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Compact and high efficiency microdisplays are essential for lightweight augmented reality (AR) glasses to ensure longtime wearing comfort. Liquid-crystal-on-silicon (LCoS) is a promising candidate because of its high-resolution density, high brightness, and low cost. However, its bulky illumination system with a polarizing beam splitter (PBS) cube remains an urgent issue to be overcome. To reduce the volume of the LCoS illumination system, here, we propose a compact structure with four thin PBS cuboids. Through simulations, the optical efficiency of 36.7% for an unpolarized input light can be achieved while maintaining reasonably good spatial uniformity. Such a novel design is expected to have a significant impact on future compact and lightweight AR glasses. [ABSTRACT FROM AUTHOR]

Blue InGaN/GaN CPC microLED with metallic sidewall can achieve a higher efficiency based on the dipole cloud model in FDTD and electrical model in TCAD. By merely optimizing the p‐GaN contact size, the EQE is improved by 8.7%. Such method helps to achieve high brightness with a lower power consumption. [ABSTRACT FROM AUTHOR]

Liquid‐crystal optics is a promising optical element for near‐eye display as it provides an ultrathin formfactor and lightweight. However, its severe chromatic aberrations impose a big challenge for full‐color display applications. In this study, we demonstrate an achromatic diffractive liquid‐crystal device to overcome this longstanding chromatic aberration issue. [ABSTRACT FROM AUTHOR]

To achieve wide‐gamut and high‐efficiency tandem white OLED (WOLED) microdisplays, we propose a new structure leveraging from the high‐order antinodes and patterned microcavities. The color gamut coverages of 95% Rec. 2020 and 92% Rec. 2020 can be achieved in B/G/R WOLED with a moderate microcavity and B/YG WOLED with a strong microcavity, respectively. We have also boosted the optical efficiency by 62% by optimizing the B/YG WOLED structure. Such a WOLED microdisplay helps to reduce the power consumption of virtual reality (VR) and mixed reality (MR) displays while keeping a wide color gamut. [ABSTRACT FROM AUTHOR]

Tone mapping and mini‐LED backlight algorithms are applied to enhance the sunlight readability of LCDs by fitting the human eye's functionality and increasing image uniformity. Both experimental and simulation results indicate that high luminance displays with an optimized gamma value help to distinguish low grayscale contents under bright ambient conditions. [ABSTRACT FROM AUTHOR]

We propose a theoretically lossless pancake optics solution that incorporates a nonreciprocal polarization rotator sandwiched between two reflective polarizers. A proof‐of‐concept experiment using a commercially available Faraday rotator (FR) is implemented. The theoretically predicted 100% efficiency can indeed be achieved approximately by using two high extinction ratio reflective polarizers. [ABSTRACT FROM AUTHOR]

We analyze the field‐of‐view (FoV) limitations in a single‐layer, full‐color waveguide‐based augmented reality display, revealing key influences from the waveguide's refractive index, exit pupil expansion (EPE) scheme, and combiner's angular response. Based on these analyses, we propose an optimized butterfly EPE scheme with gradient‐pitch polarization volume gratings (PVGs), achieving a theoretical diagonal FoV of 54.06° with a 16:10 aspect ratio. [ABSTRACT FROM AUTHOR]

The sunlight readability of display devices, such as notebook computers, transparent displays, vehicle displays, and augmented reality, is a significant technical challenge due to degraded image quality. To mitigate this problem, by fitting the human eye function, we propose a tone mapping method on a mobile phone display panel to enhance low grayscale image readability under bright ambient light. Additionally, we adapt a mini-LED backlight model to simulate real images under different ambient lighting conditions. Both experimental and simulated results indicate that high luminance displays with an optimized gamma value significantly enhance sunlight readability and image quality. Moreover, global color rendering can alleviate color shift. Such a method is also valid for the optimization of optical see-through devices under diverse environmental conditions. [ABSTRACT FROM AUTHOR]

Micro-LEDs have found widespread applications in modular large-screen TVs, automotive displays, and high-resolution-density augmented reality glasses. However, these micron-sized LEDs experience a significant efficiency reduction due to the defects originating from the dry etching process. By controlling the current distribution via engineering the electrode size, electrons will be less concentrated in the defect region. In this work, we propose a blue InGaN/GaN compound parabolic concentrator micro-LED with a metallic sidewall to boost efficiency by combining both an optical dipole cloud model and electrical TCAD (Technology Computer-Aided Design) model. By merely modifying the p-GaN contact size, the external quantum efficiency (EQE) can be improved by 15.6%. By further optimizing the passivation layer thickness, the EQE can be boosted by 52.1%, which helps enhance the display brightness or lower power consumption. [ABSTRACT FROM AUTHOR]

Pancake lens has been widely used in virtual reality (VR) and mixed reality (MR) due to its compact form factor. However, using a half mirror (HM) to fold the optical path results in a tremendous optical loss. To enhance the optical efficiency while keeping a compact form factor, we present a new folded optical system incorporating a nonreciprocal polarization rotator. In our proof‐of‐concept experiment using a commercial Faraday rotator (FR), the theoretically predicted 100% efficiency is validated. Besides, the angular response of terbium gallium garnet (TGG) material is simulated for the first time and the results indicate that such an FR is relatively insensitive to the incident angle, which can dramatically enhance the contrast ratio of our pancake design. Finally, the potential application of such pancake optics for ultracompact near‐infrared (NIR) night vision goggles is also discussed. [ABSTRACT FROM AUTHOR]

Liquid crystal polarization holograms (LCPHs) based on photo‐alignment and self‐assembled liquid crystal are attractive for the attributes like micrometer ultra‐thinness, high efficiency and dynamic tunability. Previous fabrication methods are limited in the degree‐of‐freedom (DoF) in both photoalignment process and liquid crystal deposition. This work presents an full‐DoF LCPH by freeform exposure and inkjet printing, which is exemplified by building a full‐color retinal scanning display without color crosstalk. [ABSTRACT FROM AUTHOR]

Pancharatnam‐Berry (PB) phase liquid crystal (LC) lenses show attractive benefits in optical systems because of their high efficiency, compact size and polarization‐dependent behavior. However, as a kind of diffraction‐based devices, PB LC lenses suffer from chromatic dispersion, which limits their applications in multi‐wavelength imaging systems. In this paper, we demonstrate a multispectral PB LC lens design to overcome this issue. An active multispectral PB LC lens has been fabricated and characterized. It can focus different wavelengths at the same distance so they are expected to solve the chromatic dispersion problem in the multi‐wavelength display system and other broadband optical systems. [ABSTRACT FROM AUTHOR]

This paper introduces an innovative approach to integral volumetric imaging employing time and polarization multiplexing techniques to present volumetric three-dimensional images. Traditional integral volumetric imaging systems with a coarse lens array often face moiré pattern issues stemming from layered panel structures. In response, our proposed system utilizes a combination of time and polarization multiplexing to achieve two focal planes using a single display panel. [ABSTRACT FROM AUTHOR]