A Layered Method Based on Depth of Focus for Rapid Generation of Computer-Generated Holograms

Abstract

In this paper, a layered method based on focal depth is proposed for the fast generation of computational holograms. The method layers objects with focal depth as spacing and approximates triangles on the object as projections on the layers based on the physical properties of the focal depth to simplify the computation. Finally, the diffraction distributions of all layers are calculated via angular spectral diffraction and superimposed to obtain the hologram. The proposed method has been proven to be about 20 times faster on a CPU than the analytical polygon-based method. A hologram containing tens of thousands of triangles can be computed on a GPU in a fraction of a second. In addition, this method makes it easy to attach complex textures, which is difficult with polygon-based analysis methods. Finally, holograms of objects with complex textures were generated, and the three-dimensionality of these holograms was confirmed by numerical and optical reconstruction.