Spike encoding and storage properties in mutually coupled vertical-cavity surface-emitting lasers subject to optical pulse injection

Abstract

The generation and storage properties of different spike codes in vertical-cavity surface-emitting lasers with an embedded saturable absorber (VCSELs-SA) are investigated numerically. The results show that different spike codes are generated by injecting an optical pulse into one single VCSEL-SA and can be stored in two mutually coupled VCSELs-SA. In particular, in the case of the generation of spike codes, the effects of the input strength and the temporal duration of the input optical pulse are studied; in the case of the storage of spike codes, the roles of the coupling weight and the coupling delay between the two mutually coupled VCSELs-SA are examined. Simulations reveal that spikes can be triggered if the input strength and the temporal duration exceed the threshold values, and higher values of the input strength and the temporal duration are beneficial for generating more spikes. Moreover, successful storage of a perfectly formed train of spike codes in two mutually coupled VCSELs-SA can also be realized provided that the coupling weight and the coupling delay are larger than the corresponding threshold values.

Polarization-resolved and polarization- multiplexed spike encoding properties in photonic neuron based on VCSEL-SA

“…The well-known Yamada model is successful for expressing a semiconductor laser with an embedded saturable absorber 16,21,25 . Our model is based on the combination of SFM and Yamada models 26,27 .…”

“…The time interval between the onset of EIOP and the first output spike (denoted as Δ t 1 21 ) and the time interval between two consecutive output spikes (denoted as Δ t 2 21 ) as functions of k injx ( k injy ) for both injection cases are presented in Fig. 5.…”

“…Based on a two-section rate equation model derived from the well-known Yamada model, some representative cortical spiking algorithms have been demonstrated numerically in small circuits consisting of excitable VCSELs-SA, including multistable circuit, synfire chain, and spatiotemporal pattern recognition circuit 16 . In addition, our previous numerical findings indicate that the spike codes can be stored successfully in the mutually coupled VCSELs-SA system 21 . However, the effects of polarization dynamics of VCSEL-SA on the spiking properties are not addressed in these works.…”

“…Compared with conventional VCSELs, the VCSEL with an embedded saturable absorber (VCSEL-SA) can offer the excitability threshold for photonic neuron 16,21 . Based on a two-section rate equation model derived from the well-known Yamada model, some representative cortical spiking algorithms have been demonstrated numerically in small circuits consisting of excitable VCSELs-SA, including multistable circuit, synfire chain, and spatiotemporal pattern recognition circuit 16 .…”

Electrically Controlled Neuron-Like Spiking Regimes in Vertical-Cavity Surface-Emitting Lasers at Ultrafast Rates

“…interconnection of these photonic neuromorphic elements has also been explored with the successful communication of fast spiking dynamics in a cascaded transmitter-receiver VCSEL configuration [43,44], and with detailed theoretical studies of multiple mutual coupling configurations [48,49]. The behavioural similarities that can be drawn between the investigated VCSEL-based neuronal models and biological neurons are what allow us to pursue these devices as candidates for artificial photonic neurons.…”