Self-pulsation and synchronization of optical neurons based on microrings

Abstract

Driven by the growing research enthusiasm for neuromorphic photonics, optical neurons mimicking biological properties based on microresonant cavities and lasers are attracting increasing attention, in which spiking synchronization of couple networks consisting of optical neurons based on lasers has been systematically investigated, and the emergence of neural network with biological properties based on microrings is foreseen. In this paper, considering the importance of oscillatory synchronization between neurons to achieve the basic biological functions, we investigate the period of self-pulsation which is fundamental oscillation within microring as a function of input light power and detuning, and achieve self-pulsation period synchronization of two mutually coupled microrings. In addition, the self-pulsation synchronization in time series between the unidirectionally coupled driving microring and responding microring is achieved by adding delayed feedback and adjusting key parameters, and this synchronization still exists even with the inclusion of more responding microrings. Our work provides basic investigations of the self-pulsation period as well as synchronization properties between coupled optical neurons based on microrings, and would be helpful for different concepts of neuromorphic computing based on microring, including artificial neural networks (ANN), spike neural networks (SNN) and reservoir computing.