Paul R. Haugen

Multifacet holographic optical elements for wave front transformations

A new type of holographic optical element combines some of the flexibility of computer-generated holograms with the high light efficiency of volume phase holograms to produce optical elements capable of arbitrary illumination transformations with nearly 100% light efficiency. The optical element is recorded by subdividing a volume hologram film surface into numerous small areas (facets), each of which is individually exposed. A final optical system consisting of two dichromated gelatin holograms in series is demonstrated. The first hologram spatially redistributes the incident light, and the second hologram produces a desired phase front on the redistributed light.

Image formation by multifacet holograms

A method is described in which arbitrary images are formed via Fresnel diffraction. In this method, a multifacet hologram is used to deflect small square areas of light from a given spatial location in the input plane to an arbitrarily prescribed location in the output plane, producing an image composed of small square patches of light. Five different variations of multifaceted holography are presented. Volume phase holograms are used in the deflection process resulting in nearly 100% efficiency.