JPH01209409A - Constituting method for optical fiber array - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Summary] In optical fiber communication, the present invention relates to a method of configuring an optical fiber array that is optically coupled to an optical fiber array element incorporated in an optical transmission line, and particularly relates to a method of aligning polarization-maintaining optical fibers. The purpose is to be able to easily adjust the plane of polarization without being affected by the curvature of the fiber, maintain that state, and align and fix the core wires with high precision. The V-grooves are covered with a cover plate having slits in the direction perpendicular to the groove direction, and the core wire of the polarization-maintaining optical fiber is inserted into the triangular hole in cross-section formed by the V-groove and the cover plate. A plate-shaped holding device is inserted through the slit, and the end face of the holding device presses the core wire along the groove (1) to align and fix the polarized wave plane after rotation adjustment.

[Industrial application field]

The present invention relates to a method for configuring an optical fiber array that is optically coupled to an optical fiber array element incorporated in an optical transmission line in optical fiber communication, and also relates to a method for aligning polarization-maintaining optical fibers.

In optical communication systems, optical transmission lines are being integrated not only by optical coupling between a single optical element and a single optical fiber, but also by optical coupling between an optical fiber array element and an optical fiber array.

Therefore, the alignment interval should be kept as small as possible, for example, 25
Especially in the case of polarization maintaining optical fibers (hereinafter abbreviated as optical fibers), there is a need for a method that can easily rotate and adjust the polarization plane during alignment and align and fix with high precision.

[Conventional technology]

Conventionally, as shown in the perspective view of FIG. 5, a block body 11,
For example, the cores 15a of optical fibers 5 are inserted into a flat surface of a silicon block at predetermined intervals, for example, at intervals of 0.5n.
As shown in the cross-sectional view of the main part in Figure 3, the V? 112 are arranged in parallel.

Then, the coating layer of the optical fiber 5 with an outer diameter of about 0.9 mm is removed, and the core wire 5a with an outer diameter of 125 μm is exposed and inserted one by one into each groove 12 from above. Lightly press the core wire 5a in the direction of the arrow with the flat end surface 16a of 16, rotate the core wire 5a in this state to adjust each plane of polarization, and then press the presser 16 against the core wire 5a to tighten the core wire 5a. (2) along the groove 12 and fixed using an adhesive (not shown) so as to maintain that state.

[Problem to be solved by the invention]

However, according to the above method, the flat end surface of the presser presses down a part of the core wire inserted into the V-groove, and (1) the presser is not applied to the core wire that sinks low due to the precision of the groove. Because it does not work, it is difficult to align the core wires in the groove, and because multiple wires are pressed at the same time, it is difficult to smoothly adjust the rotation of the polarization plane one by one. It is also difficult to hold at the same time.

To further increase the density of alignment, if multiple optical fibers with an outer diameter of 0.911 are arranged in parallel at intervals of, for example, 250 μm, the fibers in the rows closest to both ends will bend significantly, causing a curved state. It will be inserted into the groove. The larger the number of wires to be aligned, the greater the degree of curvature, which caused problems such as the inability to align the core wires accurately.

In view of the above problems, it is an object of the present invention to provide a method for configuring an optical fiber array in which the plane of polarization can be easily adjusted without being affected by the curvature of the optical fibers, and the plane of polarization can be maintained and aligned with high precision. purpose.

[Means to solve the problem]

In order to achieve the above object, in the method for configuring an optical fiber array of the present invention, a plurality of grooves are arranged in parallel at a predetermined interval on one surface of a block body, and the grooves are formed into slits in a direction perpendicular to the direction of the grooves. ■ Insert the core of the polarization-maintaining optical fiber into the triangular hole in cross-section formed by the groove and the cover plate, insert the plate-shaped holder through the slit, and insert the core with the end face of the polarization-maintaining optical fiber. ■It is configured so that it is pressed against the groove and aligned, the plane of polarization is adjusted by rotation, and then aligned and fixed.

[Effect]

■Since the core wire inserted into the groove is guided and restrained by the triangular hole, the curved state of the core wire is straightened and is not affected by the curvature (the rotation of the plane of polarization can be easily adjusted, and the core wire can be raised to high Can be easily aligned with precision.

