β‐Ga 2 O 3 Microwire Solar‐Blind Photodetectors with High Polarization Ratio for Multifunctional Information Encryption

Abstract Polarization represents a vital dimension of optical information. Harnessing polarization encoding offers a promising route toward high‐capacity optoelectronic systems. However, practical deployment has long been constrained by the limited performance of photodetectors, particularly their susceptibility to ambient noise in the visible/infrared range and their typically low polarization selectivity. In this work, the intrinsic polarization‐sensitive anisotropy of β ‐Ga 2 O 3 (bandgap ≈4.9 eV) is exploited to realize a lens‐free polarization photodetector fabricated via a straightforward mechanical exfoliation approach. XRD pole figure analysis reveals the twofold rotational symmetry of the monoclinic single crystal, which underlies the pronounced structural and optical anisotropy, as further verified by Raman spectroscopy and polarized absorption measurements. The resulting device exhibits solar‐blind operation immune to visible background illumination, achieving an ultrahigh polarization ratio of 137 at 254 nm with excellent reproducibility. Leveraging this outstanding polarization sensitivity, on‐chip reconfigurable OR/AND logic operations are demonstrated through polarization modulation, as well as optical encryption based on polarization‐encoded signals. This work establishes a new paradigm for high‐performance solar‐blind polarization photodetection, opening pathways toward robust optoelectronic computing and secure communication technologies.