| 摘要 |
PURPOSE:To enable bidirectional communication by providing a half mirror and a rotating mechanism to a holographic diffraction grating and projecting signal light directly to a photodetecting element, then directly executing opto electric conversion. CONSTITUTION:A lens 2 disposed in the front space of an input/output optical fiber 3 and a piece of the photodetecting element 4, and the diffraction grating 1 disposed diagonally with the optical axis of the input/output optical fiber 3 in the front space of the lens 2 are provided. The half mirror 7 is provided between the lens 2 and the diffraction grating 1. A lens 8 and a light source 9 are disposed in the direction symmetrical with the optical axis with the normal of the half mirror 7 as an axis. The rotating mechanism 5 is provided to the diffraction grating 1. Only the light of a required wavelength from plural wavelength is, therefore, received in a piece of the photodetecting element 4 by providing the rotating mechanism 5 to the holographic diffraction grating 1. In addition, an up signal is condensed and transmitted to the input fiber by the half mirror. The bidirectional tuner having the simple structure is thereby formed. |
