Efficient Optoelectronic Reservoir Computing with Three-route Input Based on Optical Delay Lines

In the reservoir computing (RC) system based on delay line structure, the dynamical reservoir has short-term memory capability and can map instantaneous time signals to a high-dimensional space, so that it can effectively classify and recognize complicated time signals. A new RC system is proposed in this paper, where three-way signals are simultaneously input into the dynamical reservoir, and simultaneously processed and classified. Therefore, the information processing speed of the RC system is promoted manyfold. The reservoir is composed of a semiconductor laser and two optical feedback loops, in which two input signals are injected into two optical feedback loops, and another input signal is added to the driving current of the semiconductor laser. The computation efficiency of the RC system is validated by two tasks of the optical packet header recognition and digital speech recognition. By optimizing the parameters, the multi-input RC system can simultaneously recognize three-way 3-bit, 8-bit, 16-bit, and 32-bit optical packet headers with the optimal word error rate (WER) of 0%, and recognize three-way digital speech signals with the optimal WER of 0.2%. It is proven that this multi-input system outperforms the single-inputting RC system based on delay line structure.