Compact holographic beam expander

Abstract

A compact planar beam expander, composed of two holographic lenses that are recorded on a signal holographic plate, is presented. The smaller lens converts a narrow input beam into a diverging spherical wave at a high offaxis angle. This wave propagates toward the second lens, undergoing total internal reflections within the plate, and emerges from 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.