Compact All-Optical Differentiator of Multi-Orders Enabled by a Single-Layer Metasurface

All-optical differentiators, which perform differential operations on target objects via light propagation, are crucial components in all-optical computing systems [1]. Metasurfaces have recently exhibited great potential in constructing diverse all-optical differentiators [2], [3]. However, existing designs typically require additional imaging modules to capture the differentiated images and often face limitations in the achieved spatial resolution as well as differentiation order. Here, we present a new kind of all-optical differentiator that operates in direct-imaging mode and with multiple orders. Based on a single-layer multiplexed metasurface, the differentiator simultaneously performs spin-multiplexed differential operations and high-resolution imaging of target objects, eliminating the need for additional imaging modules or supplementary optics (Fig. 1a).