Imaging in white light with a thick-phase transmission holographic doublet

An afocal two-element holographic imaging system is presented. This system can be used to work in white light. The holographic optical elements (holographic lenses) are made as thick phase holograms on silver halide sensitized gelatin (SHSG) and they present a maximum diffraction efficiency of 75%. Geometrical conditions at reconstruction with coherent light and with white light are studied and a resolution test chart is imaged through the system, which shows a best resolution of 57 lines/mm for coherent illumination and 15 lines/mm for white light. The two-element holographic system presents a maximum diffraction efficiency of 56%.