Optical information storage on superimposed layers.

摘要

The invention relates to a system for optical storage of information. The information is stored within the volume of a transparent layer (12) instead of being stored at the surface. Sequences of different information are stored in different strata of the layer. The means of writing and of reading (40, 42) are designed to focus a light beam in the plane of a specified stratum without focusing it on the others. Photodetectors (PD0, PD1, PD2) permit selective detection of the beam perturbations engendered by each of the respective individual strata. The material of the transparent layer is preferably a material with photoinduced index variation.