Waveguide-based augmented reality displays: perspectives and challenges

eLight, Journal Year: 2023, Volume and Issue: 3(1)

Published: Dec. 7, 2023

Abstract Augmented reality (AR) displays, as the next generation platform for spatial computing and digital twins, enable users to view images superimposed on real-world environment, fostering a deeper level of human-digital interactions. However, critical element in an AR system, optical combiners face unprecedented challenges match exceptional performance requirements human vision system while keeping headset ultracompact lightweight. After decades extensive device material research efforts, heavy investment manufacturing technologies, several promising waveguide have been developed. In this review paper, we focus perspectives displays. We will begin by introducing basic structures operation principles different architectures, then delve into combiners, including geometric diffractive combiners. Some commonly used in-couplers out-couplers, such prisms, mirrors, surface relief gratings, volume holographic polarization metasurface-based couplers, be discussed, their properties analyzed detail. Additionally, explore recent advances combiner design modeling, exit pupil expansion, wide field view, architectures full-color propagation, brightness color uniformity optimization. Finally, discuss bottlenecks future development trends technologies. The objective is provide comprehensive overview current state analyze pros cons, present

Language: Английский

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Metasurfaces for near-eye display applications

Opto-Electronic Science, Journal Year: 2023, Volume and Issue: 2(8), P. 230025 - 230025

Published: Jan. 1, 2023

Virtual reality (VR) and augmented (AR) are revolutionizing our lives. Near-eye displays crucial technologies for VR AR. Despite the rapid advances in near-eye display technologies, there still challenges such as large field of view, high resolution, image quality, natural free 3D effect, compact form factor. Great efforts have been devoted to striking a balance between visual performance device compactness. While traditional optics nearing their limitations addressing these challenges, ultra-thin metasurface optics, with light-modulating capabilities, may present promising solution. In this review, we first introduce AR displays, then briefly explain working principles metasurfaces, review recent developments devices geared toward applications, delved into several advanced based on finally discuss about remaining future perspectives associated metasurfaces applications.

Language: Английский

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Metasurface-Assisted Terahertz Sensing

Sensors, Journal Year: 2023, Volume and Issue: 23(13), P. 5902 - 5902

Published: June 25, 2023

Terahertz (THz) waves, which fall between microwaves and infrared bands, possess intriguing electromagnetic properties of non-ionizing radiation, low photon energy, being highly sensitive to weak resonances, non-polar material penetrability. Therefore, THz waves are extremely suitable for sensing detecting chemical, pharmaceutical, biological molecules. However, the relatively long wavelength (30~3000 μm) compared size analytes (1~100 nm biomolecules, <10 μm microorganisms) constrains development THz-based sensors. To circumvent this problem, metasurface technology, by engineering subwavelength periodic resonators, has gained a great deal attention enhance resonance response waves. Those metasurface-based sensors exhibit high sensitivity label-free sensing, making them appealing variety applications in security, medical applications, detection. The performance is controlled geometric structure parameters. operating mechanism divided into two main categories, passive active. have profound understanding these metasurface-assisted technologies, we review categorize those sensors, based on their mechanisms, including resonators frequency shift nanogaps enhanced field confinement, chirality handedness detection, active elements (such as graphene MEMS) advanced tunable sensing. This comprehensive can serve guideline future metasurfaces design assist

Language: Английский

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Miniature tunable Airy beam optical meta-device

Opto-Electronic Advances, Journal Year: 2024, Volume and Issue: 7(2), P. 230171 - 230171

Published: Jan. 1, 2024

Tunable Airy beams with controllable propagation trajectories have sparked interest in various fields, such as optical manipulation and laser fabrication. Existing research approaches encounter challenges related to insufficient compactness integration feasibility, or they require enhanced tunability enable real-time dynamic of the trajectory. In this work, we present a novel method that utilizes dual metasurface system surpass these limitations, significantly enhancing practical potential beam. Our approach involves encoding cubic phase profile two off-axis Fresnel lens profiles across metasurfaces. The validity proposed strategy has been confirmed through simulation experimental results. meta-device addresses existing limitations lays foundation for broadening applicability diverse domains, encompassing light-sheet microscopy, fabrication, tweezers, etc.

Language: Английский

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Nonlocal meta-lens with Huygens’ bound states in the continuum

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: Aug. 2, 2024

Abstract Meta-lenses composed of artificial meta-atoms have stimulated substantial interest due to their compact and flexible wavefront shaping capabilities, outperforming bulk optical devices. The operating bandwidth is a critical factor determining the meta-lens’ performance across various wavelengths. that operate in narrowband manner relying on nonlocal effects can effectively reduce disturbance crosstalk from non-resonant wavelengths, making them well-suitable for specialized applications such as nonlinear generation augmented reality/virtual reality display. However, meta-lenses require striking balance between local phase manipulation resonance excitation, which involves trade-offs among factors like quality-factor, efficiency, dimensions, footprint. In this work, we experimentally demonstrate meta-lens featuring Huygens’ bound states continuum (BICs) its near-infrared imaging application. All-dielectric integrated-resonant unit particularly optimized efficiently induce both quasi-BIC generalized Kerker effect, while ensuring rotation-angle robustness generating geometric phase. experimental results show single-layer possesses high quality-factor 104 achieves transmission polarization conversion efficiency 55%, exceeding theoretical limit 25%. wavelength-selective two-dimensional focusing are demonstrated well. This work will pave way efficient meta-devices.

