Research About The Issues And Realization Of Computer- Generated Holographic 3D Display System

The algorithm of Computer-Generated Holography (CGH) and relative question about holographic 3D display system is studied. Commonly, binocular disparity is utilized to obtain the stereoscopic vision. However, on account of the conflict of the convergence and accommodation, binocular disparity is likely to cause the visual fatigue. Compared with the methods using binocular disparity, the holography can reconstruct the light fields of the object, including the amplitude and the phase. It means that we can gain a more vivid 3D image. Thus, the holographic 3D display is the direction of the future research in 3D display.To acquire a traditional optical hologram, we need to record the interference fringes caused by the object light and reference light. And then we reconstruct the image by illuminating the hologram with the reference light. It needs a stable optical table for recording and reconstruction, and it is difficult to realize dynamic display. These issues are obstacles to a wide use. Therefore the CGH based on a spatial light modulator (SLM) is replacing the traditional holography and is becoming the hot spot of the current holographic research. When producing a CGH, we design the object light with computer, and get the distribution of the light, then transform it to a hologram. At Next, we utilize a SLM to load the hologram, and illuminating the SLM with laser. After that, we will reconstruct the origin object light.However, problems comes with the digitization. On one hand, the liquid crystal spatial light modulator (LCSLM) mostly used in scientific research can only encode the phase. On the other hand, the pixel structure of the SLM will lead to multi images and so on. In this dissertation, we realize the Gerchberg Saxton (GS) algorithm by MATLAB, achieve the hologram of single plane and two planes, and construct a 3D display system utilizing a He-Ne laser and a LCSLM. At next, we try to develop and analyze the parameters of the system, such as the fields of views, the position and the size of the image. And the analysis is proved by experiments. We address that there is a virtual image existing behind the SLM, which has not been mentioned before, then we discuss the reason of the appearance of the virtual image. Afterwards, for a better display effect, we load specific phase distribution on SLM. Additionally, on condition of one imaging lens, a single image without crosstalk is formed. These researches lay a foundation of more complicate and practical 3D holographic display system on the future.