JPH0430573Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an optical attenuator, and particularly to a simple optical attenuator that can variably adjust the amount of attenuation of light with a simple configuration.

[Conventional technology]

Conventional optical attenuators are generally constructed with an attenuation film made of a dielectric multilayer film.
In this case, if an attempt is made to make the attenuation variable variable, there is a drawback that the mechanism becomes complicated, such as by introducing a lens combination.

[Means for solving problems]

In the present invention, a desired amount of optical attenuation can be easily obtained by abutting fibers with oblique end faces and rotating them relative to the fiber axis.

[Effect]

The amount of optical attenuation can be variably adjusted by varying the coupling efficiency depending on the relative angle of the abutted fiber end faces.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of an optical connector, and in the present invention, the structure of the optical connector is utilized in an optical attenuator.
FIG. 2 is an enlarged view of the ferrule end face of each plug. Plug 1 and Plug 2 have Qdeg diagonal polishing applied to the ferrule 4 end face. In addition, the plugs 1 and 2 are designed to correspond to the slope direction of polishing.
Protrusions 5 and 6 are provided. FIG. 3 is an enlarged view of the adapter 3 in FIG. 1. On the other hand, the adapter 3 that connects the plugs 1 and 2 to each other is provided with grooves at several locations in the circumferential direction that fit into the protrusions 5 and 6 of the plugs, respectively. FIG. 4 shows how the amount of attenuation changes depending on the butt state of the ferrules (fibers). Lmax has a plug rotation angle of 180deg.
When (relative angle of the fiber end face 2θ is obtained and the rotation angle of the plug is 0 degrees (relative angle of the fiber end face)
has the minimum amount of attenuation.

The above value of Lmax is determined from the inclination angle θ of the ferrule end face and the NA (numerical aperture) of the fiber.

That is, it can be seen that for a desired Lmax, an appropriate inclination angle θ can be selected by taking the fiber NA into consideration. That is, as shown in FIG. 3, ferrules whose end surfaces are obliquely polished are butted against each other with a predetermined distance between the optical fibers. By abutting each other in this manner, it becomes possible to rotate the ferrules together. By rotating the ferrules, the relative angle at the end face of the optical fiber changes from 0 to 2θ, as shown in FIG.

Since the optical fiber end face is polished diagonally,
The light from the end face of the output side optical fiber is output at a predetermined output angle. By rotating the ferrule, the angle of the end face of the light-receiving optical fiber changes relative to the angle of the end face of the emitting-side optical fiber (the output angle of the emitted light). Therefore, the angle of incidence of light on the end face of the light-receiving side optical fiber changes, and the amount of incident light changes.

Therefore, the amount of light incident on the end face of the optical fiber on the light receiving side changes, and the amount of optical attenuation changes.

Also, the desired attenuation amount Ln on the attenuation curve in Figure 4
For , the corresponding plug rotation angle Bn
It can be seen that the groove of the adapter should be provided as shown in Fig. 3b.

[Effects of the Invention] According to the present invention, an optical attenuator that can change the amount of optical attenuation stepwise can be constructed with a very simple configuration, resulting in miniaturization and cost reduction.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the configuration of the optical attenuator, Figure 2 is an enlarged view of the end face of the ferrule, Figure 3 is a diagram showing the adapter, which is one of the components, and Figure 4 is the relationship between the plug rotation angle and the amount of attenuation. FIG. In the figure, 1 and 2 are plugs, 3 is an adapter, and 7 is a groove.

Claims (1)

[Claim for Utility Model Registration] The end faces of optical fiber ferrules formed at an angle are butted together with a predetermined distance between the optical fibers on the end faces of each optical fiber ferrule, and each optical fiber ferrule is aligned with respect to the axis. 1. A simple optical attenuator characterized in that by rotating the optical fibers relatively, the optical coupling efficiency between the end faces of the optical fibers can be changed, and the amount of attenuation of light can be varied.