| 摘要 |
PURPOSE:To constitute a voltage-control focal length varying element by providing an electrode on the surface of a light converging thin film waveguide. CONSTITUTION:Electrodes 3a and 3b are provided on the surface of a light converging thin film waveguide 2 by a vapor-deposition method, sputtering method, or the like. When a voltage is applied to electrodes 3a and 3b by a power source 4, an electric field is generated between electrodes 3a and 3b, and the refractive index distribution of the light converging waveguide 2 is changed by this generated electric field, and the focal length of the light converging thin film waveguide 2 is changed by this change of the refractive index distribution, and the refractive index of the light converging thin film waveguide 2 is controlled by the voltage of the power source 4. Thus, the focal length of the light converging thin film waveguide 2 is changed. |
