This PDF file contains the front matter associated with SPIE Proceedings Volume 12908, including the Title Page, Copyright information, Table of Contents, and Conference Committee information.

We present a novel design for a full-color, wide Field-of-View (FoV) Augmented Reality (AR) display, which ingeniously employs a single waveguide along with advanced polarization multiplexing reflective polarization holograms. This innovative approach surmounts the narrow FoV limitation of the present single-waveguide, full-color AR displays. The employed reflective polarization holograms are devised to operate with high efficiency across the entire visible spectrum, accommodating the incident angles required by the expanded FoV. This novel design represents a significant leap forward in AR technology, laying a foundation for immersive and vivid AR experiences.

A double-layer holographic waveguide, which is made from the acrylate photopolymers, is proposed for the see-through augmented reality. The most significant contribution is the integration of ocular lenses into the waveguides. The waveguide design, imaging principle, optical simulations, and fabrication methods are introduced. In our experiments, a prototype with a diagonal field of view of 30° is demonstrated. Compared to other multi-layer waveguides, our solution could offer a more compact form factor, which is essential for wearable devices.

The light field display (LFD) can provide realistic 3D content with feasible implementation but is encountering low spatial resolution, requiring higher-resolution picture generation units. The mini-LED backlight LCD is a strong competitor due to its high contrast, small form factor, and mature fabrication. We remove the color filter array for tripled resolution and light efficiency, namely, the field sequential color (FSC) LCD. This study reports an LFD prototype based on a 240-Hz FSC-LCD. The unique issue in FSC-LCDs, color breakup, is addressed by using three fields for one frame, but not traditional 4-field driving. The low-color-breakup driving is achieved using multi-objective optimization (MOO) to create a training set for a lightweight neural network. The MOO guarantees our system’s color breakup and image distortion are simultaneously invisible, and the lightweight neural network realizes real-time driving.

A new approach is presented to enhance the angular resolution of high-density point light source (HPLS) displays. Some of the lights emitted from the edge of point light sources (PLSs) in a conventional HPLS display do not contribute to the creation of three-dimensional (3D) images. As a result, the 3D images formed at the edges of the display have a low angular resolution. Therefore, our proposed display contains four boundary mirrors that are positioned to utilize these lights. We simulated the angular resolution in the proposed system and experimentally demonstrated the feasibility of the new method. By reflecting the light rays in the mirror that are not used to create the 3D images, we have effectively resolved the issue of low angular resolution in 3D images at the edges of the HPLS display.

Pancake lens has been widely used in mixed reality (MR) due to its compact formfactor. However, using a half mirror to fold the optical path results in a tremendous optical loss. To break this optical efficiency limit while keeping a compact formfactor, we present a new folded optical system incorporating a nonreciprocal polarization rotator. In our proof-ofconcept experiment using a commercial Faraday rotator, the theoretically predicted 100% efficiency is validated. Meanwhile, the ghost images can be suppressed to undetectable level if the optics are with anti-reflection coating. Our novel pancake optical system holds great potential for revolutionizing next-generation MR displays.

Using smaller CMOS nodes for the design of backplanes for light modulator enables the integration of additional features. This paper reports on a backplane designed in 28nm technology which embeds a complete framebuffer as well as a programmable high speed data interface which can realize up to 576Gbit/s data transfer rate to pixel array utilizing a 1440 x 1080 resolution with a 2.5 micron pixel capable for LCOS, OLED and micro-LED front planes. The programmable modulation scheme will be discussed in detail using typical scanning examples.

