3D Display Based On Computer-generated Hologram

With the rapid development of three-dimensional display technology,the resolution and color fidelity,as well as 3D display of real objects are of people's higher persuit currently.Computer-Generated Holographic(CGH)technology possesses advantages as simple and quick to use,recording the depth information of virtual and three-dimensional objects,as well as true three-dimensional display.Consequently,CGH has been paid a wide range of attention in the field of display.Based on 3D display technology combined with basic theory of holography,the digital diffraction field obtained by Fourier algorithm and convolution algorithm is investigated by theoretical simulation and serial experiments in this present dissertation.Results show that,convolution algorithm is utility to carry out the program under shorter diffraction distance,while fourier algorithm is more suitable for longer diffraction distance.So the Fourier algorithm,which is of celerity and more suitable for remote display,is chosen to calculate the diffraction field.2D object holograms are acquired by use of Boqi encoding method.Synchronously,the location of reconstructed images is researched in detail,as is mentioned,results indicate that,the reproduction and record distance should be identical to obtain a clear reconstructed image.CGHs of three-dimensional objects are more complicated than that of two-dimensional objects.CGHs of three-dimensional objects are achieved by selecting chromatography technology,referring two-dimensional hologram producing method,The chromatography,means a 3D object sliced into a 2D section along the depth,the 2D diffraction results superimposed to form a 3D object hologram.Its processing method is relatively simple,there is no limit to the internal structure of the object,and the calculation is of high efficiency.Firstly,we try to make hologram on fictional 3D object which has four sections,and get a clear reconstructed image in this paper.Secondly,the Fresnel hologram of 3DS object is produced according to the idea of chromatography.The reproduction distance must be equal to the recording distance to reconstruct 3D hologram,as so clear and strong sense of the 3D reconstructed image is obtained Consequently.Simultaneously,relevant factors of influence on the holographic reproduction quality with the pixel pitch in the Spatial Light Modulation(SLM)are discussed systematically.Research reveals that the filling factor and pixel spacing impacts on the holographic reproduction quality grievously.The intensity of reconstructed image will increase significantly with the filling factor increasing,when the pixel pitch is reduced,the size and the quality of the reconstructed image is improved,by theoretical simulation and experimental study.