided to the V groove of the V groove base 4. Next, by rotating the micrometer 2a provided on the fine movement table 2,
Is moved back and forth as indicated by arrow A so that the tips of the two optical fibers 1a are brought close to and face each other up to a predetermined distance.
Then, the two tip portions that are close to each other are melted by the melting means 5 (movable up and down.
Melt according to arrow B). Due to this melting, the tips of the two optical fibers 1 are fusion-welded.

In order to prevent axial misalignment at the portion where the two optical fibers 1a are connected, two V-grooves symmetrically arranged on the plane of FIG. 12 are formed so that their dimensions are equal to each other. And they must be precisely aligned with each other. However, in reality, there is a limit to the accuracy of the V-groove size and the alignment, and an axis deviation error easily occurs in the optical fiber 1a. Even if the V-groove can be manufactured with high accuracy, it is difficult to perform high-precision axis alignment due to the eccentricity of the core of the optical fiber generated in the manufacturing process of the optical fiber or dust adhering between the V-groove and the optical fiber. Becomes The axis misalignment in the core caused by these causes is the largest factor that influences the connection loss.

FIG. 13 shows the relationship between the amount of axis deviation (μm) and the loss due to axis deviation (dB).

The optical fiber is generally a graded multimode optical fiber having a core diameter of 50 μm and a core diameter of several μm.
The single-mode optical fiber can be roughly classified into two types. In the case of multi-core connection of graded-type multimode optical fibers, a certain degree of axis deviation error is allowed because the core diameter is relatively large. Therefore, it is possible to suppress the connection loss to 0.1 dB or less even if the axis alignment is performed only with the above V groove. However, since the core diameter of the single-mode optical fiber is several μm, as shown in FIG. 13, the connection loss due to the axis deviation is much larger than that of the graded-type multimode optical fiber. For example, the core diameter is 5 μm. If the axial deviation of 2 μm is 2 μm, the theoretical loss in the case of the corresponding graded-type multimode fiber is as small as 0.066 dB, whereas it is as low as 2 dB in the case of the single mode optical fiber. Grows to. Therefore, in order to reduce the connection loss of the single-mode optical fiber to 0.1 dB or less, it is necessary to suppress the amount of axis deviation to 0.49 μm or less. This limitation of the axis deviation does not simply realize the axis alignment only by the guide of the V groove, but the axis alignment mechanism (the axis alignment mechanism in which the individual optical fibers of the multi-fiber ribbon are aligned independently A centering mechanism) is required.

FIGS. 14 and 15 show examples of high-precision axis-aligning mechanisms that have been used for conventional single-mode connection of single-mode optical fibers. FIG. 14 is a stress strain type, while FIG. 15 is a lever type.

In both cases, the cantilever 6 or the lever 7 is moved by the fine movement of the micrometer 8 driven by a motor (not shown) to support the optical fiber 1a.
The groove base 4 is finely moved two-dimensionally (in the X and Y directions in the figure) to perform axis alignment. Note that reference numeral 9 is a buffer coil spring.

[0012]

However, if an attempt is made to perform axial alignment in the multi-core connection using the axial alignment mechanism for single-core connection, the following problems will occur.

(I) Since it is necessary to provide two cantilever beams (or levers), two micrometers and two drive sources (motors) according to the number of optical fibers, problems such as enlargement of the device occur. For example, in the case of an optical fiber tape core wire consisting of 10 cores with an optical fiber spacing of about 0.25 mm, 20 micrometers and the like are required for each, and it is extremely difficult to construct the above configuration in a space with such spacing. is there.

(Ii) If dust or the like is present between the V-groove and the optical fiber, highly accurate axial alignment is disturbed. In order to reduce the influence of dust and the like, a very compact individual axis aligning mechanism is required, but it is difficult for the reason (i) above.

Therefore, an object of the present invention is to solve the above-mentioned problems and to make each optical fiber core very compact and not affected by dust and the like existing between the optical fiber and the V groove supporting it. It is an object of the present invention to provide a connecting device for a multi-core optical fiber core wire that can be independently and highly accurately aligned.

