Effects of cavity nonlinearities and linear losses on silicon microring-based reservoir computing
This work provides insights for optimizing microring resonator design in photonic reservoir computing, but it is incremental as it builds on existing understanding of physical effects.
The authors investigated how linear losses and nonlinear effects in silicon microring resonators affect performance in time-delay reservoir computing for the NARMA-10 time-series task, identifying three operational regions with one achieving low error under low power and node count.
Microring resonators (MRRs) are promising devices for time-delay photonic reservoir computing, but the impact of the different physical effects taking place in the MRRs on the reservoir computing performance is yet to be fully understood. We numerically analyze the impact of linear losses as well as thermo-optic and free-carrier effects relaxation times on the prediction error of the time-series task NARMA-10. We demonstrate the existence of three regions, defined by the input power and the frequency detuning between the optical source and the microring resonance, that reveal the cavity transition from linear to nonlinear regimes. One of these regions offers very low error in time-series prediction under relatively low input power and number of nodes while the other regions either lack nonlinearity or become unstable. This study provides insight into the design of the MRR and the optimization of its physical properties for improving the prediction performance of time-delay reservoir computing.