JPS6033248B2 - Manufacturing method of optical fiber connector terminal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for simply and highly accurately manufacturing an optical fiber connector terminal that can connect optical fibers while maintaining good transmission characteristics.

In optical fiber transmission lines used for optical communications, interconnection of optical fibers is an extremely important issue. When connecting optical fibers, it is necessary to align the axes of the fibers with high accuracy on the order of micrometers. In this case, the optical fiber is made of glass, and the external light is 10
Since the connector terminal is thin (0 micron or less), the connector terminal must satisfy two conditions: protecting and reinforcing the optical fiber, and being able to align the axis of the connector terminals with high precision. For this reason, typical conventional connector terminals
As shown in the figure, an optical fiber 1 is covered with a plug sleeve 2 made of metal or the like, and the optical fiber and the plug sleeve 2 are fixed with an adhesive 3. In order to connect the optical fibers with each other, as shown in FIG.
The connector terminals 4 and 4' shown in the figure are inserted into the mating sleeve 5 so that they face each other. In this case, in order to obtain good connection characteristics, the central axes of the optical fiber 1 and the plug sleeve 2 must be aligned at 4 and 4', and the misalignment error should be less than a few microns. This is required. However, unless the gap between the outer diameter of the optical fiber and the inner diameter of the plug sleeve 2 is larger than the allowable axis misalignment error, the optical fiber 1 cannot actually be inserted into the hole of the plug sleeve 2. 2
The central axes of the two must be aligned.

As a typical example of this alignment method, conventionally, Fig. 3 a and b
The method shown has been adopted. In Figure 3a,
6 is the end face of the optical fiber 1, and 7 is the end face of the plug sleeve 2, which are viewed under magnification using a microscope.
By slightly moving the optical fiber or plug sleeve, the center of the end surface 6 of the optical fiber 1 and the center of the outer diameter of the end surface 7 of the plug sleeve 2 are adjusted to match.
Both end surfaces 6 and 7 are adhesively fixed.

However, although this method makes it easy to define the center of the end surface 6 of the optical fiber 1, since the outer diameter of the end surface 7 of the plug sleeve 2 is about an order of magnitude larger than the outer diameter of the end surface 6 of the optical fiber 1,
Since it is difficult to define the center of the outer diameter of the end surface 7 of the plug sleeve 2, it is necessary to simultaneously define the center of the end surface 6 of the optical fiber and the outer diameter center of the end surface 7 of the plug sleeve 2, and adjust the two centers so that they coincide. The drawback is that a complex and expensive optical device must be used for this purpose. Third
Figure b shows what is called the double eccentric method, and if the inner eccentric sleeve 8 and the outer eccentric sleeve 9 are rotated relative to each other,
The center of the end surface 6 of the optical fiber 1 and the center of the outer eccentric sleeve 9 can be made to coincide with each other.

However, this inherently has the major drawback that high-precision eccentric sleeves must be precisely assembled, and difficulties similar to those shown in Figure 3a must be overcome when fusing by rotation adjustment. . In order to eliminate these drawbacks, the present invention utilizes a precise geometrical arrangement of spheres made of steel or glass, which have the highest dimensional accuracy and are inexpensive in machining, to fuse the optical fiber and the plug sleeve. The present invention aims to provide a simple and easy method for manufacturing highly accurate connector terminals by performing matching.

The present invention will be explained in detail below with reference to the drawings. First, FIGS. 4 and 5 are examples of manufacturing a single-core optical fiber connector terminal, and FIGS. 4a and 5b are layout diagrams in a plane perpendicular to the axis of the optical fiber. b and FIG. 6b are layout diagrams in a plane perpendicular to FIG. 4a and FIG. It is a sphere of diameter. The embodiment shown in FIG. 4 is an example in which spheres are arranged on one plane. First, when three spheres 10 of the same flea are arranged closely together, a Δ-shaped recess is formed in the center.

