Experimental Investigation of an Optical Reservoir Computer with MZI-based Optical Mask
Yuanli Yue, Shouju Liu, Ruibo Zhang, Tianxiang Luan, Ailing Zhang, Chao Wang · 2023
In this paper, we have experimentally demonstrated a novel all-optical masking solution in photonic time stretch reservoir computing to eliminate the need of high-speed signal generator for digital masks. By leveraging the high chirp rate generated through an unbalanced Mach-Zehnder Interferometer (MZI) structure, we achieved a random optical mask in the spectral domain. Optical wavelengths, acting as virtual reservoir nodes, enable spectral mixing within the reservoir layer. Thanks to time-spectrum mapping in the photonic time stretch system, equivalent temporal masking is obtained. The develop system exhibits memory capacity through delayed optical feedback process. A full photonic reservoir computing system is implemented. Two experiments of waveform and digit-spoken signal classification have been carried out. Our experimental results show that MZI-based optical mask enables superior performance in photonic time stretch reservoir computing.