Multispectral imaging through metasurface with quasi-bound states in the continuum

By controlling light fields in subwavelength scales, metasurfaces enable novel ways for miniaturization and integration of spectral imaging system. Metasurfaces supporting quasi bound states in the continuum (quasi-BICs) can control the quality factor and spectral response by changing structural parameters. In this work, we present an ultra-compact multispectral imaging device, whereby spectral modulation is achieved by meta-atoms arrays supporting quasi-BICs. The designed meta-atom array can serve as filters over a wide range of wavelengths, which enables the device capable of a large operating range and high-fidelity spectral reconstruction with a fine spectral resolution. The microspectrometers composed of BIC metasurfaces also can work as imaging pixels to achieve computational imaging spectroscopy through periodic arrangement, which successfully resolves images with spatial aliasing in different channels. This spectrometer device can meet the market demand for miniaturization for rapidly object recognition and appropriate spatial spectral resolution at low cost.