| 摘要 |
PURPOSE:To make a device small in size and simple and to converge light over a wide range by providing an actuator which supports an optical deflecting element movably at right angles to the optical axis of a beam. CONSTITUTION:A movable table 12 is arranged on a base 10 movably in one direction and the actuator 14 which moves the movable table 12 to, for example, about 20 positioning points is provided. When a voltage is applied to one of transparent electrode groups 20, 22, 24, 26, and 28, a part under the transparent electrodes of the one group has optical anisotropy different from that of any other part, so a beltlike Fresnel transmissivity distribution, i.e. refractive index distribution is formed in the substrate 16. Consequently, a beam 32 emitted by a homogeneous light source 30 varies in light velocity at a part having a different refractive index while propagated in the substrate 16, so the beam is converged on a position on a screen 34 corresponding to the transparent electrode group applied with the voltage. |
