Related references
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Article
Optics
Shaghayegh Yaraghi et al.
Summary: Traditional head-up displays (HUDs) suffer from limited exit pupil and lack of compactness due to bulky optics. Holographic HUDs, on the other hand, provide a high-quality image with a wide field of view (FOV) and the ability to correct vision and adjust focus. However, the limited bandwidth of a spatial light modulator (SLM) imposes a trade-off between FOV and eye-box size. Combining a holographic system with an image-replicating element eliminates this trade-off.
Article
Optics
Zhenping Xia et al.
Summary: Incomplete optical distortion correction in VR HMDs leads to spatial dynamic distortion, which is a potential cause of VIMS. A perception experiment with three spatial distortion levels was conducted, and the subjective SSQ, five-scale VIMS level rating, and objective postural instability were used as evaluation metrics. The results showed that the level of spatial distortion significantly affected all evaluation metrics (p<0.05). As the spatial distortion level decreased, the increment of VIMS symptoms decreased. This study highlights the importance of perfect spatial distortion correction in VR HMDs for eliminating the potential aggravation effect of VIMS.
Article
Optics
Shu-Feng Lin et al.
Summary: This paper proposes a binocular full-color holographic three-dimensional near eye display system using a single spatial light modulator (SLM). The frequency spectrum shifting operation and color spectrum shifting operation are adopted to achieve frequency division multiplexing (FDM) and frequency superposition multiplexing (FSM) by manipulating the frequency spectra of each color- and view-channel sub-holograms. Optical analysis and experiments with 3D color objects confirm the feasibility of the proposed system in practical application.
Article
Optics
Chao Chen et al.
Summary: In this study, a home-made imaging Mueller matrix ellipsometer (IMME) was proposed to monitor the sidewall tilting of pixelated nanogratings. Through the combination of Mueller matrix elements, the tilting angle can be quickly and qualitatively identified for on-line quality monitoring of the device. By inversely calculating the Mueller matrix, the value of the tilting can be accurately and quantitatively obtained to meet the demands of the device design. It is expected that this method can provide guidance for the identification and detection of tilting in 3D display elements based on pixelated gratings.
Article
Optics
Jie Wang et al.
Summary: A holographic display system for complex amplitude modulation (CAM) is proposed using a phase-only spatial light modulator (SLM) and two polarization gratings (PG). The two sub-holograms of the complex-amplitude computed generated hologram (CGH) are loaded in different regions of SLM. The system achieves a large depth of field and enlarged display area, and provides high-quality holographic display with high energy efficiency.
Article
Optics
Qinghao Guo et al.
Summary: We propose a single-layer color echelle grating combined optical waveguide structure for augmented-reality display. By using echelle gratings with super-wavelength periodic scale as in-coupling, relay, and out-coupling elements, we achieve the combined propagation of three light beams in the waveguide. The deflection of beam direction between gratings is achieved by conical diffraction generated by the inclined grating, resulting in dual-channel one-dimensional pupil dilation of the original image and a field-of-view angle of 18.9 degrees x 36.87 degrees.
Article
Optics
Lihui Wang et al.
Summary: Dynamic projection mapping is an interactive display technology that enables augmented reality with naked eyes. However, the fixed and shallow depth-of-field of projectors limits its applications. This work presents a high-speed projection mapping method with dynamic focal tracking based on a variable focus lens. The system includes a high-speed variable focus lens, a high-speed camera, and a high-speed projector, allowing the detection of depth and rotation information for real-time correction and updating of projection information. As a result, well-focused projection is achieved even on 3D dynamic moving objects. The high-speed prototype has a response speed of around 5 ms, and the dynamic projection range covers from 0.5 to 2.0 m.
Article
Optics
Yu Zhao et al.
Summary: Currently, a real objects-based full-color holographic system collects data using a DSLR camera array or depth camera, and reconstructs the 3-D scene of the real objects through a spatial light modulator. However, the main challenges faced by high-quality holographic 3-D display are the limited generation speed and low accuracy of computer-generated holograms. This research tackles these issues by developing an RGB-D salient object detection model for more effective and accurate point cloud data, and proposing a divided point cloud gridding method to enhance hologram generation speed.
Article
Optics
Jeremy Goodsell et al.
