Spike-based all-optical fast XOR operation in a VCSEL under dual-polarization optical injections

We propose an approach for implementing spike-based all-optical fast neuromorphic exclusive OR (XOR) operation using a single vertical-cavity surface-emitting laser (VCSEL). Based on the polarization mode competition in the VCSEL under the influence of dual-polarization optical injections, the XOR operation is realized. Here, the inputs for the logic operations are concurrently injected into the orthogonal polarization modes of the VCSEL-neuron in the form of a square wave, achieving high stability and accuracy. The spike-based XOR operation approaches a 0.8 gigahertz (GHz) rate within only one photonic neuron, which is 3.2 times faster than that of the vertical-cavity semiconductor optical amplifier (VCSOA)- neuron. Furthermore, the feasibility of employing the XOR operations in both discrete and continuous tasks has been verified. Our approach aligns more congruently with the processing method of biological neurons for XOR operation tasks, thereby demonstrating great potential for future photonic neural computing.