Crosstalk is probably one of the main perceptual factors contributing to perceived image quality and visual comfort. The Video Quality Experts Group (VQEG) within their 3D video quality project is specifying a practical measurement procedure that will produce consistent results across laboratories. This paper is part of that effort. Two different method of measuring cross talk on shutter glasses stereo displays have been studied. One is based on time average luminance measurements and the other on temporal measurements. The results show that crosstalk is roughly 0.5% but that there are differences in the crosstalk between the two eyes in the shutter glasses. ©2011 Society for Information Display

SID Symposium Digest of Technical Papers

Glasses-free three-dimensional (3D) displays are one of the game-changing technologies that will redefine the display industry in portable electronic devices. However, because of the limited resolution in state-of-the-art display panels, current 3D displays suffer from a critical trade-off among the spatial resolution, angular resolution, and viewing angle. Inspired by the so-called spatially variant resolution imaging found in vertebrate eyes, we propose 3D display with spatially variant information density. Stereoscopic experiences with smooth motion parallax are maintained at the central view, while the viewing angle is enlarged at the periphery view. It is enabled by a large-scale 2D-metagrating complex to manipulate dot/linear/rectangular hybrid shaped views. Furthermore, a video rate full-color 3D display with an unprecedented 160° horizontal viewing angle is demonstrated. With thin and light form factors, the proposed 3D system can be integrated with off-the-shelf purchased flat panels, making it promising for applications in portable electronics. A space-variant information density three-dimensional display with ultrawide field of view is achieved by a large-scale 2D-metagrating complex, which shows great potential for portable electronic devices.

/pdf/foveated-glasses-free-3d-display-with-ultrawide-field-of-3655d27u5y.pdf

Foveated glasses-free 3D display with ultrawide field of view via a large-scale 2D-metagrating complex.

The depth of focus (DOF) of a lens is a crucial parameter in glasses-free 3D displays that affects the viewing distance range. Here we proposed a vector light field display based on intertwined flat lens for extended viewing distance. The gray-scale diffractive lens (GDL) is designed and fabricated with extended DOF for red (658 nm), green (532 nm), and blue (450 nm) colors. By integrating the intertwined GDLs with a liquid crystal display, four views form a smooth horizontal parallax with a cross talk below 26% over a viewing distance from 24 to 90 cm. The enhancement of the DOF is <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mn>1.8</mml:mn> </mml:mrow> <mml:mo>×</mml:mo> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mn>1</mml:mn> </mml:mrow> </mml:mrow> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:msup> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mn>0</mml:mn> </mml:mrow> </mml:mrow> <mml:mn>4</mml:mn> </mml:msup> </mml:mrow> </mml:math> -fold. The light efficiency of the pixelated GDL reaches 82%. The proposed vector light field 3D display has the advantages of a thin form factor, high efficiency, high color fidelity, and large viewing distance. The potential applications include portable electronics, 3D TVs, and tabletop displays.

Vector light field display based on an intertwined flat lens with large depth of focus

We demonstrate an inverse designed achromatic, flat, polarization-insensitive diffractive optic element, ie, a multilevel diffractive lens (MDL), operating across a broadband range of UV light (250 nm – 400 nm) via numerical simulations The simulated average on-axis focusing efficiency of the MDL is optimized to be as high as ∼86% We also investigate the off-axis focusing characteristics at different incident angles of the incoming UV radiation such that the MDL has a full field of view of 30° The simulated average off-axis focusing efficiency is ∼67%, which is the highest reported till date for any chromatic or achromatic UV metalens or diffractive lens to the best of our knowledge The designed MDL is composed of silicon nitride The work reported herein will be useful for the miniaturization and integration of lightweight and compact UV optical systems

Inverse designed achromatic flat lens operating in the ultraviolet

Ultra-precision manufacturing plays a crucial role in supporting the successful development of many high-tech fields, affecting profoundly the process of human society. Blazed gratings with periodically inclined structures exhibit satisfactory characteristics concentrating most of diffracted light to a single nonzero order. In addition to the well-known high diffraction efficiency, blazed gratings can also greatly improve the sensitivity, resolution and measurement range of grating measurement system, and have become core functional components to improve the level of ultra-precision manufacturing. Global efforts from the scientific and industrial circles have been devoted to the manufacture of blazed gratings. This review describes the physical principles of blazed gratings, specific approaches and the achievements of typical processing methods, including mechanical ruling, holographic ion beam etching, electron beam lithography, wet etching, etc. The strength and weakness of these fabricating methods were addressed, and prospective roads were proposed in order to improve the manufacturing of blazed gratings.

https://iopscience.iop.org/article/10.1088/1361-6463/abfd6a/pdf

A Review on Fabrication of Blazed Gratings

Multiview 3D display can reveal wondrous information of a 3D image without any visual aids. Therefore, it has great potential in many applications, such as education, game, training, and design. Among all the multiview 3D display techniques, the one that is based on diffractive optics and metasurface can present 3D images with ultrawide field of view and low crosstalk. However, the brightness of diffractive multiview 3D display is limited by the diffraction efficiency. Moreover, the low fabrication efficiency and high cost limit the commercial development of 3D display based on metasurface. Here we propose a multiview 3D display based on multi-level pixelated blazed gratings. The period and orientation of each blazed grating in the view modulator is different to form a converged light field. A 4-view prototype was assembled by integrating the view modulator with a shadow mask for the modulation of light intensity. A 3D thoracic cage model was virtually projected within the viewing angle with minimum crosstalk. The light efficiency of the prototype is significantly improved to 60% for 4-level blazed gratings.

Pixelated Blazed Gratings for High Brightness Multiview Holographic 3D Display

Directional backlight has lots of potential applications, including dual view display, anti-spy display, and 3D display. The traditional backlight module illuminates the LCD panel with an angular divergence of around ±60°, while the required angular divergence of directional backlight for anti-spy display is less than ±30°. In this paper, the proposed backlight module is consisted of a LED linear array, a coupling prism and a backlight plate. The wavelength of the gratings are such designed that the angular divergence of the emitting light from the backlight module is limited within ±6.6°. Furthermore, the depth of the gratings is well tuned over the backlight plate so that the diffraction efficiency of the nano-gratings increases as the distance from the LED light sources increases. As a result, a uniform illumination can be achieved over an area of 5.5-inch.

Feng Zhou

Papers

Pixelated Blazed Gratings for High Brightness Multiview Holographic 3D Display

A directional backlight covered with pixelated nano-grating arrays