Summary: Recently, the popularity of augmented reality (AR) displays has grown due to their immersive and realistic viewer experience. One key challenge is the trade-off between the field-of-view (FOV) and the eyebox size. This study explores the efficiency limit of waveguide-based combiners and demonstrates that the geometry of the waveguide and the in-coupler play a fundamental role. The use of metasurfaces as in-couplers shows promising results in improving efficiency compared to traditional gratings.
Article
Optics
Ning Xi et al.
Summary: We propose an implantable metaverse with retinal prostheses that work in tandem with bionic vision processing. Our approach differs from conventional retinal prostheses by rearranging electrodes to match the distribution of ganglion cells. To emulate human vision, we develop a scheme for bionic vision processing that visualizes monocular image, binocular image fusion, and parallax-induced depth map on a three-dimensional eye model.
Article
Optics
Xiao-Li Ma et al.
Summary: This article introduces an integral imaging (II) display system that simultaneously enhances depth of field (DOF) and resolution. The system utilizes a transmissive mirror device (TMD) and a semi-transparent mirror (STM) to reconstruct two central depth planes, effectively enhancing DOF. Additionally, the resolution in the overlapping DOF region is increased through interpolation of light field information from two II display units. The article analyzes the impact of the distance between the II display units and the TMD on 3D image quality and proposes optimization strategies in geometric and wave optics to eliminate ghost images and 3D pixel gaps.
Article
Optics
Lizhi Chen et al.
Summary: In this study, we propose a compact holographic near-eye display system that achieves high-quality speckle-free optical reconstructions using camera-in-the-loop optimization with phase constraint strategy. By embedding the phase constraint into the CGH optimization process, the proposed method effectively suppresses speckle noise in the reconstructed wave field.
Article
Optics
Woongseob Han et al.
Summary: We propose a new lightguide-type super multi-view near-eye display that combines a digital micromirror device and a LED array. This method uses a compact combiner optics, consisting of a thin lightguide and holographic optical elements (HOEs), to present three-dimensional images with a natural monocular depth cue. Optical experiments verify the feasibility of this method, demonstrating monocular three-dimensional image presentation over a wide depth range. The study also analyzes the degradation of image quality caused by the spectral spread of the HOEs and shows its reduction through pre-compensation using an adaptive moment estimation (Adam) optimizer.
Article
Optics
Qichao Hou et al.
Summary: This study analyzes the causes and effects of various types of stray light in pancake virtual reality head-mounted displays (VR-HMDs), and designs a VR-HMD with low stray light, large exit pupil diameter (EPD), compact form, and light weight. Several effective solutions for stray light suppression are proposed and implemented. A prototype of a compact pancake VR-HMD system is successfully demonstrated, with stray light below 2.3%, a diagonal field of view (FOV) of 96 degrees, and an EPD of 10 mm at an 11 mm eye relief (ERF).
Article
Optics
Zi Wang et al.
Summary: This paper demonstrates a lensless phase-only holographic retinal projection display (RPD) based on the error diffusion algorithm. By employing a post-addition phase method, the image quality during the error diffusion process is improved, resulting in a virtual image with enhanced quality. Additionally, the viewpoint can be easily deflected by adjusting the post-added spherical phase. A full-color holographic RPD with an adjustable eyebox is experimentally demonstrated using time-multiplexing technique.
Article
Optics
Chao Ping Chen et al.
Summary: This article presents a near-eye display with a triple-channel waveguide and chiral liquid crystal gratings. The waveguide divides the field of view into three parts using polarization orthogonality and angular separation. Experimental results show that the display has a diagonal field of view of 90 degrees, eye relief of 10 mm, transmittance of 4.9%, and uniformity of 89%.
Article
Optics
Miao Xu et al.
Summary: This work presents a straightforward, rapid, and low-cost technique for fabricating curved microlens arrays on polydimethylsiloxane (PDMS) substrates using the self-assembly technique. The proposed technique involves a reactive ion etching process followed by dip-coating and crosslinking to create a hydrophobic-hydrophilic pattern and realize the curved microlens array. The fabricated bionic compound eye structure showed a wide field of view and has potential applications in imaging sensors, medical diagnostics, machine vision systems, and photodetectors.
Article
Optics
Fu-Hao Chen et al.
Summary: Using thin-encapsulated self-emissive displays like OLEDs can widen the FOV and improve the user experience in LFD mobile applications. By aligning sub-pixels into a single column and using a moire-free parallax barrier, the spatial resolution and motion parallax of LFD can be enhanced significantly. The crosstalk effects caused by wide slits on the 3D image quality are also analyzed in the study.
