Interactive computation of holograms using a look-up table

Several methods of increasing the speed and simplicity of the computation of off-axis transmission holograms are presented, with applications to the real-time display of holographic images. the bipolar intensity approach allows for the real-valued linear summation of interference fringes, a factor of 2 speed increase, and the elimination of image noise caused by object self-interference. An order of magnitude speed increase is obtained through the use of a precomputed look-up table containing a large array of elemental interference patterns corresponding to point source contributions from each of the possible locations in image space. Results achieved using a data-parallel supercomputer to computer horizontal-parallax- only holographic patterns containing six megasamples indicate that an image comprised of 10,000 points with arbitrary brightness (gray scale) can be computed in under 1 s. Implemented on a common workstation, the look-up table approach increases computation speed by a factor of 43.