Experimental demonstration of a photonic spiking neuron based on a DFB laser subject to side-mode optical pulse injection

We proposed and experimentally demonstrated a simple and novel photonic spiking neuron based on a distributed feedback (DFB) laser subject to side-mode optical pulse injection (SMOPI). The DFB laser chip is designed and fabricated based on asymmetric equivalent π phase shift ( π -EPS) with the reconstruction-equivalent-chirp (REC) technique. Under side-mode continuous-wave (CW) optical injection, excitability pulse was experimentally observed during the dominant mode switching process due to the injection-locked effect. Based on the transition between the excitability regime and the side-mode injection locking effect, the controllable and repeatable neuron-like spiking response can be realized when external stimulus pulses are electro-optically modulated on the CW optical carrier. The experimental results show that the spike threshold, temporal integration, and refractory period, which are important spike processing mechanisms in biological neurons, can all be achieved in the optically-injected DFB laser. The experimental findings are also verified numerically with a rate equation model that considers the SMOPI. To the best of our knowledge, this is the first experimental demonstration of a photonic spiking neuron based on a DFB laser sub ject to SMOPI, which holds promise for realizing large-scale photonic spiking neuron arrays for hardware photonic spiking neural network chips.