Optical storage method and device for storing and reading digital information

摘要: Disclosed is a system for the recording of data on optic disks. Presently used disks, which can be read with lasers working in wavelengths visible region (between 0.5 and 0.8 microns), have maximum surface storage density order one bit per elementary zone having an area about square micrometer. Beyond this limit, diffraction does not allow neighboring zones to distinguished. A means proposed considerably increase capacities: layer, information written form point absorption laser light but grating determined pitch. Several gratings, pitches different from another, may superimposed at same position, enabling recording, zone, several bits. The gratings are made by periodic local variation index layer. They high energy beam, out material that vary as function energy. reading done frequency tunable enables detection, frequencies, presence or absence gratings.