Hybrid kinoform fanout holograms in dichromated gelatin

The technique for fabricating hybrid holograms, introduced by Bartelt and Case [Appl. Opt. 21, 2886 (1982)], is applied here to record extremely high-efficiency (>90%) space-invariant fanout holograms in dichromated gelatin. The object wave front corresponding to that produced by a kinoform with a continuous-phase profile is derived by appropriate spatial filtering from a binary computer-generated hologram fabricated using electron-beam lithography.