Holographic Display Of Lcd Spatial Light Modulator

Holography is a most attractive method of displaying 3D images because a single hologram includes all intensity and phase information of the object. When observing the volumetric images by the naked eyes, people can obtain all the accurate depth cues similar to the original object. With the demand of real-time display, digital holography combining the spatial light modulator (SLM) and computer-generated holography is developing, which is without of the strict recording system and the long film exposure and development process. This holographic technology has the advantages of digitization, programmable, real-time and convenience, and is the main developmental direction of the holographic display region in the future.In this paper, some relevant issues of the holographic display system based on the liquid crystal spatial light modulator is studied, concerning the theoretical study, software simulation, system realization, experimental discussion and characteristics analysis, et al. Considerable staggered progress has been made.The phase-only modulation characteristics of twisted-nematic liquid crystal device (TN-LCD) are studied in Chapter 2. Combining the research of predecessor, we analyzed the feasibility of the application of TN-LCD for phase-only modulator, and calculated the opto-electronic property of LCD with the different polarization state of incident and emergent light using Jones Matrix. Based on the theory of polarization eigenvectors, we obtained the phase-only modulation of the TN-LCD system. The study shows that the elliptically polarized eigenvectors can be generated by using a quarter wave plate at both sides of the LCD, then a configuration of phase-only modulation is achieved. The experimental results are also obtained, which proved the phase hologram has higher diffraction efficiency than amplitude hologram.In the Chapter 3, the master Fresnel zone algorithm to calculate the hologram of the three-dimensional objects is proposed which is different from the common ways depending on the 2D projections or sectional drawings. The principle, flow and applicability of the master Fresnel zone algorithm is introduced, which acts the 3Dpoints as the computational objects. The holographic reconstruction systems based on LCD are set up, and the no-slit hologram with the illumination of white light and the 3D holographic images are reconstructed, whose characteristics are analyzed.The limiting aperture opening ratio of the pixels and the matrix structure of the LC-SLM lead to the reduplicate images on the reconstruction plane. We simulated the reconstruction of the hologram displayed on the LCD by 'Splitting Pixel Method', and put forward the 'Differential Compensation Method' to eliminate the diffractive effect, obtaining the considerable result. The effect of the limited spatial resolution of the LCD on the recording process is studied, and the demands of the reference light's angel, the dimension of the object and the distance between the hologram and object are proposed.