METHOD FOR MULTIPLE-LAYER OPTICAL RECORDING OF BINARY INFORMATION Russian patent published in 1994 - IPC

FIELD: computer engineering. SUBSTANCE: two mutually coherent focused beams of optical radiation as well as additional optical beam are generated. Recording beams are modulated according to information content, all three beams are added and directed to required layer of information medium. Medium is exposed for information recording. Depth of interference pattern should be less then depth of information medium. Frequency of recording beams belongs to transparency zone of medium, frequency corresponding to sum of frequencies of additional and recording beams belongs to spectrum of maximal absorption of medium material. Material with two-step or two-photon absorption of optical radiation can be used as recording medium. Relative displacement of intersection zone of two beams is performed for recording information in other layers of medium. EFFECT: increased functional capabilities. 3 cl, 3 dwg