Single-mode photonic spiking neuron based on a laterally coupled DFB laser with a saturable absorber

We demonstrate a distributed feedback laser based on a laterally coupled grating with a saturable absorber (LCDFB-SA) as a photonic spiking neuron.So far, the conventional time domain traveling wave (TDTW) method is unable to simulate the nonlinear dynamics of the laser when the SA is under reverse bias.This problem is solved by a modified TDTW method introducing a relationship between the SA carrier lifetime and the reverse bias, by which the neuronal characteristics and tonic spiking repetition frequency tunable (TSRFT) characteristics of the device are simulated.Moreover, the side-mode suppression ratio (SMSR) of LCDFB-SA surpasses 40 dB in a tonic spiking state and is over 50 dB in a continuous laser state.Threshold, refractory period, and TSRFT characterization of the device are verified through experimental settings.Finally, frequency encoding and reconstruction of red, green, and blue (RGB) images based on TSRFT characteristics are performed.After multiple rounds of verification, the maximum normalized mean square error was 2.8808 10 -4 and the average was 1.0101 10 -4 , demonstrating good frequency coding capability.LCDFB-SA is fabricated by the standard I-line lithography process, which provides a low-cost and mass-producible photonic spiking neuronal solution.