[0016]

In order to solve the above-mentioned problems, a multi-fiber optical fiber connecting device based on the present invention is provided with a base and a symmetry provided around the base and the melting means. A connecting device for connecting a plurality of optical fibers each of which is composed of two arranged member groups having the same structure and which constitutes a multi-core optical fiber core wire based on the multi-core collective V-groove method, The member group is arranged so as to be adjacent to and in communication with a V-groove substrate on which a plurality of V-grooves for individually holding a plurality of optical fibers are formed, and a V-groove. A plurality of fine adjustment plates having a single-core holding groove for supporting the vicinity of the tip of the optical fiber protruding from one end, and a plurality of fine adjustment plates swingably supported and fixed on a base. A plurality of substrate supporting parts and fine adjustment plates are slidably connected, and A plurality of piezoelectric fine adjustment members for finely moving the optical fiber on a two-dimensional plane orthogonal to the central axis of the optical fiber by finely moving the fine adjustment plate are slidably connected to the fine adjustment plate and the fine adjustment member. Members for
An axis deviation amount measuring member for measuring the axis deviation amount of the optical fiber and a drive control member for driving the piezoelectric adjusting member based on the axis deviation amount measured by the axis deviation amount measuring member are provided. It is characterized by that.

[0017]

The plurality of optical fibers are individually held by the plurality of V-shaped grooves. Further, the individually held optical fibers are placed in a single-core holding groove arranged so that the vicinity of the tip end portion thereof is adjacent to and in communication with the V-shaped groove, and the optical fibers are aligned with the opposing optical fibers. This is performed by the piezoelectric fine adjustment member and the drive control member. When the optical fibers are aligned with each other, the tip of the optical fiber is melted by the fusing means and is connected to the opposing tip of the optical fiber.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a multi-fiber optical fiber connecting device according to the present invention is shown in FIGS. Similar to the device shown in FIG. 12 as a conventional example, the devices shown in these figures are for connecting optical fibers based on the V-groove method, and are for connecting both optical fibers by fusion. The means and the means for bringing both optical fibers close to each other are the same as conventional ones.

FIG. 1 is a front view for explaining a schematic structure of a multi-fiber optical fiber connecting device according to the present invention, and FIG. 2 is a side view thereof.

In FIG. 1, X, Y and Z are coordinate systems set for convenience of explanation of the apparatus of this embodiment.
Each is orthogonal to each other, with the Z axis extending in a direction perpendicular to the plane of FIG. 1 and the X axis extending in a direction perpendicular to the plane of FIG.

This multi-fiber optical fiber connecting device has a V-shaped groove 10 for supporting the optical fiber 1a in the Z-axis direction.
a V-groove substrate 10 on which a is formed, a base 11, and the base 1
1 and a V-groove substrate 10 interposed between the V-groove substrate 10 and the V-groove substrate 10 to fix and support the V-groove substrate 10, and a body having one end swingably supported by the substrate support unit and bent into an L shape. A plurality of fine adjustment plates (optical fiber support members) 13 and a plurality of piezoelectric fine adjustment members 14 are provided.

The fine adjustment plate 13 formed in a substantially L shape is
A V-shaped groove (single core holding groove) 13a formed to match the inclination of the inner wall of the V-shaped groove 10a is provided at the top end portion thereof.
Since the single-core holding groove 13a is finely moved along the X-axis and Y-axis directions, no slip (movement in the Z-axis direction) occurs with the optical fiber. Therefore, even if dust or the like is present between the V groove and the optical fiber, it is unlikely to be affected.

In the apparatus of this embodiment, four fine adjustment plates 13 are arranged in parallel. Each fine adjustment plate 13 is a substrate support unit 1.
It is rotatably supported in the vicinity of the upper end portion of 2 by a support pin 12a.

FIG. 3 is a schematic side view for explaining the schematic structure of the four fine adjustment plates 13 provided in the apparatus of this embodiment. On the other hand, FIG. 4 is a schematic front view of the fine adjustment plate 13.

