Cascaded crosstalk suppression in single-shot full-Stokes polarization-integrated infrared focal plane arrays

Infrared polarization detection technology can distinguish the polarization characteristics from the intensity of infrared radiation, thereby revealing the material composition, surface morphology, and physicochemical properties of the measured scene. Division of focal plane (DoFP) polarization detection schemes offer high integration and real-time capabilities, attracting significant research interest. However, inter-pixel crosstalk reduces polarization extinction ratios, limiting its utility. This work proposes a cascaded polarization crosstalk suppression scheme for mid-infrared broadband polarization-integrated detectors, based on all-silicon dielectric full-Stokes polarization metalenses. Combining transmission and geometric phase, pixel-level full-Stokes polarization beam-splitting and filtering metalenses are designed on an all-silicon platform, enabling efficient polarization decoupling and detection in the 3.5-4.5 <i>μ</i>m range. Furthermore, through the co-design of the integrated detector chip, a fourfold improvement in polarization extinction ratio (PER) over broadband is achieved compared to independent metasurface. This work lays the foundation for a coordinated optimization strategy between microstructures and detector devices, offering valuable insights into the design and integration for infrared polarization-integrated focal plane array (FPA) devices.