Controlled Propagation of Spiking Dynamics in Vertical-Cavity Surface-Emitting Lasers: Towards Neuromorphic Photonic Networks

We report experimentally and in theory on the controllable propagation of spiking regimes between two interlinked vertical-cavity surface-emitting lasers (VCSELs). We show that spiking patterns generated in a first transmitter VCSEL (T-VCSEL) are communicated to a second receiver VCSEL (R-VCSEL), which responds by firing the same spiking response. Importantly, the spiking regimes from both devices had analogous temporal and amplitude characteristics, including equal number of spikes fired, same spike and interspike temporal durations, and similar spike intensity properties. These responses are analogous to the spiking communication patterns of biological neurons yet at subnanosecond speeds, this is several (up to 8) orders of magnitude faster than the timescales of biological neurons. We have also carried out numerical simulations reproducing with high degree of agreement the experimental findings. These results obtained with inexpensive, commercially available VCSELs operating at important telecom wavelengths (1300 nm) offer great prospects for the scaling of emerging VCSEL-based photonic neuronal models into network configurations for use in novel neuromorphic photonic systems. This offers high potentials for nontraditional computing paradigms beyond digital systems and able to operate at ultrafast speeds.