METASURFACE OPTICAL ELEMENT, PROJECTION OPTICAL SYSTEM, IMAGE PROJECTION DEVICE, LIGHT SOURCE DEVICE, IMAGING DEVICE, AND OPTICAL SCANNING DEVICE

原文（中国語）

A metasurface optical element is a single optical element and includes a metasurface and a mirror surface. The metasurface includes a transmission surface that transmits light and on which a plurality of nanostructures are continuously arranged, the nanostructures being arranged with a density based on which a refractive index of the metasurface for the light is adjusted. The mirror surface has a flat plate shape and reflects the light that has passed through the metasurface. A dimension d of the nanostructures in a horizontal direction relative to the transmission surface and a wavelength λ of the light satisfy λ≥d. The optical element causes the light deflected by the metasurface to be reflected by the mirror surface so that the light is deflected in a direction different from an incident direction of the light.