Metasurface wavefront control for high-performance user-natural augmented reality waveguide glasses

Abstract

Augmented reality (AR) devices, as smart glasses, enable users to see both the real world and virtual images simultaneously, contributing to an immersive experience in interactions and visualization. Recently, to reduce the size and weight of smart glasses, waveguides incorporating holographic optical elements in the form of advanced grating structures have been utilized to provide light-weight solutions instead of bulky helmet-type headsets. However current waveguide displays often have limited display resolution, efficiency and field-of-view, with complex multi-step fabrication processes of lower yield. In addition, current AR displays often have vergence-accommodation conflict in the augmented and virtual images, resulting in focusing-visual fatigue and eye strain. Here we report metasurface optical elements designed and experimentally implemented as a platform solution to overcome these limitations. Through careful dispersion control in the excited propagation and diffraction modes, we design and implement our high-resolution full-color prototype, via the combination of analytical–numerical simulations, nanofabrication and device measurements. With the metasurface control of the light propagation, our prototype device achieves a 1080-pixel resolution, a field-of-view more than 40°, an overall input–output efficiency more than 1%, and addresses the vergence-accommodation conflict through our focal-free implementation. Furthermore, our AR waveguide is achieved in a single metasurface-waveguide layer, aiding the scalability and process yield control.

Do you have a good all-around view? Evaluation of a decision-making skills diagnostic tool using 360° videos and head-mounted displays in elite youth soccer

“…The preferences of a few players for improved video quality may be attributed to the vergence-accommodation-conflict ( 47 ) which might have led to a distorted perception of depth in a video image, especially in an HMD where the image is close to the eyes. The consequence is a blurred image of the entire virtual environment ( 48 ). To address this problem, the industry is developing gliding displays for HMDs to enable a more natural focus on virtual objects at any distance.…”

Metasurfaces for near-eye display applications

“…In 2018, Shi et al proposed the use of polarization-dependent metagratings to achieve wide FOV waveguide displays 113 . In such a system, both the in-and outcouplers are polarization-selective metagratings, achieved by spatially interleaving TE-pass and TM-pass gratings.…”

Progress and Prospects of Nanoscale Emitter Technology for AR/VR Displays

“…In practice, however, due to the angular and wavelength selectivity of gratings and undesired optical losses from multiple elements, the FOV and light output efficiency are currently limited to around 50° and a few percentage (typically, less than 2%), respectively. [5,36] Given that a compact and light form factor is in strong demand and light losses in optical systems are inevitable for both VR and AR devices, display technologies that satisfy the specifications for consumer products are also highly essential to develop high-quality VR/AR headsets. In the next section, recent progress in micro-display technologies will be discussed.…”