Reconfigurable Analog Computing Metasurfaces Based on Thin Film Lithium Niobate.

Analog computing metasurface offers significant advantages, including ultrafast computation, low power consumption, and parallel processing of data, thereby presenting a promising pathway toward the realization of a compact and integrated ultrafast all-optical information processing system. However, existing designs can only toggle between computing and noncomputing modes, falling short of achieving truly reconfigurable analog computing function. In this work, a reconfigurable transmission-type analog computing metasurface based on the electro-optic material thin film lithium niobate is demonstrated in the telecommunication band, aiming to flexibly control the operation functions. Through the dynamic regulation of the external voltages applied to individual structure units, the device transitions its function from first-order differentiation to either second-order differentiation or integration operations. The results indicate that the spatial transfer functions can be precisely engineered to meet the requirements for ideal differentiation and integration operations. This methodology facilitates high-precision spatial signal processing, as validated by inspecting Gaussian signals. Furthermore, the theoretical evaluation based on rectangular signal and complex letter pattern inputs establishes the spatial edge detection resolution of approximately 10 μm for the second-order differentiation operation. The reconfigurable lithium niobate metasurface signal processor demonstrates considerable potential for applications in fields such as remote sensing and high-speed image processing.