As shown in FIGS. 3 and 4, the fine adjustment plate 13 has a portion that abuts the optical fiber (a portion where the single-core groove portion 13a is formed), an arm portion 13b that supports the V-groove substrate, and
It is composed of a protrusion 13c provided on the back surface of the arm 13b, and a member 13d having a triangular bottom surface with a rectangular bottom surface adhered to the end of the material 13c. The arrangement position of the protrusion 13c differs depending on the fine adjustment plate 13.

Further, as shown in FIGS. 1 and 2, since the piezoelectric fine adjustment members 14 are individually provided on the respective fine adjustment plates 13, the individual piezoelectric fine adjustment members 14 will be described later. By finely moving the fine adjustment plate 13 individually, it is possible to perform fine adjustment so that the tip portions of the optical fibers 1a maintain a good fusion posture.

FIG. 5 is for explaining the structure of the piezoelectric fine adjustment member 14.

The piezoelectric fine adjustment member 14 is composed of two pillars which are erected on the base 11 and symmetrically arranged with respect to each other.
Each of the pillars has a piezoelectric element 16a or 16b fixedly supported on the base 11, and a member 15a having a pyramidal tip portion placed on the piezoelectric element 16a or 16b and having a bottom surface and one side surface at a right angle. 15b and. Member 15a
The V-shaped support portion is formed by placing the member 15b and the member 15b with their slopes facing each other.

Then, an inverted triangular member 13d is placed at the center of the tip (the above-mentioned support portion) of the pair of piezoelectric fine adjustment members 14 thus configured. The two are not fixed and are in a slip situation. Inverted triangular member 13d and member 1 attached to the tips of both voltage elements 16d, 16d
A wedge type mechanism is formed between 5a and 15b. As shown in FIG. 2, a spring 17 is attached between the fine adjustment plate 13 and the base 11, and the spring causes the fine adjustment plate 13 and the member 13d to receive a downward force to finely adjust the piezoelectric force. It is pressed by the members 15a and 15b on the member 14.

By applying a voltage to the piezoelectric element, the piezoelectric element 16
Expand and contract a and 16b. Thereby, the support member 13
The upper optical fiber 1a slightly moves, and the axial alignment operation becomes possible. Also. Here, although it is illustrated that a space is maintained between the fine adjustment plates 13, there is practically no gap, and each of the fine adjustment members 14 and the V-groove substrate 1 has no gap.
They are arranged in a shape corresponding to the 0 V-shaped groove 10a. Further, each piezoelectric fine adjustment member 14 is arranged corresponding to each fine adjustment plate 13, and depending on the arrangement interval of the optical fibers 1a,
It is fixed in parallel on the base 11 with a slight offset. By adopting such an axial aligning mechanism, the piezoelectric elements can be arranged very densely, and the axial aligning mechanism can be realized very compactly.

The axis adjusting method using the above apparatus will be described below with reference to FIGS. 6 to 10. In the present embodiment, it is assumed that the bias voltage is applied to both piezoelectric elements 16a and 16b in the extending direction (the arrow direction in the drawing) in the initial state. (Also, in these figures, the dotted line shows the position before the movement.) Then, as shown in FIG.
Optical fiber 1a held in the single core holding groove 13a
When slightly moving upward (in the direction of the arrow), a voltage is applied so as to extend both piezoelectric elements 16a and 16b.
When moving downward as shown in FIG. 7, the bias voltage may be controlled so that both piezoelectric elements 16a and 16b are contracted.

Further, when it is desired to make a slight movement to the upper right diagonally, as shown in FIG. 8, and when it is made to make a fine movement diagonally to the upper left, both piezoelectric elements 16a and 16a are formed as shown in FIG.
b is operated. In the case of lateral movement, one piezoelectric element 16b is contracted as shown in FIG. 7, and the voltage applied to both piezoelectric elements 16a and 16b is controlled so as to extend the other piezoelectric element 16a. In this way, the end portion (see FIGS. 1 and 2) on the side on which the individual optical fibers 1a supported by the V-groove substrate 10 are to be fused is 2 in the plane orthogonal to the central axis of the optical fiber. Axial alignment can be performed by moving finely in the dimension (direction along the X or Y axis).

