Monolithic Integration of an FP-SA Optical Spiking Neuron and SOA Synapse by Photonic Crystals

We demonstrate a monolithically integrated photonic chip that combines an optical spiking neuron with a tunable synaptic element. The spiking neuron is realized using a quantum-well Fabry–Perot laser integrated with a saturable absorber (FP-SA), while a semiconductor optical amplifier (SOA) functions as a photonic synapse. Two photonic-crystal (PC) mirrors define the laser cavity and enable effective modulation of the synaptic weight. Experimental results further confirm the capability of the SOA for continuous and controllable synaptic weight tuning. This work represents an important step toward scalable on-chip photonic spiking neural networks.