JP6729064B2 - Method for manufacturing spliced multi-core optical fiber - Google Patents

Description

The present invention relates to a method for manufacturing a connected multi-core optical fiber.

Patent Document 1 describes a method of aligning and connecting multi-core optical fibers. In this method, a marker is attached to the multi-core optical fiber separately from the core, the core position of each multi-core optical fiber is grasped by the marker, and fusion is performed after rotational alignment.

JP, 2013-50695, A

Conventionally, as a method of aligning a multi-core optical fiber (MCF), one end faces of two MCFs to be connected are made to face each other, and light is made incident on each core from the other end face of one MCF. There is a method of aligning the MCFs so that the power of the light emitted from the other end surface of the other MCF becomes maximum (that is, the transmission loss becomes minimum). In such a method, the center axes of the MCFs are made to coincide with each other, and then the MCFs are relatively rotated around the center axes to make the corresponding core positions coincide with each other.

However, this method is effective when multiple core positions have rotational symmetry (typically, the peripheral cores except the central core on the central axis are arranged at equal angular intervals around the central axis). Is the way. If a plurality of core positions have rotational symmetry, by coupling one peripheral core of one MCF to any peripheral core of the other MCF, the other peripheral cores are also naturally coupled to align the axes. Is completed. On the other hand, when the positions of the plurality of cores do not have rotational symmetry, it is not easy to connect the cores corresponding to each other even if the axis alignment is performed using this method. This is because even if one peripheral core of one MCF is coupled to any peripheral core of the other MCF, if it is not the corresponding peripheral core, at least one of the other peripheral cores is not coupled.

In the method described in Patent Document 1, a marker different from the core is provided in the clad in the MCF. Since such a marker is provided over the entire length of the MCF, there is a concern that the optical transmission characteristics of the MCF may be affected.

The present invention has been made in view of the above problems, and provides a method for manufacturing a connected MCF that can easily perform axis alignment even when the core position does not have rotational symmetry. The purpose is to provide.

To solve the problems described above, one embodiment of the production method of the connected MCF according to an embodiment of the present invention includes a first cladding collectively covering the first core及beauty multiple first core multiple a first end face of the 1MCF, a first step of opposing a second end face of the 2MCF having second clad collectively covering the second core及beauty multiple second core several, first A second step of adjusting the relative position of the end surface and the second end surface in the plane intersecting the central axis and the relative angle around the central axis; and a third step of connecting the first end surface and the second end surface to each other. And the first MCF and the second MCF have the same core arrangement with each other, the core positions of the first MCF and the second MCF do not have rotational symmetry, and the second step is to position the first end face at a position facing the first end face. 1 step of arranging the image pickup device and arranging the second image pickup device at a position facing the second end face, and a step of arranging the first image pickup device at a position facing the first end face and a position facing the second end face. A step of relatively moving the first MCF and the second MCF so that respective central axis lines of the first MCF and the second MCF are closer to each other based on the respective image data obtained by the arranged second imaging device; A step of obtaining the center of gravity of the core position on the first end face from the obtained image data, and a step of obtaining the center of gravity of the core position on the second end face from the image data obtained by the second imaging device; and the center of gravity of the core position on the first end face. Rotating the first MCF and the second MCF relatively around the central axis so that the point and the center of gravity of the core position on the second end surface approach each other.

According to the method of manufacturing a connected MCF according to the present invention, axis alignment can be easily performed even when the core position does not have rotational symmetry.

FIG. 1A is a front view showing an end face of the first MCF. FIG. 1B is a front view showing an end face of the second MCF. FIG. 2 is a flowchart showing each step of the manufacturing method according to the embodiment. FIG. 3 is a diagram schematically showing a step of making the end surface of the first MCF and the end surface of the second MCF face each other. FIG. 4 is a diagram schematically showing a step of adjusting the relative position of each end surface of the first MCF and the second MCF in the plane intersecting the central axis and the relative angle around the central axis. 5A and 5B show image data of the image pickup apparatus. FIG. 6A and FIG. 6B show image data of the image pickup device after the fiber moving step. FIG. 7A and FIG. 7B show image data of the image pickup device after the rotation process.

