Holographic data storage by combined use of peristrophic, angular, and spatial multiplexing

For multihologram recording, especially in a disk-shaped storage medium, a simple cost-effective method to implement the peristrophic, angular, and sp atial multiplexing techniques together is studied and its experimental demo nstration is presented. Holographic storage with both peristrophic and angu lar multiplexing is realized by controlling the reference beam directly wit h a pair of wedge prisms, while the storage with spatial multiplexing is ac hieved by shifting the storage medium. The area storage density of our syst em is strongly dependent on the f numbers of the lenses in the signal and r eference arms. For a given f number of the lens in the reference arm, we sh ow that the area storage density becomes maximal when the f number of the l ens in the signal arm is approximately twice that in the reference arm. The proposed method can be used for 3-D holographic disk memories to enhance t heir area storage density. (C) 2000 society of Photo-Optical instrumentatio n Engineers. [S0091-3286(00)01411-2].