Deep learning-based computer-generated holography (CGH) has recently demonstrated tremendous potential in three-dimensional (3D) displays and yielded impressive display quality. However, current CGH techniques are mostly limited on generating and transmitting holograms with a resolution of 1080p, which is far from the ultra-high resolution (16K+) required for practical virtual reality (VR) and augmented reality (AR) applications to support a wide field of view and large eye box. One of the major obstacles in current CGH frameworks lies in the limited memory available on consumer-grade GPUs which could not facilitate the generation of highdefinition holograms. Moreover, the existing hologram compression rate can hardly permit the transmission of high-resolution holograms over a 5G communication network, which is crucial for mobile application. To overcome the aforementioned challenges, we proposed an efficient joint framework for hologram generation and transmission to drive the development of consumer-grade high-definition holographic displays. Specifically, for hologram generation, we proposed a plug-and-play module that includes a pixel shuffle layer and a lightweight holographic super-resolution network, enabling the current CGH networks to generate high-definition holograms. For hologram transmission, we presented an efficient holographic transmission framework based on foveated rendering. In simulations, we have successfully achieved the generation and transmission of holograms with a 4K resolution for the first time on an NVIDIA GeForce RTX 3090 GPU. We believe the proposed framework could be a viable approach for the evergrowing data issue in holographic displays.

Holographic 3D display is considered as one of the ideal 3D displays. However, due to the large amount of data of 3Dobjects, the calculation speed of holograms is still relatively slow. In this paper, a fast hologram calculation method is proposed based on diffraction optimization. The information of 3D object is divided into the high-frequency part and the low-frequency part. The new look-up table (NLUT) algorithm is used to calculate the details of the high-frequency part, thus reducing the amount of diffraction calculation and ensuring the calculation accuracy of the details, while the low frequency information is diffracted by the faster angular spectrum algorithm. The sub-hologram of high-frequency information and the sub-hologram of low-frequency information are superimposed to obtain the final hologram. When the collimated light is used to illuminate the final hologram, the 3D reconstructed image of the object can be seen. Compared with the traditional NLUT algorithm, the calculation speed of the proposed method is increased by ~57.8%. Experiments verify the feasibility of the proposed method.

In virtual reality (VR) and augmented reality (AR) display, the vergence-accommodation conflict (VAC) is a significant issue. Thus, true-3D display technologies has been proposed to solve the VAC problem. Integral imaging (II) display, one of the most critical true-3D display technologies, has received increasing research recently. Significantly, anachromatic metalens array has realized a broadband metalens-array-based II (meta-II). However, the past micro-scale metalens arrays were incompatible with commercial micro-displays. Additionally, the elemental image array(EIA)rendering is slow. These device and algorithm problems prevent meta-II from being used for practical video-rate near-eye displays (NEDs). This research demonstrates a II-based NED combining a commercial micro-display and a metalens array. We make efforts in the hardware and software to solve the bottlenecks of video-rate metalens array II-based NED. The large-area nanoimprint technology fabricates the metalens array, and a novel real-time rendering algorithm is proposed to generate the EIA. We also build a see-through prototype based on our meta-II NED, demonstrating the effect of depth of field in AR, and the 3D parallax effect on the real mode. This work verifies the feasibility of nanoimprint technology for mass preparation of metalens samples, explores the potential of video-rate meta-II displays, which we can be applied in the fields of VR/AR and 3D display.

The limited eyebox size has posed a significant challenge in Maxwellian view systems, restricting users' head movement and causing potential discomfort. This paper presents innovative methods to overcome this limitation by utilizing input angle modulation at the input metasurface optical element (MOE). Through meticulous designs and rigorous simulations, we evaluate the effectiveness of these techniques in expanding the eyebox while maintaining optimal optical performance. Our research aims to enhance user comfort and satisfaction in augmented reality (AR) glasses, offering a more immersive and enjoyable experience. By addressing the constraints of small eyeboxes, this work contributes to advancing the field of AR technology and opening new possibilities for augmented reality applications.

