Synthesis of complex optical wavefronts.

For any coding scheme designed for the synthesis of an optical wavefront by a computer-generated, amplitude-transmittance hologram, two types of synthetic holograms may be defined: the first is the encoded form of the optical wavefront itself; the second is the encoded form of the Fourier transform of the wavefront. The extent of the optical wavefront produced by the first type varies inversely, while that of the second type varies directly, with resolution. Five coding schemes are characterized by two important quantities: the first is the minimum number of samples that must be numerically evaluated and drawn; the second is the product of the minimum resolution (lines/unit length) and length (per dimension) required for the drawing. These quantities are a measure of the required computer and drawing device capabilities, respectively, and knowledge of them permits comparison of the coding schemes.