Furthermore, the spheres 10 are placed in close contact with each two spheres 10.
Three spheres 11 with larger diameters are arranged and fixed on the same plane. In this case, if the dimensional accuracy of the spheres 10 and 11 is good, the center of the △-shaped recess formed by the three spheres 10 and the common center of the three spheres 11 arranged on the same plane are Matches accurately. In order to align the center of the optical fiber 1 with the outer diameter center of the plug sleeve 2 using this array sphere, first push the optical fiber into the △-shaped recess and hold it perpendicular to the array surface. 2 is stuck up so as to be in contact with the three spheres 11 and held perpendicular to the arrangement surface. At this time, depending on how the diameters of the spheres 10 and 11 are selected with respect to the outer diameter of the optical fiber 1 and the outer diameter of the plug sleeve 2, the fiber is stuck in the △-shaped recess and the sleeve is stuck in the arrangement of the spheres 11. The state can be selected as appropriate. The embodiment shown in FIG. 4 is an example in which the gap between the △-shaped recess is smaller than the outer diameter of the optical fiber, and the gap formed by the three spheres 11 is smaller than the outer diameter of the sleeve 2. And,
In this case, the end face 6 of the optical fiber 1 has three spheres 10
By contacting the three spheres 11 evenly, the center of the optical fiber and the center of the △-shaped recess are aligned, and furthermore, the outer diameter of the end surface 7 of the plug sleeve 2 is in contact with the three spheres 11 evenly.
The outer diameter center of the plug sleeve and the central axis of the optical fiber match with high precision. The sphere used here is an example of a steel ball for ball bearings that is commercially available as a JIS standard product, but other materials such as glass can also be easily made with extremely high precision, with a dimensional accuracy of 0.5 to 0.2 degrees. Among the machining methods available, it is possible to ensure the highest dimensional accuracy.

The embodiment shown in FIG. 5 is an example in which spheres are arranged three-dimensionally on two planes.

First, 12 spheres 10 of the same diameter are arranged in close contact with each other on one plane, and then six of the same spheres are dropped into a △-shaped recess formed from one sphere, and then placed in the △-shaped recess in the center. Arrange them on the same circumference as 0 and fix them. In this case, the optical fiber is thrust into the central △-shaped recess formed by the sphere 10 as in the case of FIG. Separate them. Here, the same holds true even if the number of spheres 11 is three. Figure 6 shows the case where a plurality of optical fibers are brought into close contact with each other and condensed into an axially symmetrical shape to form an optical fiber group, and the optical fiber group is treated as a single optical fiber in the same machine. FIG. 12 is an example diagram.
is optical fiber/ゞkunyou. In this example, the optical fiber/Houyang 12 bundles seven optical fibers, and since the dimensional accuracy of each optical fiber is extremely high, they are concentrated into a shape that is almost completely axially symmetrical. By inserting this optical fiber group 12 into the Δ-shaped recess formed by the arrangement of the spheres 10 and sticking it up, the central axis of the optical fiber group 12 can be aligned with the center of the Δ-shaped recess. The plug sleeve is aligned in the same way as in the case of a single-core optical fiber, by means of the central △-shaped recess and the spheres 11 arranged on the circumference of the same D. In the embodiment described above, when an optical fiber is inserted into the △-shaped recess formed by the arranged spheres, the tip of the optical fiber is cut perpendicular to the axis, but in that case, the tip of the optical fiber is heated and melted. By machining it into a spherical shape, the axis alignment operation can be performed more smoothly and reliably.

This embodiment is shown in FIGS. 7a and 7b. In Figure 7a,
Reference numeral 13 denotes a glass bulb. When the optical fiber 1 is held vertically and its tip portion is heated and melted, it solidifies into a spherical shape due to the surface tension of the molten glass.

The sphericity of this glass sphere is extremely high, and the center of the sphere is located almost completely on the central axis of the fiber. Therefore, by pressing the glass bulb 13 into the Δ-shaped recess of the sphere 10, the central axis of the optical fiber can be easily aligned with the center of the Δ-shaped recess. FIG. 7b shows an example in which a group of optical fibers is treated in the same way, and if the tips of the group of optical fibers 14 are heated and melted all at once, a glass bulb 15 can be made.
The center of the optical fiber group 14 and the center of the Δ-shaped recess can be made to coincide with each other with high accuracy in the same manner as in the case of FIG. by the way,
When two connector terminals of an optical fiber group are connected facing each other as shown in Fig. 2, the rotation angle of the fiber array of the optical fiber group in all directions around the circumference and the rotation angle of the plug sleeve in all directions around the circumference are stipulated to be constant. must have been done.

FIG. 8 is an embodiment diagram of the present invention that defines this, and 1
6 is a guide pin fixed to the plug sleeve. First, as in the previous embodiments, the optical fiber group 12 and the plug sleeve are pushed into the array sphere.

