Research On Multiview Holographic Display System Based On Grating

Glasses-free three-dimensional(3D)display can provide massive information and real visual experience,so it has attracted the attention of researchers at home and abroad.Multiview display technology and holographic display technology are two common glasses-free 3D display technologies.In recent years,researchers have developed some commercial or conceptual systems based on them,trying to provide services for many fields.However,due to the limitations of the technology and the existing process conditions,these systems still face many problems that need to be resolved.Typically,the stability of the multiview display system is limited by the point-to-point mapping method of the conventional display,and the field of view angle of the dynamic holographic display system is limited by the problem of the excessively large pixel unit of the spatial light modulation device.This thesis combines multiview display technology with holographic display,and designs a new glasses-free 3D display verification system based on grating implementation of different light splitting strategies.The system not only has the large field of view of multiview display,but also has the high stability of holographic display.The main research work and innovations of this thesis are as follows:(1)Analyze the principle and main parameters of diffraction grating,and study the relationship between grating constant and diffraction angle.Analyze and summarize common grating preparation techniques,and focus on the research of interferometric lithography to prepare gratings.Based on the Holo Maker IVB interferometric direct-write hybrid system of SVG Optronics Co.,Ltd,the preparation of multiple-parameter diffraction gratings was carried out,which verified the light splitting function of the diffraction grating and the influence of grating constant on the diffraction angle.(2)The scheme of using diffraction grating to implement diffractive light splitting strategy on the Fourier holographic display system based on Liquid Crystal on Silicon(LCOS)is studied to realize the dual-view holographic display.The two disparity maps are encoded into an optimized hologram,loaded into the LCoS,and through the process of Fourier transformation and beam splitting of the grating,different scenes can be reconstructed in two different directions.By changing the grating constant to change the angle between the reconstructed scenes,a dual-view holographic display with a large viewing angle can be realized.Based on the constructed display system,optical experiments are carried out to verify the effectiveness of the system in light splitting and dual-view display.(3)A solution to the Fourier/Fresnel holographic display verification system based on LCoS is proposed,which uses a cylindrical lens grating to implement a refraction and light splitting strategy to achieve multiview holographic display.Encode multiple disparity maps into optimized holograms,load them into LCoS,and reconstruct different views in multiple directions with the help of Fourier or Fresnel transformation and light splitting of the grating.By changing the pitch,refractive index and curvature of the lenticular Lens to change the field of view of the reconstructed scene,the multi view holographic display with large viewing angle can be realized.Optical experiments based on the constructed display system verify the effectiveness of the system in filtering interference,multiview display and reconstruction stability.