Bi-channel compressive hyperspectral imager based on polarization conversion metasurface

Metasurfaces have demonstrated remarkable capabilities in manipulating light fields and reducing the size of conventional optical elements to ultrathin devices, and compressive hyperspectral imaging systems can effectively utilize the spectral modulations of metasurfaces through spectral transmission tuning. In this paper, a bi-channel compressive hyperspectral imager based on polarization conversion metasurfaces is proposed. The metasurface layer of this device is able to modulate and convert the polarized incidence into two outputs of different transmission spectra with orthogonal polarizations, providing two channels of hyperspectral information that can be detected by a polarization image sensor in one snapshot. Additionally, this design offers a compact size, high speed, and accurate reconstruction through the utilization of a macro-pixel segmentation method for compressive sensing algorithms, and it is firmly demonstrated that the proposed hyperspectral imaging technology surpasses other traditional compressive hyperspectral image recovery methods in terms of improved reconstruction quality. Therefore, it is envisioned that this technology will find significant applications in various fields, including food safety, biomedical imaging, precision agriculture, object detection and so on.