Fully Passive and Ultra-Low-Power Technologies for Spectral Enhancement of Human Vision

In this YIP project, we achieved the following: 1. We identified an optical material-cesium lead bromide nanocrystals spun onto films and capped for protection-as an excellent candidate for fully passive down-conversion imaging. 2. We built and demonstrated an all-passive imaging system, demonstrating passive frequency conversion of ultraviolet images into the visible without any significant loss of imaging resolution. 3. We designed and demonstrated a fully passive device in the form factor of a pair of glasses that breaks binocular redundancy, with the goal of enhancing the wearer's ability to distinguished metameric spectra. 4. We demonstrated a new technique, hyperspectral interference tomography, which combines hyperspectral imaging with thin-film modeling to enable rapid nondestructive analysis of biominerals like nacre 5.We developed several metamaterial and metasurface technologies to enable future developments in imaging and focusing, which can hopefully be used in compact vision-enhancement systems. This includes metamaterials that must be described by more than one refractive index simultaneously, tunable metasurface components using graphene nanoribbons, and inverse-design methods using coupled-mode theory to design very large-scale metasurfaces quickly. 6. We explored laser-light sails, demonstrating a design based on metasurfaces that self-stabilizes in a laser beam, and thus can "ride" the beam.