METHOD FOR MULTILAYER OPTICAL DATA RECORDING AND REPRODUCTION Russian patent published in 2001 - IPC

FIELD: informatics and computer engineering; optical digital memory systems. SUBSTANCE: when recording by two optical beams, acoustical-optical cell is irradiated and train of ultrasonic wave is shaped therein, its repetition rate varying obeying sawtooth law. Beams diffracted across cell are focused and aligned on three-dimensional material field addressed, and interference pattern shaped in the process is recorded. Scanning direction is chosen so that interference pattern line shaped due to scanning and medium motion is oriented perpendicular to motion of data medium. Rate of light of one of beams is shifted during read-out relative to that of other beam. Both reproducing beams are used to irradiate acoustical- optical cell wherein mentioned train of ultrasonic waves is shaped. Each next ultrasonic train is entered with certain delay relative to preceding one and delay time is adjusted. Beams diffracted across cell are focused and aligned on address layer of three-dimensional data medium material; interference pattern obtained is aligned with pre-recorded interference pattern and reproduction signal is produced by discriminating high-frequency component from electric signal at photodetector output. EFFECT: increased speed of binary data reading and recording. 2 dwg