B.S.T.J. Briefs: Hologram Transmission via Television

Holography, or wavefront reconstruction photography, was first demonstrated by Gabor1, 2> 3 over fifteen years ago, and it has been the subject of increased investigation over the last five years since the advent of lasers. Possible applications of holography suggest themselves in the fields of three-dimensional and multicolor television.4 Furthermore, the statistics and redundancy of the hologram of an image may be deliberately made quite different from those of the original image. This has obvious possibilities in encoding schemes for television transmission in general. In this communication we report a first experimental step in this direction, namely the successful transmission via television of a Fresnel type of hologram in which the original object was a transparency. In conventional two-dimensional hologram construction a transparency is illuminated from behind by a monochromatic, spatiallycoherent light wave which then impinges on a photographic plate. This interferes with a reference or carrier wave derived from the same source that strikes the plate at an angle. A record, or hologram, is thus made of both the amplitude and phase of the light transmitted by the transparency. Reconstruction may be achieved by illuminating the hologram with a monochromatic, spatially-coherent light wave. This results in the production of a real image, a virtual image, and a direct wave. Most experimenters in the field have used relatively large angles between the reference and object beams, and the recording has been done on Kodak Spectroscopic plates with 649F emulsion.