Research Of Large Size Electronic Holographic Display Technology Based On Sparse Sampling

For the traditional optical holography, it can only record and reproduce the static 3D objects. But for the computer-generated hologram,it can be used to reconstruct dynamic 3D objects. Because of the complex spatial structure of the 3D object, the amount of computational cost of the hologram is increased. And in the process of reproduction, as the result of the size of pixel size of electronic control display, diffraction angle and the cost, the size of the reproduction image is generally small. Therefore,the researchers in the field of holographic displaying are looking for ways to reduce the amount of the computation, to reduce the cost and to achieve the method of large scale dynamic holographic display. Here, a method of large scale electrical holographic display based on sparse sampling is presented. The main research contents and results are as follows.1. The basic principles of traditional optical holography, digital holography and computer-generated holography (CGH) are studied.Focus on the generation and reconstruction step of hologram, CGH classification, the sampling theorem, coding technology, rectangular grating diffraction theory. Finally, illustrate the difficulty of the realization of large size holographic with high PPI screens.2. Since the experimental platform is set up, two kinds of diffractive holograms are manufactured and implemented on the spatial light modulator, including Fresnel diffraction hologram and Fraunhofer diffraction hologram. According to the three-dimensional object information, it is calculated by computer software with point source method, chromatography.3. Low PPI 4K LCD are used, instead of high PPI SLM to achieve large scale holographic display. It can reduce the amount of computation of the hologram generation by sparse sampling of the object light. In order to solve the problem of insufficient visible area caused by the small diffraction angle with low PPI, converging light is used to replace the parallel light. Finally, the dynamic holographic display is realized by loading multi-angle holograms. The experimental results prove the feasibility of the method..