摘要 |
A redundant Fraunhofer or Fresnel hologram is recorded by interfering a temporal-information beam with a reference beam of mutually coherent light. The temporal-information beam is intensity-modulated with each of a series of samples of the temporal information signal. The relative phase difference between the two interfering beams is selectively determined for each sample of the series and the effective value of the angular displacement between the two interfering beams is changed for each successive sample of the series. The hologram can be recorded directly from an electronic signal, such as television, without the need for a coherently illuminated object, or an intermediate imaging step, such as transcribing from television to film.
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