HOLOGRAPHIC OPTICAL ELEMENTS (DIFFRACTION, GRATING, ARRAY, LENS)

A comprehensive treatment is presented for the diffraction efficiencies of transmission holographic elements and cascade lenses when subject to broad spectral and field-angle detunings. Experimental measurements and verifications are made on holographic optical elements. The theory of holographic grating diffraction efficiency is studied through two approaches. A numerical treatment based on the theory of thin grating decomposition is implemented and shown to be in agreement with other theories. Additionally, a more approximate approach is pursued in which the volume grating is treated as a phased array of scatterers. The latter approach leads to closed-form formulas in addition to a simple physical picture of volume effects. Extensive parametrical studies are presented for the properties of volume holographic elements. It is found that three-element cascades can exhibit spectral and field angle bandwidths essentially as broad as two-element cascades; that these bandwidths are in excess of 2300 (ANGSTROM) and 7(DEGREES), respectively; and that these can more than double with specialized techniques presented. Applications of holographic elements to imaging are presented and a paraxial chromatic thickness aberration is discussed.