Optical edge detection of object under ambient illumination by incorporating phase modulation with differential metasurface

The optical edge detection technology offers the advantages of high speed and low loss in comparison to digital processing methods. The majority of optical edge detection methods, however, strongly rely on the laser environment, imposing significant limitations on the detectable range and dimensions of objects. Here, we proposed a method for optical edge detection under ambient illumination by employing a joint modulation technique that utilizes metasurface for differential operation and spatial light modulator as phase modulation. The experiment is completed in a natural environment scene, and the results indicate that this scheme not only enables the acquisition of edge information of objects under ambient illumination but also enhances the diversity and scope of test specimens. The system showcases the potential of optical differential metasurface, opening up new avenues for applications such as object classification and autonomous driving.