Photonic spiking neuron based on a single VCSEL with optical feedback

A vertical-cavity surface-emitting laser (VCSEL) under polarization selected and rotated optical feedback has been proposed and numerically investigated to generate neuron-like spiking dynamics and to show the potential functionalities in spiking information processing. The proposed optical-feedback VCSEL-neuron employs only one laser to simulate one neuron, while conventional optical-injection VCSEL-neurons often require multiple lasers. The input stimulus is conducted by modulating the feedback strength while the output response is monitored by measuring the intensity in the initially non-lasing polarization. On the one hand, the generation of tonic spiking in the form of periodic pulses is related to the frequency difference between the laser’s two orthogonal polarization modes. On the other hand, the generation of phasic spiking in the form of a single abrupt pulse is attributed to the transient response at the onset of self-injection locking. Systematically investigations reveal that the frequency of tonic spiking is roughly proportional to the stimulus strength of input, while the critical stimulus strength of phasic spiking is roughly proportional to the birefringence rate of laser. The potential functionalities of proposed VCSEL-neuron are further verified by single neuron information processing tasks.