Mask-Less Asynchronous Time-Delay Reservoir Computing Using a Passive Photonic Integrated Circuit

Photonic time-delay reservoir computing schemes usually employ an input mask as a means of performance enhancement. However, input masking usually necessitates a domain conversion, requiring a signal to be treated before sending it to the reservoir. More recent implementations have explored further ways of performance enhancement, whether through operating in the asynchronous regime, or by using post-filtering approaches. In this numerical study, we analyze the task-independent performance of a passive integrated photonic reservoir, and show that it can achieve good results on some benchmark tasks in the absence of an input mask. We also consider the effects of post-filtering and operating in the asynchronous regime through a parameter space exploration. The proposed scheme enables ultra-fast processing speeds while simultaneously reducing the associated power and complexity costs of the associated electronics. We compare the obtained results with the case of using a mask, and also with other schemes from the literature, showing comparable performance on the investigated tasks.