FIG. 11 shows an example of the configuration of a control circuit for aligning the axes of the optical fibers 1a using the multi-fiber optical fiber connecting device having such a configuration. It should be noted that, here, for the sake of simplicity of explanation, members that are not directly involved in the control are omitted. In FIG. 11, reference numeral 31 is an axial deviation measuring device for measuring the axial deviation between the end faces of the optical fibers facing each other, and 32 is a well-known PID based on the axial deviation input from the axial deviation measuring device 31. It is a controller that causes the operational amplifier (amplifier) 33 to generate an amplifier drive power source corresponding to an appropriate fine movement amount for each optical fiber 1a by control or the like.

As the above-mentioned axis deviation measuring device, there is a combination of an ITV television and an image processing system, or means for minimizing the axis deviation by the maximum value of the power passing through the core of the optical fiber 1a to be connected. Conceivable. Other than that, a method of obtaining an amount of axis deviation by monitoring an image of transmitted light from two opposing directions with respect to an optical fiber held at a facing position by a TV camera and performing an image processing is used. Good.

In the state where the end faces of the optical fibers facing each other are brought close to each other and are positioned in the vicinity of the fusion bonding, the amount of axial deviation between both optical fiber tips is measured by an axial deviation measuring device, and the axial deviation is measured. When the amount is not so large, it is possible to achieve the purpose by holding one of the core wires with a normal V-groove base and operating only the device on one side.

When the initial axial displacement is relatively large, first, one of the bases is finely adjusted so that the sum of the binary values of the axial displacement of all the cores is minimized. The control may be performed by driving only the piezoelectric elements on one base or by finely moving the piezoelectric elements on both bases facing each other.

When the amount of axis deviation is obtained as described above, the amount of axis deviation is input to the controller, an amplifier drive voltage is generated by a controller such as a PID, and this is input to the amplifier. A device driving voltage is applied to each piezoelectric device. By repeating this loop, the amount of axis deviation can be made almost zero.

[0038]

As described above, the multi-fiber optical fiber connecting device based on the present invention has the same structure as the base and the symmetrical arrangement provided on the base and centering around the melting means. And a connecting device for collectively connecting a plurality of optical fibers forming a multi-fiber optical fiber based on the multi-fiber V-groove method.
The member group is arranged so as to be adjacent to and in communication with a V-shaped groove, in which a plurality of V-shaped grooves for individually holding a plurality of optical fibers are formed, and a V-shaped groove. A plurality of fine adjustment plates having a single-core holding groove for supporting the vicinity of the tip of the optical fiber protruding from one end, and a plurality of fine adjustment plates swingably supported and fixed on a base. A plurality of piezoelectric elements which are slidably connected to a plurality of substrate supporting parts and a fine adjustment plate, and finely move the fine adjustment plate to finely move the optical fiber on a two-dimensional plane orthogonal to the central axis of the optical fiber. By the fine adjustment member, the member for slidably connecting the fine adjustment plate and the fine adjustment member, the axis deviation amount measuring member for measuring the axis deviation amount of the optical fiber, and the axis deviation amount measuring member. For driving the piezoelectric adjustment member based on the measured amount of axis deviation A plurality of optical fibers are individually held by a plurality of V-shaped grooves, and the vicinity of the tip end of each individually held optical fiber is adjacent to the V-shaped groove. In addition, in the single-core holding groove arranged so as to communicate with each other, while performing the axial alignment by the piezoelectric fine adjustment member and the drive control member, the melting means melts the optical fiber distal end portion and the opposite optical fiber distal end portion. Since they can be spliced together, it is possible to perform the splicing of multi-core optical fiber core wires, which has been difficult in the past, with high accuracy, and the optical fiber can be arranged on a two-dimensional plane orthogonal to the central axis of the optical fiber. Since it is slightly moved, even if dust or the like is interposed between the V-shaped groove and the optical fiber, it is possible to perform axis alignment without being affected, and since the above members can be densely configured, it is possible to achieve high precision and control. An effect that can be achieved transfected discrete axis alignment mechanism.