[Description of Embodiments of the Present Invention]
First, the contents of the embodiments of the present invention will be listed and described. One manufacturing method of the connected MCF according to an embodiment of the present invention includes a first end face of the 1MCF having first clad collectively covering the first core及beauty multiple first core multiple, double a first step of opposing a second end face of the 2MCF having second clad collectively covering the second core及beauty number multiple of the second core number, the first end face and second end surfaces, the central axis And a third step of connecting the first end surface and the second end surface to each other, and the first MCF and the second MCF are The core positions of the first MCF and the second MCF do not have rotational symmetry while having the same core arrangement, and in the second step , the first imaging device is arranged at a position facing the first end face, Obtained by the step of disposing the second imaging device at a position facing the end face, the first imaging device disposed at a position facing the first end face, and the second imaging device disposed at a position facing the second end face. A step of relatively moving the first MCF and the second MCF so that the respective central axes of the first MCF and the second MCF approach each other based on the respective image data obtained; The step of obtaining the center of gravity of the core position and the center of gravity of the core position on the second end face from the image data obtained by the second imaging device, and the step of determining the center of gravity of the core position on the first end face and the core position on the second end face. Rotating the first MCF and the second MCF relatively around the central axis so that the center of gravity approaches each other.

In this manufacturing method, in the second step, the end surface of each MCF is imaged by an imaging device, and the obtained image data is used to perform axis alignment. That is, after the center axes of the first MCF and the second MCF are brought close to each other based on the image data, the centers of gravity of the core positions of the first MCF and the second MCF are determined, and the first MCF and the second MCF are brought closer to each other. Rotate relative to. According to such a method, even if the core positions do not have rotational symmetry, all the cores can be coupled at the same time, so that the axes can be easily aligned.

In the method of manufacturing the connected MCF described above, in the step of disposing the first image pickup device and the second image pickup device, the coordinate center of each image data of the first image pickup device and the second image pickup device is located on one axis line. The positions of the first imaging device and the second imaging device may be adjusted so as to do so.

[Details of Embodiment of Present Invention]
A specific example of the method for manufacturing a connected MCF according to the embodiment of the present invention will be described below with reference to the drawings. It should be noted that the present invention is not limited to these exemplifications, and is shown by the scope of the claims, and is intended to include meanings equivalent to the scope of the claims and all modifications within the scope. In the following description, the same reference numerals are given to the same elements in the description of the drawings, and overlapping description will be omitted.

FIG. 1A is a front view showing an end face 10a (first end face) of the MCF 10 (first multi-core optical fiber). FIG. 1B is a front view showing an end face 20a (second end face) of the MCF 20 (second multicore optical fiber). These MCFs 10 and 20 are connection targets of the manufacturing method according to the embodiment of the present invention. As shown in FIG. 1A, the MCF 10 includes one or more (six in FIG. 1A) cores 12 (first cores) made of glass and one or more cores 12 collectively. It has a glass clad 14 (first clad) for covering and a resin coating portion 16 for covering the clad 14. Similarly, the MCF 20 includes one or more (six in FIG. 1B) cores 22 (second cores) made of glass, and a glass clad 24 (first core) that collectively covers the one or more cores 22. 2 clad) and a resin coating portion 26 that covers the clad 24.

The MCFs 10 and 20 have the same core arrangement. Here, “identical to each other” means that, when the end surface 10a of the MCF 10 and the end surface 20a of the MCF 20 are viewed from the front, the positions of the one or more cores 12 and the positions of the one or more cores 22 are mirror images of each other. Means that you can be in a relationship.

Further, the core positions of the MCFs 10 and 20 do not have rotational symmetry. The rotational symmetry means a property in which a plurality of core positions when the cross section of the MCF is rotated by a certain angle coincides with the plurality of core positions in the original cross section. For example, when six cores are arranged at equal angular intervals around the central axis, this core arrangement has 6-fold rotational symmetry. In such an MCF, the centers of gravity of the plurality of core positions coincide with the central axis. On the other hand, since the core positions of the MCFs 10 and 20 of this embodiment do not have rotational symmetry, the center of gravity of the plurality of core positions deviates from the central axis. In other words, the center of gravity at the core position has a constant distance from the central axis. This distance is sufficiently larger than the manufacturing error. When there is one core, the core position is the center of gravity.

FIG. 2 is a flowchart showing each step of the manufacturing method according to the present embodiment. Hereinafter, the manufacturing method according to the present embodiment will be described with reference to FIG.

First, as the preparation step S1, the MCFs 10 and 20 are cut by, for example, a fiber cutter or the like to form the end faces 10a and 20a capable of recognizing the cores 12 and 22.

