| 摘要 |
PURPOSE:To provide a novel high-speed light valve by the constitution in which a semicircular medium is provided as a light lead-in and lead-out part on a plate or layer consisting of a dielectric material and light is totally reflected according to the presence or absence of the electric field in the dielectric material. CONSTITUTION:A thin PLZT film 12 having an electrooptic effect is formed on a transparent sapphire base plate 11 and a silicone oil having the refractive index higher than the refractive index of the plate 11 is dropped thereon into a semicircular shape to form a light lead-in and lead-out part 13. When a voltage is applied to the electrodes 14, 14' formed on the film 12, the refractive index of the film 12 in the part therebetween decreases and the condition for the total reflection is broken, then incident light 15 is changed over from totally reflected exit light 16 to transmitted light 17. Since the light 16 passes twice the semicircular medium 2, the valve has also the advantage that the light throttled at the point 18 as if the light past a convex lens is emitted. The switching time for changing over from the exit light 16 to 17 is the order of microsecond. |
