Abstract: An optical synapse device which can be used in a neuromorphic machine vision system to enable broadband sensing and fast data processing in applications where machine vision is used, such as for example in real-time video analysis, autonomous vehicles and medical diagnosis. The novel optical synapse device enables image sensing, convolutional processing, and computing. Multiple synaptic plasticity triggered by photons can implement photonic computing and information transmission. Convolutional processing is realized by ultra-low energy kernel generators fully controlled by photons. The optical synapse device shows the ability of conductance modulations under electronic stimulations that implement neuromorphic computing. The novel two-terminal broadband optoelectronic synapse device enables front-end retinomorphic image sensing, convolutional processing, and back-end neuromorphic computing.