title: Random phase shifters for fourier transformed holograms.
abstract: The random phase shifter method for Fourier transformed holograms is discussed. It is shown that by adopting the random phase shifters of the phase quantization levels beyond 2 (4, for example), the effectiveness becomes about twice that of 2, and that the reduction of the effectiveness by the coincidence between a pattern of the information and a phase shifter can be withdrawn under the probability of 10(-10). Hologram memories of information storage density of 10(5) bits/mm(2) and 2.0 x 10(3) characters/ mm(2) are demonstrated.
authors.forename: Y
authors.initials: Y
authors.lastname: Takeda
authors.forename: Y
authors.initials: Y
authors.lastname: Oshida
authors.forename: Y
authors.initials: Y
authors.lastname: Miyamura