A team of Chinese researchers has presented a new compact prototype that integrates augmented reality (AR) displays into eyeglasses. The researchers combined two optical technologies—metasurfaces and refractive lenses—along with a MicroLED screen to create a compact hybrid lens design known as meta/refractive hybrid lenses (MRL). This system features a small entrance pupil diameter of 3.2 mm and a total track length (TTL) of less than 7.7 mm.
The metasurface is a lightweight silicon nitride film etched with specific patterns designed to manipulate light from the MicroLEDs, which produce images. The refractive lens, made from synthetic polymer, helps refine the image quality by reducing light aberrations. The researchers implemented a hardware-inspired correction neural network that enhances the apparent point-spread function (PSF) of the system. Additionally, a pre-deconvolution step from the light source corrects residual system aberrations, improving the quality of the projected AR images over traditional approaches.
The researchers claim that their tests of the prototype achieved less than 2% distortion within a 30° field of view, aligning with existing commercial AR systems that typically utilize four lenses. The research team also claims that their computational enhancement method significantly improved the similarity of reprojected AR images to the original increasing the yield rate of compact AR devices.
The researchers expressed optimism that further development could expand the technology’s capabilities from monochrome displays to full-color AR.
Reference
Chen, Q., Zhou, J., Pian, S., Xu, J., Li, X., Li, B., Lu, C., Wang, Z., Jiang, Q., Qin, S., Zhan, H., Zhang, B., Liu, X., Wang, K., & Ma, Y. (2024). Hybrid Meta-Optics Enabled Compact Augmented Reality Display with Computational Image Reinforcement. ACS Photonics, 11(9), 3794–3803. https://doi.org/10.1021/acsphotonics.4c00989
