| 摘要 |
PURPOSE:To provide an optical tuner having a simple structure capable of receiving only the light of a necessary wavelength from plural wavelengths in a piece of an output optical fiber by providing a rotating mechanism to a holographic diffraction grating. CONSTITUTION:Five different signals from the input optical fiber 3 are entrained in the light consisting of five different wavelengths and is projected diagonally to the holographic diffraction grating 1 through an aspherical lens 2, by which the light consisting of the five different wavelengths is subjected to wavelength dispersion and is reflected at the angle varying with each wavelength. This light is condensed by the aspherical lens 2 and only the light of one wavelength N in the light of the different wavelengths is focused onto the end face of the output optical fiber 4. The light of the other wavelengths is not projected onto the photodetecting element 4. The light of the other wavelengths can, therefore, be received by rotating the holographic diffraction grating by using the rotating mechanism to project the light of the required wavelength to the photodetecting element then by converting the same to an electric signal. |
