摘要 |
PCT No. PCT/NO96/00155 Sec. 371 Date Dec. 23, 1997 Sec. 102(e) Date Dec. 23, 1997 PCT Filed Jun. 24, 1996 PCT Pub. No. WO97/01171 PCT Pub. Date Jan. 9, 1997In an optical data storage medium with a storage area formed from a transparent, homogenous base material and with a number of optically active structures at one side of the storage area, the optically active structures are diffractive optical elements which can focus a beam of light incident on the storage area on to one or more points in the storage area and/or a redirected beam of light or emitted light radiation from this or these points on to a point outside the optical storage medium. During writing/reading of data in the storage medium, the diffractive optical elements are used for focusing the write/read beam in order to generate a data carrying structure or read data stored in such a data carrying structure, respectively. By exploiting the special optical properties of diffractive optical elements, it is possible to achieve parallel writing/reading of data, possibly in several parallel storage layers in the optical storage medium or randomly distributed therein, the optical storage medium thus providing a genuine volumetric storage and a corresponding genuine volumetric accessing of the stored data. |