Reconfigurable Spatiotemporal Optical Signal Processors

Analogue optical computing offers a promising approach for developing super-fast computation techniques, benefiting from its extraordinary parallel processing capability, low energy consumption, and high integrability compared to digital electronic technologies. In this work, a reconfigurable spatiotemporal optical signal processor using the phase-change material vanadium dioxide (VO2) to further expand the processing bandwidth and enrich the operation functions is demonstrated. As a specific example, a meta-device is designed that can switch between a first-order differentiator and a good reflector in the spatiotemporal domain by controlling the operation temperature. It is shown that the spatiotemporal transfer functions can be precisely engineered to meet the requirements for ideal first-order differentiation and bright-field imaging. This approach enables high-accuracy spatial and temporal signal processing, as demonstrated by inspecting Gaussian signals. The theoretical evaluation determines the resolution limits of spatial and temporal edge detection. It also highlights that the device can perform spatiotemporal signal processing for pulses with complex profiles. The presented reconfigurable spatiotemporal optical signal processor holds great potential in applications such as remote sensing and fast imaging processing, among others.