Spatial light modulator with a photoconductor on each side of a light

Abstract

A spatial light modulator which includes a light modulation layer which is interposed between two photoconductive layers and laminated to both layers; the two photo conductive layers have charge images written thereon, respectively, by illumination of a writing light carrying optical information; the illumination direction of the writing light to the photoconductive layers are different from each other; and the two photoconductive layers permit the reading light to pass therethrough. When illuminated by a reading light via either of the first or second photoconductive layers, the light modulation layer optically modulates the reading light in accordance with the first and second charge images, under the presence of a voltage applied to the modulator. Thus it reads read out the first information and second information. The first and second photoconductive layers permit the reading light to pass therethrough.