Abstract: A metasurface optical device includes a substrate, a film layer, and a metasurface structural unit array. The substrate includes a first surface and a second surface opposite to each other in a thickness direction of the substrate. The film layer is formed on the first surface of the substrate and includes at least one film group of films distributed at different positions on the first surface. Each film group includes one film, or a plurality of films stacked one over another in the thickness direction of the substrate. Each of the plurality of films includes a material with a corresponding refractive index to enhance transmission and/or reflection of light. The metasurface structural unit array includes a plurality of metasurface structural units formed on a side of the first film layer away from the substrate and extending in a direction away from the substrate.

Abstract: A spectrometer includes a collimator, a grating array, a metasurface, and a photodetector. The collimator is configured to collimate light including a plurality of portions with different wavelengths. The grating array is configured to guide, disperse, and deflect the light from the collimator. The metasurface array is configured to guide and focus the light from the grating array. The plurality of portions of the light with different wavelengths are focused by the metasurface array to different positions on a detection plane. The photodetector is configured to receive the light from the metasurface array at the detection plane.