| 摘要 |
PURPOSE:To obtain a device having a mode converting function of a low loss, by fixing the end of an optical fiber connected to both focuses of a hollowed rotary elliptical body, and fixing a plane mirror on a short axial surface of this hollowed rotary elliptical body. CONSTITUTION:Optical fibers 1, 2, a hollowed rotary elliptical body 3, focuses 4, 5 of the hollowed rotary elliptical body 3, a reflection film 6, a package 7, a short axial surface 13 of the hollowed rotary elliptical body 3, and a plane mirror 14 placed on the short axial surface 13 are shown in the figure. A light beam 12 propagated in a low mode in the optical fiber 1 by a light beam 10 which is made incident to the optical fiber 2 at a maximum photodetecting half- angle thetac is reflected by the plane mirror 14 placed on the short axial surface 13, is reflected by the reflection film 6 of the hollowed rotary elliptical body 3, and passes through the focus 4. Also, the light beam which has passed through the focus 4 is reflected by the reflection film 6 of the hollowed rotary elliptical body 3, reaches the other focus 5, and is coupled with the optical fiber 2. Accordingly, the light beam which has been propagated in a low mode in the optical fiber 1 is coupled with the optical fiber 2. |
