Holographic simulation of parabolic mirrors

A means is illustrated by which a hologram may be formed to simulate a parabolic mirror. These holographic mirrors have the advantages of being low-cost and extremely simple to form for any specified focal length. The principle and technique of the formation are similar to those of hologram zone plates as described by Kock et al. The hologram is generated by allowing plane and spherical waves to impinge on a photosensitive medium from opposite sides, hence creating a reflection hologram. Applications on spacecraft observatories appear promising because of the negligible weight of the mirrors.