Fig. 4: Metasurface spectrometer with 12 focal points under the polychromatic light beams.

Simulation and experimental results under the different combination of wavelengths. Left: 540 nm and 660 nm, middle: 500 nm, 580 nm, and 660 nm, and right: 500 nm, 540 nm, 580 nm, 620 nm, 660 nm, and 700 nm