JPH0542409Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to an optical transmission adapter that couples two optical connectors. [Background Art and Problems thereof] Recently, many optical fibers have been developed as a result of research and development of optical fibers. Among them, the GI type for long distance transmission has a core diameter of 50μm and a cladding diameter of 50μm.
For FC type optical connectors using 125μm quartz fiber, the material of the ferrule of the optical connector is
Hard materials such as SUS440C and ceramics. Therefore, the optical fiber portion on the end face of the optical connector can be polished into a concave spherical shape so that the optical fiber does not protrude from the ferrule end face of the optical connector. When optical connectors are connected to each other, light is reflected multiple times by the concave spherical surface of the optical fiber at the end face of the optical connector, which has a positive effect on the reproducibility of connection loss of the optical connectors. However, in optical connectors using optical fibers for short and medium distances, the ferrule material is a soft material such as brass, so only the optical fiber portion on the end face of the optical connector is polished into a concave spherical shape. It was difficult to polish the optical fiber so that it did not protrude from the end face of the ferrule. Therefore, when connecting optical connectors, if you design an optical transmission adapter so that the ferrule end faces of the optical connectors touch each other, reproducibility may deteriorate or the optical fibers protruding from the ferrule end faces of the optical connectors may A cracking phenomenon occurs,
This had a large impact on optical transmission loss. Also, if you design an optical transmission adapter so that there is a gap between the ferrules of the optical connector so that the optical fibers do not touch each other, the phenomenon of optical fibers breaking will disappear, but
There has been a problem in that it becomes difficult to manage gaps between the ferrules of optical connectors due to dimensional differences between adapters, dimensional differences between optical connectors, and polishing margins between ferrules of optical connectors, resulting in poor reproducibility of connection loss of optical connectors. [Purpose of the invention] The purpose of the invention is to provide an optical transmission adapter that eliminates the above-mentioned problems, prevents optical fibers from breaking, and reduces variations in connection loss of optical connectors. [Summary of the invention] This invention provides an optical transmission adapter that connects a first optical connector and a second optical connector that have at least a ferrule and an optical fiber cable. This is an optical transmission adapter in which a spacer having a through hole having a diameter larger than the core diameter of the optical fiber cable is disposed between the ferrule and the ferrule of the second optical connector. [Embodiment of the invention] FIG. 1 shows the basic configuration of an optical transmission adapter that was conceived during the course of the invention. Inside the cylindrical adapter body 1, a spacer 3 made of, for example, metal is disposed approximately at the center, that is, between the ferrule 2 of the first optical connector 5 and the ferrule 2 of the second optical connector 6 . . As shown in FIG. 2, this spacer 3 has a thickness of 0.1 mm or less, for example, a thickness of 0.05 mm.
It is made into a rectangular plate shape of mm, with a through hole 9 having a diameter larger than the diameter of the core 8 of the optical fiber cable 7 approximately in the center.
It is perforated. The thinner the spacer 3 is, the more desirable it is, but since it is a thin plate with a thickness of 0.1 mm or less as described above, if the spacer 3 is fixed inside the adapter body 1, the spacer 3 will be deformed or damaged when the optical connector is inserted. There is a fear. Therefore, in this invention, as shown in FIG. 3, a slit penetrating from the outer surface to the inner surface of the adapter body 1 is formed to provide a recess 10 on the inner surface, and a spacer 3 is inserted into the recess 10 through the slit. It is positioned so that it is movable inside the adapter body 1 in the axial direction of the adapter body 1. The width d of the recess 10 is, for example, 0.5 mm.
When the first optical connector 5 is inserted, the spacer 3 hits the ferrule 2 of the first optical connector 5 and moves together with the ferrule 2 of the first optical connector 5. When the second optical connector 6 is further inserted, the ferrule 2 of the second optical connector 6 comes into contact with the spacer 3, and the spacer 3 returns to the first optical connector 5 side. Therefore, even if the spacer 3 is thin and has low strength, an optical transmission adapter can be constructed in which deformation and damage of the spacer 3 can be suppressed. Next, a case will be described in which the first and second optical connectors are coupled using an optical transmission adapter. That is, as shown in FIG. 4, the first optical connector 5 and the second optical connector 6 are connected from both sides of the optical transmission adapter 11, respectively. In this case, each optical connector 5 , 6 is connected to an optical fiber cable 7, respectively.
The optical fiber cable 7 consists of an optical fiber 8, a jacket 12, a Keppler (not shown), and an outer fitting 13 laminated in this order. 14
is a rubber hood. Then, by tightening the lock screw 4 into the thread grooves (not shown) formed on both ends of the outer periphery of the adapter body 1, both optical connectors 5 ,
It combines 6. At this time, first, when the first optical connector 5 is connected to the optical transmission adapter, the first optical connector 5 is tightened with the lock screw 4 until the shoulder of the ferrule 2 contacts the adapter body 1, and the spacer 3 is tightened with the ferrule. It moves together with the end face of 2. Next, when the second optical connector 6 is connected, the second
The optical connector 6 is tightened and connected with the lock screw 4 until the end face of the ferrule 2 contacts the spacer 3, and the optical fiber core 7 protruding from the end face of the ferrule 2 is inserted into the through hole 9 of the spacer 3.
The vicinity of the spacer 3 is shown in FIG. In the figure, 20 is the core of the optical fiber, 22 is the cladding, and 24 is an adhesive for fixing the optical fiber within the ferrule 2. In addition, the ferrule 2 of the optical fiber 8
The amount of protrusion from the end face is generally 20 μm or less. [Effects of the invention] According to this invention, even if there is a protrusion of the optical fiber in the optical connector to be coupled, the optical fiber does not break, and optical transmission with excellent stability and good reproducibility of connection loss of the optical connector can be achieved. It becomes possible. That is, according to this invention, when the optical connectors 5 and 6 are inserted, the end face of the ferrule 2 hits the spacer 3, the core 8 of the optical fiber cable 7 protruding from the end face of the ferrule 2 is inserted into the through hole 9 of the spacer 3, and the spacer 3 Even with a thickness of
The optical fiber cable 7 is prevented from breaking. Further, since the gap between the ferrules 2 of the first optical connector 5 and the first optical connector 6 is kept constant by the spacer 3, an optical transmission adapter with good reproducibility of connection loss of the optical connector can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a schematic cross-sectional view showing an optical transmission adapter that was conceived in the middle of this invention, Fig. 2 is a plan view showing a spacer used in the optical transmission adapter of this invention, and Fig. 3 is a part of this invention. FIG. 4 is a schematic sectional view showing the optical transmission adapter according to the embodiment, FIG. 4 is a sectional view showing how the optical transmission adapter according to the embodiment is used, and FIG. 5 is a sectional view of main parts showing the vicinity of the spacer. . 1...Adapter body, 2...Ferrule, 3...
...Spacer, 5 ...First optical connector, 6 ...Second optical connector, 7 ...Optical fiber cable, 8
... core, 9 ... through hole, 10 ... recess.

Claims (1)

[Claims for Utility Model Registration] (1) An optical transmission adapter that couples a first optical connector and a second optical connector, each having at least a ferrule and an optical fiber cable, comprising: an adapter body; and approximately the center of the adapter body; a recess formed on the inner surface of the adapter body so as to be located at the inner surface of the adapter body, and a through hole having a diameter larger than the core diameter of the optical fiber cable, and the optical connector is inserted into the recess while being movable in the insertion direction of the optical connector. An optical transmission adapter characterized by comprising a plate-shaped spacer. (2) The optical transmission adapter according to claim 1, wherein the spacer is made of metal.