Non-Line-of-Sight Single-Pixel Imaging Using Polarization Speckle Modulation

Non-line-of-sight (NLOS) imaging aims to recover hidden scenes outside the direct line of sight, holding great promise for broad applications. Despite notable advancements, current methods are restricted to the manipulation of temporal or spatial degree of light. Here, we propose and demonstrate polarization-based scanning-free NLOS single-pixel imaging. By manipulating the polarization states of light incident on the visible relay wall, the interaction between a rough surface and different polarization light produces diverse speckle patterns to illuminate the hidden scenes. The reflected light is captured by a single-pixel detector, enabling the recovery of the details of the hidden object. Experimental results show that the polarization speckle diversity effectively encodes the hidden scene, achieving high-fidelity scanning-free NLOS imaging with millimeter spatial resolution through a keyhole. Furthermore, a noninvasive calibration method is developed by utilizing the angular memory effect of polarization speckles. These results not only offer new insights for single-pixel imaging and NLOS imaging techniques, but also open a new venue for the development of diverse light field modulation for optical imaging and relevant approaches to practical applications.