All-photonic reservoir computing for dynamic image classification via spatial-to-temporal encoding

We present an all-photonic reservoir computing device that integrates the reservoir and readout layers on a silicon photonic chip, enabling end-to-end optical processing of time-series data with ultralow latency. The photonic reservoir computing achieves real-time high-speed image processing by incorporating a photonic spatial-to-temporal encoding technique, which converts visual information into a time-domain signal at a rate of 25 Gigasamples per second. We experimentally demonstrated that the proposed photonic approach can recognize microsecond scale switching events that are challenging to capture using conventional electronic systems. This approach offers a scalable solution for photonic processors targeting time-critical tasks such as anomaly detection and real-time sensing applications.