Freeform optics, an emerging technology, holds immense transformative potential in imaging applications. This groundbreaking technology has permeated numerous fields, providing extremely compact design for applications including AR/VR, quantum cryptography, lighting, remote sensing, medical devices, and energy research, showcasing its versatility and growing importance. Manufacturing methods have been developed such as diamond turning, additive manufacturing, or two-photon polymerization. Compared to conventional optics, a critical difficulty that limits the wide adoption of the technology, is the difficulty to generate a good initial freeform surface that can later be optimized to meet the designer requirements. Here we present a novel design method, which takes a set of analytical constraints as input and generates freeform surfaces that precisely meet these constraints as output. We address the case of a head-up display.

We propose a novel design for high-resolution 3D display and large field of view that utilizes time-based multiplexing and adjustable light deflecting device. The device includes a two-dimensional display with an array of pixels, an array of micro cylindrical lenses, and an array of adjustable light deflecting device. By refracting and configuring light emitted from the pixels into multiple parallel beams using micro cylindrical lenses and deflecting the light with adjustable light deflecting device, the effective number of pixels is increased, resulting in enhanced resolution. A controller varies the intensity and color of light emitted by each pixel according to three-dimensional information, while also changing the deflection angle of the light deflecting device during the integration period of the human visual system.

Escape route signs provide orientation in case of emergency. However, these signs are static and guide people always in the same direction regardless of the actual situation. Dynamic escape route displays raise safety by redirecting people to an optimized route, e.g. by avoiding fire, areas with heavy smoke, congestions and blocked routes. We designed and prototyped an escape route system with the following characteristics: Use of wireless controlled e -paper displays (electrophoretic high-reflectance E Ink), fire detectors, cameras with artificial intelligence (AI) algorithms to identify the number of people in an area, persons lying on the floor, congestions (jams) and reduced visibility due to smoke and a system master controller. E-paper is bistable and therefore the default direction is always displayed even if no power is available. Thus, even if the dynamic routing system is down or not available, the safety is the same as for static signs.

This paper introduces a new methodology for simulating the burn-in of an organic light-emitting diode (OLED) microdisplay used in a virtual reality (VR) headset. The proposed simulation employs the stretched exponential decay (SED) model, which is widely used to predict the degradation of the OLED device over time. Furthermore, the model integrates the impact of user head motion on VR display image content. The study defines productivity and gaming mode surrogate image content from which to simulate burn-in and applies image processing correlating to head motion data collected from a user study. The results of this study indicate that head motion has a significant impact on OLED burn-in. Given a conservative assumption for image content and head motion, the time for visual failure due to burn-in artifacts is 4 times slower than a case with stationary image content.

The spatial light modulator (SLM) based on liquid crystal on silicon (LCoS) technology has been widely used in applications such as holography and wavelength selective switches (WSS). Although there is some progress in terms of larger filling factor, improved surface process engineering, the concern lies in the light efficiency of SLM. For the reflectivity, various dielectric layer design have been proposed. This paper presents experimental results on the reflectivity of different filling factors and surface treatments. On the diffraction efficiency, factors such as liquid crystal material, voltage control and fringe field effect are also discussed. Previous research has focus on the phase depth and phase linearity of the SLM, but this paper emphasizes the importance of cell design and voltage control in achieving higher efficiency. The efficiency of blazed gratings with different numbers of steps are compared and intentionally increasing the driving voltage for gratings with a small pitch to compensate for the decrease in sharpness in the fly-back zone are suggested. Then, to estimate the influence of the fringe field effect, four simplified model are analyzed and the calculation result with two panels applied in optical communication in different grating cases, including small pitch grating and larger pitch grating are compared with real test results. The conclusion is valuable for guiding cell design and providing insight into the small pitch large angle blazed grating. Additionally, the diffraction efficiency of a two pi blazed grating is compared for different voltage ranges, starting from the lowest to the highest, with four types of liquid crystal materials filled into identical LCoS cells. Although the changing slope and efficiency values differ, the overall trend remains similar. In conclusion, both material selection and driving voltage control are crucial. A 1550nm LCoS based SLM is designed with more than 80% reflectivity, and the diffraction efficiency is higher than 50% with 4 step single pixel grating and 83% with 16 step single pixel grating.