Sequential information retrieval from holograms.
A scheme by which information retrieved from holograms can be made in a true sequential fashion (no buffer storage) is described. By using a reduction lens and making the Fourier transform hologram only in the transverse direction, high information recording density can be achieved in both the longitudinal and transverse direction on a long tape. A tenfold or more increase in total information density as compared with direct recording methods is possible. The feasibility of using this scheme for audio recording is demonstrated. When fully implemented, a multitrack (two or more) and multichannel (four or more) audio system is possible. The hologram tape can be economically replicated.
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