A time-division multiplexing method for computer-generated holograms (CGHs) is proposed to solve the problem of the limited space-bandwidth product. A three-dimensional (3-D) scene is divided into multiple layers at different depths. The CGH corresponding to each layer is calculated by an angular-spectrum algorithm that is effective at a wide range of propagation distances. All of the CGHs are combined into several group-CGHs. These group-CGHs are sequentially uploaded onto one spatial light modulator at a high frame rate. The spacebandwidth product can be benefited by the time-division processing of the CGHs. The proposed method provides a new approach to achieve high quality 3-D display with a fast and accurate CGH computation.
Multiple three-dimensional (3D) display technologies are reviewed. The display mechanisms discussed in this paper are classified into two categories: holographic display in wave optics and light field display in ray optics, which present the 3D optical wave field in two different ways. Key technical characteristics of the optical systems and the depth cues of human visual system are analyzed. It is to be expected that these 3D display technologies will achieve practical applications with the increase of the optical system bandwidth.
We propose a method to improve the quality of the reconstructed images based on compressive sensing principles. The pseudo-inverse matrix and the total variation minimization algorithms are combined to reduce the sampling number of the computer generated hologram. Numerical simulations are performed and the results indicate that the peak signal to noise ratio is increased and the sampling ratio is decreased at the same time for holographic display.