[Brief description of drawings]

FIG. 1 is a front view for explaining a schematic configuration of a multi-fiber optical fiber connecting device according to the present invention.

2 is a side view of the device shown in FIG. 1. FIG.

FIG. 3 is a side view of a fine adjustment plate provided in the multi-core optical fiber core wire connecting device according to the present invention.

FIG. 4 is a front view of the fine adjustment plate shown in FIG.

FIG. 5 is a side view of a piezoelectric fine adjustment member provided in a multi-core optical fiber core wire connecting device according to the present invention.

FIG. 6 is a diagram for explaining a fine adjustment operation by a piezoelectric fine adjustment member provided in the multi-core optical fiber core wire connecting device according to the present invention.

FIG. 7 is a diagram for explaining a fine adjustment operation by the piezoelectric fine adjustment member provided in the multi-core optical fiber core wire connecting device according to the present invention.

FIG. 8 is a diagram for explaining a fine adjustment operation by a piezoelectric fine adjustment member included in the multi-core optical fiber core wire connecting device according to the present invention.

FIG. 9 is a diagram for explaining a fine adjustment operation by the piezoelectric fine adjustment member provided in the multi-fiber optical fiber connecting device according to the present invention.

FIG. 10 is a diagram for explaining a fine adjustment operation by the piezoelectric fine adjustment member provided in the multi-core optical fiber core wire connecting device according to the present invention.

FIG. 11 is a schematic diagram of an axis alignment control circuit provided in the multi-core optical fiber core wire connecting device according to the present invention.

FIG. 12 is a diagram for explaining a schematic configuration of a conventional multi-fiber optical fiber connecting device.

FIG. 13 is a diagram showing a characteristic curve showing the relationship between the amount of axis deviation and the connection loss due to axis deviation.

FIG. 14 is a perspective view for explaining a schematic configuration of a conventional single body alignment device.

FIG. 15 is a perspective view for explaining a schematic configuration of a conventional single body alignment device.

[Explanation of symbols]

 1 Tape Fiber 1a Optical Fiber 10 V-Groove Substrate 10a V-Shaped Groove 11 Base 13 Fine Adjustment Plate (Optical Fiber Support Member) 13a Single-Core Holding Groove 13c Protrusion 13d Inverse Triangular Member 14 Piezoelectric Fine Adjustment Member 15a, 15b Trapezoid Shape member 16a, 16b Piezoelectric element 17 Spring 31 Axis deviation measuring device 32 Controller 33 Amplifier

Claims (1)

[Claims] 1. A multi-core batch V-groove method, which comprises a base and two member groups provided on the base and symmetrically arranged around a melting means and having the same structure. In a connecting device for collectively connecting a plurality of optical fibers forming a core optical fiber, the member group is a V groove in which a plurality of V-shaped grooves for individually holding the plurality of optical fibers are formed. A plurality of substrates, and a plurality of single-core holding grooves that are arranged so as to be adjacent to and in communication with the V-shaped groove and that support the vicinity of the tip of the optical fiber protruding from one end of the V-shaped groove. A fine adjustment plate, a plurality of substrate supporting portions that swingably support the fine adjustment plate and are fixed on the base, and slidably connected to the fine adjustment plate, and The optical fiber is moved to the optical fiber by finely moving the fine adjustment plate. A plurality of piezoelectric fine adjustment members that are finely moved on a two-dimensional plane orthogonal to the central axis, a member for slidably connecting the fine adjustment plate and the fine adjustment member, and an axis shift amount of the optical fiber. And a drive control member for driving the piezoelectric adjusting member on the basis of the amount of axial displacement measured by the axial displacement measuring member. Multi-fiber optical fiber connection device.