HOLOGRAPHIC RECORD READING METHOD AND APPARATUS FOR EXECUTING SAME

摘要

A holographic process is provided for recording-reading by means of index strata in the volume of a photoexcitable storage medium. This process consists in causing two beams to interfere in this medium during two successive writing steps by using writing radiations of different wavelengths. The reading of this medium is then effected by means of a third coherent radiation having for wave vector in the medium a linear combination of the wave vectors of said writing radiations.