COMPACT HOLOGRAPHIC BEAM EXPANDER

A compact planar beam expander, composed of two holographic lenses tha t are recorded on a signal holographic plate, is presented. The smalle r lens converts a narrow input beam into a diverging spherical wave at a high off-axis angle. This wave propagates toward the second lens, u ndergoing total internal reflections within the plate, and emerges fro m the larger lens as a magnified plane wave. One such expander, having a magnification of 3.5, was designed and recorded. The design and the recording procedure, along with the experimental results, are given.