Phase-space Analysis of a Two-Section InP Laser As an All-Optical Spiking Neuron: Dependency on Control and Design Parameters

Using a rate-equation model we numerically evaluate the carrier concentrationand photon number in an integrated two-section semiconductor laser, and analyseits dynamics in three-dimensional phase space. The simulation comprises compactmodel descriptions extracted from a commercially-available generic InPtechnology platform, allowing us to model an applied reverse-bias voltage tothe saturable absorber. We use the model to study the influence of the injectedgain current, reverse-bias voltage, and cavity mirror reflectivity on theexcitable operation state, which is the operation mode desired for the laser toact as an all-optical integrated neuron. We show in phase-space that our modelis capable of demonstrating four different operation modes, i.e. cw,self-pulsating and an on-set and excitable mode under optical pulse injection.In addition, we show that lowering the reflectivity of one of the cavitymirrors greatly enhances the control parameter space for excitable operation,enabling more relaxed operation parameter control and lower power consumptionof an integrated two-section laser neuron.