All-optical synaptic neuron based on add-drop microring resonator with power-tunable auxiliary light.

We propose and demonstrate an all-optical synaptic neuron based on an add-drop microring resonator (ADMRR) with power-tunable auxiliary light. Dual neural dynamics of passive ADMRRs, having spiking response and synaptic plasticity, are numerically investigated. It is demonstrated that, by injecting two beams of power-tunable and opposite-direction continuous light into an ADMRR and maintaining their sum power at a constant value, linear-tunable and single-wavelength neural spikes can be flexibly generated, in virtue of the nonlinear effects triggered by perturbation pulses. Based on this, a weighting operation system based on cascaded ADMRRs is designed; it enables implementation of real-time weighting operations at a number of wavelengths. This work provides a novel, to the best of our knowledge, approach for integrated photonic neuromorphic systems based entirely on optical passive devices.