(The figure shows the end face of the optical fiber group and the end face 7 of the plug sleeve.) Next, when the guide pin 16 is pressed against the gap between the array spheres 11 along the plug sleeve, the guide pin 16 and the plug sleeve to be fixed. The relative arrangement of the thus fixed guide pin 16 and the fiber arrangement of the optical fiber group 12 is uniquely determined by the geometric shape of the arrangement sphere. In this way, the connector terminal can be manufactured in the same manner as the embodiment shown in FIG. After aligning the axes of the optical fiber and the plug sleeve 2 using the method described above, adhesive is put into the gap between the optical fiber 1 and the plug sleeve 2, the optical fiber 1 is fixed to the plug sleeve 2, and the tip of the optical fiber is The end face is formed by cutting and polishing to form the final connector terminal. As explained above, the manufacturing method of the optical fiber connector terminal of the present invention has the highest dimensional accuracy in terms of machining, and a precise geometrical arrangement of spheres made of easily available and inexpensive steel or glass. This method has the advantage that highly accurate connector terminals can be manufactured extremely easily compared to conventional methods.

Therefore, the present invention has extremely effective effects on the practical application of optical communications, such as making it easier to connect optical fibers, which has been a difficult problem in optical fiber transmission lines, and maintaining good characteristics of the connection parts. big.

[Brief explanation of drawings]

Figure 1 is a structural diagram of a conventional optical fiber connector terminal, Figure 2 is a structural diagram of a conventional optical fiber connector terminal.
The figure is a conceptual diagram of the iron structure of an optical fiber connector, Figure 3 is an explanatory diagram of the conventional axis alignment method between the optical fiber and the plug sleeve, and Figures 4 and 5 are the fabrication of a single-core optical fiber connector terminal. FIG. 6 is an example of the present invention in the case of a group of optical fibers, FIG. 7 is an example of the present invention in which the tip of the optical fiber is processed into a spherical shape, and FIG. 8 is a plug FIG. 3 is an embodiment diagram of the present invention that defines the rotation angle of the sleeve in the circumferential direction. 1...Optical fiber, 2...Plug sleeve, 3...Adhesive, 4
, 4'... Connector terminal, 5... Sleeve for mating,
6... End face of optical fiber, 7... End face of plug sleeve, 8... Inner eccentric sleeve, 9... Outer eccentric sleeve, 10... Sphere, 11... Sphere, 12... Light Fiber group, 13... Glass bulb, 14... Optical fiber group, 15
...Glass bulb, 16...Guide pin. Figure 1 Figure 2 Figure 3 Figure 4 Figure 6 Figure 5 Figure 7 Figure 8

Claims (1)

[Scope of Claims] 1 A plurality of spheres are arranged in close proximity to each other on an arrangement surface, and a light beam is placed in the center of a △-shaped recess formed in a triangular shape and surrounded by three adjacent spheres. a plug sleeve that is previously placed over three or more spheres other than the spheres that hold the fibers upright and perpendicular to the arrangement surface and that are arranged on a circumference surrounding the △-shaped recess; By holding the plug sleeve perpendicular to the arrangement surface so that the outsides of the fibers are in contact with each other, the optical fiber and plug sleeve can be fixed to each other with the axis of the optical fiber and the center of the outer diameter of the plug sleeve aligned. Features: A manufacturing method for optical fiber connector terminals. 2 A plurality of spheres are arranged in close proximity to each other on the arrangement surface, and a triangular shape surrounded by three adjacent spheres is formed at the center of a △-shaped concave part, which has an axial symmetry. A group of optical fibers consisting of a plurality of optical fibers that are brought together closely and focused are pushed up all at once and held perpendicular to the arrangement surface, and a group of optical fibers that is different from the sphere arranged on the circumference surrounding the △-shaped recess is Holding the plug sleeve perpendicular to the arrangement surface so that the outside of the plug sleeve that has been placed over the optical fiber group in advance contacts the three or more spheres, and the rotation angle in the circumferential direction of the optical fiber group; By defining the rotation angle of the plug sleeve in the circumferential direction by a guide pin fixed to the plug sleeve with reference to the geometric shape of the three spheres, the center of the optical fiber group and the outer diameter center of the plug sleeve are determined. A method for manufacturing an optical fiber connector terminal, characterized by fixing an optical fiber group and a plug sleeve to each other with the same state.