Toward Neuromorphic Photonic Networks of Ultrafast Spiking Laser Neurons

Abstract

We report on ultrafast artificial laser neurons and on their potentials for future neuromorphic (brain-like) photonic information processing systems. We introduce our recent and ongoing activities demonstrating controllable excitation of spiking signals in optical neurons based upon Vertical-Cavity Surface Emitting Lasers (VCSEL-Neurons). These spiking regimes are analogous to those exhibited by biological neurons, but at sub-nanosecond speeds (>7 orders of magnitude faster). We also describe diverse approaches, based on optical or electronic excitation techniques, for the activation/inhibition of sub-ns spiking signals in VCSEL-Neurons. We report our work demonstrating the communication of spiking patterns between VCSEL-Neurons towards future implementations of optical neuromorphic networks. Furthermore, new findings show that VCSEL-Neurons can perform multiple neuro-inspired spike processing tasks. We experimentally demonstrate photonic spiking memory modules using single and mutually-coupled VCSEL-Neurons. Additionally, the ultrafast emulation of neuronal circuits in the retina using VCSEL-Neuron systems is demonstrated experimentally for the first time to our knowledge. Our results are obtained with off-the-shelf VCSELs operating at the telecom wavelengths of 1310 and 1550 nm. This makes our approach fully compatible with current optical network and data centre technologies; hence offering great potentials for future ultrafast neuromorphic laser-neuron networks for new paradigms in brain-inspired computing and Artificial Intelligence.

Extreme events in quantum cascade lasers

“…65 The latter is fragmented in several subcategories called tonic spiking, phasic spiking, tonic bursting, phasic bursting, excitability, spike thresholding, and spike latency, among others. 66 While most of these subcategories have already been successfully assessed in the case of VCSELs, 53 we demonstrate that tonic spiking, phasic spiking, and spike thresholding can be achieved in a QCL under OF, as illustrated in the following. In the case of QCLs, we were able to trigger spikes in two different configurations.…”

“…This inhibition process is also of prime interest for neuromorphic schemes to interrupt regular trains of bursts. 52,53 Methods to prevent extreme events from occurring have been numerically tested for both the configuration with optical injection 35 and the configuration with OF. 40 For instance, extreme events can be anticipated by studying precursors in the time traces.…”

“…64 With VCSELs, the maximum processing rate is close to the GHz and is thus several orders of magnitude faster than the best performances with electrical circuits. 53 The purpose of neuromorphic computing systems is to process information tasks inspired by the brain's powerful computational abilities with ultrafast lasers. One of the key requirements to replicate biological neurons' response is to perform controllable inhibition and excitation (or activation).…”

VCSELs for fast neuromorphic photonic systems operating at GHz rates

“…The light output from the VCSEL is collected and analysed with an optical spectrum analyser (Anritsu) and a 13 GHz bandwidth real-time oscilloscope. For full details and a schematic depiction of the experimental setup see [13].…”

Ultrafast optical integration and pattern classification for neuromorphic photonics based on spiking VCSEL neurons

“…Due to the appealing properties of these photonic systems, growing interest has given rise to many reports of electro-optic artificial synaptic devices 13,14 and spiking photonic neuronal models based on numerous different systems, e.g. phase change materials 15 , resonant tunnelling diodes 16,17 and different types of semiconductor lasers [18][19][20][21][22][23][24][25][26][27] . However, to date, demonstrations of functional systems, based on spiking photonic neurons with continuous operation, remain elusive.This work provides a first report of a leaky integrate and fire (LIF) spiking photonic neuron based upon a Vertical-Cavity Surface-Emitting Laser (VCSEL-neuron) performing functional tasks (e.g.…”