Language: Английский

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Electrically tunable optical metasurfaces

Photonics Insights, Journal Year: 2024, Volume and Issue: 3(3), P. R07 - R07

Published: Jan. 1, 2024

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Nonlocal metasurface for dark-field edge emission

Science Advances, Journal Year: 2024, Volume and Issue: 10(16)

Published: April 17, 2024

Nonlocal effects originating from interactions between neighboring meta-atoms introduce additional degrees of freedom for peculiar characteristics metadevices, such as enhancement, selectivity, and spatial modulation. However, they are generally difficult to manipulate because the collective responses multiple meta-atoms. Here, we experimentally demonstrate nonlocal metasurface realize modulation dark-field emission. Plasmonic asymmetric split rings (ASRs) designed simultaneously excite local dipole resonance quasi-bound states in continuum spatially extended modes. With one type unit, tailored by varying array periods. ASRs at metasurface’s edge lack sufficient interactions, resulting stronger scattering thus emission properties metasurface. Pixel-level control is demonstrated simply erasing some units, providing more flexibility than conventional metasurfaces. This work paves way manipulating facilitates applications optical trapping sorting nanoscale.

Language: Английский

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High‐Responsivity Natural‐Electrolyte Undersea Photoelectrochemical Photodetector with Self‐Powered Cu@GaN Nanowires Network

Advanced Functional Materials, Journal Year: 2023, Volume and Issue: 33(29)

Published: April 16, 2023

Abstract Undersea optical communication (UOC) has been considered as the most potential next‐generation underwater wireless technology for ocean exploration. Photodetector is essential component in UOC system, however, harsh undersea environment like light attenuation and seawater corrosivity restricts applications of conventional photodetectors. Herein, a novel natural‐electrolyte self‐powered photoelectrochemical (PEC) photodetector based on core‐shell structured Cu@GaN nanowires (NWs) network demonstrated direct utilization seawater. High quality GaN shell encapsulated Cu NWs through Ga‐coating high temperature nitridation processes. A Schottky junction along radial direction formed at Cu/GaN interface due to outward diffusion into layer. Such structure provides narrowed band detection blue well efficient carrier separation. PEC designed with mini‐pipes connected device chamber, which allows indrawing channel (458 nm). This works stably both shallow deep‐sea conditions Pacific Ocean area. It shows responsivity up 5.04 mA W −1 rapid response time 0.68 ms. can be easily integrated marine equipment without waterproof packaging future energy‐saving UOC.

Language: Английский

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Deep-subwavelength multilayered meta-coatings for visible-infrared compatible camouflage

Nanophotonics, Journal Year: 2024, Volume and Issue: 13(13), P. 2391 - 2400

Published: March 21, 2024

Abstract Camouflage is a common technique in nature, enabling organisms to protect themselves from predators. The development of novel camouflage technologies, not only fundamental science, but also the fields military and civilian applications, great significance. In this study, we propose new type deep-subwavelength four-layered meta-coating consisting Si, Bi, Cr top bottom with total thickness ∼355 nm for visible-infrared compatible camouflage. visible color infrared emission properties can be independently adjusted. Colorful obtained by changing Si layer, while selective high emissivity non-atmospheric window remains. Due properties, shows angle tolerance both regions. capability our proposed region validated under different environments. deep-subwavelength, angular insensitivity, compatibility large-area fabrication feasibility promise an effective solution various applications such as weapons anti-counterfeiting.

Language: Английский

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MEMS-integrated metasurfaces for dynamic linear polarizers

Optica, Journal Year: 2024, Volume and Issue: 11(3), P. 326 - 326

Published: Jan. 22, 2024

Optical metasurfaces (OMSs), planar arrays of meticulously designed meta-atoms, are renowned for remarkable capabilities in manipulating the polarization state light at subwavelength scales. Nevertheless, most OMS-empowered optics remain static, featuring well-defined optical responses determined by their configurations set during fabrication. Here, we demonstrate a MEMS-OMS-based dynamic linear polarizer (DLP) with an electrically controlled extinction ratio, which is tunable fast and reversible fashion, combining anisotropic plasmonic OMS thin-film piezoelectric MEMS mirror. Capitalizing on MEMS-OMS DLP, further implement voltage-controlled grayscale imaging vector vortex beam generation under linearly circularly polarized excitations, respectively. Our DLP design could enable adaptive photonic systems advanced applications image encryption, displays, beyond.

Language: Английский

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