Next, as the first step S2, the end surface 10a of the MCF 10 and the end surface 20a of the MCF 20 are opposed to each other. FIG. 3 is a diagram schematically showing this step. As shown in FIG. 3, the MCF 10 is fixed to the fiber holding jig 40A (first fiber holding jig). Similarly, the MCF 20 is fixed to the fiber holding jig 40B (second fiber holding jig). These fiber gripping jigs 40A and 40B can grip the MCFs 10 and 20, respectively, and move the MCFs 10 and 20 in the directions of three axes (x axis, y axis, and z axis) orthogonal to each other. In one example, these fiber gripping jigs 40A and 40B have an x-axis stage 41, a y-axis stage 42, and a z-axis stage 43. The x-axis is an axis along the central axes of the MCFs 10 and 20, the y-axis is an axis orthogonal to the central axes of the MCFs, and the z-axis is an axis orthogonal to these axes. Further, these fiber gripping jigs 40A and 40B have a θx stage 44 that allows the MCFs 10 and 20 to rotate about their central axes, respectively. Then, the fiber holding jigs 40A and 40B are arranged so that the end surface 10a and the end surface 20a face each other along a certain common axis A1. In this step, the resin coating portions 16 and 26 of the MCFs 10 and 20 may be removed.

Then, as a second step S3, the relative position and the relative angle around the central axis of the end surfaces 10a and 20a in the plane intersecting the central axis are adjusted. FIG. 4 is a diagram schematically showing the second step S3. The second step S3 includes a camera placement step S31, a fiber moving step S32, a center-of-gravity point calculation step S33, and a rotation step S34.

(Camera placement process)
In the camera arranging step S31, the image pickup device 31 (first image pickup device) is arranged at a position facing the end face 10a, and the image pickup device 32 (second image pickup device) is arranged at a position facing the end face 20a. The image pickup devices 31 and 32 are, for example, CCD cameras. As shown in FIG. 4, these imaging devices 31 and 32 are arranged on a table 33 provided between the fiber holding jig 40A and the fiber holding jig 40B. A monitor 34 is electrically connected to the imaging device 31. A monitor 35 is electrically connected to the imaging device 32. The respective image data obtained by the image pickup devices 31 and 32 are visible on the monitors 34 and 35, respectively.

In this step, the coordinate center of each image data of the imaging devices 31 and 32 is positioned on one common axis A1 (in other words, the center of the light receiving surface of each imaging device 31 and 32 is one common axis A1. It is advisable to adjust the positions of the image pickup devices 31 and 32 so that they are located on A1). 5A and 5B show image data D1 of the image pickup device 31 and image data D2 of the image pickup device 32, respectively. The yz coordinate axes are defined in the image data D1 and D2, and the positions of the image pickup devices 31 and 32 are adjusted so that the common axis A1 is located at the origin of the yz coordinate axes.

(Fiber moving process)
As shown in FIG. 5A, the image data D1 of the imaging device 31 includes the image J1 of the end surface 10a of the MCF 10. Further, as shown in FIG. 5B, the image data D2 of the image pickup device 32 includes the image J2 of the end face 20a of the MCF 20. In the fiber moving step S32, first, the position of the central axis C1 of the MCF 10 is acquired from the contour of the end face 10a in the image data D1. Similarly, the position of the central axis C2 of the MCF 20 is acquired from the contour of the end surface 20a in the image data D2. Here, the positions of the central axis lines C1 and C2 of the MCFs 10 and 20 mean the position coordinates of the central axis lines C1 and C2 of the MCFs 10 and 20 on the yz coordinate plane. After that, by controlling the y-axis stage 42 and the z-axis stage 43 of each of the fiber gripping jigs 40A and 40B to relatively move the MCFs 10 and 20, the central axis C1 of the MCF 10 and the central axis C2 of the MCF 20 are set. Get closer to each other. In one example, the central axis C1 of the MCF 10 and the central axis C2 of the MCF 20 are both brought close to the common axis A1 (that is, the coordinate origin).

(Center of gravity point calculation process)
FIGS. 6A and 6B show image data D1 of the image pickup device 31 and image data D2 of the image pickup device 32 after the fiber moving step S32. In the center-of-gravity point calculation step S33, the center-of-gravity point of the core position on the end face 10a is obtained from the image data D1, and the center-of-gravity point of the core position on the end face 20a is obtained from the image data D2. Letting each core position be (y _i , z _i ) (where i=1, 2,..., N, n is the total number of cores), the coordinates of the center of gravity are (Σy _i /n, Σz _i /n ) Is calculated. When there is one core, the position coordinates of the core are the coordinates of the center of gravity.

