Fig. 1. Schematic diagrams of metasurface. (a) Schematic diagram of meta-atom structure: p, d, and H are the arrangement period, diameter, and height of the meta-atoms; (b) phase distribution of meta-atoms with different diameters for different wavelengths; (c) transmittances of different wavelengths of meta-atoms with different diameters; (d) layout of spectroscopic metasurface

Fig. 2. Schematic diagrams of spectral imaging. (a) Schematic diagram of the spectroscopic metasurface; (b) schematic diagram of spectral imaging system based on spectroscopic metasurface

Fig. 3. Simulated images of 11 single wavelength spectra with interval of 30 nm within 400‒700 nm of spectral imaging system. (a) 400 nm; (b) 430 nm; (c) 460 nm; (d) 490 nm; (e) 520 nm; (f) 550 nm; (g) 580 nm; (h) 610 nm; (i) 640 nm; (j) 670 nm; (k) 700 nm; (l) simulation diagram of 11 channels

Fig. 4. Full image simulation of spectroscopic metasurface. (a) Original image used for simulation; (b) simulated spectral images by ray tracing software combined with main dispersion unit; (c) spectral situation of some dispersion units

Fig. 5. Using genetic algorithm for spectral curve inversion. (a) Spectral curve inversion flow chart of genetic algorithm; (b)‒(d) spectral curve inversion results of genetic algorithms: the solid lines represent three different true white light spectral curves, and the dotted lines represent the corresponding spectral curves inverted by the genetic algorithm