Rotation-Symmetry Grating Contact Photodetector for Visible Full Linear Polarimetry Detection

Integrated linearly polarized (LP) light detectors hold importance for next-generation optoelectronic systems. However, current compact LP photodetectors relying on the scalar anisotropic absorption of natural materials or the bipolar polarization photoresponse of artificial structures are usually unable to achieve full polarization angle detection or are restricted to the long-infrared waveband. Here, we report a photodetector by integrating InSe flakes with three-fold rotation-symmetry grating contacts for zero-bias full linear polarimetry detection. The photodetector creates an asymmetric junction interface driven by the polarization-dependent propagating surface plasmon polariton wave, generating a zero-bias bipolar polarization photoresponse. By direct measurement of the photocurrents, linear polarization angle and incident power intensity detection can be achieved in a single device at 633 nm. Moreover, we demonstrate the decoding of polarization-angle-encrypted information, showing the great potential of the proposed devices in polarization information processing. Our work offers a promising strategy for developing compact full linear polarimetry photodetectors.