Abstract: A method and apparatus for modulating multilevel data arrays to make them suitable for storage in multidimensional storage media, such as in holographic storage. In order to get a uniform signal of constant energy at the recording plane, first the multilevel data array, Vout, displayed on a spatial light modulator, has frequent transitions between symbols of different levels, and second it has constant energy. The energy is defined as the summation of the values of the symbols in the data array. The first constraint is achieved using V?in=Vin?qM(q, ZO), where ?q stands for the modulo-q addition operation; M(q, Zo) is a data array with randomly distributed symbols of q levels, where q is the number of levels and ZO is the seed used to generate the random multilevel data array.

Abstract: A method and apparatus for modulating multilevel data arrays to make them suitable for storage in multidimensional storage media, such as in holographic storage. In order to get a uniform signal of constant energy at the recording plane, first the multilevel data array, Vout, displayed on a spatial light modulator, has frequent transitions between symbols of different levels, and second it has constant energy. The energy is defined as the summation of the values of the symbols in the data array. The first constraint is achieved using V′in=Vin⊕qM (q, ZO), where ⊕q stands for the modulo-q addition operation; M(q, ZO) is a data array with randomly distributed symbols of q levels, where q is the number of levels and ZO is the seed used to generate the random multilevel data array.