Ferroelectric Thin‑Film Polarization‑Sensitive Photodetector Based on the Plasmon‑Enhanced Bulk Photovoltaic Effect

ABSTRACT Polarization‑sensitive photodetection is critical for advanced imaging, optical communication, and medical diagnosis technologies. Although detectors based on low‐symmetry metasurfaces or two‐dimensional materials have been widely investigated, they generally suffer from a low polarization ratio, narrow response bandwidth, stringent fabrication precision, and poor ambient stability. Here, we demonstrate a plasmon‐enhanced ferroelectric thin‐film photodetector capable of broadband detection from 260 to 1900 nm. Notably, the device exhibits excellent polarization sensitivity across the visible to near‐infrared band (380–980 nm), achieving an ultrahigh polarization ratio of 641. The polarization ratio can be dynamically tuned from positive unipolar operation to negative bipolar operation via external bias modulation, enabling the realization of six complete optoelectronic logic gates (AND, OR, NAND, NOR, NOT, and XOR) on a single device. It also delivers robust long‐term stability with negligible performance degradation after six months of ambient storage. Leveraging these programmable logic functions, we further demonstrate a proof‐of‐concept framework for data transmission and encryption imaging, whose security performance is systematically verified using a convolutional neural network. This work demonstrates the tremendous potential of the photovoltaic effect in polarization detection, and also provides new ideas for balancing information transmission, security, and sharing functions within a single architecture.