Pulse lead/lag timing detection for adaptive feedback and control based on optical spike-timing-dependent plasticity.

Biological neurons perform information processing using a model called pulse processing, which is both computationally efficient and scalable, adopting the best features of both analog and digital computing. Implementing pulse processing with photonics can result in bandwidths that are billions of times faster than biological neurons and substantially faster than electronics. Neurons have the ability to learn and adapt their processing based on experience through a change in the strength of synaptic connections in response to spiking activity. This mechanism is called spike-timing-dependent plasticity (STDP). Functionally, STDP constitutes a mechanism in which strengths of connections between neurons are based on the timing and order between presynaptic spikes and postsynaptic spikes, essentially forming a pulse lead/lag timing detector that is useful in feedback control and adaptation. Here we report for the first time the demonstration of optical STDP that is useful in pulse lead/lag timing detection and apply it to automatic gain control of a photonic pulse processor.