Latest development of display technologies

In this review we will focus on recent progress in the field of two-dimensional（2D） and three-dimensional（3D）display technologies.We present the current display materials and their applications,including organic light-emitting diodes（OLEDs）,flexible OLEDs quantum dot light emitting diodes（QLEDs）,active-matrix organic light emitting diodes（AMOLEDs）,electronic paper（E-paper）,curved displays,stereoscopic 3D displays,volumetric 3D displays,light field3 D displays,and holographic 3D displays.Conventional 2D display devices,such as liquid crystal devices（LCDs） often result in ambiguity in high-dimensional data images because of lacking true depth information.This review thus provides a detailed description of 3D display technologies.

Color liquid crystal grating based color holographic 3D display system with large viewing angle

Holographic 3D display is highly desirable for numerous applications ranging from medical treatments to military affairs.However,it is challenging to simultaneously achieve large viewing angle and high-fidelity color reconstruction due to the intractable constraints of existing technology.Here,we conceptually propose and experimentally demonstrate a simple and feasible pathway of using a well-designed color liquid crystal grating to overcome the inevitable chromatic aberration and enlarge the holographic viewing angle,thus enabling large-viewing-angle and color holographic 3D display.The use of color liquid crystal grating allows performing secondary diffraction modulation on red,green and blue reproduced images simultaneously and extending the viewing angle in the holographic 3D display system.In principle,a chromatic aberration-free hologram generation mechanism in combination with the color liquid crystal grating is proposed to pave the way for on such a superior holographic 3D display.The proposed system shows a color viewing angle of~50.12°,which is about 7 times that of the traditional system with a single spatial light modulator.This work presents a paradigm for achieving desirable holographic 3D display,and is expected to provide a new way for the wide application of holographic display.

Holographic storage of three-dimensional image and data using photopolymer and polymer dispersed liquid crystal films

We present holographic storage of three-dimensional（3D） images and data in a photopolymer film without any applied electric field.Its absorption and diffraction efficiency are measured,and reflective analog hologram of real object and image of digital information are recorded in the films.The photopolymer is compared with polymer dispersed liquid crystals as holographic materials.Besides holographic diffraction efficiency of the former is little lower than that of the latter,this work demonstrates that the photopolymer is more suitable for analog hologram and big data permanent storage because of its high definition and no need of high voltage electric field.Therefore,our study proposes a potential holographic storage material to apply in large size static 3D holographic displays,including analog hologram displays,digital hologram prints,and holographic disks.

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

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.