Patent ID: 6885625

Claim:
An optical data storage system for writing and/or reading information with respect to an optical storage medium, the optical data storage system comprising: an optical pickup including a focusing lens generating a near field and emitting a light beam to write and/or read the information; and the optical storage medium comprising: an optical transmissive layer having a thickness of approximately several micrometers to several hundred micrometers and first and second surfaces opposing each other, wherein: the first surface opposes the focusing lens, the optical transmissive layer is a substrate comprises a pre-formatted structure for storing the information, the preformatted structure comprises a plurality of grooves or pits which are engraved toward the second surface of said optical transmissive layer, and the plurality of grooves or pits each have a width of approximately 100-150 nm; and a recording layer having a thickness of approximately 150-400 nm and positioned in the second surface of said optical transmissive layer, wherein an interval between the first surface and a surface of the focusing lens opposing the first surface is smaller than one wavelength of the light beam.