REFERENCE BEAM AUTO-FOCUS APPARATUS FOR MODULARIZED VOLUME-HOLOGRAPHIC MEMORY

摘要

In a method for addressing holograms stored in a plurality of separate storage media (10, 12, 14), a reference beam is directed to a selected one of the plurality of storage media, the reference beam is then focused so as to obtain a substantially flat wavefront within a reference beam plane of the selected storage medium, and the angle of the reference beam is then varied so as to select a hologram stored therein.