Storage of optical patterns in a zinc−oxide−on−silicon surface wave convolver

Abstract

A monolithic zinc−oxide−on−silicon surface wave convolver has been used to image optical patterns and store them for long periods of time. A light pattern is stored by projecting it onto a semitransparent top convolver electrode which has an applied negative dc bias. Slow states associated with the zinc oxide are charged in the regions exposed to the light. This charge pattern, as observed using surface wave convolution, persists even when the light is removed. Retention of the pattern for several days has been demonstrated with this device.