Application of dual probe direct interference to multilayered high density optical storage: a proposal

The author proposes an alternative approach for optical data storage in transmission holograms. Digital codes are embedded in the transparent storage medium by varying its optical thickness. The medium is sandwiched between two transparent dielectric layers of smaller refractive index. The detection scheme uses signals obtained from the direct interference between two focused optical probe beams. When the medium is scanned under the probes the stored `bits´ will be registered as intensity modulation in the interference signal. The use of a transparent medium in optical disks offers the possibility of stacking a large number of storage layers, thereby greatly increasing the storage density