Activation, Inhibition and Propagation of Spiking Regimes in Vertical Cavity Surface Emitting Lasers

Photonic techniques emulating the brain powerful computational capabilities are the subject of increasing research interest as these offer excellent prospects for ultrafast neuro-inspired information processing systems going beyond classical digital modules. One of these approaches considers the use of semiconductor lasers, as these devices can undergo a rich variety of dynamical responses similar to those observed in neurons; yet, remarkably these are obtained at speeds up to 9 orders of magnitude faster than the millisecond timescales of biological neurons. Amongst semiconductor lasers, Vertical Cavity Surface Emitting Lasers (VCSELs) are ideal for use in neuromorphic photonics as they possess important inherent advantages, e.g. low fabrication costs, ease to integrate in 2- and 3-Dimensional arrays, high coupling efficiency to optical fibres, etc.

In this talk, we will review our recent progress on the achievement of controllable and reproducible spiking patterns in VCSELs with ultrafast speed resolution. Specifically, we will show that a wide variety of spiking regimes, e.g. single and multiple spiking and bursting patterns can be controllably activated and inhibited in these devices in response to external perturbations. Additionally, we will introduce our recent results demonstrating the successful communication of spiking photonic signals between two interconnected VCSELs. Moreover, the activation, inhibition and propagation of the aforementioned spiking regimes are all obtained at sub-nanosecond speeds, thus offering high potentials for novel ultrafast non-traditional information processing capabilities with these laser sources. Also, our results, obtained with off-the-shelf inexpensive components operating at the most relevant wavelengths in present optical fibre networks (1300 and 1550 nm), make our approach fully compatible with optical communication technologies.

In summary, the reproducible and controllable activation, suppression and propagation of spiking photonic signals at high speeds in VCSELs operating at telecom wavelengths offer great potential for the use of these devices in excitatory and inhibitory photonic neuronal models for future neuromorphic photonic information processing systems.