Fig. 1. Localized coordinate system for unit structure

Fig. 2. Folded metasurface-based imager^[49]. (a) Design scheme; (b) spectral imaging system; (c) light transmission and device fabrication

Fig. 3. Metasurface-based nanocavity^[50]. (a) Structural design; (b) principle comparison; (c) imaging effect

Fig. 4. Pixelated metasurfaces^[51]

Fig. 5. Photonic crystal slab-based computationally reconstructive imaging spectroscopy chip^[52]. (a) Schematic and optical images of the chip-scale spectrometer and transmission spectra of the filtered structures; (b) verification results of hyperspectral imaging and spatial maps of the reconstructed data cubes

Fig. 6. Metasurface-based hyperspectral imaging chip^[53]

Fig. 7. Freeform shaped meta-atoms-based metasurface spectroscopy imaging chip^[54]

Fig. 8. Imaging spectral chip based on metasurface computational reconstruction technology. (a) Structure of I-type metal metasurface; (b) chip structure

Fig. 9. Comparison of low-light imaging effects