Time-domain image processing using photonic reservoir computing

¹ Institute of Science and Engineering, Kanazawa University Kakuma-machi Kanazawa, Ishikawa 920-1192, Japan
² Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi Kanazawa, Ishikawa 920-1192, Japan

^* Corresponding author: sunada@se.kanazawa-u.ac.jp

Published online: 18 October 2023

Abstract

Photonic computing has attracted much attention due to its great potential to accelerate artificial neural network operations. However, the processing of a large amount of data, such as image data, basically requires large-scale photonic circuits and is still challenging due to its low scalability of the photonic integration. Here, we propose a scalable image processing approach, which uses a temporal degree of freedom of photons. In the proposed approach, the spatial information of a target object is compressively transformed to a time-domain signal using a gigahertz-rate random pattern projection technique. The time-domain signal is optically acquired at a single-input channel and processed with a microcavity-based photonic reservoir computer. We experimentally demonstrate that this photonic approach is capable of image recognition at gigahertz rates.