Switchable Unipolar‐Barrier Van der Waals Heterostructures with Natural Anisotropy for Full Linear Polarimetry Detection

Abstract Polarization‐resolved photodetection in a compact footprint is of great interest for ultraminiaturized polarimeters to be used in a wide range of applications. However, probing the states of polarization (SOP) in materials with natural anisotropy are usually weak, limited by the material's natural dichroism or diattenuation. Here, a twisted unipolar‐barrier van der Waals heterostructure (vdWH) to construct a bias‐switchable polarization detection for retrieval of full SOP (from 0 to 180°) for linear polarized incident light is reported. As a demonstration example, this study realizes the concept in a b‐AsP/WS₂/b‐AsP vdWH relying on the natural anisotropic properties of the materials without using additional plasmonic/metasurface nanostructures to realize linear polarimetry in the mid‐infrared range. Polarimetric imaging is further demonstrated with the developed linear polarimetry by directly displaying the Jones‐vector‐described SOP distribution of certain target object. This method, with the capabilities of detecting full linear SOP, is promising for the next‐generation on‐chip miniaturized polarimeters.