Tunable liquid crystal grating based holographic 3D display system with wide viewing angle and large size

Abstract

As one of the most ideal display approaches, holographic 3-dimensional (3D) display has always been a research hotspot since the holographic images reproduced in such system are very similar to what humans see the actual environment. However, current holographic 3D displays suffer from critical bottlenecks of narrow viewing angle and small size. Here, we propose a tunable liquid crystal grating-based holographic 3D display system with wide viewing angle and large size. Our tunable liquid crystal grating, providing an adjustable period and the secondary diffraction of the reconstructed image, enables to simultaneously implement two different hologram generation methods in achieving wide viewing angle and enlarged size, respectively. By using the secondary diffraction mechanism of the tunable liquid crystal grating, the proposed system breaks through the limitations of narrow viewing angle and small size of holographic 3D display. The proposed system shows a viewing angle of 57.4°, which is nearly 7 times of the conventional case with a single spatial light modulator, and the size of the reconstructed image is enlarged by about 4.2. The proposed system will have wide applications in medical diagnosis, advertising, education and entertainment and other fields.

HoloKinect: Holographic 3D Video Conferencing

“…In addition, a parallax effect can be experienced by moving horizontally across approximately 50° of valid viewing angles. While the word holographic is used in marketing materials to describe how the Looking Glass Portrait’s 48 simultaneously rendered views resemble a 3D volume to the viewer, it should be noted that this multiscopic display is distinct from displays that rely on optical diffraction and interference, such as those used in conventional holography [ 26 , 27 ]. Figure 4 shows a pair of Looking Glass Portrait displays in use during a live two-way HoloKinect call.…”

High-Quality Holographic 3D Display System Based on Virtual Splicing of Spatial Light Modulator

“…For example, the spatial multiplexing method expands the viewing angle and size of the holographic reconstructed image by stitching multiple SLMs in space. − , However, the increasing number of SLMs leads to an expensive and complex system. The temporal multiplexing method expands the viewing angle and size of the holographic reconstructed image by utilizing the high-order diffraction images, dynamically scanning and changing the direction of the illumination light. − The multidimensional multiplexing property of the subwavelength nanostructured metasurface is also able to expand the viewing angle and size of the holographic reconstructed image. − In addition, nonperiodic photonic sieve and liquid crystal grating are introduced to increase the spatial bandwidth product of SLM. − However, increasing the viewing angle and size of the reconstructed image without sacrificing the image quality and cost savings remains challenging.…”

Generation of phase-only holograms with high-diffraction-order reconstruction by a U-Net-based neural network: A phase grating perspective

“…Compared with conventional display technologies, holography is regarded as a more promising visual display technology since it can reconstruct the whole light field of the object and can provide all visual information [1,2]. The computer-generated hologram (CGH) is a combination of computer technology and traditional holography, which is widely used in three-dimensional display [3][4][5][6][7], virtual reality and augmented reality [8,9], optical trapping [10,11], interferometry [12,13], microscopy imaging [14,15], and other fields.…”