Nonlocal metasurfaces-enabled analog light localization for imaging and lithography

Abstract

Localization of light spots in a given image is a common task in digital processing but is challenging in analog. Herein, a periodic nonlocal metasurface that has an optical transfer function defined in reciprocal space is proposed to resolve this issue. Assuming an ideal optical transfer function that encodes that of a local lens, the selective spot size reduction of incident Gaussian beams and sharpening of a patterned incidence with a Gaussian line shape are demonstrated. A realistic nonlocal metasurface comprising a trilayer structure with air grating on top that operates as a 2D analog light localizer under unpolarized incidence is presented. Nonlocal metasurfaces, combined with conventional optics, are expected to improve the resolution by sharpening the spatial features and find applications in diverse scientific fields such as medical, materials, and life science.

Selective reduction of light spot size or line width while preserving other spatial information is a common task in digital processing but remains out of reach in analog. Empowered by nonlocal metasurfaces, the analog 2D localization of light is demonstrated. Implemented on conventional optical setups, the nonlocal metasurfaces will enhance resolution by sharpening the spatial features. image