Optical Holographic Display Research Articles

Full-Color Holographic Display and Encryption with Full-Polarization Degree of Freedom.

Metasurfaces provide a compact and powerful platform for manipulating the fundamental properties of light, and have shown unprecedented capabilities in both optical holographic display and information encryption. For increasing information display/storage capacity, metasurfaces with more polarization manipulation channel and full-color holographic functionality are now an urgent requirement. Here, a minimalist dielectric metasurface with the capability of full-color holography encoded with arbitrary polarization is proposed and experimentally demonstrated. Without the daunting exploratory and computational problem in nanostructure searching, full-color holographic images can be multiplexed into arbitrary polarization channels through vectorial ptychography and k-space ptychography based on tetratomic macropixel geometric phase metasurfaces. Thanks to the full degree of freedom tuning in polarization and color spaces, the application scenarios such as holographic 3D imaging and information encryption are realized. The strategy exhibits promising potential in applications of 3Dl display, augmented/virtual reality, high-density data storage, and encryption.

Dynamic direct-writing optical holographic display based on quantum-dot-doped liquid crystal

ABSTRACT In this paper, we propose a dynamic direct-writing optical holographic display system based on quantum-dot-doped liquid crystal (QDDLC). Instead of using two-beam interference to generate the desired holographic patterns, computer-generated hologram was directly generated by a spatial light modulator (SLM) and projected to the QDDLC sample. Employing only one recording beam, the proposed system greatly simplifies the optical system complexity and eliminates the influence of environmental disturbance. We investigate the factors that affect the diffraction efficiency and response time of the QDDLC in the direct-writing system and implement a dynamic holographic 3D display refreshed at 30 Hz.

Video-Rate Holographic Display Using Azo-Dye-Doped Liquid Crystal

A video-rate optical holographic display is achieved by using an azo-dye-doped liquid crystal as the passive, updatable recording material. The response time of this material is measured in the order of several to tens of milliseconds, depending on recording beam intensities, polarization directions, and polarization states. A holographic video at a refresh rate of 25 Hz, sourced from a spatial light modulator, is demonstrated in the experiments.

51.1: Real‐Time Holographic Display Using Quantum Dot Doped Liquid Crystal

AbstractA dynamic optical holographic display featuring a quantum‐dot‐doped liquid crystal is presented. Its response time of holographic recording is measured in the order of several to tens of milliseconds, depending on recording beam intensities, applied voltage and grating periods. The transient first‐order diffraction effciency is up to 20%. A reconstructed holographic video at a refresh rate of 25 Hz is demonstrated by the experiments.

Digital holography for 3D imaging and display in the IR range: challenges and opportunities

In analog holography, the infrared (IR) range received quite some attention, since it could provide interesting information, not achievable otherwise. Since digital sensors in this band became recently available and affordable, also digital holography (DH) expanded its feasibility beyond the visible wavelengths. In fact, the IR range allows shorter recording distances, unparalleled larger field of view and less stringent requirements on system stability, together with some specific characteristics, like e.g. the possibility to test IR glasses or other materials transparent to IR radiation, which cannot be controlled in visible range. In this paper we review the activities which took place in this field and illustrate the results achieved, referring to the opportunities this technique offers, and the challenges it presents. We show efficient reconstructions of holograms of objects of various materials, recorded with different resolution digital thermal cameras, in various configurations, and moreover we demonstrate optical holographic display through a liquid crystal based Spatial Light Modulator which gives the chance to get direct 3D imaging and display of long IR range. Moreover we believe this opens the route toward holography in THz region.

Compensated phase-added stereogram for real-time holographic display

A common difficulty in displaying a Fresnel hologram in real time the required calculation of huge amounts of information. We propose a novel digital hologram generation method for real-time holographic display. It depends on compensation of the phase-added stereogram, and can generate high-quality holograms rapidly. We describe a generation algorithm for the phase-added stereogram, using the fast Fourier transform (FFT) for fast calculation, and the compensated phase-added stereogram to get a reconstructed image as clear as the Fresnel hologram. Moreover, we present a method to define the optimum size of segmentation to get a clear reconstruction image and to achieve fast computation using the FFT. We have built a demonstration system to implement the proposed method. The system consists of a server, a client, and an optical holographic display system for real-time holographic display. The server generates 3-D information and transmits it on Ethernet. The client receives the information and generates a digital hologram using the compensated phase-added stereogram. Finally, the generated hologram is displayed on the optical holographic display system in real time. We have achieved display of digital holograms at 15 frames/s with 1000 object points.