Design, materials, and manufacturing of optical metasurfaces for flat optics, devices, and applications

Augmented reality glasses have been considered a promising candidate for next-generation mobile hardware platforms. However, the bulky form factor and high-power consumption of their display systems using conventional optical components hinder the commercialization of augmented reality glasses. In this work, we demonstrate metasurface-based waveguide as an image combiner having high efficiency and large field of view. To design the metasurface-based waveguide consists of metasurface grating we propose an inverse design method based on gradient-descent optimization. In addition, our design method exploiting high degrees of freedom in meta-atom design can precisely control wave propagation through waveguides, enabling two-dimensional pupil expansion. As proof of concept, we fabricated metasurface-based waveguide providing a high efficiency of 500nit/lm and a large field of view of 50 degrees. We expect that the proposed metasurface-based waveguide opens up a new route for the development of augmented reality display systems with glass-like form factors suitable for daily wear.