Real-time masking in photonic reservoir computing based on semiconductor lasers

Photonic reservoir computing (RC) based on semiconductor lasers (SLs) has gained significant attention due to its simplicity, fast training, and low energy consumption. However, the reliance on offline masking at the input layer limits its application in real-time tasks. In this work, we propose and numerically investigate a real-time masking method for photonic RC system using an SL subjected to optical feedback and sinusoidal modulation. The mask signal is injected into a Mach–Zehnder modulator alongside input data, enabling real-time masking. We analyze the nonlinear dynamics of the mask-SL and identify optimal parameters for mask signal generation. The system demonstrates robust predictive performance for the Santa Fe time series (minimum NMSE = 0.033) and high memory capacity (MC), with MC values reaching up to 20 in specific parameter regions. Although the real-time masking RC system exhibits slight performance degradation compared to conventional offline masking (NMSE = 0.01, MC = 23) and requires additional parameter tuning for mask generation, it provides a viable solution for real-time data processing in photonic RC implementations.