JPS60164709A - Optical fiber coupling part - Google Patents

Abstract

PURPOSE:To couple each end face of an optical fiber with a high dimension accuracy, at a low cost and also by a simple work, by providing peripherally a magnetic material for operating a magnetic absorptivity, on the end part of the optical fiber to be coupled. CONSTITUTION:Connector outer cylinders 5a, 5b are installed to two optical fibers 1a, 1b, respectively, and both of them are screwed by a screw. As coupling of both the connector outer cylinders 5a, 5b is deepened by feeding the screw, each end face of the optical fibers 1a, 1b approaches each other by a magnetic attraction of magnetic material films 4a, 4b provided on the circumference of the optical fibers 1a, 1b. Also, the end faces of the optical fibers 1a, 1b are positioned exactly, and in the end, they are coupled exactly without a gap.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical fiber coupling part suitably used in a connector for coupling optical fibers together.

Optical fiber / < -1 Especially in single mode optical fiber,
The core diameter is extremely thin, several ILm or less. Therefore, in order to join the end faces of two single mode optical fibers together and couple the optical transmission line with very little loss, extremely high alignment accuracy of about ±0, 1 #Lm is required. . This makes single-mode optical fiber pairing devices expensive and makes field work difficult.

It is an object of the present invention to eliminate the problems that exist when coupling optical fibers, especially single mode optical fibers, and to provide an optical fiber coupling part that can couple the end faces of optical fibers with high dimensional accuracy, at low cost, and with simple work. The gist of the present invention is to provide a method in which a magnetic material to which a magnetic attraction force acts is provided around the end of an optical fiber to be coupled.

FIG. 1 shows a principle diagram to which the present invention is applied, in which 1a and 1b are optical fibers that are coupled at a joint surface J, respectively,
2a and 2b are the cores of the respective optical fibers, 3a and 3
b is a cladding. These optical fibers 1a, lb
In the vicinity of the bonding surface J around the periphery, there is a magnetic film 4 of uniform thickness.
a and 4b are provided. As shown in FIG. 1, the magnetic films 4a and 4b are magnetized so that the polarities differ at the bonding surface J.

Therefore, at these joint surfaces J, the left and right magnetic films 4
a and 4b are attracted to each other, and accurate alignment is naturally achieved, resulting in a reliable connection.

FIG. 2 shows an example of the structure of an optical fiber connector in which the magnetic films 4a and 4b are made of a permanent magnetic material with an extremely large coercive force. The two optical fibers 1a, lb have connector outer cylinders 5a, 5b, respectively, and are screwed together. As the connection between the two connector outer cylinders 5a and 5b is deepened by feeding the screw, the end faces of the optical fibers 1a and lb are pulled together by the magnetic attraction force of the magnetic films 4a and 4b provided around the optical fibers 1a and lb. Approaching, optical fiber 1a,
The end faces of 1b are accurately aligned and finally joined accurately without any gaps.

At this time, empty Ti! f6a, 6
b is a provision, even if the screw connection between the connector outer cylinders 5a and 5b is excessive, the optical fibers 1a and 1bc7)
) It is possible to prevent breakage of the optical fibers 1a, lb themselves. Note that 7a and 7b are jackets that cover the optical fibers 1a and lb.

Further, if the connector outer cylinders 5a, 5b are made of a transparent plastic material, the state of coupling of the optical fibers 1a, 1b can be visually observed, so that more accurate coupling can be ensured. Furthermore, when constructing the connector outer cylinders 5a, 5b from such a transparent plastic material, a window that acts as a convex lens may be provided in one of the connector outer cylinders 5a, 5b.

This is convenient because the accuracy of joining at the joining surface J can be visually checked in an enlarged manner.

When the magnetic bodies IIJ4a and 4b are made of a soft magnetic material with a low coercive force, such as a Ni-Fe alloy, the permanent magnet 8 is connected to the magnetic film 4a, as shown in FIG. 4b, and the optical fibers 1a, 1
It is possible to magnetize the magnetic films 3a and 3b at the joint ends of b so that an attractive force acts between the two magnetic films 3a and 3b. At this time, there is a risk that the magnetic films 3a and 3b may be attracted to the permanent magnet 8 before the magnetic films 3a and 3b are attracted to each other, so the permanent magnet 8 is
, As shown in (b), it is necessary to make it cylindrical so that the attraction forces between the permanent magnet 8 and the magnetic films 4a and 4b are balanced. At this time, as shown in FIG.
4b, the magnetic films 4a and 4b will be attracted to the permanent magnet 8 even if the magnetic films 4a and 4b are shifted from the center of the permanent magnet 8 and the balance of their attractive forces is broken. You can prevent this from happening.

