METHOD AND SYSTEM OF OPTICAL DATA STORAGE Russian patent published in 2018 - IPC G11B7/125 G11B7/45 

FIELD: physics.

SUBSTANCE: methods and a device for recording and retrieving optically readable data include the use of the storage medium that contains an optically active substance capable of inducing the change of the medium properties in the presence of optical radiation, having the first feature, for example, the first optical frequency and wherein the change of properties may be over-ridden by optical radiation, having the second feature, such as the second optical frequency. During recording, the area of the recording medium is irradiated with the first beam of optical radiation having the first feature. The beam has enough intensity in the central sector of the irradiated area and a sufficient duration to cause the optical induced change of the storage medium properties. Simultaneously, the area of the recording medium is irradiated with the second beam of optical radiation having the second feature. The second beam has a local minimum of intensity in the central sector of the irradiated area and a local maximum intensity in at least one section of the irradiated area, close to the central station, which is enough to suppress the optical induced change of the storage medium properties.

EFFECT: increasing the recording density.

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