Some experiments in digital holographic recording

A holographic recording system, based on the use of lowpower laser sources and high-resolution photographic film, is briefly outlined. It was devised principally for the archival storage of high-quality digital television signals and these requirements are reviewed. The development of suitable electro-optic transducers is difficult, largely because of the high data-transfer rates involved, but some progress has been made. Experimental versions of the transducers have been assembled to form a recording apparatus for writing and reading investigations at realtime rates. The results of some initial experiments are given which illustrate various problems that have been encountered, particularly with regard to the recording medium.