Solitary and Coupled Semiconductor Ring Lasers as Optical Spiking Neurons

TL;DR

This paper explores how semiconductor ring lasers can generate optical pulses and exhibit neuron-like excitability, including multi-pulse responses, with potential applications in all-optical neural networks.

Contribution

It introduces a theoretical framework for pulse generation in asymmetric SRLs and demonstrates multi-pulse excitability, advancing optical neural network design.

Findings

Phase difference controls pulse direction in SRLs

Multi-pulse excitability can be triggered by a single pulse

Coupled asymmetric SRLs enable neural network functionalities

Abstract

We theoretically investigate the possibility of generating pulses in an excitable (asymmetric) semiconductor ring laser (SRL) using optical trigger pulses. We show that the phase difference between the injected field and the electric field inside the SRL determines the direction of the perturbation in phase space. Due to the folded shape of the excitability threshold, this has an important influence on the ability to cross it. A mechanism for exciting multiple consecutive pulses using a single trigger pulse (i.e. multi pulse excitability) is revealed. We furthermore investigate the possibility of using asymmetric SRLs in a coupled configuration, which is a first step toward an all-optical neural network using SRLs as building blocks.