Study On The Three-dimensional Display Of Computer-generated Hologram

With the rapid development of display technique, the traditional two-dimensional display technology has been unable to meet the requirements of people, and three-dimensional (3D) display technology has gradually become a new research topic. As a true3D display technology, holographic3D display has the advantages of viewing with the naked eye and providing wide color gamut and full depth cues. Computer-generated hologram (CGH) is a new holographic imaging technique, which simulates the physical process of holographic record by means of using a computer. Comparing to the traditional optical holography and digital holography, it has the advantages of low requirement on environment, flexible and repeatability. However, there are still some problems to impede the further development of CGH, some research works will expand the discussion in this paper, including3D CGH theories and algorithms, coding accelerating method of true3D large data volume object,3D display method of CGH based on Spatial Light Modulator (SLM). In order to prove the result of this paper, feasibility and practicality system and experiment method of the3D holographic display is established.Analyzed the coding method of CGH and got the scope of different methods. Based on the comprehensive analysis, this study chooses the flexible and easy coding method-Burch. In order to solve CGH fast encoding of3D object, this paper expounds the way of combing VC++and powerful computing capabilities of MATLAB, which is based on the technology of component object model (COM). This method increased processing speed of hologram encoding effectively, through different size data experiment. It shows the high reliability and practical applicability of the mixed programming. In addition, multi-angle CGH of the true3D object is computed and reconstructed digitally. Otherwise, the method of getting true-color3D CGH computing images is given.To further study on3D CGH display, digital micro-mirror device (DMD) as the spatial light modulator is used.3D object uses slice image replaced, which combining with the angular spectral method gets the relationships between parameters of DMD with the hologram. Then using the3D holographic coding methods, the CGH is got. With the numerical reconstruction and experiment can get well conclusion. The results demonstrate that the proposed approach is correct, which provides an effective way for3D display in practical application.In order to achieve the high quality hologram reconstruction, this paper expounds the principle and optical modulation characteristic of DMD. Based on the principle of holographic display on DMD, this paper analyzes the Fresnel Diffraction theory and grayscale modulation theory. A new method of grayscale-adjustment CGH is proposed. And numerical reconstruction results are given. The results demonstrate that holographic display effect has an apparent improvement with grayscale-adjustment. This conclusion is very useful to study computer generated hologram display based on DMD.The paper has a study on3D computer holography, including theories, algorithms, digital reconstruction and experimental demonstration and so on. Some works and conclusions in this paper are instructive and useful in CGH3D display system study based on SLM. And it can be used for reference in real-time display system of CGH for further study.