Terahertz Metasurface for Spatial Detection of Full Stokes Parameters and Polarization Imaging

Polarimetry can unveil rich multidimensional information of the optical field. Conventional approaches encounter significant challenges when analyzing complex spatially varying vectorial optical fields. In this paper, we propose an efficient polarimetry technique based on subwavelength-scale metalenses. This technique facilitates the spatial detection of full Stokes parameters, thereby overcoming the conventional constraints imposed on the uniformity of spatial intensity and polarization. The proposed metalens achieves 4 × 4 pixels with each pixel offering 6-channel polarization focusing, from which the polarization distribution can be calculated with good accuracy. This method provides a novel and robust technological scheme for detecting complex full Stokes parameters at the terahertz band.