Further, as a method of magnetizing the magnetic films 4a and 4b made of soft magnetic material, as shown in FIG.
Magnetization can also be performed by providing a coil 10 around 4b and passing a current through it. In this case, as shown in FIG. 7, separate coils 10a and 10b are provided at the respective ends of the optical fibers 1a and lb so that the polarity of the current flowing through them generates a magnetic field in the same direction. If the body membranes 4a, 4b are attracted to each other, by reversing the polarity of one of the currents, the magnetic membranes 4a, 4
It becomes possible to make it possible for the fibers b to repel each other and break the coupling, thereby realizing a switch for optical fibers la and lb.

After the optical fibers 1a, 1b are coupled, in the case of a permanent coupling that does not require breaking the coupling again, for example, the coupling connector outer cylinders 5a, 5b and the optical fibers 1a, 1b shown in FIG.
It is sufficient to inject thermosetting resin or the like into the spaces 6a and 6b between them and harden them. In this case, even if the external magnetic field used to magnetize the magnetic films 4a and 4b is removed after solidification, good.

If it is necessary to center the optical fiber within the connector, it can be done by the means shown in FIG. That is, 11 is a holding cylinder for the optical fiber 1a which becomes a part of the connector, and a through hole 12 is provided in the center thereof, into which the optical fiber /<-1a is inserted. Optical fiber/<-1a, the jacket l-7a is still attached to the part, the optical fiber 1a is cut out at the tip, a magnetic film 4a is provided around the tip, and the holding cylinder 11 On the other hand, reference numeral 13 denotes a jig made of a non-magnetic material, and a guide member 14 made of a permanent magnet is provided inside the jig. It has a small diameter, and its tip 15 has approximately the same diameter as the magnetic film 4a provided on the optical fiber 1a, and is placed exactly at the center of the jig 13.In addition, 16 is a guide. This is a holding member made of a non-magnetic material for holding the member 14.

When performing centering, the optical fiber 1a inside the holding tube ll
The holding cylinder 11 and the jig 13 are bonded together after filling the gap therewith with an adhesive 17 that hardens over time. By doing so, the magnetic film 4a at the tip of the optical fiber 1a
is magnetically attracted to the tip 15 of the guide member 14, and its accurate position is maintained. If the adhesive 17 is left as is, the adhesive 17 is allowed to solidify, and the jig 13 is removed, the tip of the optical fiber 1a will be accurately centered. Thereafter, by polishing the tip of the optical fiber 1a that slightly protrudes from the holding tube 11, a joint with low optical loss can be obtained. The other optical fiber 1b to be joined can also be centered in the same way, and the joining can be easily carried out on site.

Furthermore, in the embodiments, the magnetic material provided around the optical fibers 1a, 1b has been described as a film, but it is not necessarily a film, but may be applied to the optical fibers 1a, 1b as a cylindrical body, for example.

As explained above, the optical fiber coupling unit according to the present invention can easily and accurately align the optical fibers using the magnetic attraction force of the magnetic material.

[Brief explanation of drawings]

The drawings show an embodiment of the optical fiber coupling part according to the present invention, Fig. 1 is a diagram of its application principle, Fig. 2 is a sectional view when an outer cylinder is attached when used as a connector, and Fig. 3 is a permanent one. A cross-sectional view when a magnetic film is magnetized by a magnet, Figure 4 (a)
) is a perspective view of the permanent magnet as a cylindrical body, (b) is its cross-sectional view, and FIG. 5 is a cross-sectional view of the case with a spacer interposed,
FIG. 6 and FIG. 7 are explanatory views when the magnetic body lIω is magnetized by a coil, and FIG. 8 is a cross-sectional view when centering is performed. Symbols 1a and lb are optical fibers, 4a and 4b are magnetic films, 5a and 5b are connectors and connector outer cylinders, 7a and 7b are jackets, 8 is a permanent magnet, 9 is a spacer, 10.1 oa and lo
b is a coil, 11 is a holding cylinder, 13 is a jig, 14 is a guide member, 1 and 7 are adhesives. Patent applicant: Machida Opto Giken Co., Ltd. Figure 1 Figure 2 Figure 30. 8

Claims (1)

[Scope of Claims] 1. An optical fiber coupling section characterized in that a magnetic material to which a magnetic attraction force acts is provided around the ends of optical fibers to be coupled. 2. The optical fiber coupling portion according to claim 1, wherein the magnetic material is a magnetic film. 3. The optical fiber coupling unit according to claim 1, wherein a coil is provided around the magnetic body, and the magnetic attraction force of the magnetic body is controlled by the coil.