Computer-Generated Holograms of Conical Waves

The flexibility of computer-generated holograms is used to advantage, e.g. in optical filtering, laser beam scanning and beam splitting, and in test of aspheric lenses. However, storage of information by CGHs either for computational use or application as a display seems a valuable goal due to the inherent advantages of holography. Problems arise in the software as well as in the hardware, especially concerning the overall handling time. Usually it is kept minimum by use of the FFT, even if this restricts the object to be a 2-D transparency.