〔Example〕

The gist of the present invention will be explained in detail below based on embodiments shown in the drawings. Note that in the figures, the same reference numerals as in the prior art indicate the same parts and portions.

In the first embodiment, as shown in the perspective view of FIG. 1, V grooves 2 with an apex angle of about 70' are formed on one flat surface of a block body 1, for example, a silicon block, at predetermined intervals, for example, minute intervals of 250 μm. A plurality of V grooves 2 are arranged in parallel, and the V grooves 2 are covered with a cover plate 3 made of metal or glass, and the grooves 2 and the cover plate 3 form a triangular hole 4 in cross section.

The dimensional accuracy of the triangular hole 4 to be formed is determined by the optical fiber 5 described later.
The outer diameter of the core wire 5a is in contact with the second surface of the groove, a slight gap is provided between the inner surface of the cover plate 3 and the core wire 5a, and the V? The depth of i2 is set to such an extent that the core wire 5a can rotate with little play.

Then, the coating layer of the optical fiber 5 with an outer diameter of about 0.9n is removed, and the core wire 5a with an outer diameter of 125 μm is exposed and inserted into the triangular hole 4, and each core wire 5a is rotated to After adjusting the direction of the polarization plane, it is fixed using adhesive (as shown) to maintain that state.

If even higher alignment accuracy is required, the dimensional accuracy of the triangular hole 4 is set to a level that allows the core wire 5a to rotate, so as shown in the side cross-sectional view of the main part in FIG. There is a slight gap between the groove surface and the core wire 5a may float above the groove surface, so centering may not necessarily be sufficient depending on the required precision.

In order to solve this problem, as shown in the side cross-sectional views of main parts in FIGS. 3a, insert a Teflon plate presser 6, and press the core wire 5a after adjusting the rotation of the polarization plane with its acute end surface 6a in the direction of the arrow to eliminate the gap so that the core wire 5a comes into contact with the groove surface. Hold it in place and fix it using adhesive (as shown). The end surface 6a of the presser 6 has an acute angle so that it is flexible and can be sunk into the groove 2 to hold the core wires 5a individually.

FIG. 4 is a perspective view showing the completed state.

According to such a method, the core wire has V? Since the core is guided and restrained by the triangular hole formed by the n and the cover plate, even if the core is highly curved, its curved state is straightened, and the polarization plane of each core can be rotated and adjusted without being affected by the curvature. can be easily done individually, and even if the number of wires to be aligned increases, since the entire surface is held down by the cover plate, it is possible to stably hold, align, and fix a large number of core wires at the same time. Furthermore, by pressing with the sharp edge of the presser,
The core wires can be reliably aligned with the V-groove and aligned and fixed with high precision.

〔Effect of the invention〕

As detailed above, according to the present invention, by attaching a cover plate that covers the groove, the polarization plane can be easily adjusted, and moreover, it can be aligned and fixed with high precision at minute intervals, and the optical fiber array can be This has extremely useful effects in practice, such as improving the degree of integration and making it possible to form an optical transmission line with good optical transmission characteristics.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of one embodiment of the present invention, and FIG. 2 is a perspective view of an embodiment of the present invention.
Figure 3 is a side sectional view of the main part of the groove shown in Figure 1 when pressed with the presser, Figure 4 is a perspective view of the completed state shown in Figure 1, and Figure 5 is a side sectional view of the main part of the groove. The figure is a perspective view according to the prior art. In the figure,

Claims (1)

[Claims] A plurality of V-grooves (2) are arranged in parallel at predetermined intervals on one side of the block body (1), and the V-grooves (2) are covered with a cover plate (3) having slits (3a) in a direction perpendicular to the V-groove direction. Cover, the V groove (
Insert the core wire (5a) of the polarization maintaining optical fiber (5) into the triangular hole (4) formed by the cover plate (3) and the cover plate (3), and insert the plate-shaped presser through the slit (3a). (6
), and the core wire (5a
) is pressed along the V-groove (2), the plane of polarization is adjusted by rotation, and then aligned and fixed.