(Rotation process)
Subsequently, in the rotating step S34, the MCFs 10 and 20 are relatively rotated about the central axes C1 and C2 so that the center of gravity of the core position on the end face 10a and the center of gravity of the core position on the end face 20a approach each other. Specifically, as shown in FIGS. 7A and 7B, the barycentric point of the core position in the image data D1 and the barycentric point of the core position in the image data D2 are lines with respect to the z-axis. The θx stage 44 of each of the fiber gripping jigs 40A and 40B is controlled to rotate the MCFs 10 and 20 relatively so that the positions are symmetrical. Therefore, if the coordinates of the center of gravity of the core position in the rotated image data D1 are (y1, z1), the coordinates of the center of gravity of the core position in the rotated image data D2 are (-y1, z1).

Finally, as the third step S4, the end faces 10a and 20a are opposed to each other by relative movement of the image pickup devices 31 and 32 with respect to the end faces 10a and 20a (for example, removal of the image pickup devices 31 and 32). Then, the x-axis stage 41 of each fiber holding jig 40A, 40B is controlled to bring the end faces 10a, 20a close to each other, and the end faces 10a, 20a are connected to each other by, for example, heat fusion or adhesion.

The effects obtained by the manufacturing method of the connected MCF of the present embodiment described above will be described. In this manufacturing method, in the second step S3, the end faces 10a, 20a of the MCFs 10, 20 are imaged by the image pickup devices 31, 32, and the obtained image data D1, D2 are used for axis alignment. That is, after the central axis lines C1 and C2 of the MCFs 10 and 20 are brought close to each other based on the image data D1 and D2, the center of gravity points of the core positions of the MCFs 10 and 20 are obtained, and the MCFs 10 and 20 are brought close to each other. Rotate relative to. According to such a method, even if the core positions do not have rotational symmetry, all the cores 12 of the MCF 10 can be coupled to all the cores 22 of the corresponding MCF 20 at the same time. Therefore, the axes of the MCFs 10 and 20 can be easily aligned.

The method of manufacturing the connected MCF according to the present invention is not limited to the above-described embodiment, and various modifications can be made. For example, the embodiments described above may be combined with each other depending on the required purpose and effect. Further, although the coordinate system of each image data has been described as an orthogonal coordinate system in the above embodiment, the coordinate system of each image data may be a polar coordinate system.

10... 1st MCF, 10a... 1st end surface, 12... 1st core, 14... 1st cladding, 16, 26... Resin coating part, 20... 2nd MCF, 20a... 2nd end surface, 22... 2nd core, 24... 2nd clad, 31... 1st imaging device, 32... 2nd imaging device, 33... Stand, 34, 35... Monitor, 40A, 40B... Fiber holding jig, 41... x-axis stage, 42... y-axis stage, 43 ... z-axis stage, 44... θx stage, A1... Common axis, C1, C2... Central axis, D1, D2... Image data.

Claims (2)

A first end surface of the first multi-core optical fiber having a first cladding collectively covering the first core and the first core before Kifuku number of multiple, second second core and the front Kifuku number of multiple A first step in which a second end face of a second multi-core optical fiber having a second cladding that collectively covers the core is opposed to each other;
A second step of adjusting the relative position of the first end face and the second end face in a plane intersecting the central axis and the relative angle around the central axis;
A third step of connecting the first end surface and the second end surface to each other,
The first multicore optical fiber and the second multicore optical fiber have the same core arrangement, and the core positions of the first multicore optical fiber and the second multicore optical fiber do not have rotational symmetry,
The second step is
Disposing a first imaging device at a position facing the first end face and disposing a second imaging device at a position facing the second end face;
The first said arranged on the end face opposite to position the first imaging device, and based on the image data obtained by arranged the second image pickup apparatus at a position opposed to the second end surface, the first multicore A step of relatively moving the first multicore optical fiber and the second multicore optical fiber so that respective central axes of the optical fiber and the second multicore optical fiber come close to each other;
Obtaining the center of gravity of the core position on the first end face from the image data obtained by the first image pickup device, and obtaining the center of gravity of the core position on the second end face from the image data obtained by the second image pickup device; ,
The first multi-core optical fiber and the second multi-core optical fiber are relatively rotated around the central axis so that the center of gravity of the core position on the first end face and the center of gravity of the core position on the second end face approach each other. A method of manufacturing a spliced multi-core optical fiber, the method including: In the step of arranging the first imaging device and the second imaging device, the first imaging is performed so that the coordinate center of each image data of the first imaging device and the second imaging device is located on one axis. The method for manufacturing a spliced multi-core optical fiber according to claim 1, wherein the positions of the device and the second imaging device are adjusted.

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