Due to the crucial information provided by light wavelength and polarization, multispectral and polarized imaging technologies are of significant interest in various science and technology fields, including archeology, biology, remote sensing, and astronomy. Conventional multispectral and polarization imaging devices are based on filters and polarization analyzers, which usually require to take multiple shots to collect desired optical information and consist of bulky multi-pass systems or mechanically moving parts and are difficult to integrate into compact and integrated optical systems.

Metasurfaces that achieve full control of light properties, such as phases, amplitudes, and polarization states, have been demonstrated. As two-dimensional optical devices consisting of sub-wavelength nanostructures, metasurfaces are suitable for the design of integrated systems. Today, metasurfaces have been used in many different types of functional optical devices, such as optical displays, orbital angular momentum devices, beam splitters, meta-holography elements, and light-field imaging.

To realize integrated and compact designs, metasurface elements have been used in polarization and multispectral optical systems. However, there remains a lack of metalens devices that can achieve both spectra- and polarization-resolved functionalities simultaneously while keeping a good imaging performance with a large numerical aperture (NA). On the technical side, although at least three projections are required to determine the polarization state, the longitude of the Poincare sphere (also expressed as polarization ellipticity) can also reflect abundant information of the scene.