A method of recording data to a layer (101) of a recording medium in which an organic luminescent precursor composition is irradiated with a first light beam (103) and a second light beam (105), the first light beam having a write wavelength for conversion of the organic luminescent precursor composition to an organic luminescent composition and the second light beam having a write inhibition wavelength for inhibiting conversion of the organic luminescent precursor composition to the organic luminescent composition. The second light beam has a central area and a surrounding area; an intensity of the second light beam in the central area being lower than an intensity of the second light beam in the surrounding area. The first light beam extends across the central area and the surrounding area of the second light beam surrounds the first light beam.

A method to record data in a solid substrate comprises modulating a polarization angle of a coherent optical pulsetrain, and, while the polarization angle is being modulated, focusing the coherent optical pulsetrain on a locus moving through the solid substrate at a relative velocity. Here the relative velocity, a width of the locus in a direction of the relative velocity, and a rate of modulation of the polarization angle are such that the substrate receives within the width of the locus two or more pulses of the optical pulsetrain differing in polarization angle. In this manner, the two or more pulses record, in different portions of the substrate within the width of the locus, two or more different symbols.

An optical data-recording system comprises a laser, a dynamic digital hologram, an electronic controller, and a scanning mechanism. The dynamic digital hologram includes a plurality of holographic zones, and is configured to direct the irradiance received thereon to an optical recording medium. The electronic controller is operatively coupled to the dynamic digital hologram and configured to control the irradiance directed from each of the holographic zones. The scanning mechanism is configured to change a relative positioning of the laser versus the dynamic digital hologram so that each of the holographic zones is irradiated in sequence by the laser.

Methods and apparatus for recording and retrieval of optically readable data employ a recording medium (100) which comprises an optically active material (108) able to induce a change in properties of the medium in the presence of optical radiation having a first characteristic, such as a first optical frequency, and wherein the change in properties can be inhibited by optical radiation having a second characteristic, such as a second optical frequency. During recording, a region of the recording medium (100) is irradiated with a first beam (506) of optical radiation having the first characteristic, the beam having a sufficient intensity within a central portion of the irradiated region and being of sufficient duration to cause an optically induced change in properties of the recording medium. Simultaneously, the region of the recording medium (100) is irradiated with a second beam (508) of optical radiation having the second characteristic, the second beam having a local intensity minimum within the central portion of the irradiated region, and a local intensity maximum in at least one portion of the irradiated region adjacent to the central portion which is sufficient to inhibit the optically induced change in properties of the recording medium. A similar method is employed for retrieval, however the intensity of the first beam (506) is reduced to prevent changes in material properties within the recording medium (100).

Methods and apparatus for recording and retrieval of optically readable data employ a recording medium (100) which comprises an optically active material (108) able to induce a change in properties of the medium in the presence of optical radiation having a first characteristic, such as a first optical frequency, and wherein the change in properties can be inhibited by optical radiation having a second characteristic, such as a second optical frequency. During recording, a region of the recording medium (100) is irradiated with a first beam (506) of optical radiation having the first characteristic, the beam having a sufficient intensity within a central portion of the irradiated region and being of sufficient duration to cause an optically induced change in properties of the recording medium. Simultaneously, the region of the recording medium (100) is irradiated with a second beam (508) of optical radiation having the second characteristic, the second beam having a local intensity minimum within the central portion of the irradiated region, and a local intensity maximum in at least one portion of the irradiated region adjacent to the central portion which is sufficient to inhibit the optically induced change in properties of the recording medium. A similar method is employed for retrieval, however the intensity of the first beam (506) is reduced to prevent changes in material properties within the recording medium (100).