Article
Optics
Shufeng Yan et al.
Summary: Eyebox uniformity is an important indicator for evaluating the performance of optical waveguide displays. A novel method based on linked list processing is proposed to optimize eyebox uniformity. The method efficiently records light trajectory and calculates optimal diffraction efficiency distribution. By solving the coupled structure of an L-shaped diffractive optical waveguide using rigorous coupled-wave analysis and the simplex method, the feasibility of the proposed method is verified using LightTools. The achieved uniformity in the FOV range is 0.9 at central viewing angle and overall eyebox uniformity is 0.617.
Article
Optics
Zhenyi Luo et al.
Summary: Liquid-crystal-based Pancharatnam-Berry optical elements are widely used in virtual reality and augmented reality. However, the mismatch between exposure wavelength and operating wavelength leads to undesired phase deviation and severe aberration. To overcome this problem and improve imaging performance, a new exposure method using two template lenses with different focal lengths is proposed and experimentally validated.
Article
Optics
Chih-Hao Chuang et al.
Summary: A miniaturized full-color holographic reconstruction system was developed in this study, using a single spatial light modulator for full-color image reconstruction and demonstrating features such as full-color display, corrected light combination, and eliminated zero-order light. The system's use of a single light guide for light combination made it less voluminous than conventional reconstruction systems, and vibrations of the light guide disrupted the temporal coherence of the laser beam to ensure imperceptible speckle in the reconstructed image.
Article
Optics
Chongli Zhong et al.
Summary: In this paper, a volume representation and improved ray tracing algorithm are proposed for real-time computer-generated hologram (CGH) generation with enhanced depth performance. Experimental results show that the proposed method can provide a real-time interactive holographic display with accurate depth precision and a large depth range.
Article
Optics
Jiwoon Yeom et al.
Summary: In this study, we analyze the image quality of a holographic lens and propose a method for implementing compact near-eye displays using non-converging signal waves. By introducing a comprehensive analysis model and validating it through simulations and experiments, we achieve satisfactory results.
Article
Optics
Dewen Cheng et al.
Summary: This article introduces a new design for a compact, lightweight, and stray-light-suppressed optical see-through head-mounted display using freeform prisms. By combining a micro-display with prisms and freeform lenses, a thin and light head-mounted display is successfully designed. Stray light in the optical-mechanical system is investigated, and effective solutions or theoretical suppression methods are provided. Experimental results show that the optical see-through head-mounted display has sufficient performance for practical applications.
Article
Optics
Junyu Zou et al.
Article
Optics
Jun Wang et al.
Summary: This paper proposes a method to expand the vertical effective viewing zone of optical 360-degree holographic display by using a conical mirror with a base angle of less than 45 degrees. The feasibility and effectiveness of the proposed method are demonstrated through optical experiments.
Article
Optics
Wei-chia Su et al.
Summary: This paper proposes a see-through screen for a computer-generated hologram projection system, which consists of a linear grating and a lens phase. The screen redirects the information light, guides information into the observer's eye, and magnifies the field of view. The screen aberration is analyzed and corrected in the hologram calculation algorithm.
Article
Optics
Ni Chen et al.
Summary: Computing wave propagation is crucial in computational optics. We present a Hybrid Taylor Rayleigh-Sommerfeld diffraction (HTRSD) method that achieves more accurate and faster wave propagation compared to the widely used angular spectrum method.
Article
Optics
Yi-Wei Zheng et al.
Summary: In this paper, a holographic near-eye display system based on liquid crystal axicon is proposed, which achieves a large viewing area through the implementation of liquid crystal axicon. The system utilizes the error diffusion algorithm to calculate the computer-generated hologram (CGH) and deflects the reconstruction light modulated by the CGH into two directions by placing the liquid crystal axicon at the back focal plane of the Fourier lens, thus extending the viewing area. Optical experiments verify the feasibility of the proposed system, which has potential applications in holographic augmented reality (AR) display.
Article
Optics
Chao Liu et al.
Summary: In this paper, a real scene acquisition and holographic near-eye display system based on a zoom industrial endoscope is proposed. By adjusting the driving current of the liquid lens, the working distance and focal length of the zoom industrial endoscope can be controlled, allowing the capture of objects at different depths. The experimental results demonstrate the intuitive display of depth relationships among real objects using this system.
