Optical storage medium with virtual track pitch

摘要

An optical data storage medium includes a superstructure of micro-lenses defining first and second repeating periods. One of the periods is longer than the other, and the presence of the longer repeating period allows the medium to be used in an optical drive that is configured to use light diffracted by the longer period for tracking purposes. The micro-lenses may be configured such that adjacent lenses have different heights, widths, or shapes. In some embodiments, the spacing between adjacent data tracks is varied to provide the first and second repeating periods.