Multidimensional detection enabled by twisted black arsenic–phosphorus homojunctions

A light field carrying multidimensional optical information, including but not limited to polarization, intensity and wavelength, is essential for numerous applications such as environmental monitoring, thermal imaging, medical diagnosis and free-space communications. Simultaneous acquisition of this multidimensional information could provide comprehensive insights for understanding complex environments but remains a challenge. Here we demonstrate a multidimensional optical information detection device based on zero-bias double twisted black arsenic–phosphorus homojunctions, where the photoresponse is dominated by the photothermoelectric effect. By using a bipolar and phase-offset polarization photoresponse, the device operated in the mid-infrared range can simultaneously detect both the polarization angle and incident intensity information through direct measurement of the photocurrents in the double twisted black arsenic–phosphorus homojunctions. The device’s responsivity makes it possible to retrieve wavelength information, typically perceived as difficult to obtain. Moreover, the device exhibits an electrically tunable polarization photoresponse, enabling precise distinction of polarization angles under low-intensity light exposure. These demonstrations offer a promising approach for simultaneous detection of multidimensional optical information, indicating potential for diverse photonic applications.