Photonic Computing With Single and Coupled Spiking Micropillar Lasers

Abstract

We review experimental and theoretical results on the computing properties of single spiking micropillar lasers and present numerical studies of propagation and computing in chains of evanescently coupled micropillar lasers. Single micropillar lasers are shown to behave as ultrafast optical neurons with sub-nanosecond spike times. They also possess absolute and relative refractory times, spike latency and show temporal summation. With delayed optical feedback, they emulate an autapse. These basic neural properties can be used for simple photonic computing. We show by numerical simulations of a chain of coupled spiking micropillar lasers that basic logical operations can be implemented in photonic circuits, as well as temporal pattern recognition based on the collision properties of pulses in this chain.Index Terms-neuromimetic photonics, laser with saturable absorber, excitability, spiking V. A. Pammi is with the

Pulse propagation in a 1D array of excitable semiconductor lasers

“…We also show that the observed pulses do not necessarily persist in the continuous limit. These results pave the way to the experimental study of such hopping dynamics in optics with potential impact on neuromimetic systems and information processing 8 .…”

“…The possibility to process information with spikes in photonic systems has attracted recently a lot of interest because of its application potential in terms of energy consumption, parallelism and speed 69 . It has been recently shown theoretically that coupled excitable semiconductor lasers can behave analogously to biological axons, allowing to transport and process information in the form of short optical spikes 8,10 .…”

Integrated Neuromorphic Photonics: Synapses, Neurons, and Neural Networks

“…Since then, various biological properties and learning tasks of spiking neurons have been demonstrated experimentally and numerically. Fiber‐based graphene excitable lasers (GELs), [ 8,112,113 ] micropillar lasers with integrated SAs, [ 48,114–116 ] DFBs, [ 117,118 ] and VCSEL‐SAs [ 102,119–122 ] all fall under this category. In addition, it is worth mentioning that a circuit model has been proposed by mapping the rate equations of excitable lasers with an embedded SA to an equivalent circuit; therefore, the signal‐processing behaviors such as excitation and inhibition can be efficiently and accurately simulated with the SPICE engine.…”

“…[ 42 ] Nonlinear activation functions in PNNs have been implemented with creative combinations of classic photonic primitives, including microring resonators (MRRs), [ 43 ] Mach–Zehnder interferometers (MZIs), [ 44 ] semiconductor optical amplifiers (SOAs), [ 45 ] and electro‐optic modulators together with photodetectors. [ 43,46 ] In addition, typical biological features of the spiking neuron have been successfully emulated with different types of excitable lasers, i.e., vertical‐cavity surface‐emitting lasers (VCSELS), [ 47 ] micropillar lasers, [ 48 ] distributed feedback lasers (DFBs), [ 49 ] and quantum‐dot (QDs) lasers. [ 50,51 ] Meanwhile, phase‐change materials (PCMs), which can be flexibly switched between multiple states of different optical properties, [ 52,53 ] have emerged as a competitive alternative in hardware emulation of both the fundamental leaky integrate‐and‐fire (LIF) functionality of neurons and the plastic weighting process of synapses.…”

Micro-lasers for neuromorphic computing

“…Even though a single optical neuron can realize simple computing tasks, coupling several such neurons is necessary to scale up the computational power [5].…”